A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
An indandione that has been used as an anticoagulant. Phenindione has actions similar to WARFARIN, but it is now rarely employed because of its higher incidence of severe adverse effects. (From Martindale, The Extra Pharmacopoeia, 30th ed, p234)
A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.
Chromatographic techniques in which the mobile phase is a liquid.
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
The dissociation of molecules in the air into positive and negative ions under the influence of an electric field.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.
Devices for accelerating charged particles in a spiral path by a constant-frequency alternating electric field. This electric field is synchronized with the movement of the particles in a constant magnetic field.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.
The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)
The pressure at any point in an atmosphere due solely to the weight of the atmospheric gases above the point concerned.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A mass spectrometric technique that is used for the analysis of a wide range of biomolecules, such as glycoalkaloids, glycoproteins, polysaccharides, and peptides. Positive and negative fast atom bombardment spectra are recorded on a mass spectrometer fitted with an atom gun with xenon as the customary beam. The mass spectra obtained contain molecular weight recognition as well as sequence information.
Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)
Derivatives of phosphatidic acid in which the hydrophobic regions are composed of two fatty acids and a polar alcohol is joined to the C-3 position of glycerol through a phosphodiester bond. They are named according to their polar head groups, such as phosphatidylcholine and phosphatidylethanolamine.
A mass-spectrometric technique that is used for microscopic chemical analysis. A beam of primary ions with an energy of 5-20 kiloelectronvolts (keV) bombards a small spot on the surface of the sample under ultra-high vacuum conditions. Positive and negative secondary ions sputtered from the surface are analyzed in a mass spectrometer in regards to their mass-to-charge ratio. Digital imaging can be generated from the secondary ion beams and their intensity can be measured. Ionic images can be correlated with images from light or other microscopy providing useful tools in the study of molecular and drug actions.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
A basis of value established for the measure of quantity, weight, extent or quality, e.g. weight standards, standard solutions, methods, techniques, and procedures used in diagnosis and therapy.
Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
The systematic study of the complete complement of proteins (PROTEOME) of organisms.
Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)
Mixtures of many components in inexact proportions, usually natural, such as PLANT EXTRACTS; VENOMS; and MANURE. These are distinguished from DRUG COMBINATIONS which have only a few components in definite proportions.
The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
Concentration or quantity that is derived from the smallest measure that can be detected with reasonable certainty for a given analytical procedure.
A highly-sensitive (in the picomolar range, which is 10,000-fold more sensitive than conventional electrophoresis) and efficient technique that allows separation of PROTEINS; NUCLEIC ACIDS; and CARBOHYDRATES. (Segen, Dictionary of Modern Medicine, 1992)
An extraction method that separates analytes using a solid phase and a liquid phase. It is used for preparative sample cleanup before analysis by CHROMATOGRAPHY and other analytical methods.
The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
A research technique to measure solvent exposed regions of molecules that is used to provide insight about PROTEIN CONFORMATION.
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)
The development and use of techniques to study physical phenomena and construct structures in the nanoscale size range or smaller.
Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
The protein complement of an organism coded for by its genome.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
Analysis of PEPTIDES that are generated from the digestion or fragmentation of a protein or mixture of PROTEINS, by ELECTROPHORESIS; CHROMATOGRAPHY; or MASS SPECTROMETRY. The resulting peptide fingerprints are analyzed for a variety of purposes including the identification of the proteins in a sample, GENETIC POLYMORPHISMS, patterns of gene expression, and patterns diagnostic for diseases.
The development and use of techniques and equipment to study or perform chemical reactions, with small quantities of materials, frequently less than a milligram or a milliliter.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.
Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.
The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)
Carbohydrates consisting of between two (DISACCHARIDES) and ten MONOSACCHARIDES connected by either an alpha- or beta-glycosidic link. They are found throughout nature in both the free and bound form.
Electrophoresis in which a second perpendicular electrophoretic transport is performed on the separate components resulting from the first electrophoresis. This technique is usually performed on polyacrylamide gels.
The sum of the weight of all the atoms in a molecule.
A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.
Metals that constitute group 1(formerly group Ia) of the periodic table. They are the most strongly electropositive of the metals. Note that HYDROGEN is not considered an alkali metal even though it falls under the group 1 heading in the periodic table.
The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.
The systematic identification and quantitation of all the metabolic products of a cell, tissue, organ, or organism under varying conditions. The METABOLOME of a cell or organism is a dynamic collection of metabolites which represent its net response to current conditions.
Substances that are energetically unstable and can produce a sudden expansion of the material, called an explosion, which is accompanied by heat, pressure and noise. Other things which have been described as explosive that are not included here are explosive action of laser heating, human performance, sudden epidemiological outbreaks, or fast cell growth.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
Pyrolysis of organic compounds at the temperature of a hydrogen-air flame to produce ionic intermediates which can be collected and the resulting ion current measured by gas chromatography.
A chromatography technique in which the stationary phase is composed of a non-polar substance with a polar mobile phase, in contrast to normal-phase chromatography in which the stationary phase is a polar substance with a non-polar mobile phase.
A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.
Alcohols derived from the aryl radical (C6H5CH2-) and defined by C6H5CHOH. The concept includes derivatives with any substituents on the benzene ring.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Compounds in which a methyl group is attached to the cyano moiety.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
A phenomenon in which the surface of a liquid where it contacts a solid is elevated or depressed, because of the relative attraction of the molecules of the liquid for each other and for those of the solid. (from McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.
The characteristic 3-dimensional shape of a carbohydrate.
Disciplines that apply sciences to law. Forensic sciences include a wide range of disciplines, such as FORENSIC TOXICOLOGY; FORENSIC ANTHROPOLOGY; FORENSIC MEDICINE; FORENSIC DENTISTRY; and others.
Macrocyclic polyethers with the repeating unit of (-CH2-CH2-O)n where n is greater than 2 and some oxygens may be replaced by nitrogen, sulfur or phosphorus. These compounds are useful for coordinating CATIONS. The nomenclature uses a prefix to indicate the size of the ring and a suffix for the number of heteroatoms.
The process of cleaving a chemical compound by the addition of a molecule of water.
GLYCEROPHOSPHOLIPIDS in which one of the two acyl chains is attached to glycerol with an ether alkenyl linkage instead of an ester as with the other glycerophospholipids.
The chemical and physical integrity of a pharmaceutical product.
Techniques for labeling a substance with a stable or radioactive isotope. It is not used for articles involving labeled substances unless the methods of labeling are substantively discussed. Tracers that may be labeled include chemical substances, cells, or microorganisms.
Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Use of various chemical separation and extraction methods, such as SOLID PHASE EXTRACTION; CHROMATOGRAPHY; and SUPERCRITICAL FLUID EXTRACTION; to prepare samples for analytical measurement of components.
The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)
Methodologies used for the isolation, identification, detection, and quantitation of chemical substances.
A component of PHOSPHATIDYLCHOLINES or LECITHINS, in which the two hydroxy groups of GLYCEROL are esterified with fatty acids. (From Stedman, 26th ed) It counteracts the effects of urea on enzymes and other macromolecules.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
The rate dynamics in chemical or physical systems.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
The characteristic three-dimensional shape of a molecule.
GLYCOSPHINGOLIPIDS with a sulfate group esterified to one of the sugar groups.
The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.
Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.
A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)
The parts of a macromolecule that directly participate in its specific combination with another molecule.
A colorless, flammable liquid used in the manufacture of FORMALDEHYDE and ACETIC ACID, in chemical synthesis, antifreeze, and as a solvent. Ingestion of methanol is toxic and may cause blindness.
Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.
Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.
The application of medical knowledge to questions of law.
Polymers made up of a few (2-20) nucleotides. In molecular genetics, they refer to a short sequence synthesized to match a region where a mutation is known to occur, and then used as a probe (OLIGONUCLEOTIDE PROBES). (Dorland, 28th ed)
Simple sugars, carbohydrates which cannot be decomposed by hydrolysis. They are colorless crystalline substances with a sweet taste and have the same general formula CnH2nOn. (From Dorland, 28th ed)
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.
A separation technique which combines LIQUID CHROMATOGRAPHY and CAPILLARY ELECTROPHORESIS.
Separation of a mixture in successive stages, each stage removing from the mixture some proportion of one of the substances, for example by differential solubility in water-solvent mixtures. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A change of a substance from one form or state to another.
A phase transition from liquid state to gas state, which is affected by Raoult's law. It can be accomplished by fractional distillation.
Oligosaccharides containing two monosaccharide units linked by a glycosidic bond.
Glycosides of GLUCURONIC ACID formed by the reaction of URIDINE DIPHOSPHATE GLUCURONIC ACID with certain endogenous and exogenous substances. Their formation is important for the detoxification of drugs, steroid excretion and BILIRUBIN metabolism to a more water-soluble compound that can be eliminated in the URINE and BILE.
Chinese herbal or plant extracts which are used as drugs to treat diseases or promote general well-being. The concept does not include synthesized compounds manufactured in China.
A drug combination that contains diphenhydramine and theophylline. It is used for treating VERTIGO, MOTION SICKNESS, and NAUSEA associated with PREGNANCY.
Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and nonsugar component (aglycone) are formed. (From Dorland, 28th ed; From Miall's Dictionary of Chemistry, 5th ed)
Proteins prepared by recombinant DNA technology.
Methods of creating machines and devices.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
The dynamic collection of metabolites which represent a cell's or organism's net metabolic response to current conditions.
A basic enzyme that is present in saliva, tears, egg white, and many animal fluids. It functions as an antibacterial agent. The enzyme catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. EC 3.2.1.17.
Neutral glycosphingolipids that contain a monosaccharide, normally glucose or galactose, in 1-ortho-beta-glycosidic linkage with the primary alcohol of an N-acyl sphingoid (ceramide). In plants the monosaccharide is normally glucose and the sphingoid usually phytosphingosine. In animals, the monosaccharide is usually galactose, though this may vary with the tissue and the sphingoid is usually sphingosine or dihydrosphingosine. (From Oxford Dictionary of Biochemistry and Molecular Biology, 1st ed)
The products of chemical reactions that result in the addition of extraneous chemical groups to DNA.
Neutral or negatively charged ligands bonded to metal cations or neutral atoms. The number of ligand atoms to which the metal center is directly bonded is the metal cation's coordination number, and this number is always greater than the regular valence or oxidation number of the metal. A coordination complex can be negative, neutral, or positively charged.
The application of TOXICOLOGY knowledge to questions of law.
Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.
A class of membrane lipids that have a polar head and two nonpolar tails. They are composed of one molecule of the long-chain amino alcohol sphingosine (4-sphingenine) or one of its derivatives, one molecule of a long-chain acid, a polar head alcohol and sometimes phosphoric acid in diester linkage at the polar head group. (Lehninger et al, Principles of Biochemistry, 2nd ed)
The evaluation of incidents involving the loss of function of a device. These evaluations are used for a variety of purposes such as to determine the failure rates, the causes of failures, costs of failures, and the reliability and maintainability of devices.
Compounds containing the -SH radical.
Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.
Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)
Negatively charged atoms, radicals or groups of atoms which travel to the anode or positive pole during electrolysis.
Elements of limited time intervals, contributing to particular results or situations.
Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.
Multicellular marine macroalgae including some members of red (RHODOPHYTA), green (CHLOROPHYTA), and brown (PHAEOPHYTA) algae. They are widely distributed in the ocean, occurring from the tide level to considerable depths, free-floating (planktonic) or anchored to the substratum (benthic). They lack a specialized vascular system but take up fluids, nutrients, and gases directly from the water. They contain CHLOROPHYLL and are photosynthetic, but some also contain other light-absorbing pigments. Many are of economic importance as FOOD, fertilizer, AGAR, potash, or source of IODINE.
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
Measurement of the intensity and quality of fluorescence.
Drugs intended for human or veterinary use, presented in their finished dosage form. Included here are materials used in the preparation and/or formulation of the finished dosage form.
A group of compounds derived from ammonia by substituting organic radicals for the hydrogens. (From Grant & Hackh's Chemical Dictionary, 5th ed)
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
A multistage process that includes the determination of a sequence (protein, carbohydrate, etc.), its fragmentation and analysis, and the interpretation of the resulting sequence information.
The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.
Proteins found in any species of bacterium.
Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.
A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water. (Grant & Hackh's Chemical Dictionary, 5th ed)
The accumulation of an electric charge on a object
Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.
Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.
A plant genus of the family LILIACEAE. Members contain tuliposides and tulipalins and have been associated with allergic contact dermatitis in florists.
Organic compounds containing the carboxy group (-COOH). This group of compounds includes amino acids and fatty acids. Carboxylic acids can be saturated, unsaturated, or aromatic.
The analysis of a chemical substance by inserting a sample into a carrier stream of reagent using a sample injection valve that propels the sample downstream where mixing occurs in a coiled tube, then passes into a flow-through detector and a recorder or other data handling device.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a choline moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and choline and 2 moles of fatty acids.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to an ethanolamine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and ethanolamine and 2 moles of fatty acids.
A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)
Inflammation of CEREBRAL VENTRICLES.
An indicator of body density as determined by the relationship of BODY WEIGHT to BODY HEIGHT. BMI=weight (kg)/height squared (m2). BMI correlates with body fat (ADIPOSE TISSUE). Their relationship varies with age and gender. For adults, BMI falls into these categories: below 18.5 (underweight); 18.5-24.9 (normal); 25.0-29.9 (overweight); 30.0 and above (obese). (National Center for Health Statistics, Centers for Disease Control and Prevention)
Organic compounds containing a carbonyl group in the form -CHO.
The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.
A broad class of substances containing carbon and its derivatives. Many of these chemicals will frequently contain hydrogen with or without oxygen, nitrogen, sulfur, phosphorus, and other elements. They exist in either carbon chain or carbon ring form.
The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES. Carbohydrates are composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n.
The covalent bonding of an alkyl group to an organic compound. It can occur by a simple addition reaction or by substitution of another functional group.
Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.
A rare, metallic element designated by the symbol, Ga, atomic number 31, and atomic weight 69.72.
Illegitimate use of substances for a desired effect in competitive sports. It includes humans and animals.
The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
Methods for assessing flow through a system by injection of a known quantity of an indicator, such as a dye, radionuclide, or chilled liquid, into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)
Procedures for collecting, preserving, and transporting of specimens sufficiently stable to provide accurate and precise results suitable for clinical interpretation.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Any compound containing one or more monosaccharide residues bound by a glycosidic linkage to a hydrophobic moiety such as an acylglycerol (see GLYCERIDES), a sphingoid, a ceramide (CERAMIDES) (N-acylsphingoid) or a prenyl phosphate. (From IUPAC's webpage)
Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.
A reagent used for the determination of iron.
Oligosaccharides containing three monosaccharide units linked by glycosidic bonds.
A plant genus of the family HYDRANGEACEAE. Members contain hydrangenol, thunberginols, hydramacrosides A and B, and secoiridoid glucosides.
The use of molecularly targeted imaging probes to localize and/or monitor biochemical and cellular processes via various imaging modalities that include RADIONUCLIDE IMAGING; ULTRASONOGRAPHY; MAGNETIC RESONANCE IMAGING; FLUORESCENCE IMAGING; and MICROSCOPY.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
The removal of a soluble component from a liquid mixture by contact with a second liquid, immiscible with the carrier liquid, in which the component is preferentially soluble. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Derivatives of GLUCURONIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that include the 6-carboxy glucose structure.
The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.
A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.
Acidic phospholipids composed of two molecules of phosphatidic acid covalently linked to a molecule of glycerol. They occur primarily in mitochondrial inner membranes and in bacterial plasma membranes. They are the main antigenic components of the Wassermann-type antigen that is used in nontreponemal SYPHILIS SERODIAGNOSIS.
Derivatives of PHOSPHATIDYLCHOLINES obtained by their partial hydrolysis which removes one of the fatty acid moieties.
A phenethylamine that is an isomer of EPHEDRINE which has less central nervous system effects and usage is mainly for respiratory tract decongestion.
A group of cytochromes with covalent thioether linkages between either or both of the vinyl side chains of protoheme and the protein. (Enzyme Nomenclature, 1992, p539)
A plant genus of the family ZYGOPHYLLACEAE. Members contain steroidal saponins. Ingestion by grazing animals causes PHOTOSENSITIVITY DISORDERS called geeldikkop (yellow thick head) in South Africa.
Proteins which contain carbohydrate groups attached covalently to the polypeptide chain. The protein moiety is the predominant group with the carbohydrate making up only a small percentage of the total weight.
Substances produced from the reaction between acids and bases; compounds consisting of a metal (positive) and nonmetal (negative) radical. (Grant & Hackh's Chemical Dictionary, 5th ed)
Unstable isotopes of cadmium that decay or disintegrate emitting radiation. Cd atoms with atomic weights 103-105, 107, 109, 115, and 117-119 are radioactive cadmium isotopes.
A tetrameric protein, molecular weight between 50,000 and 70,000, consisting of 4 equal chains, and migrating on electrophoresis in 3 fractions more mobile than serum albumin. Its concentration ranges from 7 to 33 per cent in the serum, but levels decrease in liver disease.
A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)
Lipids containing at least one monosaccharide residue and either a sphingoid or a ceramide (CERAMIDES). They are subdivided into NEUTRAL GLYCOSPHINGOLIPIDS comprising monoglycosyl- and oligoglycosylsphingoids and monoglycosyl- and oligoglycosylceramides; and ACIDIC GLYCOSPHINGOLIPIDS which comprises sialosylglycosylsphingolipids (GANGLIOSIDES); SULFOGLYCOSPHINGOLIPIDS (formerly known as sulfatides), glycuronoglycosphingolipids, and phospho- and phosphonoglycosphingolipids. (From IUPAC's webpage)
Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.
A flavonol glycoside found in many plants, including BUCKWHEAT; TOBACCO; FORSYTHIA; HYDRANGEA; VIOLA, etc. It has been used therapeutically to decrease capillary fragility.
The thermodynamic interaction between a substance and WATER.
Cytochromes of the c type that are found in eukaryotic MITOCHONDRIA. They serve as redox intermediates that accept electrons from MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX III and transfer them to MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX IV.

Characterization and analysis of a novel glycoprotein from snake venom using liquid chromatography-electrospray mass spectrometry and Edman degradation. (1/5308)

An N-linked glycosylation in a novel C-lectin protein from snake venom was observed by Edman degradation and liquid chromatography-electrospray mass spectrometry. The peptides obtained by trypsin cleavage were analyzed to confirm the amino acid sequence and Asn5 was found to be the N-glycosylation site. The result was further confirmed by N-glycosidase digestion. In addition, the protein and tryptic peptides with and without glycan chain were characterized by mass spectrometry according to the mass difference. The glycopeptide obtained from proteolytic digestion was analyzed and the glycoforms were identified as high-mannose type by tandem MS coupled with alpha-mannosidase digestion. An oxidized Met residue was detected and located in the protein by mass spectrometry.  (+info)

Acquisition of species-specific O-linked carbohydrate chains from oviducal mucins in Rana arvalis. A case study. (2/5308)

The extracellular matrix surrounding amphibian eggs is composed of mucin-type glycoproteins, highly O-glycosylated and plays an important role in the fertilization process. Oligosaccharide-alditols were released from the oviducal mucins of the anuran Rana arvalis by alkali-borohydride treatment in reduced conditions. Neutral and acidic oligosaccharides were fractionated by ion-exchange chromatographies and purified by HPLC. Each compound was identified by matrix assisted laser desorption ionization-time of flight (MALDI-TOF) spectrometry, NMR spectroscopy, electrospray ionization-tandem mass spectroscopy (ESI-MS/MS) and permethylation analyses. This paper reports on the structures of 19 oligosaccharide-alditols, 12 of which have novel structures. These structures range in size from disaccharide to octasaccharide. Some of them are acidic, containing either a glucuronic acid or, more frequently, a sulfate group, located either at the 6 position of GlcNAc or the 3 or 4 positions of Gal. This latter sulfation is novel and has only been characterized in the species R. arvalis. This structural analysis led to the establishment of several novel carbohydrate structures, demonstrating the structural diversity and species-specificity of amphibian glycoconjugates.  (+info)

MioC is an FMN-binding protein that is essential for Escherichia coli biotin synthase activity in vitro. (3/5308)

Biotin synthase is required for the conversion of dethiobiotin to biotin and requires a number of accessory proteins and small molecule cofactors for activity in vitro. We have previously identified two of these proteins as flavodoxin and ferredoxin (flavodoxin) NADP(+) reductase. We now report the identification of MioC as a third essential protein, together with its cloning, purification, and characterization. Purified MioC has a UV-visible spectrum characteristic of a flavoprotein and contains flavin mononucleotide. The presence of flavin mononucleotide and the primary sequence similarity to flavodoxin suggest that MioC may function as an electron transport protein. The role of MioC in the biotin synthase reaction is discussed, and the structure and function of MioC is compared with that of flavodoxin.  (+info)

Discrimination of dimethylamphetamine and methamphetamine use: simultaneous determination of dimethylamphetamine-N-oxide and other metabolites in urine by high-performance liquid chromatography-electrospray ionization mass spectrometry. (4/5308)

