Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
A chromatographic technique that utilizes the ability of biological molecules to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Chromatographic techniques in which the mobile phase is a liquid.
Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.
Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.
Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.
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.
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)
Salts that melt below 100 C. Their low VOLATILIZATION can be an advantage over volatile organic solvents.
Materials in intermediate state between solid and liquid.
The sum of the weight of all the atoms in a molecule.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
A type of ion exchange chromatography using diethylaminoethyl cellulose (DEAE-CELLULOSE) as a positively charged resin. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
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 microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
A method of gel filtration chromatography using agarose, the non-ionic component of agar, for the separation of compounds with molecular weights up to several million.
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.
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.
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.
The rate dynamics in chemical or physical systems.
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.
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.
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)
An analytical technique for resolution of a chemical mixture into its component compounds. Compounds are separated on an adsorbent paper (stationary phase) by their varied degree of solubility/mobility in the eluting solvent (mobile phase).
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)
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.
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.
The chemical and physical integrity of a pharmaceutical product.
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)
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.
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.
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.
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.
Electrophoresis in which a pH gradient is established in a gel medium and proteins migrate until they reach the site (or focus) at which the pH is equal to their isoelectric point.
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).
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.
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)
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.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
A series of steps taken in order to conduct research.
A hybrid separation technique combining both chromatographic and electrophoretic separation principles. While the method was invented to separate neutral species, it can also be applied to charged molecules such as small peptides.
A method of separation of two or more substances by repeated distribution between two immiscible liquid phases that move past each other in opposite directions. It is a form of liquid-liquid chromatography. (Stedman, 25th 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.
Concentration or quantity that is derived from the smallest measure that can be detected with reasonable certainty for a given analytical procedure.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
The process of cleaving a chemical compound by the addition of a molecule of water.
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.
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 species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
Artificial respiration (RESPIRATION, ARTIFICIAL) using an oxygenated fluid.
The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The pH in solutions of proteins and related compounds at which the dipolar ions are at a maximum.
Compounds in which a methyl group is attached to the cyano moiety.
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.
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.
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.
Proteins prepared by recombinant DNA technology.
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)
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.
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)
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
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)
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.
Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.
A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.
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.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
A group of compounds with the general formula M10(PO4)6(OH)2, where M is barium, strontium, or calcium. The compounds are the principal mineral in phosphorite deposits, biological tissue, human bones, and teeth. They are also used as an anticaking agent and polymer catalysts. (Grant & Hackh's Chemical Dictionary, 5th ed)
Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
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.
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)
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.
Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
Methodologies used for the isolation, identification, detection, and quantitation of chemical substances.
Elements of limited time intervals, contributing to particular results or situations.
The characteristic 3-dimensional shape of a carbohydrate.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
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)
The parts of a macromolecule that directly participate in its specific combination with another molecule.
The formation of a solid in a solution as a result of a chemical reaction or the aggregation of soluble substances into complexes large enough to fall out of solution.
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.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Presence of warmth or heat or a temperature notably higher than an accustomed norm.
High-molecular-weight insoluble polymers that contain functional cationic groups capable of undergoing exchange reactions with anions.
The systematic study of the complete complement of proteins (PROTEOME) of organisms.
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.
Proteins found in any species of bacterium.
The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.
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).
The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.
Established cell cultures that have the potential to propagate indefinitely.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.
Sulfuric acid diammonium salt. It is used in CHEMICAL FRACTIONATION of proteins.
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.
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.
Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.
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.
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)
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.
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.
Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.
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.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A CHROMATOGRAPHY method using supercritical fluid, usually carbon dioxide under very high pressure (around 73 atmospheres or 1070 psi at room temperature) as the mobile phase. Other solvents are sometimes added as modifiers. This is used both for analytical (SFC) and extraction (SFE) purposes.
The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.
The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.
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)
Transport proteins that carry specific substances in the blood or across cell membranes.
Measurement of the intensity and quality of fluorescence.
Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.
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)
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.
Cyanogen bromide (CNBr). A compound used in molecular biology to digest some proteins and as a coupling reagent for phosphoroamidate or pyrophosphate internucleotide bonds in DNA duplexes.
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.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.
Oligosaccharides containing two monosaccharide units linked by a glycosidic bond.
Centrifugation with a centrifuge that develops centrifugal fields of more than 100,000 times gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.
A very strong halogenated derivative of acetic acid. It is used in acid catalyzed reactions, especially those where an ester is cleaved in peptide synthesis.
An electrochemical process in which macromolecules or colloidal particles with a net electric charge migrate in a solution under the influence of an electric current.
Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.
The extent to which an enzyme retains its structural conformation or its activity when subjected to storage, isolation, and purification or various other physical or chemical manipulations, including proteolytic enzymes and heat.
A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)
The presence of organisms, or any foreign material that makes a drug preparation impure.
The protein complement of an organism coded for by its genome.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
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)
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)
Inorganic salts of sulfuric acid.
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.
The separation of particles from a suspension by passage through a filter with very fine pores. In ultrafiltration the separation is accomplished by convective transport; in DIALYSIS separation relies instead upon differential diffusion. Ultrafiltration occurs naturally and is a laboratory procedure. Artificial ultrafiltration of the blood is referred to as HEMOFILTRATION or HEMODIAFILTRATION (if combined with HEMODIALYSIS).
A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.
Antibodies produced by a single clone of cells.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.
Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.
The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.
Pesticides or their breakdown products remaining in the environment following their normal use or accidental contamination.
The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.
Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.
Liquid components of living organisms.
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).
Measurement and evaluation of the components of substances to be taken as FOOD.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)
The mineral component of bones and teeth; it has been used therapeutically as a prosthetic aid and in the prevention and treatment of osteoporosis.
An emulsifying agent produced in the LIVER and secreted into the DUODENUM. Its composition includes BILE ACIDS AND SALTS; CHOLESTEROL; and ELECTROLYTES. It aids DIGESTION of fats in the duodenum.
A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.
Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.
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 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)
A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.
A phase transition from liquid state to gas state, which is affected by Raoult's law. It can be accomplished by fractional distillation.
A technique that combines protein electrophoresis and double immunodiffusion. In this procedure proteins are first separated by gel electrophoresis (usually agarose), then made visible by immunodiffusion of specific antibodies. A distinct elliptical precipitin arc results for each protein detectable by the antisera.
Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.
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.
A genus of bacteria that form a nonfragmented aerial mycelium. Many species have been identified with some being pathogenic. This genus is responsible for producing a majority of the ANTI-BACTERIAL AGENTS of practical value.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.
Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.
The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.
The giving of drugs, chemicals, or other substances by mouth.
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.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
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.
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)
Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.
The relationship between the dose of an administered drug and the response of the organism to the drug.
A hexose or fermentable monosaccharide and isomer of glucose from manna, the ash Fraxinus ornus and related plants. (From Grant & Hackh's Chemical Dictionary, 5th ed & Random House Unabridged Dictionary, 2d ed)
Six-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives. Various polyneuropathies are caused by hexane poisoning.
A solventless sample preparation method, invented in 1989, that uses a fused silica fiber which is coated with a stationary phase. It is used for sample cleanup before using other analytical methods.
Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).
An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. Deficiency of galactosyl-1-phosphate uridyltransferase (GALACTOSE-1-PHOSPHATE URIDYL-TRANSFERASE DEFICIENCY DISEASE) causes an error in galactose metabolism called GALACTOSEMIA, resulting in elevations of galactose in the blood.
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.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Analogs of those substrates or compounds which bind naturally at the active sites of proteins, enzymes, antibodies, steroids, or physiological receptors. These analogs form a stable covalent bond at the binding site, thereby acting as inhibitors of the proteins or steroids.
Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.
Plants whose roots, leaves, seeds, bark, or other constituent parts possess therapeutic, tonic, purgative, curative or other pharmacologic attributes, when administered to man or animals.
Electrophoresis in which discontinuities in both the voltage and pH gradients are introduced by using buffers of different composition and pH in the different parts of the gel column. The term 'disc' was originally used as an abbreviation for 'discontinuous' referring to the buffers employed, and does not have anything to do with the shape of the separated zones.
An analytical method for detecting and measuring FLUORESCENCE in compounds or targets such as cells, proteins, or nucleotides, or targets previously labeled with FLUORESCENCE AGENTS.
A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Serum that contains antibodies. It is obtained from an animal that has been immunized either by ANTIGEN injection or infection with microorganisms containing the antigen.
Compounds containing the -SH radical.

The gas-liquid chromatograph and the electron capture detection in equine drug testing. (1/6149)

Three gas-liquid chromatographic (G.L.C.) procedures discussed have been designed around the four "esses" of detection tests--speed, sensitivity, simplicity, and specificity. These techniques are admirably applicable to the very low plasma drug levels encountered in blood testing under pre-race conditions. The methods are equally applicable to post-race testing procedures, where both blood and urine samples are tested. Drugs can only rarely be detected by the electron capture detector (E.C.D.) without a prior derivatization step, which conveys to the drug(s) high electron affinity. Because of broad applicability, two derivatizing agents, heptafluorobutyric (HFBA) and pentafluorpropionic (PFPA) anhydrides are employed. The three techniques, allowing broad coverage of various drug classes are: 1) direct derivatization of drugs to form strongly electron capturing amides and esters. 2) reductive fragmentation of drugs with lithium aluminum hydride to form alcohols, with conversion to ester derivatives. 3) oxidative fragmentation of drugs with potassium dichromate to form derivatizable groups, followed by direct derivatization.  (+info)

Research and identification of tranquillizers - use of retention index. (2/6149)

At the request of the Service des Haras, our laboratory works on the toxicological problems of the sport-horse. These studies have resulted in the setting up of an anti-doping control for equestrian competitions of various types, not only flat racing. During events, horses, must be calm and docile to the riders' order. Frequently, the latter use tranquillizers to try and win events. The analytical method for the research and identification of these compounds is described. The technique involves successively: 1. alkalinisation of the sample - saliva, blood or urine after enzymatic hydrolysis. 2. extraction with diethyl ether - the recovery is 70% to 90% depending upon the drug. 3. determination by gas-liquid chromatography with use of a retention index for qualitative analysis. We can detect up to fifteen tranquillizers in any one sample, even when present at such low concentrations as found in saliva. The use of the retention index is a reliable method for qualitative analysis. For example, the method has been used for three years, during which period the rentention index of acetylpromazine remained at 3240 +/- 7. The chromatographic analysis was performed on 3% OV-17 at 290 degrees. The chromatographic analysis has been performed by three columns of different polarity (OV-1; OV-17; SP-2250). If on the three columns, the retention index of one peak is the same as that of the tranquilizer, a further confirmation is made with the use of a thermionic detector specific for nitrogenous drugs. In conclusion, this method which is sufficiently precise and specific has been used for anti-doping control.  (+info)

An improved method for the structural profiling of keratan sulfates: analysis of keratan sulfates from brain and ovarian tumors. (3/6149)

A previously developed method for the structural fingerprinting of keratan sulfates (Brown et al., Glycobiology, 5, 311-317, 1995) has been adapted for use with oligosaccharides fluorescently labeled with 2-aminobenzoic acid following keratanase II digestion. The oligosaccharides are separated by high-pH anion-exchange chromatography on a Dionex AS4A-SC column. This methodology permits quantitative analysis of labeled oligosaccharides which can be detected at the sub-nanogram ( approximately 100 fmol) level. Satisfactory calibration of this method can be achieved using commercial keratan sulfate standards. Keratan sulfates from porcine brain phosphocan and human ovarian tumors have been examined using this methodology, and their structural features are discussed.  (+info)

Metabolism of the new liposomal anticancer drug N4-octadecyl-1-beta-D-arabinofuranosylcytosine in mice. (4/6149)

Metabolism and excretion of the new antitumor drug N4-octadecyl-1-beta-D-arabinofuranosylcytosine (NOAC) was investigated in mice. Mice were injected i.v. with tritium-labeled liposomal NOAC (4 micromol/mouse). Analysis of HPLC-purified extracts of liver homogenates by liquid chromatography coupled with mass spectrometry revealed only the presence of unmetabolized drug. To study the excretion of the administered drug, mice were injected with tritium-labeled liposomal NOAC or as comparison with 1-beta-D-arabinofuranosylcytosine (ara-C; 4 micromol/mouse) and housed up to 48 h in metabolic cages. Urine and feces were collected at different time points and the kinetics of excreted radioactivity were determined. After 48 h, 39% of the injected [5-3H]NOAC radioactivity was excreted in urine and 16% in feces, whereas ara-C radioactivity was only found in urine with 48% of the injected dose. Feces extracts and urine were purified by HPLC and radioactive fractions were further analyzed by liquid chromatography coupled with mass spectrometry. The radioactivity of feces extracts of NOAC-treated mice was composed of unmetabolized NOAC, hydroxylated NOAC (NOAC + OH), its sulfated derivative (NOAC + OSO3H), and unidentified metabolites, whereas in urine, the hydrophilic molecules ara-C and ara-U were found. During the period of 48 h only 2% of the injected NOAC was eliminated in its unmetabolized form, whereas 25% was identified as main metabolite ara-C. Urine collected during 48 h in ara-C-treated mice contained 33% of the injected dose as unmetabolized drug and 13% as the main metabolite ara-U. Thus, NOAC is metabolized by two major pathways, one leading to the hydrophilic metabolites ara-C and ara-U and the other to hydroxylated and sulfated NOAC.  (+info)

