Gas chromatography mass spectrometry. Medical search

A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.

An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.

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.

Chromatographic techniques in which the mobile phase is a liquid.

Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.

Organic compounds that have a relatively high VAPOR PRESSURE at room temperature.

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.

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 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.

The dynamic collection of metabolites which represent a cell's or organism's net metabolic response to current conditions.

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.

Oils which evaporate readily. The volatile oils occur in aromatic plants, to which they give odor and other characteristics. Most volatile oils consist of a mixture of two or more TERPENES or of a mixture of an eleoptene (the more volatile constituent of a volatile oil) with a stearopten (the more solid constituent). The synonym essential oils refers to the essence of a plant, as its perfume or scent, and not to its indispensability.

A phase transition from liquid state to gas state, which is affected by Raoult's law. It can be accomplished by fractional distillation.

A plant species of the genus OCIMUM, family LAMIACEAE. It is a condiment with carminative properties.

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)

Unsaturated androstane derivatives which are substituted with two hydroxy groups in any position in the ring system.

Compounds used extensively as acetylation, oxidation and dehydrating agents and in the modification of proteins and enzymes.

Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.

The thick green-to-black mucilaginous material found in the intestines of a full-term fetus. It consists of secretions of the INTESTINAL GLANDS; BILE PIGMENTS; FATTY ACIDS; AMNIOTIC FLUID; and intrauterine debris. It constitutes the first stools passed by a newborn.

Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.

Illegitimate use of substances for a desired effect in competitive sports. It includes humans and animals.

Isoprostanes derived from the free radical oxidation of ARACHIDONIC ACID. Although similar in structure to enzymatically synthesized prostaglandin F2alpha (DINOPROST), they occur through non-enzymatic oxidation of cell membrane lipids.

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).

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 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.

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 compounds containing the carboxy group (-COOH). This group of compounds includes amino acids and fatty acids. Carboxylic acids can be saturated, unsaturated, or aromatic.

Eicosatetraenoic acids substituted in any position by one or more hydroxy groups. They are important intermediates in a series of biosynthetic processes leading from arachidonic acid to a number of biologically active compounds such as prostaglandins, thromboxanes, and leukotrienes.

The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)

Examination of urine by chemical, physical, or microscopic means. Routine urinalysis usually includes performing chemical screening tests, determining specific gravity, observing any unusual color or odor, screening for bacteriuria, and examining the sediment microscopically.

The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.

A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).

A 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)

A group of polycyclic compounds closely related biochemically to TERPENES. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (STEROLS), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. (From Hawley's Condensed Chemical Dictionary, 11th ed)

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 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.

The characteristic 3-dimensional shape of a carbohydrate.

Chemical compounds which pollute the water of rivers, streams, lakes, the sea, reservoirs, or other bodies of water.

The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.

An enzyme of the oxidoreductase class primarily found in PLANTS. It catalyzes reactions between linoleate and other fatty acids and oxygen to form hydroperoxy-fatty acid derivatives.

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.

A major group of unsaturated cyclic hydrocarbons containing two or more rings. The vast number of compounds of this important group, derived chiefly from petroleum and coal tar, are rather highly reactive and chemically versatile. The name is due to the strong and not unpleasant odor characteristic of most substances of this nature. (From Hawley's Condensed Chemical Dictionary, 12th ed, p96)

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)

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 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.

An unsaturated, essential fatty acid. It is found in animal and human fat as well as in the liver, brain, and glandular organs, and is a constituent of animal phosphatides. It is formed by the synthesis from dietary linoleic acid and is a precursor in the biosynthesis of prostaglandins, thromboxanes, and leukotrienes.

The process of cleaving a chemical compound by the addition of a molecule of water.

The systematic study of the complete complement of proteins (PROTEOME) of organisms.

A naturally occurring prostaglandin that has oxytocic, luteolytic, and abortifacient activities. Due to its vasocontractile properties, the compound has a variety of other biological actions.

A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.

FATTY ACIDS in which the carbon chain contains one or more double or triple carbon-carbon bonds.

Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.

A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.

Six-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives. Various polyneuropathies are caused by hexane poisoning.

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)

Elements of limited time intervals, contributing to particular results or situations.

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.

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.

The rate dynamics in chemical or physical systems.

A plant family of the order Eucommiales, subclass Hamamelidae, class Magnoliopsida (some botanists have classified this in the order Hamamelidales or Urticales). Eucomia is an elmlike tree of central and eastern China. Leaves are alternate; deciduous flowers are solitary and unisexual and lack petals and sepals. The male flowers have 6 to 10 stamens and female flowers have one ovary of two carpels, one of which aborts during development so the fruit (a dry, winged structure) contains only one seed. The latex is a source of RUBBER. Tochu tea is an aqueous extract of Eucommia ulmoides leaves and a popular beverage in Japan. (Mutat Res 1997 Jan 15;388(1):7-20).

Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.

The 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.

Physiological processes in biosynthesis (anabolism) and degradation (catabolism) of LIPIDS.

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.

Five-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives.

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.

A 20-carbon-chain fatty acid, unsaturated at positions 8, 11, and 14. It differs from arachidonic acid, 5,8,11,14-eicosatetraenoic acid, only at position 5.

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 protein complement of an organism coded for by its genome.

Concentration or quantity that is derived from the smallest measure that can be detected with reasonable certainty for a given analytical procedure.

Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.

A plant genus of the family CRASSULACEAE. Members contain rhodioloside. This roseroot is unrelated to the familiar rose (ROSA). Some species in this genus are called stonecrop which is also a common name for SEDUM.

Any tests done on exhaled air.