A simple and sensitive method by high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) has been investigated for the simultaneous determination of dimethylamphetamine (DMA), its specific yet labile main metabolite dimethylamphetamine-N-oxide (DMAO), and other metabolites, methamphetamine (MA) and amphetamine (AP), in urine. A combination of Bond Elut SCX columns for the solid-phase extraction of urine and a semi-micro SCX column for LC separations provided satisfactory results. The use of acetonitrile/5mM ammonium acetate buffer adjusted to pH 4 (65:35, v/v) as the mobile phase at a flow rate of 0.2 mL/min was found to be the most effective. The detection limits were 5 ng/mL for DMAO, 10 ng/mL for DMA and MA, and 50 ng/mL for AP in the SIM mode.  (+info)

A sulfenic acid enzyme intermediate is involved in the catalytic mechanism of peptide methionine sulfoxide reductase from Escherichia coli. (5/5308)

Methionine oxidation into methionine sulfoxide is known to be involved in many pathologies and to exert regulatory effects on proteins. This oxidation can be reversed by a ubiquitous monomeric enzyme, the peptide methionine sulfoxide reductase (MsrA), whose activity in vivo requires the thioredoxin-regenerating system. The proposed chemical mechanism of Escherichia coli MsrA involves three Cys residues (positions 51, 198, and 206). A fourth Cys (position 86) is not important for catalysis. In the absence of a reducing system, 2 mol of methionine are formed per mole of enzyme for wild type and Cys-86 --> Ser mutant MsrA, whereas only 1 mol is formed for mutants in which either Cys-198 or Cys-206 is mutated. Reduction of methionine sulfoxide is shown to proceed through the formation of a sulfenic acid intermediate. This intermediate has been characterized by chemical probes and mass spectrometry analyses. Together, the results support a three-step chemical mechanism in vivo: 1) Cys-51 attacks the sulfur atom of the sulfoxide substrate leading, via a rearrangement, to the formation of a sulfenic acid intermediate on Cys-51 and release of 1 mol of methionine/mol of enzyme; 2) the sulfenic acid is then reduced via a double displacement mechanism involving formation of a disulfide bond between Cys-51 and Cys-198, followed by formation of a disulfide bond between Cys-198 and Cys-206, which liberates Cys-51, and 3) the disulfide bond between Cys-198 and Cys-206 is reduced by thioredoxin-dependent recycling system process.  (+info)

Biological mass spectrometry: a primer. (6/5308)

Biological polymers undergo numerous significant and fascinating interactions, such as post-translational modifications, non-covalent associations and conformational changes. A valuable parameter for the characterization of a biopolymer is molecular weight. Modern methods of mass spectrometry, including electrospray ionization and matrix-assisted laser desorption ionization mass spectrometry, are ideally suited for the accurate determination of the molecular weight of a biopolymer of interest. Molecular weight measurements are now routinely utilized in the qualitative and quantitative analysis of macromolecules. In many cases small sample quantities (i.e. a few micrograms) limit the utility of nuclear magnetic resonance spectroscopy and X-ray crystallography in obtaining structural information. Thus, mass spectrometry offers an attractive alternative to the more traditional bioanalytical methods for rapid and sensitive measurements. The ultimate goal of these experiments is to obtain sufficient information in order to map the complex molecular circuitry which operates within the cell. In the analysis of complex mixtures mass spectrometry is even more powerful when utilized in conjunction with separation methods. Herein we present some of the aspects of modern biological mass spectrometry for the investigation of large molecules. For more advanced or detailed technical descriptions we refer the reader to a number of recently published reports.  (+info)

Topological alteration of the CYP3A4 active site by the divalent cation Mg(2+). (7/5308)

Phenyldiazene reacted with lymphoblast-expressed CYP3A4 to give a stable phenyl-iron complex that could be induced to rearrange in situ producing approximately equal amounts of four N-phenyl-protoporphyrin IX isomers (N(B):N(A):N(C):N(D), 01:01:02:02). In the presence of 10 mM MgCl(2), the formation profile of the protoporphyrin isomers was markedly altered compared with control, favoring the N(A) isomer (N(B):N(A):N(C):N(D), 01:34:01:02). In addition, an investigation of MgCl(2) effects on CYP3A4-mediated metabolism of triazolam revealed that 10 mM MgCl(2) increased the apparent K(m) of triazolam 4-hydroxylation from 83 to 173 microM and reduced the V(max) for the reaction from 3.4 to 2.4 min(-1). Moreover, when the reaction kinetics of the oxidation of pyrene by CYP3A4 was examined in the absence of MgCl(2), it was found that the substrate-velocity curve was best approximated by a sigmoidal velocity curve (Hill coefficient 1.7 +/- 0.1). However, when the reaction was conducted in the presence of 10 mM MgCl(2), the resulting pyrene kinetics was not sigmoidal but rather biphasic (Hill coefficient 0.80 +/- 0.07). Based on the current results, it appears that CYP3A4 is conformationally sensitive to its in vitro environment and parameters, such as the presence of a divalent magnesium, can have a measurable effect on active site topography and consequently catalytic activity.  (+info)

Kinetic basis for the donor nucleotide-sugar specificity of beta1, 4-N-acetylglucosaminyltransferase III. (8/5308)

The kinetic basis of the donor substrate specificity of beta1, 4-N-acetylglucosaminyltransferase III (GnT-III) was investigated using a purified recombinant enzyme. The enzyme also transfers GalNAc and Glc moieties from their respective UDP-sugars to an acceptor at rates of 0.1-0.2% of that for GlcNAc, but Gal is not transferred at a detectable rate. Kinetic analyses revealed that these inefficient transfers, which are associated with the specificity of the enzyme, are due to the much lower V(max) values, whereas the K(m) values for UDP-GalNAc and UDP-Glc differ only slightly from that for UDP-GlcNAc. It was also found that various other nucleotide-Glc derivatives bind to the enzyme with comparable affinities to those of UDP-GlcNAc and UDP-Glc, although the derivatives do not serve as glycosyl donors. Thus, GnT-III does not appear to distinguish UDP-GlcNAc from other structurally similar nucleotide-sugars by specific binding in the ground state. These findings suggest that the specificity of GnT-III toward the nucleotide-sugar is determined during the catalytic process. This type of specificity may be efficient in preventing a possible mistransfer when other nucleotide-sugars are present in excess over the true donor.  (+info)