Studies on cytochrome P-450-mediated bioactivation of diclofenac in rats and in human hepatocytes: identification of glutathione conjugated metabolites. (5/6149)

The nonsteroidal anti-inflammatory drug diclofenac causes a rare but potentially fatal hepatotoxicity that may be associated with the formation of reactive metabolites. In this study, three glutathione (GSH) adducts, namely 5-hydroxy-4-(glutathion-S-yl)diclofenac (M1), 4'-hydroxy-3'-(glutathion-S-yl)diclofenac (M2), and 5-hydroxy-6-(glutathion-S-yl)diclofenac (M3), were identified by liquid chromatography-tandem mass spectrometry analysis of bile from Sprague-Dawley rats injected i.p. with a single dose of diclofenac (200 mg/kg). These adducts presumably were formed via hepatic cytochrome P-450 (CYP)-catalyzed oxidation of diclofenac to reactive benzoquinone imines that were trapped by GSH conjugation. In support of this hypothesis, M1, M2, and M3 were generated from diclofenac in incubations with rat liver microsomes in the presence of NADPH and GSH. Increases in adduct formation were observed when incubations were performed with liver microsomes from phenobarbital- or dexamethasone-treated rats. Adduct formation was inhibited by polyclonal antibodies against CYP2B, CYP2C, and CYP3A (40-50% inhibition at 5 mg of IgG/nmol of CYP) but not by an antibody against CYP1A. Maximal inhibition was obtained when the three inhibitory antibodies were used in a cocktail fashion (70-80% inhibition at 2.5 mg of each IgG/nmol of CYP). These data suggest that diclofenac undergoes biotransformation to reactive metabolites in rats and that CYP isoforms of the 2B, 2C, and 3A subfamilies are involved in this bioactivation process. With respect to CYP2C isoforms, rat hepatic CYP2C7 and CYP2C11 were implicated as mediators of the bioactivation based on immunoinhibition studies using antibodies specific to CYP2C7 and CYP2C11. Screening for GSH adducts also was carried out in human hepatocyte cultures containing diclofenac, and M1, M2, and M3 again were detected. It is possible, therefore, that reactive benzoquinone imines may be formed in vivo in humans and contribute to diclofenac-mediated hepatic injury.  (+info)

Ethyl glucuronide--a marker of alcohol consumption and a relapse marker with clinical and forensic implications. (6/6149)

Ethyl glucuronide (EtG) is a non-volatile, water-soluble, direct metabolite of ethanol that can be detected in body fluids and hair. We investigated urine and serum samples from three patient groups: (1) 33 in-patients in acute alcohol withdrawal; (2) 30 detoxified in-patients (treated for at least 4 weeks) from a 'motivation station'; and (3) 43 neuro-rehabilitation patients (non-alcoholics; most of them suffering from stroke, traumatic brain injury, Parkinson's disease etc.) using gas chromatography/mass spectrometry (GC/MS) with deuterium-labelled EtG as the internal standard and additionally in the second group of patients using liquid chromatography (LC/MS-MS). We found no correlation between the concentration of EtG in urine at hospitalization and the blood-ethanol concentration (r = 0.17), the time frame of detection (r = 0.5) or the total amount of clomethiazole required for the treatment of withdrawal symptoms (r = 0.28). In four out of 30 in-patients from the 'motivation station'--where neither clinical impression nor routine laboratory findings gave indications of relapse--concentrations of EtG in urine ranged between 4.2 and 196.6 mg/l. EtG concentrations in urine of between 2.89 and 23.49 mg/l were found in seven out of 43 neuro-rehabilitation patients using GC/MS. The GC/MS and the LC/MS-MS results showed a correlation of 0.98 with Pearson's correlation test and 1.0 with Spearman's correlation test. We suggest that EtG is a marker of alcohol consumption that can be detected for an extended time period after the complete elimination of alcohol from the body. When used as a relapse marker with a specific time frame of detection intermediate between short- and long-term markers, EtG fills a clinically as well as forensically important gap. Its specificity and sensitivity exceed those of all other known ethanol markers.  (+info)

Lignocellulose degradation by Phanerochaete chrysosporium: purification and characterization of the main alpha-galactosidase. (7/6149)

The main alpha-galactosidase was purified to homogeneity, in 30% yield, from a solid culture of Phanerochaete chrysosporium on 1 part wheat bran/2 parts thermomechanical softwood pulp. It is a glycosylated tetramer of 50 kDa peptide chains, which gives the N-terminal sequence ADNGLAITPQMG(?W)NT(?W)NHFG(?W)DIS(?W)DTI. It is remarkably stable, with crude extracts losing no activity over 3 h at 80 degrees C, and the purified enzyme retaining its activity over several months at 4 degrees C. The kinetics of hydrolysis at 25 degrees C of various substrates by this retaining enzyme were measured, absolute parameters being obtained by active-site titration with 2',4',6'-trinitrophenyl 2-deoxy-2, 2-difluoro-alpha-D-galactopyranoside. The variation of kcat/Km for 1-naphthyl-alpha-D-galactopyranoside with pH is bell-shaped, with pK1=1.91 and pK2=5.54. The alphaD(V/K) value for p-nitrophenyl-alpha-D-glucopyranoside is 1.031+/-0.007 at the optimal pH of 3.75 and 1.114+/-0.006 at pH7.00, indicating masking of the intrinsic effect at optimal pH. There is no alpha-2H effect on binding galactose [alphaD(Ki)=0.994+/-0.013]. The enzyme hydrolyses p-nitrophenyl beta-L-arabinopyranoside approximately 510 times slower than the galactoside, but has no detectable activity on the alpha-D-glucopyranoside or alpha-D-mannopyranoside. Hydrolysis of alpha-galactosides with poor leaving groups is Michaelian, but that of substrates with good leaving groups exhibits pronounced apparent substrate inhibition, with Kis values similar to Km values. We attribute this to the binding of the second substrate molecule to a beta-galactopyranosyl-enzyme intermediate, forming an E.betaGal. alphaGalX complex which turns over slowly, if at all. 1-Fluoro-alpha-D-galactopyranosyl fluoride, unlike alpha-D-galactopyranosyl fluoride, is a Michaelian substrate, indicating that the effect of 1-fluorine substitution is greater on the first than on the second step of the enzyme reaction.  (+info)

Oxidized low-density lipoprotein as a delivery system for photosensitizers: implications for photodynamic therapy of atherosclerosis. (8/6149)

Photodynamic therapy is a promising new strategy in the treatment of cardiovascular diseases. Photodynamic therapy for vascular diseases may be improved by the specific delivery of photosensitizers to the atherosclerotic lesion. In this study, we studied whether oxidatively modified low-density lipoprotein (OxLDL) could be used as a specific carrier for photosensitizers, thereby using the scavenger receptor expressed on macrophages as a target. The photosensitizer aluminum phthalocyanine chloride (AlPc) was incorporated into OxLDL, and its photodynamic effects were studied. Macrophages (RAW 264.7) were incubated with various concentrations of OxLDL-AlPc for different periods. After illumination of the cells with red light, cytotoxicity was observed that was dependent on the time of illumination and incubation. Macrophages incubated with OxLDL-AlPc that were not illuminated revealed no cytotoxicity. The uptake of the OxLDL-AlPc complexes was mediated by scavenger receptors expressed on macrophages. In the presence of the polyanion polyinosinic acid, a specific ligand for scavenger receptors, no cytotoxicity could be observed. Serum incubations of the OxLDL-AlPc complexes revealed that these complexes stay intact after incubation. No redistribution of AlPc to other plasma (lipo-) proteins could be detected, and 80-90% of the AlPc remained associated with the OxLDL particle. These results indicate that OxLDL may function as a specific delivery system for photosensitizers to the scavenger receptors expressed on the macrophages in the atherosclerotic lesion, increasing the beneficial effects of photodynamic therapy for cardiovascular diseases.  (+info)