TY - JOUR. T1 - The characterisation of coumarins from selected structural classes by electrospray ionisation quadrupole time-of-flight tandem mass spectrometry. AU - Smyth, Franklin. AU - Morgan, Jason L.. AU - OKane, Edmund. AU - Millar, Tommy J.. AU - Ramachandran, Venkataraman N.. PY - 2011/5. Y1 - 2011/5. N2 - Electrospray ionisation quadrupole time-of-flight tandem mass spectrometry (ESI-QTOF-MS/MS) has been used for characterisation of a selection of naturally occurring and synthetic coumarins from different structural classes. The product ions, suggested in earlier studies by electrospray ionisation ion trap mass spectrometry (ESI-MSn), are unequivocally established for the representative coumarins by virtue of accurate mass measurement. Synthetic coumarins that are unsubstituted in the heterocyclic ring give rise to a major product ion by loss of CO2, whereas those substituted in the heterocyclic ring generally undergo alternative fragmentation releasing neutral species such as ketene ...
TY - JOUR. T1 - Development of liquid chromatography electrospray ionization tandem mass spectrometry methods for analysis of DNA adducts of formaldehyde and their application to rats treated with N-nitrosodimethylamine or 4-(methylnitrosamino) -1-(3-pyridyl)-1-butanone. AU - Wang, Mingyao. AU - Cheng, Guang. AU - Villalta, Peter W. AU - Hecht, Stephen S. PY - 2007/8. Y1 - 2007/8. N2 - Reaction of formaldehyde with DNA in vitro produces a variety of adducts among which are observed the cross-link di-(N6-deoxyadenosyl)methane (dAdo-CH2-dAdo, 1) and the hydroxymethyl adduct N6- hydroxymethyl-dAdo (N6-HOCH2-dAdo, 2). While the structures of these adducts have been known for decades, there have been no reports of their formation in vivo. Formaldehyde is released during intracellular metabolism of carcinogenic N-nitrosomethyl compounds such as N-nitrosodimethylamine (NDMA) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), but DNA adducts formed by this pathway have not been previously ...
Biological fluids such as urine, saliva and whole blood were analyzed for contents of drugs by a new combination of desorption electrospray ionization mass spectrometry (DESI-MS) and thin liquid membrane extraction (TLME). Analytes from the sample were extracted into a thin liquid membrane of hexadecane deposited on a porous Teflon membrane, from which they were subsequently analyzed directly by DESI. The total analysis time was 15 minutes for analysis of several samples with a potential analysis time of less than a minute per sample. Thanks to the pre-concentration and sample clean-up built into the method, methadone was detected in urine in full-scan mode with an LOD of 4 ng mL(-1), while amitriptyline, nortriptyline and pethidine showed LODs of 17 ng mL(-1). Quantification was possible for several basic drugs using one common internal standard, providing relative accuracies in the range of 10-30%. A reliability test was performed on 20 samples with methadone, amitriptyline, nortriptyline and ...
TY - JOUR. T1 - Flavor release measurement by atmospheric pressure chemical ionization ion trap mass spectrometry, construction of interface and mathematical modeling of release profiles. AU - Haahr, Anne-Mette. AU - Madsen, Henrik. AU - Smedsgaard, Jørn. AU - Bredie, W.L.P.. AU - Stahnke, Louise Heller. AU - Refsgaard, Hanne. PY - 2003. Y1 - 2003. N2 - An instrumental on-line retronasal flavor analysis was developed to obtain information about the release of flavor compounds in expired air from humans during eating. The volatile flavor compounds were measured by ion trap mass spectrometry with an atmospheric pressure chemical ionization source (APCI). An interface was designed to sample the breath directly from the nose. The repeat-ability in vitro for seven different flavor compounds came out with relative standard derivation less than 10% in most cases, which is acceptable. In vitro quantification was carried out by a determination of the concentration in the gas phase over a flavor solution ...
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TY - JOUR. T1 - Optimized extraction of phospholipids and lysophospholipids for nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry. AU - Byeon, Seul Kee. AU - Lee, Ju Yong. AU - Moon, Myeong Hee. PY - 2012/1/21. Y1 - 2012/1/21. N2 - The efficiencies of four different methods for the extraction of phospholipids (PLs) and lysophospholipids (LPLs) from human plasma samples were examined by comparing extraction recovery values using nanoflow liquid chromatography-electrospray ionization-mass spectrometry (nLC-ESI-MS). For recovery measurements, six PL and six LPL standards of different head groups were spiked into a human plasma sample, and the peak areas of each individual species after extraction were measured from the chromatograms of the nLC-ESI-MS runs. Recovery was calculated by comparing the peak area of an extracted standard species with that of the same species spike after extraction of the same plasma sample. For lipid extraction, four different extraction ...
A procedure based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) is described for the determination of nicotine and its principal metabolites cotinine, trans-3-hydroxycotinine and cotinine-N-oxide, caffeine and arecoline in breast milk, using N-ethylnorcotinine as internal standard. Li …
TY - JOUR. T1 - Fast Quantitative Detection of Cocaine in Beverages Using Nanoextractive Electrospray Ionization Tandem Mass Spectrometry. AU - Hu, Bin. AU - Peng, Xuejiao. AU - Yang, Shuiping. AU - Gu, Haiwei. AU - Chen, Huanwen. AU - Huan, Yanfu. AU - Zhang, Tingting. AU - Qiao, Xiaolin. PY - 2010/2/1. Y1 - 2010/2/1. N2 - Without any sample pretreatment, effervescent beverage fluids were manually sprayed into the primary ion plume created by using a nanoelectrospray ionization source for direct ionization, and the analyte ions of interest were guided into an ion trap mass spectrometer for tandem mass analysis. Functional ingredients (e.g., vitamins, taurine, and caffeine, etc.) and spiked impurity (e.g., cocaine) in various beverages, such as Red Bull energy drink, Coco-cola, and Pepsi samples were rapidly identified within 1.5 s. The limit of detection was found to be 7 ∼ 15 fg (S/N = 3) for cocaine in different samples using the characteristic fragment (m/z 150) observed in the MS3 ...
In Mays featured publication, Dr. Agar and colleagues developed tools using mass spectrometry to be used to characterize meningioma tumor from healthy brain tissue during surgery. These tools could therefore enable surgeons to detect the borders of the tumor better, and remove only the tumor tissue, leaving the healthy brain tissue behind. These developments could be extended to other brain tumor types in the future, improving surgical procedures.. ...
TY - JOUR. T1 - Screening of Threading Bis-Intercalators Binding to Duplex DNA by Electrospray Ionization Tandem Mass Spectrometry. AU - Mazzitelli, Carolyn L.. AU - Chu, Yongjun. AU - Reczek, Joseph J.. AU - Iverson, Brent L.. AU - Brodbelt, Jennifer S.. PY - 2007/2/1. Y1 - 2007/2/1. N2 - The DNA binding of novel threading bis-intercalators V1, trans-D1, and cis-C1, which contain two naphthalene diimide (NDI) intercalation units connected by a scaffold, was evaluated using electrospray ionization mass spectrometry (ESI-MS) and DNAse footprinting techniques. ESI-MS experiments confirmed that V1, the ligand containing the -Gly3-Lys- peptide scaffold, binds to a DNA duplex containing the 5′-GGTACC-3′ specific binding site identified in previous NMR-based studies. The ligand formed complexes with a ligand/DNA binding stoichiometry of 1:1, even when there was excess ligand in solution. Trans-D1 and cis-C1 are new ligands containing a rigid spiro-tricyclic scaffold in the trans- and cis- ...
Close The Infona portal uses cookies, i.e. strings of text saved by a browser on the users device. The portal can access those files and use them to remember the users data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser. ...
TY - JOUR. T1 - Screening and classifying small-molecule inhibitors of amyloid formation using ion mobility spectrometry-mass spectrometry. AU - Young, Lydia M.. AU - Saunders, Janet C.. AU - Mahood, Rachel A.. AU - Revill, Charlotte H.. AU - Foster, Richard J.. AU - Tu, Ling Hsien. AU - Raleigh, Daniel P.. AU - Radford, Sheena E.. AU - Ashcroft, Alison E.. PY - 2015/1/1. Y1 - 2015/1/1. N2 - The search for therapeutic agents that bind specifically to precursor protein conformations and inhibit amyloid assembly is an important challenge. Identifying such inhibitors is difficult because many protein precursors of aggregation are partially folded or intrinsically disordered, which rules out structure-based design. Furthermore, inhibitors can act by a variety of mechanisms, including specific or nonspecific binding, as well as colloidal inhibition. Here we report a high-throughput method based on ion mobility spectrometry-mass spectrometry (IMS-MS) that is capable of rapidly detecting small ...
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TY - JOUR. T1 - Identification of glyceollin metabolites derived from conjugation with glutathione and glucuronic acid in male ZDSD rats by online liquid chromatography-electrospray ionization tandem mass spectrometry. AU - Quadri, Syeda S.. AU - Stratford Jr., Robert. AU - Boué, Stephen M.. AU - Cole, Richard B.. PY - 2014/3/26. Y1 - 2014/3/26. N2 - Glyceollin-related metabolites produced in rats following oral glyceollin administration were screened in plasma, feces, and urine, and these metabolites were identified by precursor and product ion scanning using liquid chromatography coupled online with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Precursor ion scanning in the negative ion (NI) mode was used to identify all glyceollin metabolites based on production of a diagnostic radical product ion (m/z 148) upon decomposition. Using this approach, precursor peaks of interest were found at m/z 474 and 531. Tandem mass spectra of these two peaks allowed us to characterize ...
Carbamazepine (CBZ) and oxcarbazepine (OXCBZ) are both antiepileptic drugs, which are prescribed as first-line drugs for the treatment of partial and generalized tonic-clonic epileptic seizures. In this paper, a specific and sensitive liquid chromatography-electrospray ionization mass spectrometry m …
We have demonstrated an on-line laser ablation sampling system and coupling of the system to liquid chromatography (LC) using an infrared (IR) laser to ablate and transfer materials into a flowing solvent stream. With this approach, samples are depos
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DNA adduct formation of the aromatic amine, 4-aminobiphenyl (4-ABP), a known human carcinogen present in tobacco smoke, and the heterocyclic aromatic amines (HAAs), 2-amino-9H-pyrido[2,3-b]indole (AαC), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), and 2-amino-3,8-dimethylmidazo[4,5-f]quinoxaline (MeIQx), potential human carcinogens, which are also present in tobacco smoke or formed during the high-temperature cooking of meats, was investigated in freshly cultured human hepatocytes. The carcinogens (10 μM) were incubated with hepatocytes derived from eight different donors for time periods up to 24 h. The DNA adducts were quantified by liquid chromatography-electrospray ionization mass spectrometry with a linear quadrupole ion trap mass spectrometer. The principal DNA adducts formed for all of the carcinogens were N-(deoxyguanosin-8-yl) (dG-C8) adducts. The levels of adducts ranged from 3.4 to 140 adducts per 10(7) DNA bases. The highest level of
A reversed-phase high-performance liquid chromatographic (HPLC) method is applied for the determination of galacturonic acid (GA) of pectins in different commercial fruit juices. The separation was carried out on a C18 column using precolumn derivatization with p-aminobenzoic acid (p-ABA) and UV detection at 304 nm. The identification of GA was confirmed by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) in positive ion mode. The concentration of GA in the samples analyzed ranged from 12.9 ± 0.5 to 49.4 ± 0.5 mgGA L−1. Amongst the samples analyzed, mango juice was found to be richest in GA content, and therefore a good source of pectins. Detection and quantification limits of the described methodology were 1.2 and 3.9 mg L−1, respectively. Quantitative GA recoveries in the beverages had a range between 90 and 98%. The results showed that the HPLC method proposed was precise and suitable for the identification and quantification of GA ...
A sensitive, accurate and reliable bioanalytical method for the enantioselective determination of metoprolol in plasma and saliva samples utilizing liquid chromatography-electrospray ionization tandem mass spectrometry was developed and validated. Human plasma and saliva samples were pretreated by microextraction by packed sorbent (MEPS) prior to analysis. A new MEPS syringe form with two inputs was used. Metoprolol enantiomers and internal standard pentycaine (IS) were eluted from MEPS sorbent using isopropanol after removal of matrix interferences using aliquots of 5% methanol in water. Complete separation of metoprolol enantiomers was achieved on a Cellulose-SB column (150 × 4.6 mm, 5 μm) using isocratic elution with mobile phase 0.1% ammonium hydroxide in hexane-isopropanol (80:20, v/v) with a flow rate of 0.8 mL/min. A post-column solvent-assisted ionization was applied to enhance metoprolol ionization signal in positive mode monitoring (+ES) using 0.5% formic acid in isopropanol at a ...
Parkinsons disease (PD) is a progressive neurodegenerative disease affecting the nigrostriatal pathway, where patients do not manifest motor symptoms until ,50% of neurons are lost. Thus, it is of great importance to determine early neuronal changes that may contribute to disease progression. Recent attention has focused on lipids and their role in pro- and anti-apoptotic processes. However, information regarding the lipid alterations in animal models of PD is lacking. In this study, we utilized high performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) and novel HPLC solvent methodology to profile phosphatidylcholines and sphingolipids within the substantia nigra. The ipsilateral substantia nigra pars compacta was collected from rats 21 days after an infusion of 6-hydroxydopamine (6-OHDA), or vehicle into the anterior dorsal striatum. We identified 115 lipid species from their mass/charge ratio using the LMAPS Lipid MS Predict Database. Of these, ...
The gold standard for cystic fibrosis (CF) diagnosis is the determination of chloride concentration in sweat. Current testing methodology takes up to 3 h to complete and has recognized shortcomings on its diagnostic accuracy. We present an alternative method for the identification of CF by combining desorption electrospray ionization mass spectrometry and a machine-learning algorithm based on gradient boosted decision trees to analyze perspiration samples. This process takes as little as 2 min, and we determined its accuracy to be 98 ± 2% by cross-validation on analyzing 277 perspiration samples. With the introduction of statistical bootstrap, our method can provide a confidence estimate of our prediction, which helps diagnosis decision-making. We also identified important peaks by the feature selection algorithm and assigned the chemical structure of the metabolites by high-resolution and/or tandem mass spectrometry. We inspected the correlation between mild and severe CFTR gene mutation types ...
Altered metabolism is an inherent property of cancer and provides a rich opportunity for exploring its underlying biology and developing diagnostic biomarkers. We used desorption electrospray ionization mass spectrometry ...
Os tumores bif sicos da mama formam um grupo heterog neo de tumores que apresentam na histologia dois componentes, o epitelial e o estromal. Esses tumores podem ser benignos ou malignos, alguns podem recidivar ou dar met stase. O seu progn stico varia conforme a sua classifica o histol gica, a presen a de met stase e a adequabilidade do seu tratamento. Por m, por vezes, h ainda dificuldade em diferenci -los quando h sobreposi o das caracter sticas histol gicas que s o utilizadas para realizar o diagn stico no exame anatomopatol gico. Visando um novo m todo para diferenciar esses tumores entre si, al m do exame anatomopatol gico habitual, buscou-se analisar esses tumores atrav s de uma t cnica da qu mica anal tica de ioniza o ambiente, utilizando espectrometria de massas, o DESI-MSI (Desorption Electrospray Ionization Mass Spectrometry Imaging). Foram utilizados cortes de amostras congeladas em l minas para analisar no DESI-MSI e, atrav s dessa an lise, obteve-se os espectros de massas e as ...
366 Pearmain, ebook quadrupole ion trap mass spectrometry, content. 368 Ian Hill, range; IB Regional policies, coast; In The International reference: facing in Education. There were then BuzzFeed who was Chinese to play over when ebook quadrupole ion trap mass Got.
TY - JOUR. T1 - Identification of ethyl pyruvate and dihydrocinchonidine adducts by electrospray ionization mass spectrometry. AU - Bartók, Mihály. AU - Szabó, Pál Tamás. AU - Bartók, Tibor. AU - Szöllösi, György. PY - 2000/1/1. Y1 - 2000/1/1. N2 - Several ethyl pyruvate and dihydrocinchonidine adducts, formed by non-covalent interactions with alkali cations, have been identified for the first time using electrospray ionization mass and tandem mass spectrometry. This type of adduct may have an important role in asymmetric reactions of pyruvates in the presence of cinchonas. Copyright (C) 2000 John Wiley and Sons, Ltd.. AB - Several ethyl pyruvate and dihydrocinchonidine adducts, formed by non-covalent interactions with alkali cations, have been identified for the first time using electrospray ionization mass and tandem mass spectrometry. This type of adduct may have an important role in asymmetric reactions of pyruvates in the presence of cinchonas. Copyright (C) 2000 John Wiley and ...
Bisphenol A (BPA) is a weak estrogen. Pharmacokinetic studies of BPA have demonstrated a rapid and extensive metabolism of BPA to the nonestrogenic BPA-monoglucuronide (BPA-gluc). Some investigators have reported that BPA was found at parts per billion concentrations in the tissues or urine of humans without known exposure to BPA. This work developed a rapid and sensitive method for the determination of BPA and BPA-gluc in plasma and urine based on liquid chromatography-tandem mass spectrometry. The liquid chromatography-electrospray ionization-tandem mass spectrometry method for quantitation of BPA and BPA-gluc uses stable isotope-labeled internal standards. A linear ion trap mass spectrometer permits identification and quantitation of BPA-gluc and BPA without sample workup. Development of separation conditions reduced the BPA-background in solvent samples to below 2.5 pmol/ml for BPA. Limit of quantitation (LOQ) for BPA in control urine was 15 pmol/ml; LOQ for BPA-gluc was 65 pmol/ml. ...
This thesis presents three different series of high energy (keV) collision experiments as well as a brief scientific introduction to the field. In the first series, protonated glycine and leucine were collided with carbon dioxide and a beam attenuation method was applied to determine their total fragmentation cross sections. A technique was also presented for how to restore the resolution in mass spectra obtained with a hemispherical electrostatic analyzer followed by a position sensitive detector (micro-channel plate equipped with a resistive anode). In the second series of experiments, Collision Induced Dissociation (CID) and Electron Capture Induced Dissociation (ECID) studies were performed on the nucleotide adenosine 5-monophosphate anion (AMP-) in water complexes. The two dissociation techniques revealed different fragmentation patterns and a numerical solvent evaporation model was used to interpret the spectra. It was then found that the CID and ECID processes were associated with ...
TY - JOUR. T1 - Probing conformational changes of ubiquitin by host-guest chemistry using electrospray ionization mass spectrometry. AU - Lee, Jong Wha. AU - Heo, Sung Woo. AU - Lee, Shin Jung C.. AU - Ko, Jae Yoon. AU - Kim, Hyungjun. AU - Kim, Hugh I.. PY - 2013/1/1. Y1 - 2013/1/1. N2 - We report mechanistic studies of structural changes of ubiquitin (Ub) by host-guest chemistry with cucurbit[6]uril (CB[6]) using electrospray ionization mass spectrometry (ESI-MS) combined with circular dichroism spectroscopy and molecular dynamics (MD) simulation. CB[6] binds selectively to lysine (Lys) residues of proteins. Low energy collision-induced dissociation (CID) of the protein-CB[6] complex reveals CB[6] binding sites. We previously reported (Anal. Chem. 2011, 83, 7916-7923) shifts in major charge states along with Ub-CB[6] complexes in the ESI-MS spectrum with addition of CB[6] to Ub from water. We also reported that CB[6] is present only at Lys6 or Lys11 in high charge state (+13) complex. In this ...
Negative electrospray ionization mass spectrometry of synthetic and chemically modified oligonucleotides.: We report here on the analysis of synthetic oligonucl
We report here a simple and rapid method for the quantification of brominated vegetable oil (BVO) in soft drinks based upon liquid chromatography-electrospray ionization mass spectrometry. Unlike previously reported methods, this novel method does not require hydrolysis, extraction or derivatization steps, but rather a simple dilute and shoot sample preparation. The quantification is conducted b ...
We report here a simple and rapid method for the quantification of brominated vegetable oil (BVO) in soft drinks based upon liquid chromatography-electrospray ionization mass spectrometry. Unlike previously reported methods, this novel method does not require hydrolysis, extraction or derivatization steps, but rather a simple dilute and shoot sample preparation. The quantification is conducted b ...
Author: Göth, Melanie et al.; Genre: Thesis; Keywords: native mass spectrometry; ion mobility; protein complexes; Title: Investigation of Protein-Ligand Complexes by Native Mass Spectrometry and Ion Mobility-Mass Spectrometry
A precise HPLC/MS/MS approach; Lipidomics in Diabetes and the Metabolic Syndrome; LC-MS-MS research of impartial Eicosanoids; Quantification Of F2-Isoprostanes In organic Fluids And Tissues As A degree Of Oxidant rigidity; dimension of goods of Docosahexaenoic Acid Peroxidation, Neuroprostanes, and Neurofurans; Enantiomeric separation of hydroxy and hydroperoxy eicosanoids through chiral column chromatography; exact Chiral Lipidomics research by means of Liquid Chromatography Electron seize Atmospheric strain Chemical Ionization Mass Spectrometry (LC-ECAPCI/MS); Shotgun Lipidomics by means of Tandem Mass Spectrometry lower than Data-Dependent Acquisition keep an eye on; id of Intact Lipid Peroxides via Ag+ Coordination Ionspray Mass Spectrometry (CIS-MS); Quantification of Cardiolipin by means of Liquid Chromatography Electrospray Ionization Mass Spectrometry ...
J Chromatogr B Analyt Technol Biomed Life Sci. 2007 Sep 15;857(1):1-8. Epub 2007 Jun 29. Comparative Study; Evaluation Studies; Research Support, N.I.H., Extramural
Soybean seeds are an important source of vegetable oil and biomaterials. The content of individual triacylglycerol species (TAG) in soybean seeds is difficult to quantify in an accurate and rapid way. The present study establishes an approach to quantify TAG species in soybean seeds utilizing an electrospray ionization tandem mass spectrometry with multiple neutral loss scans. Ten neutral loss scans were performed to detect the fatty acyl chains of TAG, including palmitic (P, 1650), linolenic (Ln, 1853), linoleic (L, 1852), oleic (O, 1851), stearic (S, 1850), eicosadienoic (2052), gadoleic (2051), arachidic (2050), erucic (2251), and behenic (2250). The abundance of ten fatty acyl chains at 46 TAG masses (mass-to-charge ratio, m/z) were determined after isotopic deconvolution and correction by adjustment factors at each TAG mass. The direct sample infusion and multiple internal standards correction allowed a rapid and accurate quantification of TAG species. Ninety-three TAG species were resolved ...
Title:Effect of Electrospray Ionization Source Parameters on Pharmaceuticals Analysis Using Quadrupole Time-of-Flight Mass Spectrometry. VOLUME: 12 ISSUE: 4. Author(s):Ummi N.S.B. Masseren, Soo W. Khor, Kheng S. Tay* and Mhd R.B. Abas*. Affiliation:Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.. Keywords:Environmental analysis, HPLC, organic pollutants, ESI, MS, pharmaceuticals and personal care products.. Abstract:. Introduction: The presence of pharmaceuticals in the environment has caused increasing concern. In the development of analytical method, selection of sensitive analytical instrument is also an important consideration. Among various analytical instruments, HPLC coupled with ESI based QTOF high resolution MS has recently emerged as a powerful analytical tool for the analysis of trace pharmaceuticals in environmental waters. This study evaluated the influence of ESI source parameters which include capillary voltage, nozzle voltage, ...
Phosphatidylethanolamines (PEs) are one of the major constituents of cellular membranes, and, along with other phospholipid classes, have an essential role in the physiology of cells. Profiling of phospholipids in biological samples is currently done using mass spectrometry (MS). In this work we describe the MS fragmentation of sodium adducts of 2-oleoyl-1-palmitoyl-sn-glycero-3-phosphatidylethanolamine (POPE) and 2-linoleoyl-1-palmitoyl-sn-glycero-3-phosphatidylethanolamine (PLPE). This study was performed by electrospray ionization tandem mass spectrometry (ESI-MS/MS) using three different instruments and also by matrix-assisted laser desorption/ionization tandem mass spectrometry (MALDI-MS/MS). All MS/MS spectra show product ions related to the polar head fragmentation and product ions related to the loss of acyl chains. In ESI-MS/MS spectra, the product ions [M+Na-R1COOH-43]+ and [M+Na-R2COOH-43]+ show different relative abundance, as well as [M+Na-R1COOH]+ and [M+Na-R2COOH]+ product ions, ...
Unfixed tissue specimens most frequently are stored for long term research uses at either -80° C or in vapor phase liquid nitrogen (VPLN). There is little information concerning the effects such long term storage on tissue RNA or protein available for extraction. Aliquots of 49 specimens were stored for 5-12 years at -80° C or in VPLN. Twelve additional paired specimens were stored for 1 year under identical conditions. RNA was isolated from all tissues and assessed for RNA yield, total RNA integrity and mRNA integrity. Protein stability was analyzed by surface-enhanced or matrix-assisted laser desorption ionization time of flight mass spectrometry (SELDI-TOF-MS, MALDI-TOF-MS) and nano-liquid chromatography electrospray ionization tandem mass spectrometry (nLC-ESI-MS/MS). RNA yield and total RNA integrity showed significantly better results for -80° C storage compared to VPLN storage; the transcripts that were preferentially degraded during VPLN storage were these involved in antigen ...
BACKGROUND: Low-dose methotrexate (MTX) is the first-line therapy in early rheumatoid arthritis (eRA). Up to 40% of eRA patients do not benefit from MTX therapy. MTX has been shown to inhibit one-carbon metabolism, which is involved in the donation of methyl groups. In this study, we investigate baseline global DNA methylation and changes in DNA methylation during treatment in relation to clinical non-response after 3 months of MTX treatment. METHODS: Two hundred ninety-four blood samples were collected from the Treatment in the Rotterdam Early Arthritis Cohort (tREACH, ISRCTN26791028), a multicenter, stratified single-blind clinical trial of eRA patients. Global DNA (hydroxy)methylation was quantified using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) and validated with a global DNA LINE-1 methylation technique. MTX response was determined as ΔDAS28. Additionally, patients were stratified into two response groups according to the European League Against ...
A new platinum(II) complex with methionine sulfoxide was synthesized and characterized by chemical and spectroscopic techniques. Elemental analyses, mass spectrometric measurements (electrospray ionization quadrupole time-of-flight mass spectrometry), and thermal analyses of the solid compound fit the composition [(C5H10NO3S)Pt(mu-Cl)(2)Pt(C5H10NO3S)]center dot 2.5H(2)O. Infrared spectroscopic data indicate coordination of the ligand to Pt(II) through the nitrogen of NH2 and the sulfur of the S=O group. H-1-N-15 nuclear magnetic resonance spectroscopic data confirm nitrogen coordination. Antibacterial activities were evaluated by antibiogram assays using the disc diffusion method. The platinum(II) complex showed antibacterial activity against Gram-negative Pseudomonas aeruginosa bacterial cells ...
TY - JOUR. T1 - A combination of molecular probe-tandem electrospray ionization mass spectrometry. T2 - A technique for tracing structural changes in phospholipid hydroperoxides. AU - Shimizu, Rumiko. AU - Nagai, Ai. AU - Tominaga, Hiroko. AU - Imura, Megumi. AU - Onyango, Arnold N.. AU - Izumi, Minoru. AU - Nakajima, Shuhei. AU - Tahara, Shoichi. AU - Kaneko, Takao. AU - Baba, Naomichi. PY - 2009. Y1 - 2009. N2 - An ethyl-labeled phosphatidylcholine hydroperoxide (PC-OOH/Et 2) was synthesized as a molecular probe for naturally occurring PC-OOH 1. Applying the precursor ion scan mode in tandem ESI mass spectrometry at m/z 198, a signal of the PC-OOH/Et 2 alone could be selectively detected even in the presence of a large excess of a complex mixture of phospholipids in the blood. Furthermore, molecular species that formed from PC-OOH/Et 2 by its degradation in the blood were also observed in the same spectrum. Since the molecular probe-and-mass spectrometry-assisted analytical method presented ...
Native nanoelectrospray ionization mass spectrometry is an underutilized technique for fragment screening. In this study, the first demonstration is provided of the use of native mass spectrometry for screening fragments against a protein-DNA interaction. EthR is a transcriptional repressor of EthA expression in Mycobacterium tuberculosis (Mtb) that reduces the efficacy of ethionamide, a second‐line antitubercular drug used to combat multidrug‐resistant Mtb strains. A small‐scale fragment screening campaign was conducted against the EthR-DNA interaction using native mass spectrometry, and the results were compared with those from differential scanning fluorimetry, a commonly used primary screening technique. Hits were validated by surface plasmon resonance and X‐ray crystallography. The screening campaign identified two new fragments that disrupt the EthR-DNA interaction in vitro (IC50=460-610 μm) and bind to the hydrophobic channel of the EthR dimer ...
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Allium hookeri (AH) is widely consumed as a vegetable and herbal medicine in southeastern Asia. AH has been reported antioxidant, antimicrobial, improvement of bone health and antidiabetic effects. In the present study, we investigated the inhibitory effect of a methanol extract of AH root (AHE) on inflammatory response in lipopolysaccharide (LPS)-induced RAW264.7 cells. Initially, characterization of organic sulfur compounds in AHE was determined using high performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS). Cells were incubated with LPS and AHE for 24 h. The productions of nitric oxide (NO), reactive oxygen species (ROS), and inflammation-related cytokines were examined. Gene and protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were assessed by polymerase chain reaction and Western blotting. Key factor, nuclear factor kappa B (NF-κB) was also determined. AHE contained organosulfur compounds
Allium hookeri (AH) is widely consumed as a vegetable and herbal medicine in southeastern Asia. AH has been reported antioxidant, antimicrobial, improvement of bone health and antidiabetic effects. In the present study, we investigated the inhibitory effect of a methanol extract of AH root (AHE) on inflammatory response in lipopolysaccharide (LPS)-induced RAW264.7 cells. Initially, characterization of organic sulfur compounds in AHE was determined using high performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS). Cells were incubated with LPS and AHE for 24 h. The productions of nitric oxide (NO), reactive oxygen species (ROS), and inflammation-related cytokines were examined. Gene and protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were assessed by polymerase chain reaction and Western blotting. Key factor, nuclear factor kappa B (NF-κB) was also determined. AHE contained organosulfur compounds
DNA methylation is an epigenetic mechanism regulating gene expression that has been insufficiently studied in the blood of rheumatoid arthritis (RA) patients, as only T cells and total peripheral blood mononuclear cells (PBMCs) from patients with established RA have been studied and with conflicting results. Five major blood cell subpopulations: T, B and NK cells, monocytes, and polymorphonuclear leukocytes, were isolated from 19 early RA patients and 17 healthy controls. Patient samples were taken before and 1 month after the start of treatment with methotrexate (MTX). Analysis included DNA methylation with high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry-selected reaction monitoring (HPLC-ESI-MS/MS-SRM) and expression levels of seven methylation-specific enzymes by quantitative polymerase chain reaction (qPCR). Disease-modifying anti-rheumatic drug (DMARD)-naïve early RA patients showed global DNA hypomethylation in T cells and monocytes, together with a lower
Rapid analysis of anabolic steroid metabolites in urine by combining field asymmetric waveform ion mobility spectrometry with liquid chromatography and mass spectrometry
OBJECTIVE To study alkaloids of Senecio scandens growing in Guangdong. METHODS The rapid resolution liquid chromatography-electrospray ionization mass spectrometry (RRLC-ESI-MS/MS) was used to analyse alkaloids of Senecio scandens growing in Guangdong, and senkirkine was isolated and purified by silica gel column chromatography. RESULTS Four alkaloids were identified as senkirkine, dehydrosenkirkine, monocrotaline and adonifoline, and senkirkine was firstly isolated from Senecio scandens growing in Guangdong. CONCLUSION Senkirkine is the main component of Senecio scandens growing in Guangdong.
Feijoa fruit is becoming increasingly popular, yet limited studies have focused on the antioxidant capacity and phenolic profiling of its extracts. In this research, optimization of phenolic extraction from feijoa flesh, peel, and whole fruit from four New Zealand grown cultivars was conducted using orthogonal design. Antioxidant activities of the extracts were assessed, followed by phenolic profiling by a validated liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method. For feijoa flesh and whole fruit, the extraction was optimized using 70% ethanol, material to solvent ratio of 1:30, at extraction temperature of 50 °C for 30 min. For feijoa peel, extraction at 50 °C for 60 min using 50% ethanol with a material to solvent ratio of 1:30 were the optimized conditions. Results showed feijoa peel had higher total phenolic content (TPC) and antioxidant activities than the flesh and whole fruit. Overall, the Unique cultivar had a relatively higher TPC and ...
Fibrates, such as fenofibrate, are peroxisome proliferator-activated receptor-α (PPARα) agonists and have been used for several decades as hypolipidemic agents in the clinic. However, contradictory observations exist on the role of fibrates in host response to acute inflammation, with unclear mechanisms. The role of PPARα in colitis was assessed using fenofibrate and Ppara-null mice. Wild-type or Ppara-null mice were subjected to acute colitis under three distinct protocols, dextran sulfate sodium, trinitrobenzenesulfonic acid, and Salmonella Typhi. Serum and colon lipidomics were analyzed to characterize the metabolic profiles by ultra-performance liquid chromatography-coupled with electrospray ionization quadrupole time-of-flight mass spectrometry. Messenger RNAs of PPARα target genes and genes involved in inflammation were determined by qunatitative PCR analysis. Fenofibrate treatment exacerbated inflammation and tissue injury in acute colitis, and this was dependent on PPARα activation.
Anthocyanins are naturally occurring polyphenols that impart bright color to fruits, vegetables and plants. In this study, the extraction of anthocyanins from freeze-dried fruit skin of downy rose-myrtle (Rhodomyrtus tomentosa (Ait.) Hassk var. Gangren) was optimized using response surface methodology (RSM). Using 60% ethanol containing 0.1% (v/v) hydrochloric acid as extraction solvent, the optimal conditions for maximum yields of anthocyanin (4.358 ± 0.045 mg/g) were 15.7:1 (v/w) liquid to solid ratio, 64.38 °C with a 116.88 min extraction time. The results showed good fits with the proposed model for the anthocyanin extraction (R2 = 0.9944). Furthermore, the results of high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) analysis of the anthocyanins extracted from the fruit skin of downy rose-myrtle revealed the presence of five anthocyanin components, which were tentatively identified as delphinidin-3-glucoside, cyanidin-3-glucoside, peonidin-3-glucoside,
TY - JOUR. T1 - Proteomic analysis of pathogenic and attenuated alcelaphine herpesvirus 1. AU - Dry, Inga. AU - Haig, David M. AU - Inglis, Neil F. AU - Imrie, Lisa. AU - Stewart, James P.. AU - Russell, George C. PY - 2008/6. Y1 - 2008/6. N2 - The gammaherpesvirus alcelaphine herpesvirus 1 (AlHV-1) causes malignant catarrhal fever in susceptible ungulates but infects its natural host, wildebeest, without obvious clinical signs. In tissue culture, AlHV-1 is initially predominantly cell associated and virulent but on extended culture becomes cell-free and attenuated. We wanted to determine what changes in protein composition had taken place during the transition from virulent to attenuated virus in culture. Purified virus preparations were fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and proteins were analyzed by liquid chromatography-electrospray ionization-tandem mass spectrometry. Peptides were identified in serial gel slices by using MASCOT software to ...
Looking for online definition of electrospray ionisation in the Medical Dictionary? electrospray ionisation explanation free. What is electrospray ionisation? Meaning of electrospray ionisation medical term. What does electrospray ionisation mean?
Polar components in fuels may enable differentiation between fuel types or commercial fuel sources. A range of commercial fuels from numerous sources were analyzed by flow injection analysis/electrospray ionization/mass spectrometry without extensive sample preparation, separation, or chromatography. This technique enabled screening for unique polar components at parts per million levels in commercial hydrocarbon products, including a range of products from a variety of commercial sources and locations. Because these polar compounds are unique in different fuels, their presence may provide source information on hydrocarbons released into the environment. This analysis was then applied to mixtures of various products, as might be found in accidental releases into the environment. Copyright ?? Taylor & Francis Group, LLC....
TY - JOUR. T1 - Matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight (MALDI-QIT-TOF)-based imaging mass spectrometry reveals a layered distribution of phospholipid molecular species in the mouse retina. AU - Hayasaka, Takahiro. AU - Goto-Inoue, Naoko. AU - Sugiura, Yuki. AU - Zaima, Nobuhiro. AU - Nakanishi, Hiroki. AU - Ohishi, Kentaro. AU - Nakanishi, Setsuko. AU - Naito, Takayuki. AU - Taguchi, Ryo. AU - Setou, Mitsutoshi. PY - 2008/11/15. Y1 - 2008/11/15. N2 - We recently developed a matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight (MALDI-QIT-TOF)-based imaging mass spectrometry (IMS) system. This system enables us to perform structural analyses using tandem mass spectrometry (MS/MS), as well as to visualize phospholipids and peptides in frozen sections. In the retina, phototransduction is regulated by the light-sensitive interaction between visual pigment-coupled receptor proteins, such as rhodopsin, and G proteins, such as transducin. ...
The gas-phase acidities and proton affinities of analogs of protein amino acids were investigated. The gas-phase acidities of the lysine homologues were measured by the extended kinetic method in a quadrupole ion trap mass spectrometer. Deprotonation entropy changes were also measured. For ornithine, 2,4-diaminobutyric acid, and 2,3-diaminopropionic acid, the gas-phase acidities measured were 1416 ± 17 kJ/mol, 1420 ± 8 kJ/mol, and 1405 ± 24 kJ/mol. Their changes in entropy were measured to be -19 J/mol K, 1 J/mol k, and -24 J/mol K, respectively. The gas-phase acidities and entropies of two structural analogs of arginine, citrulline and canavanine, were measured by the extended kinetic method. The gas-phase acidity of citrulline was measured to be 1366 ± 11 kJ/mol, and the gas-phase acidity of canavanine was measured to be 1401 ± 13 kJ/mol. The proton affinity and protonation entropy change for citrulline was measured as well. The proton affinity was determined to be 984 ± 11 kJ/mol with an
Structure analysis of partially depolymerized methyl cellulose was performed by nanoelectrospray ionization tandem mass spectrometry (nano-ESI-MS/MS) and by matrix-assisted laser desorption/ionization tandem mass spectrometry (MALDI-MS/MS). Dimethylamine (DMA) was used for the first time as a reducing end derivatization reagent for oligosaccharides. This is an attractive reagent since it could be easily removed from the reaction mixture. Most important it also introduces a basic functional group that increased the sensitivity in both MALDI and nano-ESI. Depolymerization was made in two ways: one by the cellulose selective endoglucanase 5A from Bacillus agaradhaerens (Ba Ce15A) and the other by trifluoroacetic acid. The DMA derivatives formed both protonated and sodiated molecules in nano-ESI and MALDI. Tandem MS of protonated molecules yielded predominantly Y fragments from which the distribution of the substituents in the oligomers could be measured. Fragments obtained in tandem MS of sodiated ...
A method for the extraction and quantitation of procaine in equine plasma was developed for use with liquid chromatography-mass spectrometry (LC-MS). Procaine was isolated from equine plasma by liquid-liquid extraction at pH 11 with dichloromethane using procaine-d10 as an internal standard. Quantitation was achieved by LC-MS using a 3-µm C-18 column coupled to an electrospray ionization source on a linear ion-trap mass spectrometer. The limit of detection and limit of quantitation was determined to be 50 and 200 pg/mL, respectively. The lowest limit of detection determined by previous methods was 1 ng/mL. Administration samples were obtained as part of a larger study to determine a regulatory limit for procaine in racehorses and procaine concentrations were determined using this method.. ...
Introduction The fast, precise, and accurate measurement of the new generation of oral anticoagulants such as dabigatran and rivaroxaban in patients plasma my provide important information in different clinical circumstances such as in the case of suspicion of overdose, when patients switch from existing oral anticoagulant, in patients with hepatic or renal impairment, by concomitant use of interaction drugs, or to assess anticoagulant concentration in patients blood before major surgery. Methods Here, we describe a quick and precise method to measure the coagulation inhibitors dabigatran and rivaroxaban using ultra-performance liquid chromatography electrospray ionization-tandem mass spectrometry in multiple reactions monitoring (MRM) mode (UPLC-MRM MS). Internal standards (ISs) were added to the sample and after protein precipitation; the sample was separated on a reverse phase column. After ionization of the analytes the ions were detected using electrospray ionization-tandem mass ...
NOTE: Where studies included discovery and validation cohorts, diagnostic metrics of the validation set included for analysis.. Abbreviations: EAC, esophageal adenocarcinoma; ESCC, esophageal squamo-cellular carcinoma; GAC, gastric adenocarcinoma; CRC, colorectal adenocarcinoma; UPLC-TQMS, ultra-performance liquid chromatography-triple quadrupole mass spectrometry; NMR, nuclear magnetic resonance spectroscopy; ESI-TOFMS, electrospray ionization time-of-flight mass spectrometry; RRLC, rapid relaxing liquid chromatography; GC-MS, gas chromatography mass spectrometry; HPLC, high-performance liquid chromatography; FTICR-MS, Fourier transform ion cyclotron mass spectrometry; MS/MS, tandem mass spectrometry; TQMRM, triple quadrupole multiple reaction monitoring; DI, direct ionization; SPME, solid phase microextraction; PLS-DA, partial least squares discriminant analysis; ROC, receiver operating characteristic curve; PCA, principle component analysis; OPLS-DA, orthogonal projection to latent structures ...
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Isoliensinine, a natural phenolic bisbenzyltetrahydroisoquinoline alkaloid, has received considerable attention for its potential biological effects such as antioxidant and anti-HIV activities. From the dog hepatic microsomes of isoliensinine, three new N-demethylated and O-demethylated metabolites, 2-N-desmethyl-isoliensinine (M1), 2-N-desmethylisoliensinine (M2), and 2-N-6-O-didesmethylisoliensinine (M3), were identified by high-performance liquid chromatography and data-dependent electrospray ionization tandem mass spectrometry. Possible metabolic pathways for isoliensinine have been proposed. The result should prove very helpful for evaluation of the drug-like properties of isoliensinine and other bisbenzylisoquinoline alkaloids.
Electrospray mass spectrometry was used to characterize metal-complexing ligands derived from tannic acid, a component of natural dissolved organic matter. Complexes formed by tannin ligands with copper and other biogeochemically important metals were identified from the mass-to-charge ratios of the corresponding deprotonated molecular ions, allowing stoichiometry and metal oxidation state to be determined. Ligand ion intensities were proportional to tannic acid concentration, with detection limits on the order of 5 nM for individual compounds in 50:50 water/acetonitrile. The relative abundance of free ligand and complex ions indicated the degree of complexation under different solution conditions (metal concentration, pH, ionic strength). Using tandem mass spectrometry, the structure and principal copper binding site for one of the tannins were also determined, providing unique information with regard to metal complexation by these polyfunctional ligands. The technique can be combined with high ...
Electrospray mass spectrometry was used to characterize metal-complexing ligands derived from tannic acid, a component of natural dissolved organic matter. Complexes formed by tannin ligands with copper and other biogeochemically important metals were identified from the mass-to-charge ratios of the corresponding deprotonated molecular ions, allowing stoichiometry and metal oxidation state to be determined. Ligand ion intensities were proportional to tannic acid concentration, with detection limits on the order of 5 nM for individual compounds in 50:50 water/acetonitrile. The relative abundance of free ligand and complex ions indicated the degree of complexation under different solution conditions (metal concentration, pH, ionic strength). Using tandem mass spectrometry, the structure and principal copper binding site for one of the tannins were also determined, providing unique information with regard to metal complexation by these polyfunctional ligands. The technique can be combined with high ...
The Global Clinical Mass Spectrometry Market, by product type (GAS Chromatography-Mass Spectrometry, Instrument, Liquid Chromatography-Mass Spectrometry, Instrument, MALDI TOF Mass Spectrometer, Capillary Electrophoresis-Mass Spectrometry, and Ion Mobility Spectrometry-Mass Spectrometry), by application (Clinical Testing, Proteomics, and Drug Discovery), and by end user (Hospitals, Research Laboratories, and Diagnostic Laboratories) was valued at US$ 4,665.3 million in 2016 and is projected to exhibit a CAGR of 7.3% over the forecast period (2017-2025), as highlighted in a new report published by Coherent Market Insights. Focus of key players on development of products through advanced technology and rising prevalence of lifestyle related diseases are attributed to drive meteoric growth of the clinical mass spectrometry market over the forecast period.. Request Sample Copy of the Business Report: https://www.coherentmarketinsights.com/insight/request-sample/193. Clinical mass spectrometry is ...
Simultaneous determination of β-hydroxybutyrate and β-hydroxy-β-methylbutyrate in human whole blood using hydrophilic interaction liquid chromatography electrospray tandem mass ...
G-quadruplexes are nucleic acids structures stabilized by physiological concentration of potassium ions. Because low stability G-quadruplexes are hardly detectable by mass spectrometry, we optimized solvent conditions: isopropanol in a triethylamine/hexafluoroisopropanol mixture highly increased G-quadruplex sensitivity with no modification of the physiological G-quadruplex conformation.
A method was developed and validated for the enantioselective determination of flurbiprofen in rat plasma using liquid chromatography/electrospray ionization-tandem mass spectrometry under reversed-phase elution mode. Two polysaccharide derivatized chiral stationary phases and a homemade β-cyclodextrin (β-CD
Dissociation of peptides induced by interaction with (free) electrons (electron-induced dissociation, EID) at electron energies ranging from near 0 to ,30 eV was carried out using a radio-frequency-free electromagnetostatic (EMS) cell retrofitted into a triple quadrupole mass spectrometer. The product-ion mass spectra exhibited EID originating from electronically excited even electron precursor ions, reduced radical cations formed by capture of low-energy electrons, and oxidized radical cations produced by interaction with high-energy electrons. The spectra demonstrate, within the limits of the triple quadrupoles resolving power, that high-energy EID product-ion spectra produced with an EMS cell exhibit essentially the same qualitative structural information, i.e. amino acid side-chain (SC) losses and backbone cleavages, as observed in high-energy EID spectra produced with a Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. The levels of fragmentation efficiency evident in ...
משני יינון electrospray ספקטרומטריית מסה (SESI-MS) מאפשרת זיהוי של תרכובות אורגניות נדיפות (VOCs) ללא צורך המקדים כל המדגם. פרוטוקול זה ...
Positive ion electrospray mass spectrometry (MS) has been used to investigate the interaction of Hg2+, [MeHg]+ and [PhHg]+ cations with cysteine (Cys), glutathione (GSH) and a 27-residue polypeptide (Pp) containing one cysteinyl sulfur located at the N-terminus. MSIMS experiments showed that organomercury adduction occurs primarily at the sulfhydryl group, with some evidence for isomeric species in which the organomercury cation is bound to either an amino or a carboxylic group. Following Ellman modification of GSH and Pp, the maximum number of adducted organomercury cations was reduced by 2 and 1, respectively, indicating a 2:1 and a 1:1 interaction between [RHg]+ and the cysteinyl sulfur. Unlike [PhHg]+, [MeHg]+ showed an almost exclusive affinity for the cysteinyl sulfur of GSH and Pp, Both Cys and GSH reacted with Hg2+ to form polynuclear species. Collisional activation mass spectra of the [2Cys + Hg -H]+ ion indicated that the Hg(II) was most probably bridged between the two cysteinyl ...