Tea is the second most consumed beverage in the world and its consumption has been associated with numerous potential health benefits. Factors such as fermentation methods, geographical origin and season can affect the primary and secondary metabolite composition of tea. In this study, a hydrophilic interaction liquid chromatography (HILIC) method coupled to high resolution mass spectrometry in both positive and negative ionisation modes was developed and optimised. The method when combined with principal component analysis to analyse three different types of tea, successfully distinguished samples into different categories, and provided evidence of the metabolites which differed between them. The accurate mass and high resolution attributes of the mass spectrometric data were utilised and relative quantification data were extracted post-data acquisition on 18 amino acids, showing significant differences in amino acid concentrations between tea types and countries. This study highlights the ...
A method for the analysis of dextran-1 has been developed using hydrophilic interaction liquid chromatography (HILIC) with charged corona aerosol detection (CCAD) as a potential alternative to the size exclusion chromatography method described in the European Pharmacopoeia (EP). Click to read more...
Title: Stable isotope dilution liquid chromatography/mass spectrometry analysis of cellular and tissue medium- and long-chain acyl-coenzyme A thioesters.. Authors: Snyder, Nathaniel W; Basu, Sankha S; Zhou, Zinan; Worth, Andrew J; Blair, Ian A. Published In Rapid Commun Mass Spectrom, (2014 Aug 30). Abstract: Acyl-Coenzyme A (CoA) thioesters are the principal form of activated carboxylates in cells and tissues. They are employed as acyl carriers that facilitate the transfer of acyl groups to lipids and proteins. Quantification of medium- and long-chain acyl-CoAs represents a significant bioanalytical challenge because of their instability.Stable isotope dilution liquid chromatography/selected reaction monitoring-mass spectrometry (LC/SRM-MS) provides the most specific and sensitive method for the analysis of CoA species. However, relevant heavy isotope standards are not available and they are challenging to prepare by chemical synthesis. Stable isotope labeling by essential nutrients in cell ...
Differential mobility spectrometry for improved selectivity in hydrophilic interaction liquid chromatography-tandem mass spectrometry analysis of paralytic shellfish toxins
article{167611, author = {Van de Wiele, Mieke and De Wasch, Katia and VERCAMMEN, J and COURTHEYN, D and De Brabander, Hubert and Impens, Sandra}, issn = {0021-9673}, journal = {JOURNAL OF CHROMATOGRAPHY A}, language = {eng}, number = {2}, pages = {203--209}, title = {Determination of 16 beta-hydroxystanozolol in urine and faeces by liquid chromatography-multiple mass spectrometry.}, volume = {904}, year = {2000 ...
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Simultaneous determination of β-hydroxybutyrate and β-hydroxy-β-methylbutyrate in human whole blood using hydrophilic interaction liquid chromatography electrospray tandem mass ...
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A recently developed stable isotope dilution liquid chromatography-multiple reaction/mass spectrometry method to quantify focal adhesion kinase (FAK) activation loop phosphorylation was used to study endogenous Src kinase activity. This revealed that bis-phosphorylated pTyr576/Tyr577-FAK was a biomarker of Src activity and inactivation in vitro and in cell culture. Mouse embryonic fibroblasts (MEFs) expressing endogenous Src family kinases contained 65% unmodified Tyr576/Tyr577, 33% mono-phosphorylated-pTyr576-FAK, and 6% bis-phosphorylated-pTyr576/pTyr577-FAK. In contrast, MEFs expressing oncogenic Y529FSrc contained 38% unmodified Tyr576/Tyr577-FAK, 29% mono-phosphorylated-pTyr576-FAK, and 19% bis-phosphorylated-pTyr576/pTyr577-FAK. This new method has made it possible to accurately determine the absolute amounts of FAK phosphorylation that occur after Src inhibition in cell culture and in vitro with increasing concentrations of the Src inhibitor ...
To better understand the molecular mechanisms underpinning physiological variation in human populations, metabolic phenotyping approaches are increasingly being applied to studies involving hundreds and thousands of biofluid samples. Hyphenated ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) has become a fundamental tool for this purpose. However, the seemingly inevitable need to analyze large studies in multiple analytical batches for UPLC-MS analysis poses a challenge to data quality which has been recognized in the field. Herein, we describe in detail a fit-for-purpose UPLC-MS platform, method set, and sample analysis workflow, capable of sustained analysis on an industrial scale and allowing batch-free operation for large studies. Using complementary reversed-phase chromatography (RPC) and hydrophilic interaction liquid chromatography (HILIC) together with high resolution orthogonal acceleration time-of-flight mass spectrometry (oaTOF-MS), exceptional measurement precision is
Mitochondrial dysfunction plays a role in a wide range of diseases resulting in an enormous public health burden. The goal of this thesis is to identify metabolic pathways that are disrupted in response to mitochondrial insults. A large proportion of this work is based on the generation of stable isotope labelled metabolites to allow for the rigorous quantification of intracellular metabolites by liquid chromatography-mass spectrometry. Once developed, this methodology was employed in cell culture models initially to characterize an unidentified acyl-CoA thioester induced by propionate metabolism. This novel pathway was identified as the direct formation of 2-methyl-2-pentenoyl-CoA, and using isotopic labeling by metabolic precursors served as a critical component to this pathway elucidation. These same techniques were then applied to studying rotenone, a mitochondrial complex I inhibitor associated with Parkinsonâ??s disease. Previous work by our group has shown that rotenone inhibits components of
PubMed Central Canada (PMC Canada) provides free access to a stable and permanent online digital archive of full-text, peer-reviewed health and life sciences research publications. It builds on PubMed Central (PMC), the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature and is a member of the broader PMC International (PMCI) network of e-repositories.
Quantification of highly homologous human liver drug-metabolizing enzymes (DMEs) has been a challenging task in drug metabolism and disposition research, due to a lack of specific antibodies and marker substrates. Mass spectrometry (MS) techniques and applications have evolved significantly, striving to achieve absolute and specific quantification of these enzymes. Since the first absolute quantification of cytochrome P450s (CYPs) using the attachment of isotope tags to free thiols (iCAT), MS-based quantification has become much more versatile, cheaper, and easier to use. Today, variations of liquid chromatography-multiple reaction monitoring (LC-MRM)-based targeted proteomics, such as AQUA (absolute quantification) and QconCAT (concatenated signature peptides), have become the gold standards for quantification. These new methods have driven the absolute quantification of DMEs to become a routine laboratory task. Many drug metabolism-related projects require absolute enzyme quantification. For ...
In a preliminary study in healthy subjects, the investigators determined the pharmacokinetic and pharmacodynamic of enteric-coated acetylsalicylic acid (ASA) (Adiro 100 mg, Bayer), and the variability (coefficient of variation), accuracy and precision of a novel biomarker of ASA action, i.e., quantification of the extent of COX-1 acetylation at serine-529, using a stable isotope dilution liquid chromatography multiple reaction monitoring/mass spectrometry (LC-MS) technique.. Now, the investigators will perform a clinical study in individuals undergoing Colorectal cancer (CRC) to validate the hypothesis that that low-dose ASA given once daily is acting primarily by selectively acetylating platelet COX-1 and suppressing its activity throughout the 24-hour dosing interval. In contrast, it is expected that the inhibitory effect on extra-platelet sources of COX-1 will be short-lasting, if any, affecting only partially COX-1, and this effect will be completely reversed at 24 hours after dosing. This ...
A novel bioanalytical method was developed and validated for the quantitative determination of erlotinib in human plasma by using the supported liquid extraction (SLE) sample cleanup coupled with hydrophilic interaction liquid chromatography and tandem mass spectrometric detection (HILIC-MS/MS). The SLE extract could be directly injected into the HILIC-MS/MS system for analysis without the solvent evaporation and reconstitution steps. Therefore, the method is simple and rapid. In the present method, erlotinib-d6 was used as the internal standard. The SLE extraction recovery was 101.3%. The validated linear curve range was 2 to 2,000 ng/mL based on a sample volume of 0.100-mL, with a linear correlation coefficient of | 0.999. The validation results demonstrated that the present method gave a satisfactory precision and accuracy: intra-day CV | 5.9% (
Protein recovery is crucial for shotgun metaproteomics to study the in situ functionality of microbial populations from complex biofilms but still poorly addressed by far. To fill this knowledge gap, we systematically evaluated the sample preparation with extraction buffers comprising four detergents for the metaproteomics analysis of a terephthalate-degrading methanogenic biofilm using an on-line two-dimensional liquid chromatography tandem mass spectrometry (2D-LC-MS/MS) system. Totally, 1018 non-repeated proteins were identified with the four treatments. On the whole, each treatment could recover the biofilm proteins with specific distributions of molecular weight, hydrophobicity, and isoelectric point. The extraction buffers containing zwitterionic and anionic detergents were found to harvest the proteins with better efficiency and quality, allowing identification up to 76.2% of total identified proteins with the LC-MS/MS analysis. According to the annotation with a relevant metagenomic
Biosero provide liquid chromatography & mass spectrometry software. The LC/MS method is useful because it can analyze large volumes of material with specificity and sensitivity.
Biosero provide liquid chromatography & mass spectrometry software. The LC/MS method is useful because it can analyze large volumes of material with specificity and sensitivity.
Table IV shows that 91% of the 229 proteins reported by Mascot are correct. This slight discrepancy between the predicted performance of Mascot and that reported can be explained by the confusion/difficulty in defining a correct answer. Eight of the 20 proteins that we have defined as incorrect for Mascot are proteins that are homologous to proteins that are present in the sample (i.e. some of the peptide matches to this protein are correct, but the unique peptide matches to this protein are incorrect). Although these matches are not correct, they do share extensive homology to correct matches. Adding these matches leads to the Mascot scoring performing as its scoring model predicts (94.8% correct).. Protein Prospector searching against the Swiss-Prot database and using a 0.5 peptide match probability threshold for reporting proteins returns 256 protein matches plus a further 57 homologous proteins. Protein Prospector tries to separate homologous proteins out of the main protein list, so ...
New Liquid Chromatography-Mass Spectrometry Workstream Offers Comprehensive Solution for Toxicology - read this article along with other careers information, tips and advice on BioSpace
Lin XH,WangQuancai,Yin PY,et al. A method for handling metabonomics data from liquid chromatography mass spectrometry: combinational use of support vector machine recursive feature elimination, genetic algorithm and random forest for feature selection[J]. Metabolomics,2011,4(待补充):549 ...
Agilent Technologies Inc. announced analyses of carbamates and phenyl ureas using liquid chromatography/mass spectrometry (LC/MS). The sources for these tes
Interest in chromatography using hydrophilic interaction liquid chromatography (HILIC) has continued to build in recent years. Although HILIC chromatography is known to provide valuable retention and selectivity of polar compounds and provide highly compa...
Currently, statins are the only drugs acting on the mammalian isoprenoid pathway. The mammalian genes in this pathway are not easily amenable to genetic manipulation. Thus, it is difficult to study the effects of the inhibition of various enzymes on the intermediate and final products in the isoprenoid pathway. In fission yeast, antifungal compounds such as azoles and terbinafine are available as inhibitors of the pathway in addition to statins, and various isoprenoid pathway mutants are also available. Here in these mutants, treated with statins or antifungals, we quantified the final and intermediate products of the fission yeast isoprenoid pathway using liquid chromatography-mass spectrometry/mass spectrometry. In hmg1-1, a mutant of the gene encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), ergosterol (a final sterol product), and squalene (an intermediate pathway product), were decreased to approximately 80% and 10%, respectively, compared with that of wild-type cells. Consistently
[163 Pages] Global liquid chromatography-mass spectrometry market is expected to be valued at US$ 3,683.7 million in 2019. Liquid Chromatography-Mass Spectrometry Market by Type, by Sensitivity, by End User, and Regional Outlook 2019 - 2027
Methylation aberrations play an important role in many metabolic disorders including cancer. Methylated metabolites are direct indicators of metabolic aberrations, and currently, there is no liquid chromatography-mass spectrometry (LC-MS) based method available to cover all classes of methylated metabolites at low detection limits. In this study, we have developed a method for the detection of methylated metabolites, and its biological application. In this approach, we used a HILIC based HPLC method combined with MS to measure methylated organic acids, amino acids, and nucleotides. These metabolites were separated from each other by their hydrophobic interactions and analyzed using a targeted metabolomics approach by single reaction monitoring in positive and negative modes of electrospray ionization. These metabolites were quantified, and the interday reproducibility was ,10% relative standard deviation. Furthermore, by applying this method, we identified high levels of methylated metabolites ...
Polysaccharides from Baizhu were separated by preparative hydrophilic interaction liquid chromatography on an XAmide column and its components were characterised as inulin-type polysaccharides with structures of alpha-D-glucopyranosyl-[-(1 -> 2) -beta-D-fructofuranosyl-](n-1)-(1 -> 2) -beta-D-fructofuranoside (n=3-20) by a combinatory application of electrospray-ionisation mass spectrometry, nuclear magnetic resonance and IR, as well as the chemical analysis of monosaccharide composition. In addition, the contents of nystose and 1F-fructofranosylnystose in the crude and purified Baizhu polysaccharides were determined to be 5.81%, 4.92% and 0.70%, 0.84% (w/w), respectively. In addition, MTT assay indicated that the Baizhu polysaccharides could effectively promote spleen lymphocyte transformation for the enhancement of organism immunity. It is for the first time that inulin-type polysaccharides were discovered in Baizhu and its immuno-enhancing activity was reported, which is a vigorous evidence ...