You may also wish to search for items by Stone, J. and Stone. 10 matching references were found. Stone, J.A.; Splinter, D.E., A high-pressure mass spectrometric study of the binding of (CH3)3Sn+ to lewis bases in the gas phase, Int. J. Mass Spectrom. Ion Processes, 1984, 59, 169. [all data] Stone, J.A.; Wytenberg, W.J., A high pressure mass spectrometric study of the formation and chemistry of the pentafluorosulphur cation (SF5+), Int. J. Mass Spectrom. Ion Processes, 1989, 94, 269. [all data] Stone, J.A., Binding energies of (CH3)3Si+ to neutrals, Mass Spectrom. Rev., 1997, 16, 25. [all data] Stone, J.M.; Stone, J.A., A high pressure mass spectrometric study of the binding of (CH3)3Si+ and (CH3)3C+ to toluene and benzene, Int. J. Mass Spectrom. Ion Processes, 1991, 109, 247-264. [all data] Zhang, W.; Beglinger, C.; Stone, J.A., High-pressure mass spectrometric study of the gas-phase association of Cl- with alpha,omega-diols, J. Phys. Chem., 1995, 99, 30, 11673, ...
The article evaluated the degradation of the captopril in aqueous solution after ozonation and chlorination. The process was continuously monitored focusing on the identification, mass spectrometry and elucidation of its by-products by applying direct infusion and high performance liquid chromatography, electrospray ionization high resolution mass spectrometry, in the negative ion mode. The cytotoxicity of its by-products solutions were evaluated with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. It was observed through that after 30 min of ozonation and chlorination, there was complete oxidation of captopril, i.e., 100% removal efficiency. At these conditions, the rate of mineralization, by total organic carbon, was only 7.63% for ozonation and 6.40% for chlorination, evidencing the formation of degradation by-products. Ten captopril by-products were identified and their respective chemical structures elucidations are proposed. The treated samples and their by-products
Se fullstendig oversikt over publikasjoner i CRIStin.. Araujo P, Zeng YX, , Du ZY, Ngyuen TT, Frøyland L, Grung B (2010): Discrimination of n-3 Rich Oils by Gas Chromatography, Lipids, 45, 1147-1158. Zeng YX, Araujo P, Du ZY, Ngyuen TT, Frøyland L, Grung B (2010): Elucidation of triacylglycerols in cod liver oil by liquid chromatography electrospray tandem ion-trap mass spectrometry, Talanta, 82, 1261-1270. Kvalheim OM, Grung B, Nodland E, Rajalahti T (2010): The 11th Scandinavian Symposium on Chemometrics, Loen, Norway, 8-11 June 2009, Journal of Chemometrics, 24, 343-345. Mjøs SA, Grung B (2009): A rank annihilation approach to reducing the scan-effect in gas chromatography-mass spectrometry data, Analytica Chimica Acta, 640, 33-39. Flåten GR, Grung B, Kvalheim OM (2007): A comparison of different pre-treatment procedures for reducing heteroscedasticity and other irrelevant features in data prior to modelling of benthic count profiles, Journal of Chemometrics, 21, 386-396 ...
The invention discloses a new interface with non-circular conductance limit aperture(s) useful for effective transmission of non-circular ion beams between stages with different gas pressure. In particular, the invention provides an improved coupling of field asymmetric waveform ion mobility spectrometry (FAIMS) analyzers of planar or side-to-side geometry to downstream stages such as mass spectrometry or ion mobility spectrometry. In this case, the non-circular aperture is rectangular; other geometries may be optimum in other applications. In the preferred embodiment, the non-circular aperture interface is followed by an electrodynamic ion funnel that may focus wide ion beams of any shape into tight circular beams with virtually no losses. The jet disrupter element of the funnel may also have a non-circular geometry, matching the shape of arriving ion beam. The improved sensitivity of planar FAIMS/MS has been demonstrated in experiments using a non-contiguous elongated aperture but other embodiments (e
Gloria Ulasi is a PhD student. Her project title is High Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) and Mass Spectrometry for Proteomics. The project aims to develop FAIMS coupled to liquid chromatography tandem mass spectrometry with electron transfer dissociation (ETD) and collision induced dissociation (CID) for analysing complex proteomics samples with particular emphasis on post-translational modifications (PTMs), such as glycosylation.. One aspect of the project is to apply the LC-FAIMS-MS/MS approach to investigate glycosylation in Campylobacter jejuni (C. jejuni NCTC 11168). C. jejuni is the leading cause of gastroenteritis world-wide. The Fla A protein of C. jejuni has been found to be highly glycosylated and it has also been linked to the virulence of C. jejuni.. ...
Mass spectrometry has become an invaluable tool to a wide range of biological, chemical, and physical research endeavors. It is routinely used in both the pharmaceutical and biotechnology industries, as well as the environmental field and for homeland security applications. Electrospray and nanospray ionization, especially when mated to separations techniques, have become one of the indispensable techniques for biomolecular analysis. The use of both of these methods in the course of this research has resulted in the identification and verification of a reported glutathione thionitrate species. Supporting evidence for its existence was also obtained through the use of ESI/Nanospray mated to quadrupole ion trap mass spectrometry. In addition, a suspected internal sulfonamide species was investigated and tandem MS data were obtained which shed light into its structure. The separation technique of gas chromatography was mated with electron impact ionization and mass spectrometry to identify VOC ...
A comprehensive Collision Cross Section (CCS) library was obtained via Travelling Wave Ion Guide mobility measurements through direct infusion (DI). The library consists of CCS and Mass Spectral (MS) data in negative and positive ElectroSpray Ionisation (ESI) mode for 463 and 479 endogenous metabolites, respectively. For both ionisation modes combined, TWCCSN2 data were obtained for 542 non-redundant metabolites. These data were acquired on two different ion mobility enabled orthogonal acceleration QToF MS systems in two different laboratories, with the majority of the resulting TWCCSN2 values (from detected compounds) found to be within 1% of one another. Validation of these results against two independent, external TWCCSN2 data sources and predicted TWCCSN2 values indicated to be within 1-2% of these other values. The same metabolites were then analysed using a rapid reversed-phase ultra (high) performance liquid chromatographic (U(H)PLC) separation combined with IM and MS (IM-MS) thus ...
Pyrolysis and mass spectrometry studies of meteoritic organic matter Mass Spectrometry Reviews , 2012, 31 , 560-569 M.A. Sephton Abstract Meteorites are fragments of extraterrestrial materials that fall to the Earths surface. The carbon-rich meteorites are derived from ancient asteroids that have remained relatively unprocessed since the...
Wong, C., K.L.; Chan, T.W.Dominic, 1997: Cationization processes in matrix-assisted laser desorption/ionization mass spectrometry: Attachment of divalent and trivalent metal ions
Gruisen, J.A.E. (2019) Matrix-assisted laser desorption/ionisation mass spectrometry imaging for bone fracture hematoma analysis. Full text not available from this repository. ...
Rapid and Highly Accurate Detection of Steryl Glycosides by Ultraperformance Liquid Chromatography−Quadrupole Time-of-Flight Mass Spectrometry (UPLC-Q-TOF-MS ...
Figure 11: ESI-mass spectra of cyt c in water containing 3% methanol and 0.5 mM ammonium acetate at (a) pH 6.4, (b) pH 4.2, (c) pH 2.6, and (d) pH 2.3. The pH was adjusted by the addition of hydrochloric acid. (Reprinted with permission from Biochemistry [80], Copyright 1997, American Chemical Society ...
A mammalian N-acetylglucosamine (GlcNAc) transferase I (GnT I)-independent fucosylation pathway is revealed by the use of matrix-assisted laser desorption/ionization (MALDI) and negative-ion nano-electrospray ionization (ESI) mass spectrometry of N-linked glycans from natively folded recombinant glycoproteins, expressed in both human embryonic kidney (HEK) 293S and Chinese hamster ovary (CHO) Lec3.2.8.1 cells deficient in GnT I activity. The biosynthesis of core fucosylated Man5GlcNAc2 glycans was enhanced in CHO Lec3.2.8.1 cells by the alpha-glucosidase inhibitor, N-butyldeoxynojirimycin (NB-DNJ), leading to the increase in core fucosylated Man5GlcNAc2 glycans and the biosynthesis of a novel core fucosylated monoglucosylated oligomannose glycan, Glc1Man7GlcNAc2Fuc. Furthermore, no fucosylated Man9GlcNAc2 glycans were detected following inhibition of alpha-mannosidase I with kifunensine. Thus, core fucosylation is prevented by the presence of terminal alpha1-2 mannoses on the 6-antennae but not the 3
Electrospray ionization (ESI) mass spectrometry (MS) in combination with liquid chromatography (LC) is an excellent tool for the identification of drug metabolites. Utilizing this hyphenated technique in combination with proper sample pretreatment, the metabolic pathways of the analgesic drug ketobemidone were investigated in human urine and rat microdialysate from blood and brain. Two novel phase I metabolites (ketobemidone N-oxide and meta-hydroxymethoxyketobemidone) and three novel phase II metabolites (glucuronic acid conjugates of ketobemidone, norketobemidone and hydroxymethoxyketobemidone) were identified in human urine. Further, norketobemidone and ketobemidone N-oxide were identified in rat microdialysate from brain after regional distribution of ketobemidone in striatum. This indicates that the brain itself has the possibility to metabolize ketobemidone. Synthetic ketobemidone metabolites were used for comparison of retention times and tandem MS spectra with the possible metabolites ...
Polynuclear platinum compounds represent a new class of potential platinum anticancer therapeutics. Derived from the most widely used platinum anticancer drug, cisplatin, these novel compounds are distinct in their interactions with bio-molecules. The effectiveness of platinum anticancer agents is influenced by three pharmacological factors: (i) their resistance to deactivating sulfur nucleophiles, (ii) the ability to gain cellular entry and efficient cellular uptake, and (iii) the ability to form stable and specific complexes with DNA. BBR 3464, the first multinuclear platinum compound to reach phase II clinical trials, has created a new approach to cancer drug design. Large, highly charged platinum compounds have been shown to form favorable covalent and noncovalent interactions with bio-molecular structures. Compounds such as BBR 3464, form an immediate pre-association with anionic structures on biomolecules before covalent attachment. To better characterize these interactions, a new set of
Derivatisation for the characterisation of neutral oxosteroids by electrospray and matrix-assisted laser desorption/ionisation tandem mass spectrometry: The Girard P derivative / W.J. Griffiths; S. Liu; G. Alvelius; J. Sjövall; William Griffiths ...
0059] FIG. 12 includes plots for CH, NOS, N1S2, N2, S1 and S2 classes obtained for Light Sour crude oil with TMAH. The signal for these classes is either absent (CH, NOS, NS2, S2 classes) or very week (N2, S1 classes) at the use of NH4OH. Thus, TMAH provides significantly improved information and is suitable for detection of classes with a higher heteroatom content. Hydrocarbon class (CH) appears at a DBE of 9-24, which indicate condensed polycyclic structures. A lower DBE observed is 9 and is likely to correspond to fluorenyl anion (alkyl) derivatives. As discussed above such cyclic compounds can be deprotonated from the sp3 carbon in the presence of an extremely strong base to generate resonance-stabilized carbanions. NOS, N1S2, N2 classes are detected in the wide range of DBE (from 9 to over 30) and Carbon number (from 20 to 70) and appear to have either pyrolic nitrogen (NOS, N1S2, N2 classes), or/and thio-group (NOS, N1S2 classes) or/and phenolic group (NOS class). S1 and S2 classes contain ...
The International Journal of Analytical Chemistry is a peer-reviewed, Open Access journal that publishes original research articles reporting new experimental results and methods, especially in relation to important analytes, difficult matrices, and topical samples. Focussed review articles are also welcomed.
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If you have a question about this talk, please contact Dr Konstantin Barylyuk.. Abstract not available. This talk is part of the Seminars at the Department of Biochemistry series.. ...
Abraham Badu-Tawiah obtained his Ph.D. (2012) in Chemistry with R. Graham Cooks at Purdue University. During that time he worked on the mechanism of desorption electrospray ionization, which led to the development of novel instrumentation for ambient ion soft landing, and ionic reactions with neutral species adsorbed on ambient surfaces. This training in ion manipulation at atmospheric pressure laid the ground work for the creation of analytical devices that permit ion chemistry to be performed more effectively using charged micro-droplets as reaction vessels. During his time at Purdue, Dr. Badu-Tawiah was awarded Andrews (2007 - 2009), Bilsland Dissertation (2011), and Lilly Innovative (2012) Fellowships. From 2012 to 2014, he was a postdoctoral fellow at Harvard University under the direction of George M. Whitesides, where his research focused on the development of methods for performing molecular recognition (immunoassay) on ambient paper surfaces for use in resource-limited disease ...
TY - CHAP. T1 - Automated cell-by-cell tissue imaging and single-cell analysis for targeted morphologies by laser ablation electrospray ionization mass spectrometry. AU - Li, Hang. AU - Smith, Brian K.. AU - Shrestha, Bindesh. AU - Márk, L.. AU - Vertes, Akos. PY - 2014/10/31. Y1 - 2014/10/31. N2 - Mass spectrometry imaging (MSI) is an emerging technology for the mapping of molecular distributions in tissues. In most of the existing studies, imaging is performed by sampling on a predefined rectangular grid that does not reflect the natural cellular pattern of the tissue. Delivering laser pulses by a sharpened optical fiber in laser ablation electrospray ionization (LAESI) mass spectrometry (MS) has enabled the direct analysis of single cells and subcellular compartments. Cell-by-cell imaging had been demonstrated using LAESI-MS, where individual cells were manually selected to serve as natural pixels for tissue imaging. Here we describe a protocol for a novel cell-by-cell LAESI imaging approach ...
The possibility of using capillary electrophoresis-electrospray ionisation (ESI)/MS to separate and quantify cobalt and iron was explored. It was necessary to tackle and overcome problems from different sources, some of them being rather unpredictable. The results obtained suggest the occurrence of oxidation processes of metal ions during the formation of the electrospray. The quantitative oxidation of cobalt(II) to cobalt(III), a process at our knowledge never described before, appears particularly interesting. The results obtained, though not optimised for sensitivity appear promising, since a limit of detection of the order of tenths of picograms was obtained. Further, from the comparison with the results obtained by optical detection, the use of CE-ESI/MS appears advantageous. (c) 2007 Elsevier B.V. All rights reserved.. The possibility of using capillary electrophoresis-electrospray ionisation (ESI)/MS to separate and quantify cobalt and iron was explored. It was necessary to tackle and ...
"Synchronized Desorption Electrospray Ionization Mass Spectrometry Imaging". Analytical Chemistry. 88 (2): 1169-1175. doi: ... "Imaging of Proteins in Tissue Samples Using Nanospray Desorption Electrospray Ionization Mass Spectrometry". Analytical ... Zare is also involved in the development of desorption electrospray ionization (DESI) techniques, which are being used for mass ... "Diagnosis of prostate cancer by desorption electrospray ionization mass spectrometric imaging of small metabolites and lipids ...
Profiling based on electrospray ionization tandem mass spectrometry (ESI-MS/MS) is capable of providing quantitative data and ... Takáts Z, Wiseman JM, Cooks RG (2005). "Ambient mass spectrometry using desorption electrospray ionization (DESI): ... of spectrometric methods in general and soft ionization techniques for mass spectrometry such as electrospray ionization (ESI ... "Application of desorption electrospray ionization mass spectrometry imaging in breast cancer margin analysis". Proceedings of ...
by liquid chromatography/electrospray ionisation tandem mass spectrometry". Phytochemical Analysis. 19 (4): 335-41. doi:10.1002 ... When they are viewed in mass, such as with a spore print, the spores appear white. Observing with a light microscope reveals ...
"Glycerophospholipid identification and quantitation by electrospray ionization mass spectrometry". Lipidomics and Bioactive ... 2007). Lipodomics and Bioactive Lipids: Mass Spectrometry Based Lipid Analysis. Methods in Enzymology. 423. Boston: Academic ... Lipids: MassSpectrometry-Based Lipid Analysis. Methods in Enzymology. 432. pp. 21-57. doi:10.1016/S0076-6879(07)32002-8. ISBN ... Cambridge, Massachusetts: Blackwell Publishers. p. 342. ISBN 978-1-4051-3066-0. Stryer et al., p. 749. Bouillon R, Verstuyf A, ...
"Analysis of oligonucleotides by HPLC-electrospray ionization mass spectrometry". Anal. Chem. 69: 1320-1325. doi:10.1021/ ... Because of its acidity (pKa = 9.3), it can be used as acid in volatile buffers for ion pair HPLC - mass spectrometry of nucleic ...
An analysis of glycated hemoglobins by electrospray ionization mass spectrometry". Clinical Chemistry. 44 (9): 1951-58. PMID ...
Vitória in different maturation stages using electrospray ionization mass spectrometry". Journal of the Science of Food and ...
by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry". Journal of Pharmaceutical and ...
"Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry". Journal of Chromatography A. 891 ( ...
"Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry". Journal of Chromatography A. 891 ( ... Liu Y, Wang Q, Yang J, Guo X, Liu W, Ma S, Li S (April 2018). "Polygonum multiflorum Thunb.: A Review on Chemical Analysis, ... 4-MA - inhibits types 1 and 2 (IC50 = 8.5 nM), but also 3β-HSD inhibitor, investigated extensively but found to be hepatotoxic ...
... ongoing studies is that of Rapid Genotyping of Human Papillomavirus by Desorption Electrospray Ionization Mass Spectrometry ( ... By utilizing ambient ionization mass spectrometry to detect oligonucleotides from restriction fragment mass polymorphism (RFMP ... "Rapid Genotyping of Human Papillomavirus by Desorption Electrospray Ionization Mass Spectrometry". Bulletin of the Korean ... Its main service is to diagnose DNA mutations based on its proprietary technology of restriction fragment mass polymorphism ( ...
Eberlin LS, Ferreira CR, Dill AL, Ifa DR, Cooks RG (November 2011). "Desorption electrospray ionization mass spectrometry for ... 2014). Ambient Ionization Mass Spectrometry:. New Developments in Mass Spectrometry. Cambridge: Royal Society of Chemistry. doi ... October 2014). "Application of desorption electrospray ionization mass spectrometry imaging in breast cancer margin analysis". ... October 2018). "Multicenter Study Using Desorption-Electrospray-Ionization-Mass-Spectrometry Imaging for Breast-Cancer ...
"Conformational changes in proteins probed by hydrogen-exchange electrospray-ionization mass spectrometry". Rapid Communications ... Wales TE, Engen JR (2006). "Hydrogen exchange mass spectrometry for the analysis of protein dynamics". Mass Spectrometry ... HPLC separation of the peptic digest is often carried out at low temperature just prior to electrospray mass spectrometry to ... Detecting the change in the mass of a protein upon deuteration was made possible by modern protein mass spectrometry, first ...
Electrospray ionisation (ESI) is frequently used for this application. Although MRM has been used extensively in metabolomics ... In recent years, high performance liquid chromatography online coupled to mass spectrometry became very popular. By choosing ... Table 1:Advantages and disadvantages of mass spectrometry in glycan analysis Lectin and antibody arrays provide high-throughput ... Sometimes glycan pools are analyzed directly by mass spectrometry without prefractionation, although a discrimination between ...
Dole in 1968 was the first to use electrospray ionization with mass spectrometry. Dole, Malcolm (1935). Principles of ... Birendra N. Pramanik; A.K. Ganguly; Michael L. Gross (28 February 2002). Applied Electrospray Mass Spectrometry: Practical ... Electrospray is a process in which a high voltage is applied to a liquid to create an aerosol containing highly charged ... that the atomic weight of oxygen in air is greater than that of oxygen in water and for his work on electrospray ionization, ...
"Characterization of Urinary Sulfatides in Metachromatic Leukodystrophy Using Electrospray Ionization-Tandem Mass Spectrometry ...
... fruits by high performance liquid chromatography-electrospray ionisation mass spectrometry. Pengzhan Liu, Heikki Kallio, Deguo ...
Deyde VM, Sampath R, Gubareva LV (January 2011). "RT-PCR/electrospray ionization mass spectrometry approach in detection and ... Boston MA: Academic Press Inc. ISBN 978-0-12-369428-7. Kan YW, Lee KY, Furbetta M, Angius A, Cao A (January 1980). " ... Hamburg MA, Collins FS (July 2010). "The path to personalized medicine". The New England Journal of Medicine. 363 (4): 301-4. ... Habibzadeh P, Mofatteh M, Silawi M, Ghavami S, Faghihi MA (February 2021). "Molecular diagnostic assays for COVID-19: an ...
The confirmatory method include reversed-phase HPLC/electrospray ionization triple tandem quadrupole mass spectrometry. The ... This resulted in mass protests in the capital city, Taipei, by swine farmers insisting that the ban remain in place. Health ...
"Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry". Journal of Chromatography A. 891 ( ...
based on 27Al NMR spectroscopy and electrospray ionisation mass spectrometry evidence. They reported that the degree of ...
Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry. Pirjo Mämmelä, Heikki Savolainen, ... Louis, MO & Harvard University Herbaria, Cambridge, MA. Niche Timbers White Oak Archived October 13, 2008, at the Wayback ... Louis, MO & Harvard University Herbaria, Cambridge, MA. "Quercus alba L." Germplasm Resources Information Network (GRIN). ...
Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry. Pirjo Mämmelä, Heikki Savolainenb, ... Louis, MO & Harvard University Herbaria, Cambridge, MA. "Britain's record-breaking trees", The Daily Telegraph Ducousso, A. & ... Louis, MO & Harvard University Herbaria, Cambridge, MA. Huang, Chengjiu; Zhang, Yongtian; Bartholomew, Bruce. "Quercus robur". ...
"Thermal energy distribution observed in electrospray ionization". Journal of Mass Spectrometry: JMS. 34 (12): 1373-1379. ... and copolyesters by electrospray ionization on a Fourier transform ion cyclotron resonance mass spectrometer". Journal of Mass ... Rapid Communications in Mass Spectrometry 2002 Bert L. Schram Award, Dutch Society for Mass Spectrometry (NVMS) Ščupáková, ... energy of protonated biomolecules in electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry". ...
... electrospray ionization mass spectrometry (ESI/MS). Lipidomics is a research field that studies the pathways and networks of ... Han X, Gross RW (2005). "Shotgun lipidomics: electrospray ionization mass spectrometric analysis and quantitation of cellular ... fingerprinting cellular lipidomes directly from biological samples by two-dimensional electrospray ionization mass spectrometry ... "Global analyses of cellular lipidomes directly from crude extracts of biological samples by ESI mass spectrometry: a bridge to ...
Zhu Y, Fang Q (October 2010). "Integrated droplet analysis system with electrospray ionization-mass spectrometry using a ... "Analysis of samples stored as individual plugs in a capillary by electrospray ionization mass spectrometry". Analytical ... "Fraction collection from capillary liquid chromatography and off-line electrospray ionization mass spectrometry using oil ... "Interfacing droplet microfluidics with matrix-assisted laser desorption/ionization mass spectrometry: label-free content ...
... determination of synthetic polymers by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry". ... Other methods for characterization of polymers where end-groups are used are mass spectrometry and vibrational spectrometry, ... and electrospray ionization-mass spectroscopy (ESI-MS). One of the biggest disadvantages of this technique is that much like ... Mass Spectrometry is helpful for the determination of the molecular weight of the polymer, structure of the polymer etc. ...
Secondary Electrospray Ionization Mass Spectrometry (SESI-MS) Selected ion flow tube mass spectrometry (SIFT-MS) Breath ... Gas chromatography-mass spectrometry GC-MS Gas chromatography-UV spectrometry GC-UV Proton transfer reaction mass spectrometry ... "Standardization procedures for real-time breath analysis by secondary electrospray ionization high-resolution mass spectrometry ... tube mass spectrometry SIFT-MS Ion mobility spectrometry IMS Fourier transform infrared spectroscopy FTIR Laser spectrometry ...
He was semi-retired when he first published his research on electrospray ionization for mass spectrometry. Fenn felt that his ... many using electrospray ionization. Electrospray ionization provides a way to get accurate information about the mass of a ... the American Society for Mass Spectrometry presented him with their Award for Distinguished Contributions in Mass Spectrometry ... Fenn and Tanaka split half of the award for their work in developing ionization techniques for using mass spectrometry to ...
... of flavonoids in honey by HPLC coupled with coulometric electrode array detection and electrospray ionization mass spectrometry ... Feitelson MA, Arzumanyan A, Kulathinal RJ, Blain SW, Holcombe RF, Mahajna J, Marino M, Martinez-Chantar ML, Nawroth R, Sanchez- ... Barnes S, Prasain J, D'Alessandro T, Arabshahi A, Botting N, Lila MA, Jackson G, Janle EM, Weaver CM (May 2011). "The ...
... lateriflora by liquid chromatography with ultraviolet photodiode array and electrospray ionization tandem mass spectrometry". ... Liu X, Hong SI, Park SJ, Dela Peña JB, Che H, Yoon SY, Kim DH, Kim JM, Cai M, Risbrough V, Geyer MA, Shin CY, Cheong JH, Park H ...
Mass Spectrometry. Mass spectrometry. Fast atom bombardment. Electron ionization. Chemical ionization. Electrospray ionization ... Quadrupole mass analyzer. Time-of-flight mass spectrometry. Electron multiplier. Faraday cup. Carbon-13. Infrared multiphoton ...
However, electrospray ionization methods coupled with mass spectrometry allow a rapid and direct analysis of samples with ... The spray is then ionised by extractive electrospray ionisation (EESI) and analysed using tandem mass spectrometry (MS/MS). An ... Ultrasound-assisted extractive electrospray ionization mass spectrometry (EESI-MS) has been developed at ETH Zurich ( ... of melamine in untreated milk and wheat gluten by ultrasound-assisted extractive electrospray ionization mass spectrometry ( ...
"Base composition analysis of human mitochondrial DNA using electrospray ionization mass spectrometry: A novel tool for the ... Mass spectrometry may be used to determine DNA sequences. Matrix-assisted laser desorption ionization time-of-flight mass ... The mass of each nucleotide is different from the others and this difference is detectable by mass spectrometry. Single- ... Edwards JR, Ruparel H, Ju J (2005). "Mass-spectrometry DNA sequencing". Mutation Research. 573 (1-2): 3-12. doi:10.1016/j. ...
Electrospray and atmospheric pressure chemical ionization[edit]. Electrospray and atmospheric pressure chemical ionization have ... List of mass spectrometry software. References[edit]. *^ Terrence A. Lee (4 February 1998). A Beginner's Guide to Mass Spectral ... It is commonly used for the identification of organic compounds from electron ionization mass spectrometry.[3][4] Organic ... the "Gold Book") (1997). Online corrected version: (2006-) "electron ionization". *^ a b c d e f g h Pavia, Donald L. ...
electrospray ionization mass spectrometry.[13]. *crossover experiments.[14]. Theoretical modeling[edit]. A correct reaction ... J. Mass Spectrom.; 2005; 246 pp 84 - 104; (Review) doi:10.1016/j.ijms.2005.08.016 ...
... may be used as the carrier gas in gas chromatography and in electrospray ionization mass spectrometry; it is the gas of ... Argon constitutes 0.934% by volume and 1.288% by mass of the Earth's atmosphere,[18] and air is the primary industrial source ... Argon is used in the poultry industry to asphyxiate birds, either for mass culling following disease outbreaks, or as a means ... Argon has electronic properties (ionization and/or the emission spectrum) desirable for some applications. ...
Catalyzed Azide-Alkyne Cycloaddition Directly Observed by Electrospray Ionization Mass Spectrometry". Angewandte Chemie ... This luciferin fluorescence can be then quantified by spectrometry following a wash, and used to determine the relative ... and fluorescence spectrometry (in which the fluorophore is attached to a target of interest and the target quantified or ... equipping the reaction with a built-in spectrometry handle. ...
"Peptide and protein analysis by electrospray ionization-mass spectrometry and capillary electrophoresis-mass spectrometry". ... accelerator mass spectrometry (AMS), thermal ionization-mass spectrometry (TIMS) and spark source mass spectrometry (SSMS). ... Main article: Ion-mobility spectrometry-mass spectrometry. Ion mobility spectrometry-mass spectrometry (IMS/MS or IMMS) is a ... Fenn JB, Mann M, Meng CK, Wong SF, Whitehouse CM (October 1989). "Electrospray ionization for mass spectrometry of large ...
Mass spectrometer. *Electrospray ionization. *Matrix-assisted laser desorption ionization. *Matrix-assisted laser desorption ... Mass spectrometry techniques are used.. Proteomics[edit]. Proteome is the entire complement of proteins, including the ... Mass spectrometry techniques are used. *Immunoproteomics: study of large sets of proteins (proteomics) involved in the immune ... Uses proteomics mass spectrometry data for protein expression studies. *Proteogenomics: An emerging field of biological ...
Charge residue model, a model explaining electrospray ionization in mass spectrometry. *Cis-regulatory module, a region of DNA ...
"Glycerophospholipid identification and quantitation by electrospray ionization mass spectrometry". Methods in Enzymology 432: ... 2007). 》Lipodomics and Bioactive Lipids: Mass Spectrometry Based Lipid Analysis》. Methods in Enzymology 423. Boston: Academic ... Deacon J (2005). 》Fungal Biology》. Cambridge, Massachusetts: Blackwell Publishers. 342쪽. ISBN 978-1-4051-3066-0. .. ...
"Peptide and protein analysis by electrospray ionization-mass spectrometry and capillary electrophoresis-mass spectrometry". ... accelerator mass spectrometry (AMS), thermal ionization-mass spectrometry (TIMS) and spark source mass spectrometry (SSMS). ... Main article: Ion-mobility spectrometry-mass spectrometry. Ion mobility spectrometry-mass spectrometry (IMS/MS or IMMS) is a ... Hard ionization and soft ionization[edit]. Quadrupole mass spectrometer and electrospray ion source used for Fenn's early work ...
"A rapid liquid chromatography electrospray ionization mass spectrometry method for evaluation of synephrine in Citrus aurantium ... and synephrines in urine using capillary column gas chromatography negative ion chemical ionization mass spectrometry." Anal. ... and their metabolites in biological tissues and fluids by gas chromatography-negative ion chemical ionization mass spectrometry ... G. Ma, S. A. Bavadeka, B. T. Schaneberg, I. A. Khan, and D. R. Feller (2010). "Effects of synephrine and beta-phenylephrine on ...
... adenine dinucleotide and related compounds by liquid chromatography/electrospray ionization tandem mass spectrometry». Anal. ... Ma B, Pan SJ, Zupancic ML, Cormack BP «Assimilation of NAD(+) precursors in Candida glabrata». Mol. Microbiol., 66, 1, 2007, ... laboradors al Massachusetts Institute of Techonolgy el 2000) de les proteïnes diacilcetases dependents de NAD anomenades ...
Vitória in different maturation stages using electrospray ionization mass spectrometry". Journal of the Science of Food and ...
... can be in the ion source of the mass spectrometer by increasing the nozzle-skimmer voltage in electrospray ionization. ... Targeted mass spectrometry. References[edit]. *^ Doerr, Allison (2014). "DIA mass spectrometry". Nature Methods. 12 (1): 35-35 ... "Multiplexed and data-independent tandem mass spectrometry for global proteome profiling". Mass Spectrometry Reviews. 33 (6): ... In mass spectrometry, data-independent acquisition (DIA) is a method of molecular structure determination in which all ions ...
... adenine dinucleotide and related compounds by liquid chromatography/electrospray ionization tandem mass spectrometry". Anal. ... Ma B, Pan SJ, Zupancic ML, Cormack BP (2007). "Assimilation of NAD(+) precursors in Candida glabrata". Mol. Microbiol. 66 (1): ... descubrisen no Instituto de Tecnoloxía de Massachusetts (MIT) as proteínas chamadas sirtuínas; que son encimas deacetilases ...
He was semi-retired when he first published his research on electrospray ionization for mass spectrometry.[5] Fenn felt that ... many using electrospray ionization.[8] Electrospray ionization provides a way to get accurate information about the mass of a ... the American Society for Mass Spectrometry presented him with their Award for Distinguished Contributions in Mass Spectrometry ... Fenn and Tanaka split half of the award for their work in developing ionization techniques for using mass spectrometry to ...
Detection is here done by mass spectrometry, but in instead of MALDI-MS, electrospray ionisation (ESI) is more frequently used ... In recent years, high performance liquid chromatography online coupled to mass spectrometry became very popular. By choosing ... Table 1:Advantages and disadvantages of mass spectrometry in glycan analysis Lectin and antibody arrays provide high-throughput ... Sometimes glycan pools are analyzed directly by mass spectrometry without prefractionation, although a discrimination between ...
Argon may be used as the carrier gas in gas chromatography and in electrospray ionization mass spectrometry; it is the gas of ... Argon constitutes 0.934% by volume and 1.288% by mass of the Earth's atmosphere,[20] and air is the primary industrial source ... Argon is used in the poultry industry to asphyxiate birds, either for mass culling following disease outbreaks, or as a means ... Argon has electronic properties (ionization and/or the emission spectrum) desirable for some applications. ...
Ambient ionization methods such as desorption electrospray ionization (DESI),[13] laser ablation electrospray ionization (LAESI ... Mass spectrometry imaging (MSI) (also known as imaging mass spectrometry) is a technique used in mass spectrometry to visualize ... McDonnell LA, Heeren RM (2007). "Imaging mass spectrometry". Mass spectrometry reviews. 26 (4): 606-43. PMID 17471576. doi: ... "Automated Platform for High-Resolution Tissue Imaging Using Nanospray Desorption Electrospray Ionization Mass Spectrometry". ...
An analysis of glycated hemoglobins by electrospray ionization mass spectrometry". Clinical Chemistry. 44 (9): 1951-58. PMID ...
Analysis by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry". Biomedical Chromatography ... Chloroquine treatment can induce porphyria attacks within the first couple of months of treatment due to the mass mobilization ...
Glycerophospholipid identification and quantitation by electrospray ionization mass spectrometry. Methods in Enzymology. ... Brown HA (编). Lipodomics and Bioactive Lipids: Mass Spectrometry Based Lipid Analysis, Volume 432 (Methods in Enzymology). ... Cambridge, MA: Blackwell Publishers. 2005: 342. ISBN 1-4051-3066-0.. *^ Kuzuyama T, Seto H. Diversity of the biosynthesis of ... Ma Y.; Olendzki, Barbara C.; Hafner, Andrea R.; Chiriboga, David E.; Culver, Annie L.; Andersen, Victoria A.; Merriam, Philip A ...
... electrospray, fast atom bombardment, matrix assisted laser desorption ionization, and others. Also, mass spectrometry is ... Mass spectrometry measures mass-to-charge ratio of molecules using electric and magnetic fields. There are several ionization ... gas chromatography-mass spectrometry, gas chromatography-infrared spectroscopy, liquid chromatography-mass spectrometry, liquid ... "High-performance Liquid Chromatography/NMR Spectrometry/Mass Spectrometry:Further Advances in Hyphenated Technology". Journal ...
"Liquid chromatography-electrospray ionization ion trap mass spectrometry for analysis of mesocarp and its metabolites in human ... "Validation of liquid chromatography-electrospray ionization ion trap mass spectrometry method for the determination of mesocarb ... Subsequently, with the advent of mass spectroscopy, it has been shown that presence of amphetamine in prior studies was an ... artifact of gas chromatography method.[21] More recent studies using mass spectroscopy show that negligible levels of ...
... adenine dinucleotide and related compounds by liquid chromatography/electrospray ionization tandem mass spectrometry". Anal. ... Ma B, Pan SJ, Zupancic ML, Cormack BP (2007). "Assimilation of NAD+ precursors in Candida glabrata". Mol. Microbiol. 66 (1): 14 ... Bakker BM, Overkamp KM, Kötter P, Luttik MA, Pronk JT (2001). "Stoichiometry and compartmentation of NADH metabolism in ...
Electrospray Ionization for Mass-Spectrometry of Large Biomolecules ... Electrospray Ionization for Mass-Spectrometry of Large Biomolecules (1989) by J B Fenn ... papers to Tanakas 1988 Rapid Communications in Mass Spectrometry paper on Laser Ionization Time-of-Flight Mass Spectrometry. ... and electrospray ionization mass spectrometry (ESI MS) (=-=Fenn et al., 1989-=-) have literally revolutionized our ability to ...
The application of liquid sample desorption electrospray ionization mass spectrometry (liquid sample DESI-MS) for quantifying ... Loo, J.A.: Studying noncovalent protein complexes by electrospray ionization mass spectrometry. Mass Spectrom. Rev. 16, 1-23 ( ... Direct analysis of liquid samples by desorption electrospray ionization-mass spectrometry (DESI-MS). J. Am. Soc. Mass Spectrom ... Quantifying labile protein-ligand interactions using electrospray ionization mass spectrometry. J. Am. Soc. Mass Spectrom. 21, ...
Toward the bilayer proteome, electrospray ionization-mass spectrometry of large, intact transmembrane proteins. J. P. ... electrospray ionization-mass spectrometry of large, intact transmembrane proteins. J. P. Whitelegge, J. le Coutre, J. C. Lee, C ... electrospray ionization-mass spectrometry of large, intact transmembrane proteins. J. P. Whitelegge, J. le Coutre, J. C. Lee, C ... Toward the bilayer proteome, electrospray ionization-mass spectrometry of large, intact transmembrane proteins ...
In this study, we established the capability of desorption electrospray ionization mass spectrometry imaging (DESI-MSI) to ... We show that desorption electrospray ionization mass spectrometry imaging (DESI-MSI) can successfully locate microscopic ... Distinguishing malignant from benign microscopic skin lesions using desorption electrospray ionization mass spectrometry ... Distinguishing malignant from benign microscopic skin lesions using desorption electrospray ionization mass spectrometry ...
Microfluidics Mass spectrometry Electrospray ionization Signal stability This is a preview of subscription content, log in to ... Lazar I.M. (2019) Achieving Stable Electrospray Ionization Mass Spectrometry Detection from Microfluidic Chips. In: Dutta D. ( ... Xue Q, Dunayevskiy YM, Foret F, Karger BL (1997) Integrated multichannel microchip electrospray ionization mass spectrometry: ... A microfabricated dialysis device for sample cleanup in electrospray ionization mass spectrometry. Anal Chem 70:3553-3556 ...
Detection and quantitation of eicosanoids via high performance liquid chromatography-electrospray ionization-mass spectrometry. ... one that high-performance liquid chromatography-mass spectrometry (LC-MS) is well suited to handle. We have developed a LC-MS/ ... we have established a library that includes relative chromatographic retention times and tandem mass spectrometry data for the ... Spectrometry, Mass, Electrospray Ionization/methods*. Substance. *Eicosanoids. Grant support. *T32 DK007202/DK/NIDDK NIH HHS/ ...
Desorption electrospray ionization (DESI) mass spectrometry (MS) is applied in a continuous on-line process at rates that ... Desorption electrospray ionization (DESI) mass spectrometry (MS) is applied in a continuous on-line process at rates that ... High throughput reaction screening using desorption electrospray ionization mass spectrometry M. Wleklinski, B. P. Loren, C. R ... High throughput reaction screening using desorption electrospray ionization mass spectrometry Michael Wleklinski,a Bradley P. ...
... Conference Poster ... In this study, we will first develop a method to quantify DFO using liquid chromatography/mass spectrometry (LC/MS), which can ... Thus far, manual injections of DFO into the LCQ1 ion trap MS with electrospray ionization (Thermo Scientific, West Palm Beach, ... Similar analysis combining LC/MS using a QTRAP 5500 (AB Sciex, Framingham, MA), a more advanced model that uses multiple ...
The method combines a continuous flow mixing technique with an electrospray mass spectrometer. Different protein conformations ... in solution are detected by the different charge states they produce during electrospray ionization. … ... Cytochrome c folding kinetics studied by time-resolved electrospray ionization mass spectrometry Biochemistry. 1997 May 6;36(18 ... The method combines a continuous flow mixing technique with an electrospray mass spectrometer. Different protein conformations ...
Electrospray ionization mass spectrometry (ESI-MS) is a method of choice and the present work takes benefit of the ... In positive ionization mass spectrometry, an electrospray device acts as an anode, which implies oxidation reactions. Thus, ... Finally, a biphasic electrospray ionization (BESI) source has been built in the goal of probing interfacial complexes in MS. ... Mass spectrometry is one of the commonly used techniques in bioinorganic analyses to fulfill these requirements. ...
Studies on Transition Metal-Quercetin Complexes Using Electrospray Ionization Tandem Mass Spectrometry. Yuanzhen Liu 1. ... Liu Y, Guo M. Studies on Transition Metal-Quercetin Complexes Using Electrospray Ionization Tandem Mass Spectrometry. Molecules ... Liu, Y.; Guo, M. Studies on Transition Metal-Quercetin Complexes Using Electrospray Ionization Tandem Mass Spectrometry. ... "Studies on Transition Metal-Quercetin Complexes Using Electrospray Ionization Tandem Mass Spectrometry." Molecules 20, no. 5: ...
... and a mass spectrometer (MS) has allowed researchers to improve the sensitivity and detection capability of the widely-used ... ... Adding the equivalent of a miniature tornado to the interface between electrospray ionization (ESI) ... Tiny tornado boosts performance of electrospray ionization mass spectrometry. by John Toon, Georgia Institute of Technology ... Citation: Tiny tornado boosts performance of electrospray ionization mass spectrometry (2017, June 29) retrieved 24 May 2019 ...
By utilizing a molecular-specific approach, namely desorption electrospray ionization mass spectrometry imaging (DESI-MSI), we ... of multiple neurotransmitters and neuroactive substances in the brain by desorption electrospray ionization mass spectrometry. ... Biomolecular Imaging and Proteomics, National Resource for Mass Spectrometry Imaging, Department of Pharmaceutical Biosciences ... Biomolecular Imaging and Proteomics, National Resource for Mass Spectrometry Imaging, Department of Pharmaceutical Biosciences ...
... desorption ionization and electrospray ionization combined with Fourier transform ion cyclotron resonance mass spectrometry. ... desorption ionization and electrospray ionization combined with Fourier transform ion cyclotron resonance mass spectrometry," ... Institute of Mass Spectrometry, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam, The Netherlands. ...
R. B. Cole, "Some tenets pertaining to electrospray ionization mass spectrometry," Journal of Mass Spectrometry, vol. 35, no. 7 ... J. A. Loo, "Studying noncovalent protein complexes by electrospray ionization mass spectrometry," Mass Spectrometry Reviews, ... "Advantages of high-resolution and high-mass range magnetic-sector mass spectrometry for electrospray ionization," Organic Mass ... "Principles and practice of electrospray ionization-mass spectrometry for large polypeptides and proteins," Mass Spectrometry ...
... and thus provide simple and easy to interpret tandem mass spectra. ... Mass spectrometry. ESI-MS was performed on a SYNAPT G2 hybrid quadrupole / ion mobility /oa-ToF mass spectrometer fitted with ... of Human Hemoglobin Protein Variants Using Electrospray Ionization-Electron Transfer Dissociation Mass Spectrometry. ... of Human Hemoglobin Protein Variants Using Electrospray Ionization-Electron Transfer Dissociation Mass Spectrometry ...
... mass spectrometry is presented as an ambient pressure liquid extraction-ionization technique for analysis of organic and ... desorption electrospray ionization. : an ambient method for liquid-. extraction. surface sampling in mass spectrometry. P. J. ... desorption electrospray ionization. : an ambient method for liquid-. extraction. surface sampling in mass spectrometry. ... desorption electrospray ionization. (nano-DESI) mass spectrometry. is presented as an ambient pressure liquid extraction. - ...
Desorption electrospray ionization mass spectrometry (DESI-MS) is an ambient method by which samples, including biological ... Imaging of Biological Tissues by Desorption Electrospray Ionization Mass Spectrometry Article doi: 10.3791/50575 July 12th, ... Desorption electrospray ionization mass spectrometry (DESI-MS) is an ambient method by which samples, including biological ... By rastering the sample below the ionization probe, this spray-based technique provides sufficient spatial resolution to ...
Previous Document: Silver (?)-assisted enantiomeric analysis of ginsenosides using electrospray ionization tandem mass .... ... Title: Journal of mass spectrometry : JMS Volume: 47 ISSN: 1096-9888 ISO Abbreviation: J Mass Spectrom Publication Date: 2012 ... The ablated material is captured in an exposed flowing solvent stream that carries the ablated material to the electrospray ...
APCI Atmospheric pressure chemical ionization EI Electron ionization ESI Electrospray ionization FT-ICR Fourier-transform ion ... ions by multiple-stage linear ion-trap mass spectrometry with electrospray ionization. J Am Soc Mass Spectrom. 2014;25:1412-20. ... Electrospray mass spectrometry of phospholipids. Mass Spectrom Rev. 2003;22:332-64.PubMedCrossRefGoogle Scholar ... Engel K.M., Popkova Y. (2019) Electrospray Ionization Mass Spectrometry of Phospholipids. In: Wenk M. (eds) Encyclopedia of ...
In this work a hydrophilic interaction liquid chromatography/positive ion electrospray mass spectrometric assay (HILIC/ESI-MS) ...
Title: Comprehensive quantification of triacylglycerols in soybean seeds by electrospray ionization mass spectrometry with ... Comprehensive quantification of triacylglycerols in soybean seeds by electrospray ionization mass spectrometry with multiple ... establishes an approach to quantify TAG species in soybean seeds utilizing an electrospray ionization tandem mass spectrometry ... mass-to-charge ratio, m/z) were determined after isotopic deconvolution and correction by adjustment factors at each TAG mass. ...
This application note demonstrates the flexibility of desorption electrospray ionization (DESI) imaging, showing that the same ... of Multiple Images from a Single Tissue Section with Dual Polarity Desorption Electrospray Ionization Mass Spectrometry. ... of Multiple Images from a Single Tissue Section with Dual Polarity Desorption Electrospray Ionization Mass Spectrometry ... Mass spec imaging of tissue sections was accomplished by using a SYNAPT G2-Si HDMS Mass Spectrometer equipped with a 2D-DESI ...
... of commercial fuels from numerous sources were analyzed by flow injection analysis/electrospray ionization/mass spectrometry ... Differentiation of commercial fuels based on polar components using negative electrospray ionization/mass spectrometry. Series ... Differentiation of commercial fuels based on polar components using negative electrospray ionization/mass spectrometry. ... of commercial fuels from numerous sources were analyzed by flow injection analysis/electrospray ionization/mass spectrometry ...
Hydrolytic stability in rat plasma assessed as half life by electrospray ionization mass spectrometry. ...
... intercepting the ablation plume by an electrospray plume to form ions, and detecting the ions by mass spectrometry. ... In various embodiments, a method of laser ablation electrospray ionization mass spectrometry (LAESI-MS) may generally comprise ... Electrospray-assisted laser-induced acoustic desorption ionization mass spectrometer and a method for mass spectrometry ... Electrospray-assisted laser-induced acoustic desorption ionization mass spectrometer and a method for mass spectrometry ...
4. Electrospray ionization mass spectrometry as a tool for determination of drug binding sites to human serum albumin by ... Electrospray Ionization Mass Spectrometry for Determination of Noncovalent Interactions in Drug Discovery. Benkestock, Kurt KTH ... Open this publication in new window or tab ,,Electrospray ionization mass spectrometry as a tool for determination of drug ... A method for ligand screening by automated nano-electrospray ionization mass spectrometry (nano-ESI/MS) is described. The core ...
"משני יינון electrospray ספקטרומטריית מסה (SESI-MS) מאפשרת זיהוי של תרכובות אורגניות נדיפות (VOCs) ללא צורך המקדים כל המדגם. ... Wu, C., Siems, W. F., Hill, H. H. Secondary electrospray ionization ion mobility spectrometry/mass spectrometry of illicit ... Direct analysis of fatty acid vapors in breath by electrospray ionization and atmospheric pressure ionization-mass spectrometry ... Bean, H. D., Zhu, J., Hill, J. E. Characterizing Bacterial Volatiles using Secondary Electrospray Ionization Mass Spectrometry ...
Attempts have been made to combine IMAC with electrospray ionization mass spectrometry (ESI-MS) to characterize marine Cu ... but results have proven inconclusive due to the lack of tandem mass spectrometry (MS/MS) data to confirm ligand recovery. We ... but results have proven inconclusive due to the lack of tandem mass spectrometry (MS/MS) data to confirm ligand recovery. We ... Attempts have been made to combine IMAC with electrospray ionization mass spectrometry (ESI-MS) to characterize marine Cu ...
A method involving reversed-phase, liquid chromatography coupled to electrospray ionisation mass spectrometry (LC-ESI-MS) was ... hexabroomcyclodocane in sediments and biota by liquid chromatography-electrospray ionization mass spectrometry. ... Single-quadrupole and ion-trap mass analysers as well as LC separations were optimised using pure and individual HBCD ...