Immunoassay has been used to measure the blood concentration of drugs, steroids, and vitamin D. However, the immunoassay methods have limitations related to the differences of the methods, variation in the reagents, sensitivity, and specificity. Recently liquid chromatograph mass spectrometers (LC/MS/MS) are being used to improve analytical accuracy and precision based on its superior specificity. On the other hand, in the analysis of biological samples like serum by LC/MS/MS, sample preparation is required to carry out protein precipitation and sample dilution. These procedures cause a risk of variations and mistakes, depending on the operators procedure. In this article, the validation of 25-OH vitamin D2/D3 and steroids in serum using a fully automated sample preparation LC/MS/MS system is described.. Keywords: Sample preparation, Vitamin D, Steroids, LC/MS/MS. ...
Spatial lipid composition, distribution and regulation are very important factors for mediating lipid functionality and, when disrupted, can cause pathophysiological processes leading to cancer, obesity, atherosclerosis, and neurodegeneration. The novel LESAPLUS surface analysis approach combines the standard liquid extraction surface analysis with an additional step of a nano liquid chromatography separation. This combination is ideally suited to investigate small molecule drugs, metabolites or lipids from thin tissue sections.. ...
LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY FOR THE STUDY OF ARACHIDONIC ACID METABOLITES Xiaojing Liu Ian A. Blair, PhD Arachidonic acid (AA) oxidation metabolism has been an important research topic for decades, and numerous oxidation products as well as enzymes involved in AA metabolism together with their downstream metabolites have been identified, although unknown pathways still remain to be characterized. In the present a study a new AA metabolite, 11-oxo-eicosatetraenoic acid (ETE), generated from a major product of cyclooxygenase (COX-2), 11(R)-hydroxyeicosatetraenoic acid (HETE), through 15-hydroxyprostaglandine dehydrogenase (15-PGDH)-mediated oxidation. 11-Oxo-ETE was found to have an anti-proliferative effect on human umbilical vein endothelial cells (HUVECs), with a similar IC50 to a well- known anti-inflammatory mediator, 15-deoxy-12,14-prostaglandin J2 (15d-PGJ2). It was also found that 11-oxo-ETE could be inactivated through the glutathione-S-transferase (GST)/glutathione (GSH) pathway
Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that controls blood phosphate levels by increasing renal phosphate excretion and reducing 1,25-dihydroxyvitamin D3 [1,25(OH)2D] production. Disorders of FGF23 homeostasis are associated with significant morbidity and mortality, but a fundamental understanding of what regulates FGF23 production is lacking. Because the kidney is the major end organ of FGF23 action, we hypothesized that it releases a factor that regulates FGF23 synthesis. Using aptamer-based proteomics and liquid chromatography-mass spectrometry-based (LC-MS-based) metabolomics, we profiled more than 1600 molecules in renal venous plasma obtained from human subjects. Renal vein glycerol-3-phosphate (G-3-P) had the strongest correlation with circulating FGF23. In mice, exogenous G-3-P stimulated bone and bone marrow FGF23 production through local G-3-P acyltransferase-mediated (GPAT-mediated) lysophosphatidic acid (LPA) synthesis. Further, the stimulatory effect of G-3-P ...
The carotenoid test allows one to build a simple classification map of stationary phases used in reversed‑phase liquid chromatography, on the basis of the shape recognition (plotted on the x axis), the polar surface activity (plotted on the y axis), and the phase hydrophobicity (related by the bubble size).
Reverse Phase Liquid Chromatography the most popular process and used in 80% of methods. Advanced chromatographers use advanced forms of RP-chromatography
The Sustainable Environment Research Centre (SERC) undertakes national and world-leading research into waste treatment and the sustainable production of energy from waste and grown biomass. To achieve this, considerable investment has been made into the facilities available to researchers and students.. Waste Water Treatment and Fermentative Hydrogen Production Laboratory. This is a dedicated laboratory for the development and testing of lab scale bio-reactors. Research undertaken includes the optimisation of hydrogen and methane production from various waste substrates, and has been key to the successful development of several field-scale systems.. Ultra Performance Liquid Chromatography Laboratory. SERC is one of only a handful of sites in the UK to be undertaking environmental research using state-of-the-art Ultra Performance Liquid Chromatography / Mass Spectrometry (UPLC-MS). This analytical method provides highly accurate results to nano-gram concentrations. The equipment is currently ...
Dittmar, T. , Whitehead, K. , Minor, E. C. and Koch, B. (2007): Tracing terrigenous dissolved organic matter and its photochemical decay in the ocean by using liquid chromatography/mass spectrometry , Marine chemistry ...
LC/MS analysis of the chimeric OMT reaction products using laudanosoline as a substrate. Upper panel; OMT reactions and their predicted ions in LC/MS analysis.
...With the advent of liquid chromatography/ mass spectrometry and inform... Abstract ... The Q TRAP instrument is based on a triple quadrupole ion path and is... ...,Simultaneously,characterizing,and,quantifying,chloramphenicol,and,its,metabolite,using,LC/MS/MS,biological,advanced biology technology,biology laboratory technology,biology device technology,latest biology technology
New Thermo Scientific Tox Explorer Collection provides instruments, columns and consumables with reliable and validated methods for reproducible results.
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Note: *The Download PDF brochure only consist of Table of Content (ToC), Research Framework of the actual report, and Research Methodology adopted for it ...
This application brief demonstrate the unique ability of charged surface hybrid (CSH Technology) C18 to produce high peak capacity peptide separations at high mass loads in nanoLC chromatography
Liquid chromatography with tandem mass spectrometry (LC-MS/MS) based quantitative proteomics provides the relative different protein abundance in healthy and disease-afflicted patients, which offers the information for molecular interactions, signaling pathways, and biomarker identification to serve the drug discovery and clinical research. Typical analysis workflow begins with the peptide feature detection and intensity calculation from LC-MS map. We are the first to propose a deep learning based model, DeepIso, that combines recent advances in Convolutional Neural Network (CNN) and Recurrent Neural Network (RNN) to detect peptide features of different charge states, as well as, estimate their intensity. Existing tools are designed with limited engineered features and domain-specific parameters, which are hardly updated despite a huge amount of new coming proteomic data. On the other hand, DeepIso consisting of two separate deep learning based modules, learns multiple levels of representation ...
Capillary columns (50, 75 and 100 μm I.D.) were packed with silica C₁₈ sub-2 μm particles for 50mm and were employed in nano-liquid chromatography (nano-LC) for
Discovering and identifying molecular biomarkers in large liquid chromatography-mass spectrometry (LC-MS) data sets requires automation without loss of accuracy. Benjamin Van Mooy from the Wood Hole Oceanographic Institution reveals a lipidomics strategy using LOBSTAHS to identify lipid, oxidized lipid, and oxylipin biomarkers in high mass accuracy high performance (HP) LC-MS data.
Due to the high prescription of antidepressants and their frequent involvement in clinical and forensic intoxications, reliable analytical techniques for identification and quantification of these...
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List of Authors: J. Caixach, C. Flores, L. Spoof, J. Meriluoto, W. Schmidt, H. Mazur-Marzec, A. Hiskia, T. Kaloudis, A. Furey ...
Easy-to-use data acquisition and processing for LC-MS/MS analysis with software features to improve productivity in the clinical laboratory.
We are skilled in the development of analytical methods for determination of trace amounts of tracked impurities. For our customers we usually develop methods for assessment of toxic impurities at levels much below those demanded by corresponding regulatory authorities. Often we deal with systems where the target components are susceptible to decomposition or can react easily with the active ingredient or sample matrix. Despite these challenges, we continue to succeed with the development of such methods. For this purpose we use LC/MS (HPLC 2695 Alliance(Waters)/LTQ (Thermo-Finnigan)) or GC/MS (7890A/5975C(Agilent Technologies)) technique. Routinely, we are able to achieve a sensitivity at ppm levels on both these systems which is usually sufficient for most pharmaceutical applications.. When necessary, we benefit from cooperation with our bioanalytical department. There we may use several (mostly triple-quadrupole) LC/MS instruments in tandem offering a sensitivity in the order of units ...
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 ...
Florentina Laura Chiriac, Iuliana Paun, Florinela Pirvu, Luoana Florentina Pascu, Marcela Niculescu, Toma Galaon - Liquid Chromatography Tandem Mass Spectrometry Method for Ultra-Trace Analysis of Organic UV Filters in Environmental Water Samples
TY - JOUR. T1 - Comparison of gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry methods to quantify α-tocopherol and αtocopherolquinone levels in human plasma. AU - Mottier, Pascal. AU - Gremaud, Eric. AU - Guy, Philippe A.. AU - Turesky, Robert J.. PY - 2002/2/1. Y1 - 2002/2/1. N2 - Two mass spectrometric methods were established for the quantitative analyses of α-tocopherol (TH) and its oxidation product α-tocopherolquinone (TQ) in human plasma. Both methods make use of isotopically labeled internal standards of different levels of deuteration (d3-TH and d6-TQ). Plasma (100 μl) was saponified in the presence of a mixture of antioxidants, and then TH and TQ were extracted with hexane. With the GC-MS method, the analytes were first converted into O-trimethylsilyl derivatives before analysis in the selective ion monitoring mode. The derivatization procedure led to the quantitative conversion of TQ into the O-trimethylsilyl derivative of ...
A novel liquid chromatography-tandem mass spectrometry method is described for the quantitative determination of the endogenous CYP 3A4/5 marker 4β-hydroxycholesterol in human K(2)-EDTA plasma. It is based on alkaline hydrolysis to convert esterified to free 4β-hydroxycholesterol, followed by analyt …
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
RATIONALE Neonicotinoids (NNIs) are the fastest expanding group of pesticides in the world over the last two decades; however, they may be a significant contributing factor to bee mortality. The widespread use of NNIs makes it critical to monitor their residuals in the environment. Published methods for NNI analysis are mainly focused on agricultural and food products, and many of them only measured a portion of the commercially available NNIs. METHODS Utilizing a biphenyl stationary-phase column, a sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed to determine eight NNIs, including acetamiprid, clothianidin, dinotefuran, flonicamid, imidacloprid, nitempyram, thiacloprid and thiamethoxam in environmental water. Two multiple reaction monitoring (MRM) transitions were monitored for each compound to ascertain true positive identification. Isotope-labelled NNIs, d3-acetamiprid, d3-clothianidin, d4-imidacloprid and d3-thiamethoxam, were used to compensate for
Abstract: A liquid chromatography tandem mass spectrometry method was developed for quantifying ten cannabinoids in oral fluid (OF). This method utilizes OF collected by the Quantisal device and concurrently quantifies cannabinol (CBN), cannabidiol (CBD), Δ9-tetrahydrocannabinol (THC), 11-hydroxy-Δ9-THC (11-OH-THC), 11-nor-9-carboxy-Δ9-THC (THC-COOH), 11-nor-9-carboxy-Δ9-THC glucuronide (THC-COOH-gluc), Δ9-THC glucuronide (THC-gluc), cannabigerol (CBG), tetrahydrocannabiverin (THCV), and Δ9-tetrahydrocannabinolic acid A (THCA-A). Solid phase extraction was optimized using Oasis Prime HLB 30 mg 96-well plates. Cannabinoids were separated by liquid chromatography over a BEH C18 column and detected by a Waters TQ-S micro tandem mass spectrometer. The lower limits of quantification (LLOQ) were 0.4 ng/mL for CBN, CBD, THC, 11-OH-THC, THC-gluc, and THCV; and 1.0 ng/mL for THC-COOH, THC-COOH-gluc, CBG and THCA-A. Linear ranges extended to 2000 ng/mL for THC and 200 ng/mL for all other analytes. ...
TY - JOUR. T1 - Analysis of metribuzin and its metabolites in livestock products and seafoods by liquid chromatography-tandem mass spectrometry. AU - Kai, Shigemi. AU - Akaboshi, Takeshi. AU - Waki, Masumi. AU - Fuzimaki, Teruhisa. AU - Kanazawa, Hideko. PY - 2011/2. Y1 - 2011/2. N2 - A method for simultaneous determination of metribuzin (MET) and three metribuzin metabolites in livestock products and seafoods by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. MET and its metabolites were extracted from a sample with acetonitrile, followed by InertSepC18 and BondElut SAX cartridge cleanup. The LC separation was performed on a C18 column using 0.01 mol/L ammonium formate-acetonitrile-methanol (70 : 21 : 9) as the mobile phase and MS detection with both positive and negative ion electrospray ionization. The mean recoveries from 10 livestock products and seafoods were generally ,60%, and the relative standard deviations were ,20%.. AB - A method for simultaneous ...
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TY - JOUR. T1 - Validation of a high throughput method for serum/plasma testosterone using liquid chromatography tandem mass spectrometry (LC-MS/MS). AU - Singh, Ravinder Jit. PY - 2008/12/12. Y1 - 2008/12/12. N2 - Testosterone, the major androgenic hormone in humans, is commonly measured to aid in the diagnosis of clinical conditions related to its excess or deficiency. In addition, testosterone measurements are used to monitor testosterone replacement-, or antiandrogen therapy. Most commonly, automated direct immunoassays have been used to measure testosterone in human serum. Their advantage compared with other methodologies, lies in high- and rapid sample throughput with minimal human intervention. However, many automated testosterone immunoassays suffer from poor accuracy at the low concentration levels (,50 ng/dL) seen in women and children, or in men undergoing anti-androgen therapy. Our objective was to develop a LC-MS/MS method which measures testosterone in human serum while fulfilling ...
The obligate intracellular lifestyle of Plasmodium falciparum and the difficulties in obtaining sufficient amounts of biological material have hampered the study of specific metabolic pathways in the malaria parasite. Thus, for example, the pools of sugar nucleotides required to fuel glycosylation reactions have never been studied in-depth in well-synchronized asexual parasites or in other stages of its life cycle. These metabolites are of critical importance, especially considering the renewed interest in the presence of N-, O-, and other glycans in key parasite proteins. In this work, we adapted a liquid chromatography tandem mass spectrometry (LC-MS/MS) method based on the use of porous graphitic carbon (PGC) columns and MS-friendly solvents to quantify sugar nucleotides in the malaria parasite. We report the thorough quantification of the pools of these metabolites throughout the intraerythrocytic cycle of P. falciparum The sensitivity of the method enabled, for the first time, the targeted ...
Liquid chromatography tandem mass spectrometry is one of the most specific techniques available in clinical laboratories. In the past, immunoassays were the primary methodology for analysis of steroids in biological samples because they are rapid and easy to perform. However, these methods were shown to suffer from the lack of specificity for measuring many of the diagnostically important steroids. LC-MS/MS overcomes many of the limitations of immunoassays, enhances diagnostic utility of the testing, and expands diagnostic capabilities in endocrinology. In addition to the superior quality of the measurements, LC-MS/MS allows high throughput testing using small sample volume with minimal sample preparation, and frees the laboratory from dependence on suppliers of assay specific reagents. LC-MS/MS is being widely employed for routine measurement of steroids, and the methodology plays an important role in the standardization and harmonization of measurements among clinical laboratories.. ...
A highly sensitive and selective liquid chromatography-mass spectrometry (LC-MS) method has been developed for the determination of epirubicin in serum and c...
A stereoselective, sensitive and rapid liquid chromatography-tandem mass spectrometry (LC-MSMS) method for the determination of R-acenocoumarol and S-acenocoumarol in human plasma was developed and validated at IPRC bioanalytical labs. The procedure involved solid phase extraction of both enantiomers and their corresponding internal standard. The chromatographic separation was accomplished employing a chiral column and proper mobile phase. Detection was carried out using Waters Micromass® Quattro Premier mass spectrometer in multiple reaction monitoring (MRM) mode using turbo ion spray with negative ionization. The method was validated over a linear range of 0.40 - 40.00 ng/ml for R-acenocoumarol and 0.20 - 20.00 ng/ml for the S-acenocoumarol. Method validation covered different parameters such as linearity, accuracy, precision and stability. The method was successfully applied for the determination of R and S-acenocoumarol in plasma samples of 28 healthy subjects who participated in a pharmacokinetics
TY - JOUR. T1 - Reference ranges for testosterone in men generated using liquid chromatography tandem mass spectrometry in a community-based sample of healthy nonobese young men in the framingham heart study and applied to three geographically distinct cohorts. AU - Bhasin, Shalender. AU - Pencina, Michael. AU - Jasuja, Guneet Kaur. AU - Travison, Thomas G.. AU - Coviello, Andrea. AU - Orwoll, Eric. AU - Wang, Patty Y.. AU - Nielson, Carrie. AU - Wu, Frederick. AU - Tajar, Abdelouahid. AU - Labrie, Fernand. AU - Vesper, Hubert. AU - Zhang, Anqi. AU - Ulloor, Jagadish. AU - Singh, Ravinder. AU - DAgostino, Ralph. AU - Vasan, Ramachandran S.. PY - 2011/8/1. Y1 - 2011/8/1. N2 - Context: Reference ranges are essential for partitioning testosterone levels into low or normal and making the diagnosis of androgen deficiency. We established reference ranges for total testosterone (TT) and free testosterone (FT) in a community-based sample of men. Methods: TT was measured using liquid chromatography ...
An improved method for determining levels of levosulpiride in human plasma using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed and validated. The protein precipitation method was used for plasma sample preparation. Levosulpiride and an internal standard (IS) were isocratically separated on a UPLC BEN C(18) column with a mobile phase of ammonium formate buffer (1 mM, adjusted to pH 3 with formic acid) and acetonitrile (60:40, v/v). MS/MS detection was performed by monitoring the parent -, daughter pair of levosulpiride and the IS at m/z 342 -, 112 and 329 -, 256, respectively. The method was linear from 2.5 to 200 ng/mL and exhibited acceptable precision and percent recovery. The method was successfully demonstrated in pharmacokinetic and bioequivalence studies of two levosulpiride oral formulations administered to healthy volunteers. When compared to the previous LC-MS methods, the proposed method is faster, well-validated, and uses lesser plasma ...
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 …
TY - JOUR. T1 - Effect of ionization modifiers on the simultaneous analysis of all classes of phospholipids by nanoflow liquid chromatography/tandem mass spectrometry in negative ion mode. AU - Bang, Dae Young. AU - Lim, Sangsoo. AU - Moon, Myeong Hee. N1 - Funding Information: This study was supported by the National Research Foundation (NRF) of Korea grant (No. 2011-0016438 ) funded by the Korean government (MEST) and in part by a grant (No. 2011-0001125 ). PY - 2012/6/1. Y1 - 2012/6/1. N2 - The effect of ionization modifiers added to the mobile phase of nanoflow liquid chromatography-tandem mass spectrometry (nLC-ESI-MS 3) on the simultaneous analysis of all phospholipid (PL) classes in negative ion mode has been investigated. While MS analysis of most PL classes is carried out in negative ion mode, analysis of neutral polar (polar but electrically neutral) lipids like phosphatidylcholine (PC) and sphingomyelin (SM) is highly efficient in positive ion mode. Therefore, analysis of PL mixture ...
SICHILONGO, Kwenga F.; MUCKOYA, Vallerie A. y NINDI, Mathew M.. A rapid and sensitive LC-MS/MS method for the determination of multi-class residues of antibiotics in chicken liver. S.Afr.j.chem. (Online) [online]. 2015, vol.68, pp.01-06. ISSN 1996-840X. http://dx.doi.org/10.17159/0379-4350/2015/v68a1.. A very sensitive, simple and cost-effective liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method for the determination of multi-class antibiotics in chicken liver was developed. The drugs under consideration were sulfaguanidine and sulfamethazole, trimethoprim, tetracycline, chlortetracycline and tylosin. Linear calibrations were established for all the analytes and the R2 values ranged between 0.9990 and 0.9997. The limits of quantitation (LOQs) varied between 0.025 and 78.8 μg kg-1. The limit of detections (LODs) were better than those that have been reported for the same antibiotics in many instances in other studies and ranged between 0.010-31.5 μg kg-1 with the ...
SICHILONGO, Kwenga F.; MUCKOYA, Vallerie A. e NINDI, Mathew M.. A rapid and sensitive LC-MS/MS method for the determination of multi-class residues of antibiotics in chicken liver. S.Afr.j.chem. (Online) [online]. 2015, vol.68, pp.01-06. ISSN 1996-840X. http://dx.doi.org/10.17159/0379-4350/2015/v68a1.. A very sensitive, simple and cost-effective liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method for the determination of multi-class antibiotics in chicken liver was developed. The drugs under consideration were sulfaguanidine and sulfamethazole, trimethoprim, tetracycline, chlortetracycline and tylosin. Linear calibrations were established for all the analytes and the R2 values ranged between 0.9990 and 0.9997. The limits of quantitation (LOQs) varied between 0.025 and 78.8 μg kg-1. The limit of detections (LODs) were better than those that have been reported for the same antibiotics in many instances in other studies and ranged between 0.010-31.5 μg kg-1 with the ...
Busulfan is an alkylating agent widely used in the ablation of bone marrow cells before hematopoietic stem cell transplant. Due to large intraindividual and interindividual variations, and narrow therapeutic window, therapeutic drug monitoring of busulfan is warranted. A quick and reliable HPLC-MS/MS method was developed for the assay of plasma busulfan. HPLC involved C18 column, and MS/MS was used in electrospray ionization (ESI) positive mode. Quantitation and identification of busulfan was made using various multiple reactions monitoring (MRMs). Isotopic labeled busulfan-d8 was used as the internal standard. The method is linear from 50 to 2500 ng/mL and has with-in run and between-run imprecision of |10|%.
Sigma-Aldrich offers abstracts and full-text articles by [Gabriela Peste, Nela Bibire, Mihai Apostu, Aurel Vlase, Corneliu Oniscu].
An original liquid chromatography-tandem mass spectrometry (LC-MS-MS) method coupled to online extraction has been developed for cyanide determination in blood. A method involving fluorimetric detection after naphthalene-2,3-dicarboxyaldehyde (NDA) complexation by taurine in the presence of cyanide was previously described. Its performance was limited because of the absence of an internal standard (IS). Using cyanide isotope 13C15N as IS allowed quantification in MS-MS. After the addition of 13C15N, 25 µL of blood were diluted in water and deproteinized with methanol. Following derivatization with NDA and taurine for 10 min at 4°C, 100 µL was injected into the online LC-MS-MS system. An Oasis HLB was used as an extraction column, and a C18 Atlantis was the analytical column. The chromatographic cycle was performed with an ammonium formate (20 mM, pH 2.8) (solvent A) and acetonitrile/solvent A (90:10, v/v) gradient in 6 min. Detection was performed in negative electrospray ionization mode ...
TY - JOUR. T1 - Performance metrics for liquid chromatography-tandem mass spectrometry systems in proteomics analyses. AU - Rudnick, Paul A.. AU - Clauser, Karl R.. AU - Kilpatrick, Lisa E.. AU - Tchekhovskoi, Dmitrii V.. AU - Neta, Pedatsur. AU - Blonder, Nikša. AU - Billheimer, Dean D.. AU - Blackman, Ronald K.. AU - Bunk, David M.. AU - Cardasis, Helene L.. AU - Ham, Amy Joan L.. AU - Jaffe, Jacob D.. AU - Kinsinger, Christopher R.. AU - Mesri, Mehdi. AU - Neubert, Thomas A.. AU - Schilling, Birgit. AU - Tabb, David L.. AU - Tegeler, Tony J.. AU - Vega-Montoto, Lorenzo. AU - Variyath, Asokan Mulayath. AU - Wang, Mu. AU - Wang, Pei. AU - Whiteaker, Jeffrey R.. AU - Zimmerman, Lisa J.. AU - Carr, Steven A.. AU - Fisher, Susan J.. AU - Gibson, Bradford W.. AU - Paulovich, Amanda G.. AU - Regnier, Fred E.. AU - Rodriguez, Henry. AU - Spiegelman, Cliff. AU - Tempst, Paul. AU - Liebler, Daniel C.. AU - Stein, Stephen E.. PY - 2010/2. Y1 - 2010/2. N2 - A major unmet need in LC-MS/MS-based ...
TY - JOUR. T1 - Bioanalysis of 6-diazo-5-oxo-l-norleucine in plasma and brain by ultra-performance liquid chromatography mass spectrometry. AU - Alt, Jesse. AU - Potter, Michelle C.. AU - Rojas, Camilo. AU - Slusher, Barbara. PY - 2015/4/1. Y1 - 2015/4/1. N2 - Glutamine is an abundant amino acid that plays pivotal roles in cell growth, cell metabolism, and neurotransmission. Dysregulation of glutamine-using pathways has been associated with pathological conditions such as cancer and neurodegenerative diseases. 6-Diazo-5-oxo-l-norleucine (DON) is a reactive glutamine analog that inhibits enzymes affecting glutamine metabolism such as glutaminase, 2-N-amidotransferase, l-asparaginase, and several enzymes involved in pyrimidine and purine de novo synthesis. As a result, DON is actively used in preclinical models of cancer and neurodegenerative disease. Moreover, there have been several clinical trials using DON to treat a variety of cancers. Considerations of dose and exposure are especially ...
GE AKTA fast protein liquid chromatography system is an eagle-i resource of type Fast protein liquid chromatography instrument at Universidad Central del Caribe.
Liquid Chromatography / Tandem Mass Spectrometry (LS/MS/MS). Liquid chromatography/tandem mass spectrometry provides identification of analytes of interest within a mixture based on retention time and characteristic parent/daughter ion fragmentation patterns, which provides the compounds unique molecular fingerprint. When liquid chromatography is suitable for separation of compounds, LC/MS/MS can provide significantly greater sensitivity than the corresponding gas chromatography/mass spectrometry (i.e., GC/MS). KorvaLabs employs LC/MS/MS for the identification of substances in white powders - such as in the case of certification of dietary supplements - and for certain compounds in urine where GC/MS is not sufficient.. Gas Chromatography / Mass Spectrometry (GC/MS). Like LC/MS, the related gas chromatography/mass spectrometry (i.e., GC/MS)provides identification based on retention time and ion fragmentation patterns; however, GC/MS… KorvaLabs uses GC/MS for the detection of most banned ...
Steuer, Andrea E; Poetzsch, Michael; Stock, Lorena; Eisenbeiss, Lisa; Schmid, Yasmin; Liechti, Matthias E; Kraemer, Thomas (2017). Development and validation of an ultra-fast and sensitive microflow liquid chromatography-tandem mass spectrometry (MFLC-MS/MS) method for quantification of LSD and its metabolites in plasma and application to a controlled LSD administration study in huma. Drug Testing and Analysis, 9(5):788-797. ...
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 ...
University of Leicester researchers writing in the journal Chemical Research in Toxicology say they have found convincing evidence that cannabis smoke damages DNA and it could potentially increase the risk of cancer development in humans.Using a newly developed highly sensitive liquid chromatography-tandem mass spectrometry method, the University
Disease-specific compounds (biomarkers) are analyzed in clinical laboratories to assist with diagnosing diseases. This thesis describes development and validation of liquid chromatography tandem mass spectrometry (LC-MS/MS) based tests for diagnosing a diverse group of endocrine and metabolic diseases. The analytical methods used on-line and off-line sample extraction and analytical derivatization as means of enhancing the analytical sensitivity, specificity and clinical utility. All developed methods were extensively validated and reference intervals for the biomarker concentrations were established in blood samples of healthy adults and children. Advantages of the LC-MS/MS as an analytical technique include possibility of simultaneous measurement of multiple analytes and ability of confirming their identity. In this thesis we proposed and evaluated approaches for the assessment of the specificity of analysis in the methods that use tandem mass spectrometry detection. To enhance throughput of ...
Abstract To support therapeutic drug monitoring of patients with cancer, a fast and accurate method for simultaneous quantification of the registered anticancer drugs afatinib, axitinib, ceritinib, crizotinib, dabrafenib, enzalutamide, regorafenib and trametinib in human plasma using liquid chromatography tandem mass spectrometry was developed and...