  • The application of liquid sample desorption electrospray ionization mass spectrometry (liquid sample DESI-MS) for quantifying protein-carbohydrate interactions in vitro is described. (springer.com)
  • We show that desorption electrospray ionization mass spectrometry imaging (DESI-MSI) can successfully locate microscopic aggregates of a common skin cancer, basal cell carcinoma (BCC), and distinguish them from adjacent normal skin. (pnas.org)
  • In this study, we established the capability of desorption electrospray ionization mass spectrometry imaging (DESI-MSI) to distinguish between micrometer-sized tumor aggregates of basal cell carcinoma (BCC), a common skin cancer, and normal human skin. (pnas.org)
  • Sen AK, Darabi J, Knapp DR (2009) Design, fabrication and test of a microfluidic nebulizer chip for desorption electrospray ionization mass spectrometry. (springer.com)
  • Simultaneous imaging of multiple neurotransmitters and neuroactive substances in the brain by desorption electrospray ionization mass spectrometry. (nih.gov)
  • Desorption electrospray ionization mass spectrometry (DESI-MS) is an ambient method by which samples, including biological tissues, can be imaged with minimal sample preparation. (jove.com)
  • This study evaluated a comprehensive metabolic phenotyping method in breast cancer tissue that uses desorption electrospray ionization mass spectrometry imaging (DESI MSI), both as a novel diagnostic tool and as a method to further characterize metabolic changes in breast cancer tissue and the tumor microenvironment. (aacrjournals.org)
  • Desorption Electrospray Ionization Mass spectrometry Imaging (DESI-MSI) is an area of great interest and a promising tool in the field of chemical imaging. (byu.edu)
  • Desorption electrospray ionization mass spectrometry (DESI-MS) was used in an imaging mode to interrogate the lipid profiles of thin tissue sections of canine spontaneous invasive transitional cell carcinoma of the urinary bladder (a model of human invasive bladder cancer) as well as adjacent normal tissue from four different dogs. (pubfacts.com)
  • Lazar IM, Sundberg SA, Ramsey RS, Ramsey JM (1999) Subattomole-sensitivity microchip nanoelectrospray source with time-of-flight mass spectrometry detection. (springer.com)
  • Eibisch M, Fuchs B, Schiller J, Süß R, Teuber K. Analysis of phospholipid mixtures from biological tissues by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS): a laboratory experiment. (springer.com)
  • Gros M, Borros S, Amabilino DB, Veciana J, Folch I. Characterization of the vulcanization products of squalene by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry: model studies on the vulcanization of natural rubber. (springer.com)
  • The present work presents a fast and sensitive capillary liquid chromatography (µLC) column-switching method with electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) detection for the simultaneous determination of dopamine (D), epinephrine (E), norepinephrine (NE) and serotonin (SE). (uio.no)
  • This study describes how VOC may be sampled from skin and recovered from a polydimethylsilicone sampling coupon and analysed by thermal desorption (TD) interfaced to secondary electrospray ionisation (SESI) time-of-flight mass spectrometry (MS) for the high throughput screening of volatile fatty acids (VFAs) from human skin. (lboro.ac.uk)
  • Ummi N.S.B. Masseren, Soo W. Khor, Kheng S. Tay* and Mhd R.B. Abas*, "Effect of Electrospray Ionization Source Parameters on Pharmaceuticals Analysis Using Quadrupole Time-of-Flight Mass Spectrometry", Current Pharmaceutical Analysis (2016) 12: 300. (eurekaselect.com)
  • Analysis of transthyretin in human serum by capillary zone electrophoresis electrospray ionization time-of-flight mass spectrometry. (semanticscholar.org)
  • Figeys D, Gygi SP, McKinnon G, Aebersold R (1998) An integrated microfluidics-tandem mass spectrometry system for automated protein analysis. (springer.com)
  • In the course of setting up the LC-MS system, we have established a library that includes relative chromatographic retention times and tandem mass spectrometry data for the most common eicosanoids. (nih.gov)
  • Guo, M. Studies on Transition Metal-Quercetin Complexes Using Electrospray Ionization Tandem Mass Spectrometry. (mdpi.com)
  • Liu Y, Guo M. Studies on Transition Metal-Quercetin Complexes Using Electrospray Ionization Tandem Mass Spectrometry. (mdpi.com)
  • If variant ions with three or more charges are detected, Electron Transfer Dissociation (ETD) of these ions has the potential to aid in the identification of human Hb variants, and thus provide simple and easy to interpret tandem mass spectra. (waters.com)
  • applied a combination of electrospray ionization and tandem mass spectrometry (ESI-MS/MS) on an ESI-coupled Orbitrap Elite mass spectrometer (Thermo Scientific) to analyze free metals resulting from metal-ligand complexes. (thermofisher.com)
  • The present study establishes an approach to quantify TAG species in soybean seeds utilizing an electrospray ionization tandem mass spectrometry with multiple neutral loss scans. (osti.gov)
  • Attempts have been made to combine IMAC with electrospray ionization mass spectrometry (ESI-MS) to characterize marine Cu ligands, but results have proven inconclusive due to the lack of tandem mass spectrometry (MS/MS) data to confirm ligand recovery. (frontiersin.org)
  • We report here a powerful analytical method based on hydrophilic interaction liquid chromatography-electrospray ionization tandem mass spectrometry (HILIC-ESI-MS/MS), further tested on rat retina. (arvojournals.org)
  • Using tandem mass spectrometry, the structure and principal copper binding site for one of the tannins were also determined, providing unique information with regard to metal complexation by these polyfunctional ligands. (ubc.ca)
  • A procedure based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) is described for the determination of nicotine and its principal metabolites cotinine, trans-3-hydroxycotinine and cotinine-N-oxide, caffeine and arecoline in breast milk, using N-ethylnorcotinine as internal standard. (nih.gov)
  • Separated analytes were determined by electrospray ionization tandem mass spectrometry in the positive ion mode using multiple reaction monitoring. (nih.gov)
  • Determination of nicotine and nicotine metabolites in urine by hydrophilic interaction chromatography-tandem mass spectrometry: Potential use of smokeless tobacco products by ice hockey players. (nih.gov)
  • Details and Download Full Text PDF: Desorption electrospray ionization (DESI) mass spectrometry and tandem mass spectrometry (MS/MS) of phospholipids and sphingolipids: ionization, adduct formation, and fragmentation. (pubfacts.com)
  • Full scan DESI mass spectra and tandem (MS/MS) spectra for this representative set of physiological phospho/sphingolipids are presented. (pubfacts.com)
  • Glycerophospholipids and sphingolipids, as well as fatty acids, were detected in both the negative and positive ion modes and identified through tandem mass spectrometry (MS/MS) product ion scans using collision-induced dissociation and accurate mass measurements. (pubfacts.com)
  • The glycerophospholipids and sphingolipids that appear as intense signals in both the negative ion and positive ion modes were identified by tandem mass spectrometry product ion scans using collision-induced dissociation. (pubfacts.com)
  • OBJECTIVE To establish criteria for the diagnosis of medium chain acyl-CoA dehydrogenase (MCAD) deficiency in the UK population using a method in which carnitine species eluted from blood spots are butylated and analysed by electrospray ionisation tandem mass spectrometry (ESI-MS/MS). (bmj.com)
  • Tandem mass spectrometry has revealed that Streptomyces chartreusis, an antibiotic-producing bacterium, releases more metabolites into the surrounding medium than scientists assumed based on the analysis of the genome. (technologynetworks.com)
  • A method based on liquid chromatography (reversed-phase)-electrospray (negative) ionization-tandem triple quadrupole mass spectrometry [LC-ESI(-)-MS-MS], in the multiple reaction monitoring mode, was developed for determination of urinary benzylmercapturic acid (BMA). (oup.com)
  • An Efficient High-performance Liquid Chromatography Combined with Electrospray Ionization Tandem Mass Spectrometry Method to Elaborate the Changes of Components Between the Raw and Processed Radix Aconitum kusnezoffii. (semanticscholar.org)
  • Several ethyl pyruvate and dihydrocinchonidine adducts, formed by non-covalent interactions with alkali cations, have been identified for the first time using electrospray ionization mass and tandem mass spectrometry. (elsevier.com)
  • Processed fruits and vegetables by miniaturized extraction-partition and liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) equipped with multiple reaction monitoring (MRM) detection. (bioz.com)
  • However, other gas- phase methods such as tandem mass spectrometry, infrared multiphoton dissociation spectroscopy and quantum chemical calculations have also been involved to unravel and support the findings and proposals. (cuni.cz)
  • The method combines a continuous flow mixing technique with an electrospray mass spectrometer. (nih.gov)
  • The DRILL device is connected to a mass spectrometer to sort charged droplets and improve desolvation of ionized biomolecules for analysis. (phys.org)
  • The device requires no modification of the mass spectrometer, and can be accommodated within the standard work flow now used by researchers. (phys.org)
  • Adding the equivalent of a miniature tornado to the interface between electrospray ionization (ESI) and a mass spectrometer (MS) has allowed researchers to improve the sensitivity and detection capability of the widely-used ESI-MS analytical technique. (phys.org)
  • In this application, one of many potential uses for DRILL, the smaller droplets are directed to enter the mass spectrometer , while the larger ones - which still contain solvent - remain in the vortex flow until the solvent evaporates. (phys.org)
  • Removing the solvent allows analysis of additional ions that may be lost in current techniques and reduces the chemical "noise" that inhibits selectivity of the mass spectrometer. (phys.org)
  • This schematic represents how the DRILL device operates as it transmits ions to the mass spectrometer using a carefully-designed vortex flow. (phys.org)
  • The ejected droplets then break up into smaller droplets, creating a plume that expands spatially beyond the inlet intake capacity of the mass spectrometer, resulting in sample loss. (phys.org)
  • The resulting mixture of peptides was diluted a further 10-fold (final solution in 50.0% aqueous acetonitrile containing 0.2% formic acid) for direct infusion into the ESI source of the mass spectrometer. (waters.com)
  • ESI-MS was performed on a SYNAPT G2 hybrid quadrupole / ion mobility /oa-ToF mass spectrometer fitted with ETD functionality. (waters.com)
  • One capillary supplies solvent to create and maintain the bridge, while the second capillary transports the dissolved analyte from the bridge to the mass spectrometer . (rsc.org)
  • A high voltage applied between the inlet of mass spectrometer and the primary capillary creates a self-aspirating nanospray. (rsc.org)
  • The extreme sensitivity of MS, its considerable mass accuracy, and high mass resolution (dependent on the used mass spectrometer and the quality of its mass analyzer) enable the detailed analysis of complex biological lipid mixtures. (springer.com)
  • As the droplets impact upon the surface, chemical constituents are desorbed and carried towards the atmospheric inlet of the mass spectrometer. (waters.com)
  • Mass spec imaging of tissue sections was accomplished by using a SYNAPT G2-S i HDMS Mass Spectrometer equipped with a 2D-DESI source. (waters.com)
  • A 2D-DESI source was mounted onto a SYNAPT G2-S i HDMS Mass Spectrometer. (waters.com)
  • In both modes of ionization, plentiful lipids and endogenous metabolites were detected, giving intense peaks for analysis by the mass spectrometer. (waters.com)
  • An electrospray ionization (ESI)-mass spectrometer analysis systems include an ESI device with at least one emitter configured to electrospray ions and a mass spectrometer in fluid communication with the at least one emitter of the ESI device. (patents.com)
  • The mass spectrometer includes a mass analyzer held in a vacuum chamber. (patents.com)
  • Addition of primary alkanols to ε186-θ in 0.1 M ammonium acetate (pH 8), led to dissociation of the complex, as observed in the mass spectrometer. (edu.au)
  • In-source collision-induced dissociation experiments and other results suggested that the ε186-θ complex dissociated in the mass spectrometer, and that the stability (with respect to dissociation) of the complex in vacuo was dependent on the solution from which it was sampled. (edu.au)
  • We coupled a secondary electrospray ionization (SESI) source to a commercial high-resolution mass spectrometer to interrogate the headspace from bacterial cultures and human saliva. (uzh.ch)
  • Electrospray ionization (ESI) mass spectra have been measured on a magnetic-sector double-focusing mass spectrometer for a number of proteins and peptides. (warwick.ac.uk)
  • It is pointed out how in theory raising the mass resolution of a mass spectrometer from 800-1000 to 2400-3000 significantly increases the precision with which the envelope of isotopic peaks of a protein ion (or other organic ion) can be defined, particularly at higher masses. (warwick.ac.uk)
  • Samples for injection into the electrospray ionization mass spectrometer work the best if they are first purified. (libretexts.org)
  • The method can include producing a first analyte solution comprising an analyte composition and an effective amount of silver triflate, and analyzing the first analyte solution with an electrospray ionization mass spectrometer. (patentsencyclopedia.com)
  • The method can also include producing a second analyte solution comprising a portion of the analyte composition and an effective amount of a compound of formula I, and analyzing the second analyte solution with an electrospray ionization mass spectrometer. (patentsencyclopedia.com)
  • and analyzing a second analyte solution with an electrospray ionization mass spectrometer, wherein second analyte solution comprises a portion of said analyte composition and an effective amount of a compound of formula I, wherein formula I is: [NX.sub. (patentsencyclopedia.com)
  • 6. The method of enhanced speciation of an analyte of claim 1, wherein said analyzing of said first analyte solution comprises analyzing said first analyte solution with said electrospray ionization mass spectrometer in positive ion mode. (patentsencyclopedia.com)
  • 14. The electrospray ionization spectrometry methodology of claim 9, wherein said analyzing step comprises analyzing said analyte solution with said electrospray ionization mass spectrometer in negative ion mode. (patentsencyclopedia.com)
  • In preliminary work, it is found that the sensitivity achieved using a miniature mass spectrometer with a discontinuous atmospheric pressure interface (DAPI) is comparable with those achieved using lab-scale instruments with hundreds-fold greater pumping capacity. (purdue.edu)
  • The Analytical and Surface Chemistry Program of NSF supports this work to devise means of performing significant parts of the mass spectrometric experiment outside the mass spectrometer, in the open laboratory environment. (purdue.edu)
  • Working with ions in the ambient environment also enables fuller exploration of the fundamental chemical relationships between the reactions of ions in solution and those of ions in the mass spectrometer. (purdue.edu)
  • This will be done by acquiring small-volume fluid samples, subjecting them to on-line separation and preconcentration in a nanofluidic-microfluidic emitter chip and then characterizing them using on-line mass spectrometry in a miniature mass spectrometer. (purdue.edu)
  • We developed a microchip electrophoresis (MCE) method for rapid separation of phosphopeptides with on-chip electrospray ionization (ESI) facilitating online sample introduction to the mass spectrometer (MS). With the method, two monophosphorylated positional isomers of insulin receptor peptide (IR1A and IR1B) and a triply phosphorylated insulin receptor peptide (IR3), all with the same amino acid sequence, were separated from the nonphosphorylated peptide (IR0) in less than one minute. (aalto.fi)
  • In the selected ion flow tube mass spectrometer, SIFT-MS, ions are generated in a microwave plasma ion source, usually from a mixture of laboratory air and water vapor. (wikipedia.org)
  • The newly formed "product ions" flow into the mass spectrometer chamber, which contains a second quadrupole mass filter, and an electron multiplier detector, which are used to separate the ions by their mass-to-charge ratios (m/z) and measure the count rates of the ions in the desired m/z range. (wikipedia.org)
  • Various orbitrap instruments, including the commercially available linear ion trap-orbitrap hybrid mass spectrometers, are also discussed with emphasis on the different methods used to inject ions into the trap. (psu.edu)
  • The DRILL device provides a new way to solve that problem by increasing the number of ions we can get into the mass spec instrument so we can productively detect them. (phys.org)
  • The ions are there now, but not necessarily in a form that the mass spec can handle. (phys.org)
  • The key idea of DRILL is based on Fedorov's 2007 invention "Confining/Focusing Vortex Flow Transmission Structure, Mass Spectrometry Systems, and Methods of Transmitting Particles, Droplets, and Ions. (phys.org)
  • Generally, this is straightforward, since there are very few cases of interference between the ions in the mass spectrum. (waters.com)
  • Mass spectrometry is an analytical technique used to identify unknown compounds, quantify known materials, and elucidate the chemical and structural properties of molecules, based on the generation of ions that are subsequently detected. (scielo.br)
  • or (b) electrospray ions directly into the vacuum chamber with the mass analyzer. (patents.com)
  • Complexes formed by tannin ligands with copper and other biogeochemically important metals were identified from the mass-to-charge ratios of the corresponding deprotonated molecular ions, allowing stoichiometry and metal oxidation state to be determined. (ubc.ca)
  • This thesis explores the evaporation and Rayleigh discharge dynamics of highly charged micron-sized droplets and explores new methodologies for extracting ions for mass analysis from neutral droplets using strong electric fields in a technique termed field-induced droplet ionization. (caltech.edu)
  • Images of droplets from a vibrating orifice aerosol generator illustrate this phenomenon, and mass spectrometric sampling of the progeny droplets demonstrates that they are a viable source of desolvated gas-phase ions. (caltech.edu)
  • We report here on the analysis of synthetic oligonucleotides by electrospray ionization mass spectrometry (ESI-MS). After intensive removal of salt ions (especially sodium cations), negative ion mass spectra, allowing mass measurement with an accuracy of 0.01%, were obtained on several oligonucleotides up to 80 nucleotides. (mysciencework.com)
  • These protonated and desolvated molecular ions will then be passed through the mass analyzer to the detector, and the mass of the sample can be determined. (libretexts.org)
  • Has a mass range for singly charged ions of 10-2000 Daltons with unit resolution across the entire mass range. (edu.au)
  • Selected-ion flow-tube mass spectrometry (SIFT-MS) is a quantitative mass spectrometry technique for trace gas analysis which involves the chemical ionization of trace volatile compounds by selected positive precursor ions during a well-defined time period along a flow tube. (wikipedia.org)
  • From the formed plasma, a single ionic species is selected using a quadrupole mass filter to act as "precursor ions" (also frequently referred to as primary or reagent ions in SIFT-MS and other processes involving chemical ionization). (wikipedia.org)
  • Concurrently, the neutral analyte molecules of a sample vapor enter the flow tube, via a heated sampling tube, where they meet the precursor ions and may undergo chemical ionization, depending on their chemical properties, such as their proton affinity or ionization energy. (wikipedia.org)
  • The aim of this work was to develop and apply a method for the real-time analysis of electronic cigarette aerosols, based on the secondary electrospray ionization technique coupled to high-resolution mass spectrometry, by mimicking the "vaping" process. (uzh.ch)
  • The amino acid profiles in 37 individuals were determined by ion-exchange HPLC in blood plasma and simultaneously in breath by secondary electrospray ionization coupled to high-resolution mass spectrometry. (aaccjnls.org)
  • For ETD type fragmentation, a sub-ambient pressure (~2 mbar) glow discharge anion source was used to fill the Trap T-Wave cell with quadrupole mass selected ETD reagent anions formed from para-nitrotoluene ( m/z 137). (waters.com)
  • Quantification of arecoline (areca nut alkaloid) in neonatal biological matrices by high-performance liquid chromatography/electrospray quadrupole mass spectrometry. (nih.gov)
  • A quadrupole mass analyzer can also be used for this method, which means that a sample's structure can be determined fairly easily. (libretexts.org)
  • Detection and quantitation of eicosanoids via high performance liquid chromatography-electrospray ionization-mass spectrometry. (nih.gov)
  • M. Grayson, "John Bennett Fenn: a curious road to the prize," Journal of The American Society for Mass Spectrometry , vol. 22, no. 8, pp. 1301-1308, 2011. (hindawi.com)
  • Ion soft-landing into liquids: protein identification, separation, and purification with retention of biological activity," Journal of the American Society for Mass Spectrometry , vol. 15, no. 12, pp. 1874-1884, 2004. (hindawi.com)
  • Ionization and Transmission Efficiency in an Electrospray Ionization-Mass Spectrometry Interface" American Society for Mass Spectrometry, 2007. (patents.com)
  • Another modification of MS is electrospray ionization (ESI), which is a solution-based analytical technology =-=(19)-=- optimized for coupling liquid chromatography (LC) technology directly to the MS detection units. (psu.edu)
  • The implementation of mass spectrometry (MS) detection systems on these devices has become inevitable, and various chip-MS ionization interfaces have been developed. (springer.com)
  • As electrospray ionization (ESI) is particularly relevant for the analysis of large biological molecules such as proteins or peptides, efforts have focused on advancing interfaces that meet the demands of nano-separation techniques that are typically used prior to MS detection. (springer.com)
  • The DRILL device provides an effective interface for collection and transmission of charged analytes from ionization sources, such as ESI, to detection devices, such as mass spectrometers, resulting in significantly improved detection capability. (phys.org)
  • On occasion, however, the variant peptide ion occurs in a part of the mass spectrum where there is interference from another ion, which makes detection and identification difficult or impossible. (waters.com)
  • A method involving reversed-phase, liquid chromatography coupled to electrospray ionisation mass spectrometry (LC-ESI-MS) was developed for separation, detection and quantitation of the alpha-, beta- and gamma-diastereoisomers of hexabromocyclododecane (HBCD). (wur.nl)
  • Analysis times were reduced by 79% compared to gas chromatography-mass spectrometry methods (GC-MS) and limits of detection in the range 300 to 900 pg cm−2 for VFA skin concentrations were obtained. (lboro.ac.uk)
  • Apple juice samples by matrix solid-phase dispersion (MSPD) and gas chromatography-mass selective detection (GC-MSD) with electron impact (EI) ionization. (bioz.com)
  • Detection and identification of viral pathogens in patients with hand, foot, and mouth disease by multilocus PCR, reverse-transcription PCR and electrospray ionization mass spectrometry. (cdc.gov)
  • We are using the ESI-MS modification preferentially for proteins and peptides of low molecular mass th. (psu.edu)
  • R. Guevremont, K. W. M. Siu, J. C. Y. Le Blanc, and S. S. Berman, "Are the electrospray mass spectra of proteins related to their aqueous solution chemistry? (hindawi.com)
  • It was recently established that electrospray ionization mass spectrometry (ESI-MS) is capable of capturing transient interactions between membrane proteins and their lipid environment, and a detailed understanding of the underlying processes is therefore of high importance. (diva-portal.org)
  • We find that exogenously added lipids did not bind to soluble proteins, suggesting that lipids have a low propensity to form electrospray ionization adducts. (diva-portal.org)
  • For soluble proteins, these complexes arise from nonspecific contacts between the protein and detergent/lipid micelles in the electrospray droplet. (diva-portal.org)
  • Here, we applied native electrospray ionization mass spectrometry (ESI-MS) for screening defined sets of fragments against four different target proteins. (fu-berlin.de)
  • Mass spectrometry (MS) is a recognized approach for characterizing proteins and the complexes they assemble into. (technologynetworks.com)
  • A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. (mcw.edu)
  • Electrospray ionization is a soft ionization technique that is typically used to determine the molecular weights of proteins, peptides, and other biological macromolecules. (libretexts.org)
  • This means that ionization of samples such as proteins, peptides, olgiopeptides, and some inorganic molecules can be performed. (libretexts.org)