In this study, the anti-melanogenesis efficacy of clinically used herbal prescription LASAP-C, which consists of four herbal medicines-Rehmanniae Radix Crudus, Lycii Fructus, Scutellariae Radix, and Angelicae Dahuricae Radix, was investigated. The chemical profile of LASAP-C was established by conducting ultra-performance liquid chromatography-electrospray ionization-mass spectrometry. Anti-melanogenic efficacy was evaluated by tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 expression in B16F10 melanoma cells. In vivo evaluation was performed by using zebrafish model. Molecular evidences suggested that melanin synthesis was inhibited via the down-regulation of tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 expression in B16F10 melanoma cells treated with LASAP-C. The anti-melanogenesis efficacy was also confirmed in vivo by using the zebrafish model. The results of this study provide strong evidences that LASAP-C can be used as an active component in cosmeceutical products for
In this study, we developed the stable isotope dilution hydrophilic interaction liquid chromatography with tandem mass spectrometry (HILIC-MS/MS) technique for the accurate, reasonable and simultaneous quantification of glutamic acid (Glu), glutamine (Gln), pyroglutamic acid (pGlu), γ-aminobutyric acid (GABA) and theanine in mouse brain tissues. The quantification of these analytes was accomplished using stable isotope internal standards and the HILIC separating mode to fully correct the intramolecular cyclization during the electrospray ionization. It was shown that linear calibrations were available with high coefficients of correlation (r(2) | 0.999, range from 10 pmol/mL to 50 mol/mL). For application of the theanine intake, the determination of Glu, Gln, pGlu, GABA and theanine in the hippocampus and central cortex tissues was performed based on our developed method. In the region of the hippocampus, the concentration levels of Glu and pGlu were significantly reduced during reality-based theanine
A polyacrylamide (PAAm)-modified monolithic silica capillary column of increased phase ratio, 200T-PAAm, for hydrophilic interaction liquid chromatography (HILIC) was prepared. The column showed high separation efficiency, with a theoretical plate height H = 7â€20 μm at a linear velocity, u = 1â€7 mm/s. From a kinetic plot analysis, it was expected that the monolithic column could provide three times faster separation than particle-packed HILIC columns under a pressure limit at 20 MPa. HILIC coupled with electrospray ionization (ESI)â€mass spectrometry (HILIC-ESI-MS) using the 200T-PAAm column was employed for the analysis of underivatized carbohydrates to achieve fast and efficient separations of mixtures containing mono-, di-, and trisaccharides within 5 min. Under single MS full scan mode, 200 pg of oligosaccharides was detected by the system. The limit of detection (LOD) of the LC-ESI-MS/MS system was determined using selected reaction monitoring (SRM) to be as low as 3.2 ...
1,2-Dehydro-N-acetyldopamine (dehydro NADA) and its derivatives have been identified as important cuticular sclerotizing precursors responsible for the hardening of the exoskeleton of soft-bodied insects. In addition, these compounds may serve as precursors in the biosynthesis of the large number of bioactive compounds present in the exoskeleton of marine invertebrates. In this work the products of non-enzymatic oxidation of 1,2-dehydro N-acyldopamine were examined using reversed-phase high performance liquid chromatography/electrospray/tandem mass spectrometry (RP-HPLC/ESI/MS-MS). In addition, the role of tyrosinase-catalyzed oxidation of dehydro-N-acetyldopamine in the cross-linking of cuticle proteins was studied by examining two thiol-containing nucleophiles and a model peptide using RP- HPLC/ESI/MS-MS. Finally, the tyrosinase-catalyzed oxidative cyclization and polymerization of N-acetyl-1,2-dehydro Dopa was examined as a possible biosynthetic pathway for forming bioactive compounds called
ePIC (electronic Publication Information Center) is the official repository for publications and presentations of Alfred Wegener Institute for Polar and Marine Research (AWI)
We report the refinement of a high-throughput, liquid chromatography/mass spectrometry (LC/MS)-based screening method for the identification of ...
Learn about Agilent׷ liquid chromatography/mass spectrometry (LC/MS). Agilent LC/MS enables a wide array of applications by combining sample preparation, liquid chromatography (LC), mass spectrometry (MS), and dedicated software tools like compound databases and libraries.
Detailed HPLC/MS/MS studies on blood samples collected from normal healthy human subjects were performed to generate a reference of sphingolipid (SPL) levels for future investigations into diseases utilizing blood as a matrix. The impact of sample collection (serum, plasma, and anticoagulants), attributes of blood donors (gender, fasting state) and handling of blood were investigated. In addition, the SPL metabolomic profiles (18C sphingoid backbone, C14 to C26 N-acyl chain) of human plasma were determined. Blood was collected from healthy males and non-pregnant females under fasting and nonfasting conditions with and without various anticoagulants (EDT A, citrate and heparin). Plasma prepared with EDT A was determined to be ideal over the other blood formulations for SPL analyses, yielding the lowest variances in determination of most analyzed SPL classes. Sph1 P levels were higher in serum than plasma (0.67~M vs. 0.32jJM) with no effect on other SPLs in EDTA plasma. There were no variances on ...
Journal of Chemistry is a peer-reviewed, Open Access journal that publishes original research articles as well as review articles on all aspects of fundamental and applied chemistry.
Manufacturer of Liquid Chromatography Mass Spectrometry - LCMS QQQ 6460 Mass Spectrometer, CAH Mass Solution offered by Trivitron Healthcare Pvt. Ltd., Chennai, Tamil Nadu.
Many direct immunoassays in use today for testosterone analysis are little better than a guess at the low levels that are sometimes required.  This has led many clinical societies to adv
The nearly 50% production capacity increase is in response to growing global demand for purification media from the antibody drug manufacturing industry.. At a cost of approximately ¥5 billion, the Nanyo Complexs Toyopearl production facilities are being expanded. Construction began in October 2016 and is slated for completion in August 2018. Commercial operations at the expanded production facilities are expected to commence in April 2019.. Liquid chromatography separation and purification media are used in the production of biopharmaceutical ingredients. Employing differences in charge, hydrophobicity, specific affinity, and molecular size, these media are designed to separate and purify target components. Given the rapid growth of the market for biopharmaceutical products, in Japan, the United States, and countries in Europe and in China, India, and other emerging nations, these media are in high demand. And Tosoh is committed to meeting that demand.. With its high strength, superior ...
Lai, Yongquan, Development and application of liquid chromatography mass spectrometry methods for the analysis and toxicity study of polybrominated diphenyl ether metabolites (2013). Restricted Access Theses and Dissertations. 1437 ...
BACKGROUND: Prenylquinones are key compounds of the thylakoid membranes in chloroplasts. To understand the mechanisms involved in the response of plants to changing conditions such as high light intensity, the comprehensive analysis of these apolar lipids is an essential but challenging step. Conventional methods are based on liquid chromatography coupled to ultraviolet and fluorescence detection of a single or limited number of prenylquinones at a time. Here we present an original and rapid approach using ultra-high pressure liquid chromatography-atmospheric pressure chemical ionization-quadrupole time-of-flight mass spectrometry (UHPLC-APCI- QTOFMS) for the simultaneous profiling of eleven prenylquinones in plant tissues, including a-tocopherol, phylloquinone, plastochromanol-8 and plastoquinone-9. |br|RESULTS AND DISCUSSION: Mass spectrometry and chromatography parameters were optimized using pure standards. Sample preparation time was kept to minimum and different extraction solvents were
BACKGROUND: Prenylquinones are key compounds of the thylakoid membranes in chloroplasts. To understand the mechanisms involved in the response of plants to changing conditions such as high light intensity, the comprehensive analysis of these apolar lipids is an essential but challenging step. Conventional methods are based on liquid chromatography coupled to ultraviolet and fluorescence detection of a single or limited number of prenylquinones at a time. Here we present an original and rapid approach using ultra-high pressure liquid chromatography-atmospheric pressure chemical ionization-quadrupole time-of-flight mass spectrometry (UHPLC-APCI- QTOFMS) for the simultaneous profiling of eleven prenylquinones in plant tissues, including a-tocopherol, phylloquinone, plastochromanol-8 and plastoquinone-9. |br|RESULTS AND DISCUSSION: Mass spectrometry and chromatography parameters were optimized using pure standards. Sample preparation time was kept to minimum and different extraction solvents were
"Recent developments in liquid chromatography-mass spectrometry and related techniques". Journal of Chromatography A. 1259: 3-15 ... Niessen, Wilfried (2006). Liquid Chromatography Mass spectrometry. 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL ... The analyte in solution is introduced from a direct inlet probe or a liquid chromatography (LC) eluate into a pneumatic ... The sensitivity of APCI combined with the sensitivity and specificity of LC/MS and liquid chromatography-tandem mass ...
During a sabbatical with Prof JC Giddings in Utah in 1964, Knox was introduced to column liquid chromatography. Back home in ... In the 1970s Knox and his Edinburgh research group invented new micro-particulate packing materials for liquid chromatography, ... Berthod, Alain (1989). "On the Use of the Knox Equation". Journal of Liquid Chromatography. 12 (7): 1187-1201. doi:10.1080/ ... now used commonly to describe the spreading of a solute into bands in liquid chromatography. John Knox was elected a Fellow of ...
Gladney, HM; Dowden, BF; Swalen, JD (1969). "Computer-Assisted Gas-Liquid Chromatography". Anal. Chem. 41 (7): 883-888. doi: ... An alternative but equivalent form of the EMG distribution is used for description of peak shape in chromatography. This is as ... "Characterization of Exponentially Modified Gaussian Peaks in Chromatography". Analytical Chemistry. 44 (11): 1733-1738. doi: ...
Laser spray is one of several ion sources that can be coupled with liquid chromatography-mass spectrometry for the detection of ... Hiraoka, Kenzo; Saito, Shimpei; Katsuragawa, Jun; Kudaka, Ichiro (1998-09-15). "A new liquid chromatography/mass spectrometry ... Blakley, C; McAdams, M; Vestal, M (1978). "Crossed-beam liquid chromatoraph-mass spectrometer combination". Journal of ... Chromatography A. 158: 261-276. doi:10.1016/S0021-9673(00)89972-0. Murray, K. K.; D. H. Russell (1994). "Laser Spray Ionization ...
"Improving Sensitivity in Liquid Chromatography-Mass Spectrometry". Journal of Chromatography B. 825 (2): 134-143. doi:10.1016/j ... This is usually done by high-performance liquid chromatography (HPLC), but can also use the simpler technique of thin layer ... ultra-high pressure liquid chromatography) that operate at pump pressure a few-fold higher than HPLC instruments (see High- ... performance liquid chromatography#Pump pressure). Several factors effect the assay outcome and a recent review summarizes the ...
3.0.CO;2-8 Chemical Analysis of Single Neurons by Open Tubular Liquid Chromatography, R.T. Kennedy, R.L. St Claire III, J.G. ... "Two-Dimensional High-Performance Liquid Chromatography/Capillary Electrophoresis", J.W. Jorgenson and M.M. Bushey, U.S. Patent ... "Two-Dimensional High-Performance Liquid Chromatography/Capillary Electrophoresis", J.W. Jorgenson and M.M. Bushey, U.S. Patent ... "Sample injector system for liquid chromatography", Gerhardt; Geoff C., Jorgenson; James W., Fadgen; Keith, U.S. Patent No. ...
It was fortunate indeed that, just around that time, the technique of high pressure liquid chromatography (HPLC) had been ... Huber, J. F. K. (1969). "High Efficiency, High Speed Liquid Chromatography in Columns". Journal of Chromatographic Science. 7 ( ...
33 by preparative high-performance liquid chromatography". Journal of Chromatography A. 314: 379-385. doi:10.1016/S0021-9673(01 ... which can be purified through high performance liquid chromatography. D&C Red #33 (CI 17200) at Household Products Database ...
Bark by High-Performance Liquid Chromatography-Mass Spectrometry". Journal of Agricultural and Food Chemistry. 59 (17): 9386-93 ...
Q. Alan Xu (1 April 2013). Ultra-High Performance Liquid Chromatography and Its Applications. John Wiley & Sons. pp. 1-. ISBN ...
Hydrophilic Interaction Liquid Chromatography (HILIC) and Advanced Applications. CRC Press. p. 295-30. ISBN 978-1-4398-0753-8. ... Fast-in-process method for the determination ioversol and related polar compounds by hydrophilic interactive chromatography". ...
... gas chromatography (GC), and high-performance liquid chromatography (HPLC). These methods provide useful information regarding ... One of the primary techniques to achieve this is to separate the chemical species with high-performance liquid chromatography ( ... Bhavya, Sri; Fatima, Amina; Swethasri, R; Sumakanth, M (2019). "High Performance Liquid Chromatography-Inductively coupled ... Samples to be analyzed are introduced into this central channel, usually as a mist of liquid formed by passing the liquid ...
By choosing porous graphitic carbon as a stationary phase for liquid chromatography, even non derivatized glycans can be ... Fractionated glycans from high-performance liquid chromatography (HPLC) instruments can be further analyzed by MALDI-TOF-MS(MS ... N-glycans from glycoproteins are analyzed routinely by high-performance-liquid-chromatography (reversed phase, normal phase and ... Ruhaak LR, Deelder AM, Wuhrer M (May 2009). "Oligosaccharide analysis by graphitized carbon liquid chromatography-mass ...
ISBN 978-0-471-92863-8. Abian, J. (1999). "The coupling of gas and liquid chromatography with mass spectrometry". Journal of ... Samples can be introduced by flow injection, microdialysis, or by coupling with liquid chromatography. Flow rates are typically ... 174-. ISBN 978-0-8493-6293-4. De Pauw, E.; Agnello, A.; Derwa, F. (1991). "Liquid matrices for liquid secondary ion mass ... liquid chromatography-mass spectrometry, and more. In 1983 a paper was published describing the use of fast atom bombardment ...
High-performance liquid chromatography Gas-liquid chromatography Silica gel Nanotechnology. ...
Denaturing high performance liquid chromatography (DHPLC) uses reversed-phase HPLC to interrogate SNPs. The key to DHPLC is the ... Oefner PJ; Underhill PA (1995). "Comparative DNA sequencing by denaturing high-performance liquid chromatography (DHPLC)". Am J ...
Liquid-liquid extraction can be also performed or countercurrent chromatography. Solid phase extraction can also be made on C18 ... Instrumental chemistry analyses include separation by high performance liquid chromatography (HPLC), and especially by reversed ... liquid chromatography (RPLC), can be coupled to mass spectrometry. Purified compounds can be identified by the means of nuclear ... Phosphomolybdic acid is used as a reagent for staining phenolics in thin layer chromatography. Polyphenols can be studied by ...