  • The investigation of noncovalent complexes between DNA, proteins, and peptides with a variety of synthetic and biological relevant structures has become increasingly more common with the coupling of electrospray ionization and mass spectrometry (ESI-MS). Mass spectrometry has been useful to the drug design community by allowing the rapid and accurate characterization of drug binding sites. (vcu.edu)
  • Zare and his students have also developed cavity ring-down spectroscopy (CRDS) for quantitative diagnosis, and for high performance liquid chromatography (HPLC) Zare is also involved in the development of desorption electrospray ionization (DESI) techniques, which are being used for mass spectrometric imaging of lipids, metabolites and proteins in tissue samples, including prostate cancer. (wikipedia.org)
  • The caveats inherent to the basic approach of using electrospray and MS to characterize protein complexes are weighed and evaluated. (portlandpress.com)
  • Electrospray mass spectrometry was used to characterize metal-complexing ligands derived from tannic acid, a component of natural dissolved organic matter. (ubc.ca)
  • We have used on-line sample clean-up, concentration, and chromatography with electrospray ionization mass spectrometry (ESI-MS), to characterize and determine the presence of disulfide bonds in recombinant full-length rat brain calbindin D(28K) and two deletion mutants of the protein, one lacking EF-hand 2 (calbindin Δ2) and the other lacking EF-hands 2 and 6 (calbindin Δ2,6). (elsevier.com)
  • Infrared laser ablation sample transfer for on-line liquid chromatography electrospray ionization mass spectrometry. (biomedsearch.com)
  • The apparatuses and methods described herein generally relate to ionization sources for mass spectrometers and methods of mass spectrometry, and in particular, laser ablation electrospray ionization (LAESI) mass spectrometry (MS), as well as methods of making and using the same. (google.com)
  • Here, we introduce a novel (time-resolved) TiO 2 -photocatalysis laser ablation electrospray ionization (LAESI) MS method for the analysis of drug candidates. (springer.com)
  • The reference protein method, which was originally developed to correct ESI mass spectra for the occurrence of nonspecific ligand-protein binding, was shown to reliably correct liquid sample DESI mass spectra for nonspecific binding. (springer.com)
  • Griesinger H, Fuchs B, Süß R, Matheis K, Schulz M, Schiller J. Stationary phase thickness determines the quality of thin-layer chromatography/matrix-assisted laser desorption and ionization mass spectra of lipids. (springer.com)
  • After preliminary analysis by positive and negative modes, samples and mixtures of standards were derivatized by methylation to minimize ionization sites and reanalyzed.Positive ionization was less effective and produced more complex spectra than negative ionization. (usgs.gov)
  • Since the weight average molecular weight decreased, it is likely that aggregate formation in the fulvic acid was present prior to derivatization, rather than multiple charging in the mass spectra. (usgs.gov)
  • By setting the mass spectral pattern of the untreated bacterial cells as a reference, our results show that the spectra of the bacterial cells exposed to the low pH media differs from the untreated cells. (uncg.edu)
  • FIDI mass spectra are presented for several species, including tetraheptyl ammonium cation, deprotonated benzene tetracarboxylic acid, and multiply protonated cytochrome c. (caltech.edu)
  • A technique was also presented for how to restore the resolution in mass spectra obtained with a hemispherical electrostatic analyzer followed by a position sensitive detector (micro-channel plate equipped with a resistive anode). (diva-portal.org)
  • SIFT-MS utilises an extremely soft ionisation process which greatly simplifies the resulting spectra and thereby facilitates the analysis of complex mixtures of gases, such as human breath. (wikipedia.org)
  • T. R. Covey, A. P. Bruins, and J. D. Henion, "Comparison of thermospray and ion spray mass spectrometry in an atmospheric pressure ion source," Organic Mass Spectrometry , vol. 23, pp. 178-186, 1988. (hindawi.com)
  • J. R. Chapman, R. T. Gallagher, E. C. Barton, J. M. Curtis, and P. J. Derrick, "Advantages of high-resolution and high-mass range magnetic-sector mass spectrometry for electrospray ionization," Organic Mass Spectrometry , vol. 27, pp. 195-203, 1992. (hindawi.com)
  • The identification and quantitation of all eicosanoids in a single biological sample are a challenging task, one that high-performance liquid chromatography-mass spectrometry (LC-MS) is well suited to handle. (nih.gov)
  • In this study, we will first develop a method to quantify DFO using liquid chromatography/mass spectrometry (LC/MS), which can detect compounds with very high sensitivity and specificity, and then use it to answer questions about drug distribution in a rat model. (healthpartners.com)
  • Publications] Y.Mizooku, M.Yoshikawa, T.Tsuneyoshi, R.Arakawa: 'Analysis of Oxidized Epigallocatechin Gallate by Liquid Chromatography Mass Spectrometry]'Rapid Comm.Mass Spectrom. (nii.ac.jp)
  • Basal and A23187-stimulated release of 15-, 5-, and 12-hydroxyeicosatetraenoic acids (HETEs) from females and males were measured by liquid chromatography/mass spectrometry. (ahajournals.org)
  • Classification of congenital disorders of glycosylation based on analysis of transferrin glycopeptides by capillary liquid chromatography-mass spectrometry. (semanticscholar.org)
  • We used ESI-MS =-=(17)-=- to measure the potential zinc ion binding of SAG by comparing the molecular mass of SAG under denaturing and nondenaturing solution conditions (37, 72). (psu.edu)
  • Similar analysis combining LC/MS using a QTRAP 5500 (AB Sciex, Framingham, MA), a more advanced model that uses multiple reaction monitoring, has also shown a retention time of 3.3 min, a molecular ion at 561.3 m/z, and specific fragments at 201, 242, 319, and 361 m/z. (healthpartners.com)
  • The use of both positive and negative ionization modes increased the number of identified molecular targets. (nih.gov)
  • By rastering the sample below the ionization probe, this spray-based technique provides sufficient spatial resolution to discern molecular features of interest within tissue sections. (jove.com)
  • This application brief demonstrates the flexibility of desorption electrospray ionization (DESI) imaging, showing that the same tissue can repeatedly be imaged at the molecular level in positive and negative ion mode, to maximize information about molecular distribution in tissue. (waters.com)
  • Electrospray ionization mass spectrometry of neat ionic liquids does not require continuous sample injection and the presence of a molecular solvent facilitates analysis of the ionic liquid itself and dissolved analytes. (epfl.ch)
  • Effects of methylation, molar response, multiple charging, solvents, and positive and negative ionization on molecular weight distributions of aquatic fulvic acid were investigated by electrospray ionization/mass spectrometry. (usgs.gov)
  • Electrospray ionization mass spectrometry confirms the results obtained by MST indicating stable molecular ion peaks for the complexes of deferiprone with either Fe3+, Zn2+, Cu2+, Co2+, Ni2+, and Mn2+, but no binding was observed for deferiprone with either Ca2+ and Mg2+ under a gas phase state. (muni.cz)
  • Molecular mass determinations of calbindin Δ2,6 showed that this protein contains a highly active cysteine residue that covalently binds a mercaptoethanol group, or forms a homodimer via a disulfide bond. (elsevier.com)
  • Better definition of the isotopic envelope ought to lead to higher precision in the experimental determination of molecular mass, which has been demonstrated. (warwick.ac.uk)
  • Soft ionization is a useful technique when considering biological molecules of large molecular mass, such as the aformetioned, because this process does not fragment the macromolecules into smaller charged particles, rather it turns the macromolecule being ionized into small droplets. (libretexts.org)
  • We report here on the first analysis of polymerase chain reaction (PCR) products amplified from a small amount of human blood DNA by electrospray ionization mass spectrometry (ESI‐MS). Adenomatous polyposis coli (APC) gene fragment of about 50 base pairs (bp) with a relative molecular mass (M r ) of approximately 15 000 u was amplified from human blood DNA by PCR. (elsevier.com)
  • Reverse-transcription PCR (RT-PCR) coupled with electrospray ionization mass spectrometry (ESI-MS) is a high-throughput nucleic acid-based technology that relies on the accurate measurement of the molecular weight of PCR amplicons that can be used to deduce the base counts (number of As, Gs, Cs and Ts) of DNA. (cdc.gov)
  • Developed by researchers at the Georgia Institute of Technology with support from North Carolina State University, DRILL can be added to existing electrospray ionization mass spectrometers without modifying them. (phys.org)
  • Accordingly, more efficient and/or cost-effective ionization sources for mass spectrometers and methods of making and using the same are desirable. (google.com)
  • The mass spectrometers are available for self use by graduate students and post-docs after training by MS Facility staff. (edu.au)
  • Figeys D, Ning Y, Aebersold R (1997) A microfabricated device for rapid protein identification by microelectrospray ion trap mass spectrometry. (springer.com)
  • A blood sample was submitted for investigation by mass spectrometry because an abnormality had been detected during a routine screen in a hematology laboratory. (waters.com)
  • Moreover, the complexes were stable for investigation by mass spectrometry under a soft ionization technique like used electrospray ionization, which aided to confirm binding stoichiometry. (muni.cz)
  • Xue Q, Dunayevskiy YM, Foret F, Karger BL (1997) Integrated multichannel microchip electrospray ionization mass spectrometry: analysis of peptides from on-chip tryptic digestion of mellitin. (springer.com)
  • During acquisition, the source polarity and quadrupole set mass were switched to allow triply-charged peptides formed from ESI to interact with stored reagent anions in the Trap T-Wave. (waters.com)
  • For mass spectral analysis, the sample was prepared and analyzed as described previously. (waters.com)
  • Nanospray desorption electrospray ionization (nano-DESI) mass spectrometry is presented as an ambient pressure liquid extraction -ionization technique for analysis of organic and biological molecules on substrates. (rsc.org)
  • Phospholipids as cancer biomarkers: mass spectrometry-based analysis. (springer.com)
  • Brügger B. Lipidomics: analysis of the lipid composition of cells and subcellular organelles by electrospray ionization mass spectrometry. (springer.com)
  • Atmospheric pressure chemical ionization mass spectrometry for analysis of lipids. (springer.com)
  • Domingues MR, Reis A, Domingues P. Mass spectrometry analysis of oxidized phospholipids. (springer.com)
  • Surface analysis of lipids by mass spectrometry: more than just imaging. (springer.com)
  • DESI imaging, a surface analysis technique incorporating an electrospray probe, can be utilized as an imaging technique by rastering a surface under an ionizing solvent sprayer using a high precision X,Y stage. (waters.com)
  • A range of commercial fuels from numerous sources were analyzed by flow injection analysis/electrospray ionization/mass spectrometry without extensive sample preparation, separation, or chromatography. (usgs.gov)
  • Mass spectrometry is an analytical technique that has been successfully used in chemistry, biology, and other fields for qualitative and quantitative analysis. (google.com)
  • The analysis of single cells and subcellular components by conventional methods of mass spectrometry may be problematic. (google.com)
  • For example, matrix-assisted laser desorption ionization (MALDI) may suffer from time consuming and complex sample preparation, and in situ analysis of a sample under vacuum may be difficult. (google.com)
  • Mass spectrometry may be combined with separation techniques, such as capillary electrophoresis and fractionation, however, these techniques may increase the analysis time, complexity and/or cost. (google.com)
  • Analysis of reaction products is commonly achieved with mass spectrometry coupled to chromatography. (springer.com)
  • Traditionally, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry is used for the analysis of intact bacterial cells. (uncg.edu)
  • Desorption electrospray ionization (DESI) mass spectrometry has been used for the imaging and analysis of rat spinal cord cross sections. (pubfacts.com)
  • The removal of sodium dodecyl sulfate (SDS) in SDS-assisted proteomics with electrospray-ionization-mass-spectrometric (ESI-MS) analysis is an essential step in the analysis. (edu.au)
  • Together with existing mass spectrometry methodologies for lipid analysis, the present methodology will provide a useful tool for clinical and biochemical studies and expands the lipid spectrum that can be analyzed from one lipid sample on a single instrumental platform. (uni-regensburg.de)
  • Analysis of variable N-glycosylation site occupancy in glycoproteins by liquid chromatography electrospray ionization mass spectrometry. (ox.ac.uk)
  • This quantitative analysis is done by considering the mass to charge ratios of the various peaks in the spectrum (Figure 1). (libretexts.org)
  • Means of delivering nonvolatile analytes into the gas phase for mass analysis. (edu.au)
  • A systematic study, including simulations, theoretical modeling, experimental characterizations and instrumentation development, is proposed to investigate the critical factors affecting efficiencies of ion focusing in air, ion loss and desolvation through an atmospheric pressure interface as well as the mass analysis at high pressure. (purdue.edu)
  • New devices and methods will be developed based on these studies to allow a much improved efficiency for mass spectrometry analysis with simple instrumentation configurations. (purdue.edu)
  • The validation of the technologies developed in this project on large scale instruments will potentially result in a significant increase in sensitivity of mass analysis and allow us to attack the most challenging problems in biological science where ultra high sensitivity is required to analyze samples available only in extremely small amounts. (purdue.edu)
  • The mass spectral results obtained from analysis of 1% HNO 3 /methanol solution containing the ligands and dissolved lanthanide salts reveal that the favorable stoichiometries of the ligand/metal/nitrate complexes are 2:1:2 for the bidentate ligand A, 1:1:2 for the tridentate ligand B, and 3:1:2 for the monodentate tributyl phosphate. (elsevier.com)
  • On-line immunoaffinity solid-phase extraction capillary electrophoresis mass spectrometry using Fab´antibody fragments for the analysis of serum transthyretin. (semanticscholar.org)
  • Paul O. Staneke and Nico M. M. Nibbering, "Matrix-assisted laser desorption ionization and electrospray ionization combined with Fourier transform ion cyclotron resonance mass spectrometry," Spectroscopy , vol. 13, no. 2, pp. 145-150, 1997. (hindawi.com)
  • J. F. J. Todd, "Recommendations for nomenclature and symbolism for mass spectroscopy," Pure and Applied Chemistry , vol. 63, pp. 1541-1566, 1991. (hindawi.com)
  • Fuchs B, Schiller J. Mass spectrometry of biological molecules. (springer.com)
  • Ionization of the desorbed molecules occurs via the charge imparted onto the droplets. (waters.com)
  • The volatilized analyte molecules are then analyzed by mass spectrometry. (mcw.edu)
  • We performed structural variations of small molecules for fine-tuning their electronic properties, such as ionization potentials and mechanistic pathways for reactivity towards different targets. (nature.com)
  • Groessl M, Graf S, Knochenmuss R. High resolution ion mobility-mass spectrometry for separation and identification of isomeric lipids. (springer.com)
  • Desorption electrospray ionization imaging mass spectrometry of lipids in rat spinal cord. (pubfacts.com)
  • Figures of merit such as resolving power, mass accuracy, dynamic range and sensitivity of each type of instrument are compared. (psu.edu)
  • Engel KM, Schiller J. A comparison of PC oxidation products as detected by MALDI-TOF and ESI-IT mass spectrometry. (springer.com)
  • Fuchs B, Süss R, Schiller J. An update of MALDI-TOF mass spectrometry in lipid research. (springer.com)
  • Studies have demonstrated the capability of MALDI mass spectrometry as a tool in distinguishing cellular response to various stressing conditions based on their mass spectral pattern. (uncg.edu)
  • One of these techniques, called nanospray desorption electrospray ionization (nanospray DESI), is a modification of DESI mass spectrometry that has been used to analyse bacteria directly on the agar plate. (uncg.edu)
  • In this project, nanospray DESI mass spectrometry will be explored as a tool for rapidly distinguishing the response of bacterial cells to low pH conditions. (uncg.edu)
  • These findings demonstrate the capability of nanospray DESI mass spectrometry as a tool for rapidly distinguishing the bacterial response to stress. (uncg.edu)
  • This approach enables the separation of desorption and ionization events, thus providing independent control of desorption, ionization, and transport of the analyte . (rsc.org)
  • The present invention is an interface between a capillary electrophoresis separation capillary end and an electrospray ionization mass spectrometry emitter capillary end, for transporting an anolyte sample from a capillary electrophoresis separation capillary to a electrospray ionization mass spectrometry emitter capillary. (energy.gov)
  • However, sample throughput can be substantially increased by eliminating pretreatment steps and exploiting the potential of ambient ionization mass spectrometry (MS). Furthermore, online monitoring of reactions in a time-resolved way would identify sequential modification steps. (springer.com)
  • Ambient ionization techniques allow intact bacterial cells to be analysed in their native state without the use of a matrix for ionization. (uncg.edu)
  • Several ambient ionization techniques have been utilized as a means of analysing whole cells without any specific reagents or extraction procedures. (uncg.edu)
  • Similarities with other ionization methods in terms of fragmentation behavior were strong, although ambient ionization of untreated samples is only available with DESI. (pubfacts.com)
  • Evaluation of recent literature highlights the tension between the analytical utility of ambient ionisation approaches for skin profiling and the practicality of undertaking larger campaigns (higher statistical power), or undertaking research in remote locations. (lboro.ac.uk)
  • With the instrumentation improvements based on the proposed research, an immediate benefit will be made for miniaturization of mass spectrometry by allowing a transfer of MS methods developed on large laboratory instruments to the miniature MS devices. (purdue.edu)
  • Electrospray ionization mass spectrometry research was pioneered by the analytical chemistry professor John Bennet Fenn, who shared the Nobel Prize in Chemistry with Koichi Tanaka in 2002 for his work on the subject. (libretexts.org)
  • משני יינון electrospray ספקטרומטריית מסה (SESI-MS) מאפשרת זיהוי של תרכובות אורגניות נדיפות (VOCs) ללא צורך המקדים כל המדגם. (jove.com)
  • משני יינון electrospray ספקטרומטריית מסה (SESI-MS) היא שיטה שפותחה לצורך זיהוי מהיר של תרכובות נדיפות, ללא צורך המקדים המדגם. (jove.com)
  • In this study, a sensitive ultra-performance liquid chromatography-electrospray ionization-mass spectrometry method with a shorter chromatographic running time was developed and validated for simultaneous quantification of ten ginsenosides. (springeropen.com)
  • Desorption ionization methods can be performed on solid or liquid samples, and allows for the sample to be nonvolatile or thermally unstable. (libretexts.org)
  • Deng Y, Henion J, Li J, Thibault P, Wang C, Harrison DJ (2001) Chip-based capillary electrophoresis/mass spectrometry determination off carnitines in human urine. (springer.com)
  • The last article in the thesis reports studies of noncovalent interactions by means of nanoelectrospray ionization mass spectrometry (nanoESI-MS) for determination of the specific binding of selected drug candidates to HSA. (diva-portal.org)
  • While initial studies focused on the elucidation of stoichiometry by means of simple mass determination, developments in MS technology and methodology now allow researchers to address questions of shape, inter-subunit connectivity and protein dynamics. (technologynetworks.com)
  • The first paper in this thesis investigated the complicated electrospray ionization process with regards to noncovalent complexes. (diva-portal.org)
  • Electrospray ionization has made possible the transference of non-covalently bound complexes from solution phase to high vacuum. (portlandpress.com)
  • Reversibly self-assembling host-guest complexes of the softball type are characterized by electrospray ionization mass spectrometry. (fu-berlin.de)
  • Sjödahl J, Melin J, Griss P, Emmer A, Stemme G, Roeraade J (2003) Characterization of micromachined hollow tips for two-dimensional nanoelectrospray mass spectrometry. (springer.com)
  • Electrospray ionization mass spectrometry showed characteristic disaccharide fragments from glycosaminoglycans, indicating their structural characterization in the tissues analyzed. (scielo.br)
  • Desorption electrospray ionization (DESI) mass spectrometry was evaluated for the characterization of glycerophospholipid standards, including glycerophosphocholine (GPCho), glycerophosphoglycerol (GPGro), glycerophosphoethanolamine (GPEtn), glycerophosphoserine (GPSer), glycerophosphoinositol (GPIns), cardiolipin (CL), and sphingolipid standards, including sulfatides (ST) and sphingomyelin (SM). (pubfacts.com)
  • Lipid imaging by mass spectrometry - a review. (springer.com)
  • Lipid profiles of canine invasive transitional cell carcinoma of the urinary bladder and adjacent normal tissue by desorption electrospray ionization imaging mass spectrometry. (pubfacts.com)
  • Ramsey RS, Ramsey JM (1997) Generating electrospray from microchip devices using electroosmotic pumping. (springer.com)
  • Schultz GA, Corso TN, Prosser SJ, Zhang S (2000) A fully integrated monolithic microchip electrospray device for mass spectrometry. (springer.com)
  • El-Hawiet, A., Kitova, E.N., Klassen, J.S.: Quantifying protein interactions with isomeric carbohydrate ligands using a catch and release electrospray ionization-mass spectrometry assay. (springer.com)
  • This chapter is aimed at providing a step-by-step protocol for producing stable and efficient electrospray sample ionization from microfluidic chips that are used for capillary electrophoresis (CE) separations. (springer.com)
  • Single-quadrupole and ion-trap mass analysers as well as LC separations were optimised using pure and individual HBCD stereoisomers, and determinations were performed using selected ion monitoring (m/z 640.7) of the [M-H](-) ion. (wur.nl)
  • Another advantage is that this ionization method is one of the softest ionization methods available, therefore it has the ability to analyze biological samples that are defined by non-covalent interactions. (libretexts.org)
  • Engel KM, Griesinger H, Schulz M, Schiller J. Normal-phase versus reversed-phase thin-layer chromatography (TLC) to monitor oxidized phosphatidylcholines by TLC/mass spectrometry. (springer.com)
  • Spray ionization process in which either cations or anions in solution are transferred to the gas phase via formation and desolvation at atmospheric pressure of a stream of highly charged droplets that result from applying a potential difference between the tip of the electrospray needle containing the solution and a counter electrode. (lsu.edu)
  • A major challenge for detecting small quantities of biomolecules using mass spectrometry technology is that we can't see everything that is actually in the sample," said Matthew Torres, an assistant professor in Georgia Tech's School of Biological Sciences. (phys.org)
  • Imaging mass spectrometry allows for the direct investigation of tissue samples to identify specific biological compounds and determine their spatial distributions. (pubfacts.com)
  • Lazar IM, Ramsey RS, Jacobson SC, Foote RS, Ramsey JM (2000) Novel microfabricated device for electrokinetically induced pressure flow and electrospray ionization mass spectrometry. (springer.com)
  • Thus far, manual injections of DFO into the LCQ1 ion trap MS with electrospray ionization (Thermo Scientific, West Palm Beach, FL), have shown that even without optimization, the instrument can detect DFO at incredibly low concentrations (0.5 pg). (healthpartners.com)
  • In contrast to other ionization techniques often used for tissue imaging (i.e. (waters.com)
  • In this study, gas and solvent flow rates as well as ionization voltages are optimized to allow DESI imaging experiments that preserve the tissue sample being analyzed. (waters.com)
  • Another solution is to use ion mobility coupled with mass spectrometry (IM-MS) to separate the variant peptide ion from the interfering ion. (waters.com)
  • Electrospray ionization (ESI) has become one of the most commonly used ionization techniques for mass spectrometry (MS) and ion mobility spectrometry (IMS), and efforts continue to improve its performance. (byu.edu)
  • We have proposed a model that may explain how the equilibrium between a protein and ligand changes during the droplet evaporation/ionization process. (diva-portal.org)
  • Field-induced droplet ionization (FIDI) occurs at sufficient field strengths as the droplets eject opposing jets of positively and negatively charged progeny droplets. (caltech.edu)