... liquid chromatography-mass spectrometry, liquid chromatography-NMR spectroscopy. liquid chromagraphy-infrared spectroscopy and ... Holt, R. M.; Newman, M. J.; Pullen, F. S.; Richards, D. S.; Swanson, A. G. (1997). "High-performance Liquid Chromatography/NMR ... For example, gas chromatography-mass spectrometry, gas chromatography-infrared spectroscopy, ... Chromatography, electrophoresis and field flow fractionation are representative of this field. Combinations of the above ...
The basic principle combines adsorption, chromatography and liquid-liquid extraction. The principle of Solvent Impregnated ... While during conventional liquid-liquid extraction the solvent and the extractant have to be dispersed, in a SIR setup the ... The setup would consist of a packed column or a fluidized bed rather than liquid-liquid extraction equipment with additional ... The figure shows that no emulsification occurs in the SIR system, whereas the liquid-liquid system shows turbidity implying ...
Liquid Column Chromatography a Survey of Modern Techniques and Applications. Burlington: Elsevier. p. 603. ISBN 9780080858036. ... Callow, R.K.; Campbell, P.N.; Datta, S.P (2013). The Chromatography of Steroids: International Series of Monographs on Pure and ... The Zimmermann reagent is used as a simple spot-test used in chromatography to presumptively identify alkaloids, especially ...
"Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry". Journal of Chromatography A. 891 ( ...
Reardon GE, Caldarella AM, Canalis E (1979). "Determination of serum cortisol and 11-deoxycortisol by liquid chromatography" ( ...
Smith, Roger; Young, E.; Sharp, B. (2012). "Liquid chromatography-flame ionisation detection using a nebuliser/spray chamber ... To heat water at 25 °C to liquid water at 250 °C at 5 MPa requires only 976 kJ/kg. It is also possible to recover much of the ... Superheated water is liquid water under pressure at temperatures between the usual boiling point, 100 °C (212 °F) and the ... Above about 300 °C, water starts to behave as a near-critical liquid, and physical properties such as density start to change ...
"Characterization of aromatic heptaene macrolide antibiotics by high performance liquid chromatography". The Journal of ...
Liquid chromatography-mass spectrometry Gas chromatography-mass spectrometry Kanu, Abu B.; Dwivedi, Prabha; Tam, Maggie; Matz, ... The use of microscale FAIMS in electrospray ionization MS and liquid chromatography MS can significantly improve peak capacity ... Recently, microscale FAIMS has been integrated with electrospray ionization MS and liquid chromatography MS to rapidly separate ... Journal of Chromatography A. 1058 (1-2): 3-19. doi:10.1016/S0021-9673(04)01478-5. PMID 15595648. Kolakowski BM, Mester Z ( ...
He developed partition chromatography whilst working on the separation of amino acids, and later developed gas-liquid ... Martin, A J P; Synge, R L M (1941). "A new form of chromatogram employing two liquid phases A theory of chromatography. 2. ... Archer Martin's 1954 paper with A. T. James, "Gas-Liquid Chromatography: A Technique for the Analysis and Identification of ... JAMES, AT; MARTIN, AJ (1954). "Gas-liquid chromatography; a technique for the analysis and identification of volatile materials ...
MIRAGE Liquid chromatography guidelines for reporting of liquid chromatography (LC) glycan data. The MIRAGE reporting ... from mass spectrometry and liquid chromatography experiments). As the guidelines include the definitions of the minimum ... GlycoStore a curated Chromatography, Electrophoresis and Mass spectrometry derived composition database of N-, O-, ... Record in Fairsharing.org for MIRAGE Glycan array guidelines Record in Fairsharing.org for MIRAGE Liquid chromatography ...
Analytical measurements may be performed using gas or liquid chromatography-mass spectrometry. The biogenic origin of ... conventional biological fluids by gas chromatography/mass spectrometry after Salvia divinorum smoking". Rapid Communications in ...
It is a combination of high-performance liquid chromatography and capillary electrophoresis. The capillaries is packed with ... It is a combination of size exclusion chromatography (gel filtration chromatography) and gel electrophoresis. These separation ... Capillary electrochromatography (CEC) is an electrochromatography technique in which the liquid mobile phase is driven through ... Chromatography Protein electrophoresis Electrofocusing Two-dimensional gel electrophoresis Temperature gradient gel ...
Ross R, Cao X, Yu N, Limbach PA (2016). "Sequence mapping of transfer RNA chemical modifications by liquid chromatography ... the enzymes responsible for the modifications and liquid chromatography/mass spectrometry(LC/MS) data of the modified RNAs. As ... include site-specific cleavage and radioactive-labeling followed by ligation-assisted extraction and thin-layer chromatography ...
... simultaneous quantitation of four aminopyrine metabolites by high-performance liquid chromatography". Arch. Biochem. Biophys. ...
"Deposition of HfO2 and ZrO2 films by liquid injection MOCVD using new monomeric alkoxide precursors". Journal of Materials ... derivatives are amenable to analysis by gas chromatography. ...
... from retinol in serum and other tissues and quantified with the use of methods such as high-performance liquid chromatography.[ ...
In liquid chromatography, the eluent is the liquid solvent; in gas chromatography, it is the carrier gas.[1] ... In a liquid chromatography experiment, for example, an analyte is generally adsorbed, or "bound to", an adsorbent in a liquid ... For instance, a mixture of amino acids may be separated by ion-exchange chromatography. Under a particular set of conditions, ... Brown, Phillis (2001). Advances in chromatography. CRC Press. p. 36. ISBN 0-8247-0509-2. .. ...
... pyrene in Human Bronchoalveolar H358 Cells Using Liquid Chromatography-Mass Spectrometry". Chem. Res. Toxicol. 20 (9): 1331- ...
At high temperatures used to prepare glass, the material is a viscous liquid. The structure of glass forms into an amorphous ... chromatography, thermal analysis, electron microscope analysis, etc. Structure is studied at various levels, as detailed below ...
"Profiling the indole alkaloids in yohimbe bark with ultra-performance liquid chromatography coupled with ion mobility ... "A validated high performance thin layer chromatography method for determination of yohimbine hydrochloride in pharmaceutical ...
"Identification of phenolic compounds from Scutellaria lateriflora by liquid chromatography with ultraviolet photodiode array ...
High performance liquid chromatography (HPLC) is used to measure the amount of capsaicin and major capsaicinoids within pepper ... Direct close-range spray can cause more serious eye irritation by attacking the cornea with a concentrated stream of liquid ( ... any weapon of whatever description designed or adapted for the discharge of any noxious liquid, gas or other thing." ... any liquid, spray, powder or other substance that is capable of injuring, immobilizing or otherwise incapacitating any person" ...
... it occurs in a more ordered phase like liquid or solid as is the case with water (H2O); a liquid at room temperature because ... They can be analyzed using the tools of chemical analysis, e.g. spectroscopy and chromatography. Scientists engaged in chemical ... Matter can be studied in solid, liquid, gas and plasma states, in isolation or in combination. The interactions, reactions and ... The most familiar examples of phases are solids, liquids, and gases. Many substances exhibit multiple solid phases. For example ...
... by reverse-phase high-performance liquid chromatography estimation.. *^ Ashton CH (February 2001). "Pharmacology and effects of ... enantio-selective separation of phytocannabinoids by enantioselective ultra high performance supercritical fluid chromatography ...
"Measurement of intracellular vitamin C levels in human lymphocytes by reverse phase high performance liquid chromatography ( ...
MDPV may be quantified in blood, plasma or urine by gas chromatography-mass spectrometry or liquid chromatography-mass ... by gas chromatography/mass spectrometry and liquid chromatography/quadrupole time-of-flight mass spectrometry". Rapid ...
Gas chromatography. High-performance liquid chromatography. Capillary electrochromatography. Ion chromatography. Micellar ... Paper chromatography. Reversed-phase chromatography. Size-exclusion chromatography. Thin-layer chromatography. Two-dimensional ... Chromatography. Affinity chromatography. Column chromatography. Displacement chromatography. Electrochromatography. ... chromatography. Van Deemter equation. Chapter 3. Fundamental Spectroscopy. Raman spectroscopy. Rayleigh scattering. ...
Liquid culture: Cells are grown inside a liquid media. Microbial growth is determined by the time taken for the liquid to form ... Acids, alcohols and gases are usually detected in these tests when bacteria are grown in selective liquid or solid media, as ... Møller M; El Maghrabi R; Olesen N; Thomsen VØ (November 2004). "Safe inoculation of blood and bone marrow for liquid culture ...
PETN forms eutectic mixtures with some liquid or molten aromatic nitro compounds, e.g. trinitrotoluene (TNT) or tetryl. Due to ... in plasma using gas chromatography-mass spectrometry.[49] ... of PETN sewn into his underwear by adding liquid from a syringe ...
"Liquid chromatography-mass spectrometry: potential in forensic and clinical toxicology". Journal of Chromatography B. 733 (1-2 ... chromatography, etc.), the size boundaries that distinguish peptides from polypeptides and proteins are not absolute: long ...
"Optimization of Separation of Ytterbium and Lutetium by Displacement Complexing Chromatography". Russian Journal of Applied ... ytterbium has the smallest liquid range of all the metals.[6] ...
"Analysis of derivatized and underivatized theanine enantiomers by high-performance liquid chromatography/atmospheric pressure ... Finger, Andreas; Kuhr, Susanne; Engelhardt, Ulrich (1992). "Chromatography of tea constituents". Journal of Chromatography. 624 ...
Hey J, Posch A, Cohen A, Liu N, Harbers A (2008). Fractionation of complex protein mixtures by liquid-phase isoelectric ... Various types of chromatography are then used to isolate the protein or proteins of interest based on properties such as ... As a result, when the lysate is passed over a chromatography column containing nickel, the histidine residues ligate the nickel ... and chromatography; the advent of genetic engineering has made possible a number of methods to facilitate purification. Methods ...
Emil Fischer Hermann Staudinger heterocyclic compound Hexane Hiddenite Hideki Shirakawa High performance liquid chromatography ... Anfinsen Chromatography Chromite Chromium Chrysoberyl Chrysolite cinnabar Cinnabarite Citric acid Citrine quartz Clay Cleveite ... principle Lead Leopold Ružička Lepidolite Leucite Lewis acid Lewis base Ligand Lignite Limestone Limonite Linus Pauling liquid ...
Quantitative amino acid analysis is typically performed using the ninhydrin reaction, followed by liquid chromatography to ...
3) were found to be less hazardous and may be used as a liquid substitute for toxic germane gas in semiconductor applications. ... Sol-Gel Hybrid Organic-Inorganic Coatings for Capillary Microextraction and Gas Chromatography". Anal. Chem. 79 (24): 9441-9451 ... For example, germanium chloride and germane (GeH4) are a liquid and gas, respectively, that can be very irritating to the eyes ... Under normal conditions GeI4 is a solid, GeF4 a gas and the others volatile liquids. For example, germanium tetrachloride, GeCl ...
... coumarin and cinnamyl alcohol in cinnamon and cassia by high-performance liquid chromatography", Journal of Chromatography 447 ...
Extracts include liquid extracts, dry extracts, and nebulisates. Liquid extracts are liquids with a lower ethanol percentage ... For this reason, thin layer chromatography is sometimes used by growers to assess the content of their products before use. ... There are many forms in which herbs can be administered, the most common of which is in the form of a liquid that is drunk by ... Herbal teas, or tisanes, are the resultant liquid of extracting herbs into water, though they are made in a few different ways ...
... of Proanthocyanidin A2 Content in Phenolic Polymer Isolates by Reversed-Phase High Performance Liquid Chromatography". Journal ... of Chromatography A. 1216 (9): 1403-1409. doi:10.1016/j.chroma.2008.12.086. PMID 19168185.. CS1 maint: extra punctuation (link ...
"Analysis of benzodiazepine derivative mixture by gas-liquid chromatography". Medicina (Kaunas) 38 (3): 316-20. PMID 12474705. ...
Luttinger liquid. MEdit. *Madison Symmetric Torus. *MagBeam, also called Magnetized beamed plasma propulsion, plasma wind ... Chromatography detector. *Chromo-Weibel instability. *Classical-map hypernetted-chain method. *Cnoidal wave ...
... both based on liquid chromatography - mass spectrometry (LC/MS) detection after hydrophilic interaction liquid chromatography ( ... The existing methods for melamine determination using a triple quadrupole liquid chromatography - mass spectrometry (LC/MS) ... the FDA began using a high performance liquid chromatography test to determine the melamine, ammeline, ammelide, and cyanuric ... and high performance liquid chromatography. The result of the analysis showed that the calculus was composed of melamine and ...
"Dye Analysis of Pre-Columbian Peruvian Textiles with High-Performance Liquid Chromatography and Diode-Array Detection". Journal ... which either is itself a liquid or is soluble in its vehicle (resulting in a solution). A colorant can act as either a pigment ...
New Liquid Chromatography-Mass Spectrometry Workstream Offers Comprehensive Solution for Toxicology - read this article along ... New Liquid Chromatography-Mass Spectrometry Workstream Offers Comprehensive Solution for Toxicology. Published: Sep 24, 2020 ... can now easily and rapidly optimize their liquid chromatography-mass spectrometry (LC-MS) methods for targeted screening and ... www.prnewswire.com/news-releases/new-liquid-chromatography-mass-spectrometry-workstream-offers-comprehensive-solution-for- ...
... isotope labelled metabolites to allow for the rigorous quantification of intracellular metabolites by liquid chromatography- ... Worth, Andrew J., "Liquid Chromatography-Mass Spectrometry Analysis of Dysfunctional Mitochondrial Metabolism: Insights into ... Liquid Chromatography-Mass Spectrometry Analysis of Dysfunctional Mitochondrial Metabolism: Insights into Rotenone Toxicity and ... isotope labelled metabolites to allow for the rigorous quantification of intracellular metabolites by liquid chromatography- ...
Nuclear magnetic resonance spectroscopy (NMR) together with chiral liquid chromatography-mass spectrometry (LC-MS) analysis ... LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY FOR THE STUDY OF ARACHIDONIC ACID METABOLITES Xiaojing Liu Ian A. Blair, PhD ... Liu, Xiaojing, "Liquid Chromatography - Mass Spectrometry for the Study of Arachidonic Acid Metabolites" (2012). Publicly ... Nuclear magnetic resonance spectroscopy (NMR) together with chiral liquid chromatography-mass spectrometry (LC-MS) analysis ...
Keywords: two-dimensional chromatography, liquid chromatography, chemical identification and classification, pattern matching, ... Multidimensional Liquid Chromatography: Theory and Applications in Industrial Chemistry and the Life Sciences. New York NY: ... Smart Templates for Peak Pattern Matching with Comprehensive Two-Dimensional Liquid Chromatography. Stephen E. Reichenbach,a,* ... Comprehensive two-dimensional liquid chromatography (LCxLC) provides an order-of-magnitude increase in peak separation capacity ...
announced analyses of carbamates and phenyl ureas using liquid chromatography/mass spectrometry (LC/MS). The sources for these ... announced analyses of carbamates and phenyl ureas using liquid chromatography/mass spectrometry (LC/MS). The sources for these ... Agilent Technologies analyzes carbamates and phenyl ureas using liquid chromatography/mass spectrometry. - Anzeige - ...
... 2 October 2020. Science ... can now easily and rapidly optimize their liquid chromatography-mass spectrometry (LC-MS) methods for targeted screening and ... chromatography and mass spectrometry, Thermo Fisher Scientific. "The Thermo Scientific Tox Explorer Collection provides a ...
Determination of 16 beta-hydroxystanozolol in urine and faeces by liquid chromatography-multiple mass spectrometry.. Mieke Van ... "Determination of 16 Beta-hydroxystanozolol in Urine and Faeces by Liquid Chromatography-multiple Mass Spectrometry." Journal of ... "Determination of 16 Beta-hydroxystanozolol in Urine and Faeces by Liquid Chromatography-multiple Mass Spectrometry." JOURNAL OF ... Determination of 16 beta-hydroxystanozolol in urine and faeces by liquid chromatography-multiple mass spectrometry. JOURNAL OF ...
Non-targeted analysis of tea by hydrophilic interaction liquid chromatography and high resolution mass spectrometry. ... In this study, a hydrophilic interaction liquid chromatography (HILIC) method coupled to high resolution mass spectrometry in ... This study highlights the potential of HILIC chromatography combined with non-targeted mass spectrometric methods to provide a ...
Tracing terrigenous dissolved organic matter and its photochemical decay in the ocean by using liquid chromatography/mass ... Tracing terrigenous dissolved organic matter and its photochemical decay in the ocean by using liquid chromatography/mass ...
MEASUREMENT OF PLASMA CHOLECYSTOKININS (CCKS) USING HIGH-PRESSURE LIQUID-CHROMATOGRAPHY (HPLC) AND RADIOIMMUNOASSAY (RIA) - ... MEASUREMENT OF PLASMA CHOLECYSTOKININS (CCKS) USING HIGH-PRESSURE LIQUID-CHROMATOGRAPHY (HPLC) AND RADIOIMMUNOASSAY (RIA) - ... MEASUREMENT OF PLASMA CHOLECYSTOKININS (CCKS) USING HIGH-PRESSURE LIQUID-CHROMATOGRAPHY (HPLC) AND RADIOIMMUNOASSAY (RIA) - ...
Micellar liquid chromatography (MLC) is a form of reversed phase liquid chromatography that uses an aqueous micellar solutions ... "Causes and remediation of reduced efficiency in micellar liquid chromatography". Journal of Chromatography A. 780 (1-2): 191- ... "Evaluation of distribution coefficients in micellar liquid chromatography". Journal of Chromatography A. 780 (1-2): 103-116. ... "Characterisation of retention in micellar high-performance liquid chromatography and in micellar electrokinetic chromatography ...
Chromatography: …at the microgram-to-milligram level and preparative-scale liquid chromatography at the tens-of-grams level ... In biotechnology, preparative-scale liquid chromatography is especially important for purification of proteins and peptide ... Other articles where Preparative-scale liquid chromatography is discussed: separation and purification: ... Preparative-scale liquid chromatography. chemistry. Learn about this topic in these articles:. chemical separation and ...
... liquid chromatography with samples at the microgram-to-milligram level and preparative-scale liquid chromatography at the tens- ... In biotechnology, preparative-scale liquid chromatography is especially important for purification of proteins and peptide ... Both analytical-scale liquid chromatography with samples at the microgram-to-milligram level and preparative-scale liquid ... Analytical-scale liquid chromatography. chemistry. THIS IS A DIRECTORY PAGE. Britannica does not currently have an article on ...
High-performance liquid chromatography (HPLC) has become a standard technique in the laboratory. The intent of this chapter is ... High-performance liquid chromatography (HPLC) has become a standard technique in the laboratory. The intent of this chapter is ... Stein S. (1982) High-Performance Liquid Chromatography. In: Lajtha A. (eds) Experimental Neurochemistry. Springer, Boston, MA. ... Jones, B. N., Pääbo, S., and Stein, S., 1981, J. Liquid Chromatogr. 4:565-586.CrossRefGoogle Scholar ...
... Liquid chromatography (LC) testing and analysis.. Intertek provides Liquid Chromatography (LC) ... Liquid chromatography allows for selective and highly sensitive detection of trace and molecular-species specific compounds. ... Liquid chromatography analytical techniques: *High Performance Liquid Chromatography [LC, HPLC] *Liquid Chromatography Mass ...
But the labor intensity of the procedure is now a thing of the past for researchers in the Oregon Health & Science University School of Medicine. The Proteomics Shared Resource, an unassuming but state-of-the-art lab on the fifth floor of OHSUs Medical Research Building, can process more than three times as many protein samples in half a day, and much of it can be done by one person.. ...
Introduction to Liquid Chromatography webinar. 2. An interactive Q&A session for Dr Polites Resolution in Liquid ... Liquid-liquid and liquid-solid extractions (LLE and LSE) * Static headspace extraction (SHE) * Solid phase extraction (SPE) * ... Introduction to Liquid Chromatography webinar.. 2. An interactive Q&A session for Dr Polites Resolution in Liquid ... Introduction to Liquid Chromatography webinar.. 2. An interactive Q&A session for Dr Polites Resolution in Liquid ...
Whats the difference between High Performance Liquid Chromatography and Ion Chromatography? What are the capabilities and ... New high-performance liquid chromatography system maximizes the delivery of precise results Pharmaceutical, food and industrial ... High Quality Purification of Proteins Through Liquid Chromatography In this interview, AZoNetwork speaks to Knauer about the ... Asynt has introduced GasTrap gas purifiers for analytical laboratories using Gas Chromatography (GC), High Performance Liquid ...
Gas-liquid chromatography in diagnosis of pyogenic arthritis. Br Med J 1978; 2 :1402 ... Gas-liquid chromatography in diagnosis of pyogenic arthritis.. Br Med J 1978; 2 doi: https://doi.org/10.1136/bmj.2.6149.1402 ( ...
Purchase Gradient Elution in Column Liquid Chromatography, Volume 31 - 1st Edition. Print Book & E-Book. ISBN 9780444421241, ... Gradient Elution in Column Liquid Chromatography, Volume 31 1st Edition. Theory and Practice. 0.0 star rating Write a review ... qu:This book is devoted to an important field in liquid chromatography - gradient elution... (it) fills a very important niche ... and anyone wishing to improve his or her skills in liquid chromatography. @source: Journal of the American Chemical Society ...
... is a useful tool for those learning about the technology of liquid chromatography (LC), with a focus on high-performance liquid ... The Beginners Guide to Liquid Chromatography, a 56-page paperback book, ... chromatography (HPLC). The Beginners Guide offers an uncomplicated look at LC/HPLC and includes clear and colorful diagrams to ...
U.S. Geological Survey (USGS) scientist using a high-performance liquid chromatography (HPLC) system to fractionate water ...
Buy Liquid Chromatography Analysis products including 176002534 - Beverage Analysis Kit, 186006006 - Beverage Analysis Mobile ... The 2017/18 Waters Quality Parts, Chromatography Columns and Supplies Catalog is available! Download or order your copy today. ... The 2017/18 Waters Quality Parts, Chromatography Columns and Supplies Catalog is available! Download or order your copy today. ... Ultra Performance Liquid Chromatography High Liquid Chromatography Performance Liquid Chromatography Liquid Chromatography ...
... and these solvent systems can be used in liquid-liquid separations and countercurrent chromatography. The wide... ... Ionic liquids can form biphasic solvent systems with many organic solvents and water, ... The comparison of ionic liquid-liquid chromatography, high-performance liquid-liquid chromatography, high-performance liquid ... as ionic liquid-liquid chromatography (ILLC).. 3.2 The Use of Ionic Liquids in Chromatography. The use ionic liquids in ...
The liquid chromatography device comprises a separation substrate defining an introduction channel between an entrance orifice ... The exit orifice of the liquid chromatography device may be homogeneously interfaced with the entrance orifice of the ... a liquid chromatography device and an electrosprayliquid chromatography system are disclosed. The electrospray device comprises ... 47 shows a liquid chromatography-electrospray system 600 comprising a liquid chromatography device 602 of the present invention ...
Get the latest liquid chromatography product news on Environmental XPRT, the worlds largest environmental industry marketplace ... liquid chromatography product News. Related terms for "liquid chromatography product ": chromatography news , chromatography ... PerkinElmer broadens liquid chromatography portfolio with new high performance platform and chromatography data system ... PerkinElmer expands chromatography offering with new liquid chromatography autosampler PerkinElmer Life and Analytical Sciences ...
Get the latest quaternary liquid chromatography news on Environmental XPRT, the worlds largest environmental industry ... "quaternary liquid chromatography ": chromatography news , liquid chromatography news , quaternary liquid chromatography system ... infinity quaternary liquid chromatography system news , infinity quaternary liquid chromatography news ... Agilent Technologies Introduces New Version of Intelligent System Emulation Technology for Liquid Chromatography Systems ...
... - published on openPR.com ... One of the advanced forms of liquid chromatography is the high-performance liquid chromatography (HPLC) for ultra-trace ... Global Liquid Nitrogen Market 2017 Global Liquid Nitrogen Report 2017 Major Manufacture Analysis Of Liquid Nitrogen Market 2017 ... You can edit or delete your press release Liquid Chromatography Market Opportunity Analysis, 2018-2026 here. Delete press ...
This track contains a series of modules that cover general liquid chromatography (LC) topics and concepts. It covers the ... This track contains a series of modules that cover general liquid chromatography (LC) topics and concepts. It covers the ... The 2017/18 Waters Quality Parts, Chromatography Columns and Supplies Catalog is available! Download or order your copy today. ... The 2017/18 Waters Quality Parts, Chromatography Columns and Supplies Catalog is available! Download or order your copy today. ...
Preparative Liquid Chromatography (H. Colin).. Process High Performance Liquid Chromatography (W. Skea).. Precision in HPLC (E ... Carbon in Liquid Chromatography (J. Knox & B. Kaur).. Organic Polymeric Stationary Phases (D. Pietrzyk).. Size-Exclusion Liquid ... The Theory of the Dynamics of Liquid Chromatography (S. Weber & P. Carr).. Mechanism of Solute Retention in Chromatography (R. ... High-Speed Liquid Chromatography (R. Simpson).. A Theoretical Approach to Derivatizations for HPLC (I. Krull, et al.).. ...
Standard linear filters are not effective for reducing noise in liquid chromatography-mass spectrometry (LC-MS) data because ... spiked noise is reduced in chromatography-mass spectrometry data by applying a nonlinear filter such as a moving median filter ... In liquid chromatography-mass spectrometry (LC-MS) or gas chromatography-mass spectrometry (GC-MS) data, the noise intensity is ... a series of mass spectra are generated by chromatography (e.g., liquid chromatography) and mass spectrometry. A total ion ...
... biological profiles have been obtained by means of thin-layer chromatography (TLC). This paper summarizes the application of ... liquid chromatographic techniques for the purpose of biological fingerprint analysis (BFA) of complex herbal samples. In case ... high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC), gas chromatography (GC), or high-speed counter ... "Antioxidant activity assays on-line with liquid chromatography," Journal of Chromatography A, vol. 1210, no. 2, pp. 121-134, ...
... high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC), gas chromatography (GC), or high-speed counter ... "Antioxidant activity assays on-line with liquid chromatography," Journal of Chromatography A, vol. 1210, no. 2, pp. 121-134, ... "Comprehensive two-dimensional high-performance liquid chromatography system with immobilized liposome chromatography column and ... Biological detection in liquid chromatography gives an opportunity to comprehensively analyze herbal samples. Apart from ...
"Liquid chromatography MS platforms and cGMP" in a lecture held on October 30, 2019. ... Workshop discusses advances in liquid chromatography Workshop discusses advances in liquid chromatography ...
In a pump for liquid chromatography including a cylinder and a plunger that reciprocates in the cylinder to suck and discharge ... a small-flow-rate pump that feeds the liquid by the plunger, motion conversion means that converts the rotational motion of a ... The invention provides a pump for liquid chromatography excellent in feeding liquid stably at an extremely low flow rate and in ... fluid, the pump further includes a large-flow-rate pump that feeds liquid by the plunger, ...
... the United States High-performance Liquid Chromatography(HPLC) market is valued at USD XX million in 2016 and is expected to ... 7 High-performance Liquid Chromatography(HPLC) Manufacturing Cost Analysis. 7.1 High-performance Liquid Chromatography(HPLC) ... United States High-performance Liquid Chromatography(HPLC) Market Report 2017. 1 High-performance Liquid Chromatography(HPLC) ... of High-performance Liquid Chromatography(HPLC) (2012-2022). 1.5.1 United States High-performance Liquid Chromatography(HPLC) ...
Uremia and HbA1c Measured by High-Performance Liquid Chromatography. Didier Chevenne, Michèle Fonfrède, Rolande Ducrocq, ... Uremia and HbA1c Measured by High-Performance Liquid Chromatography. Didier Chevenne, Michèle Fonfrède, Rolande Ducrocq, ... Uremia and HbA1c Measured by High-Performance Liquid Chromatography Message Subject (Your Name) has forwarded a page to you ...
Preparative liquid chromatography is also discussed, as is the role of liquid chromatography to evaluate food authenticity, ... Liquid Chromatography: Principles, Technology and Applications. $45.00. - $205.00. Fernando Ramos, PhD (Editor). Faculty of ... Chapter V - Liquid Chromatography for the Determination of Tocopherols and Tocotrienols (Vitamin E) in Food of Plant Origin. ( ... The versatility of liquid chromatography (LC) allows its applicability to countless areas. From the quality control of various ...
A form of chromatography in which the mobile phase is a gas and the stationary phase is a liquid, usually on small beads packed ... gas-liquid-chromatography. Noun (uncountable). *(chemistry) A form of chromatography in which the mobile phase is a gas and the ... gas-liquid-chromatography. (n.d.). Retrieved January 15th, 2019, from https://www.yourdictionary.com/gas-liquid-chromatography ... "gas-liquid-chromatography." YourDictionary, n.d. Web. 15 January 2019. ,https://www.yourdictionary.com/gas-liquid- ...