The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.

Substances or organisms which pollute the water or bodies of water. Use for water pollutants in general or those for which there is no specific heading.

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.

Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.

Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.

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 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.

A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.

The relationship between the dose of an administered drug and the response of the organism to the drug.

The monitoring of the level of toxins, chemical pollutants, microbial contaminants, or other harmful substances in the environment (soil, air, and water), workplace, or in the bodies of people and animals present in that environment.

The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.

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.

Polyhydric alcohols having no more than one hydroxy group attached to each carbon atom. They are formed by the reduction of the carbonyl group of a sugar to a hydroxyl group.(From Dorland, 28th ed)

A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).

Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.

Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.

Inorganic or organic compounds that contain sulfur as an integral part of the molecule.

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.

Chemicals that kill or inhibit the growth of fungi in agricultural applications, on wood, plastics, or other materials, in swimming pools, etc.

Compounds consisting of benzene rings linked to each other in either ortho, meta or para positions. Permitted are any substitutions, but ring fusion to any of the benzene rings is not allowed.

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.

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.

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.

Methods for assessing flow through a system by injection of a known quantity of an indicator, such as a dye, radionuclide, or chilled liquid, into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)

A mass-spectrometric technique that is used for microscopic chemical analysis. A beam of primary ions with an energy of 5-20 kiloelectronvolts (keV) bombards a small spot on the surface of the sample under ultra-high vacuum conditions. Positive and negative secondary ions sputtered from the surface are analyzed in a mass spectrometer in regards to their mass-to-charge ratio. Digital imaging can be generated from the secondary ion beams and their intensity can be measured. Ionic images can be correlated with images from light or other microscopy providing useful tools in the study of molecular and drug actions.

Atomic species differing in mass number but having the same atomic number. (Grant & Hackh's Chemical Dictionary, 5th ed)

The sum of the weight of all the atoms in a molecule.

Pesticides or their breakdown products remaining in the environment following their normal use or accidental contamination.

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 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.

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)

Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.

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.

Glycosides of GLUCURONIC ACID formed by the reaction of URIDINE DIPHOSPHATE GLUCURONIC ACID with certain endogenous and exogenous substances. Their formation is important for the detoxification of drugs, steroid excretion and BILIRUBIN metabolism to a more water-soluble compound that can be eliminated in the URINE and BILE.

An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.

Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.

Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)

Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.

Oligosaccharides containing two monosaccharide units linked by a glycosidic bond.

Drugs intended for human or veterinary use, presented in their finished dosage form. Included here are materials used in the preparation and/or formulation of the finished dosage form.

A 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.

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)

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)

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.

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.

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)

A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.

Substances or energies, for example heat or light, which when introduced into the air, water, or land threaten life or health of individuals or ECOSYSTEMS.

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.

A group of compounds derived from ammonia by substituting organic radicals for the hydrogens. (From Grant & Hackh's Chemical Dictionary, 5th ed)

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.

Proteins prepared by recombinant DNA technology.

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.

Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.

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 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.

Organic compounds containing the -CO-NH2 radical. Amides are derived from acids by replacement of -OH by -NH2 or from ammonia by the replacement of H by an acyl group. (From Grant & Hackh's Chemical Dictionary, 5th ed)

Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.

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.

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)

Widely distributed enzymes that carry out oxidation-reduction reactions in which one atom of the oxygen molecule is incorporated into the organic substrate; the other oxygen atom is reduced and combined with hydrogen ions to form water. They are also known as monooxygenases or hydroxylases. These reactions require two substrates as reductants for each of the two oxygen atoms. There are different classes of monooxygenases depending on the type of hydrogen-providing cosubstrate (COENZYMES) required in the mixed-function oxidation.

Fatty acid derivatives that have specificity for CANNABINOID RECEPTORS. They are structurally distinct from CANNABINOIDS and were originally discovered as a group of endogenous CANNABINOID RECEPTOR AGONISTS.

Proteins found in any species of bacterium.

The giving of drugs, chemicals, or other substances by mouth.

A statistical means of summarizing information from a series of measurements on one individual. It is frequently used in clinical pharmacology where the AUC from serum levels can be interpreted as the total uptake of whatever has been administered. As a plot of the concentration of a drug against time, after a single dose of medicine, producing a standard shape curve, it is a means of comparing the bioavailability of the same drug made by different companies. (From Winslade, Dictionary of Clinical Research, 1992)

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.

The application of medical knowledge to questions of law.

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).

A cytochrome P-450 suptype that has specificity for a broad variety of lipophilic compounds, including STEROIDS; FATTY ACIDS; and XENOBIOTICS. This enzyme has clinical significance due to its ability to metabolize a diverse array of clinically important drugs such as CYCLOSPORINE; VERAPAMIL; and MIDAZOLAM. This enzyme also catalyzes the N-demethylation of ERYTHROMYCIN.

Sequential operating programs and data which instruct the functioning of a digital computer.

A research technique to measure solvent exposed regions of molecules that is used to provide insight about PROTEIN CONFORMATION.

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.

A large group of cytochrome P-450 (heme-thiolate) monooxygenases that complex with NAD(P)H-FLAVIN OXIDOREDUCTASE in numerous mixed-function oxidations of aromatic compounds. They catalyze hydroxylation of a broad spectrum of substrates and are important in the metabolism of steroids, drugs, and toxins such as PHENOBARBITAL, carcinogens, and insecticides.

Amides composed of unsaturated aliphatic FATTY ACIDS linked with AMINES by an amide bond. They are most prominent in ASTERACEAE; PIPERACEAE; and RUTACEAE; and also found in ARISTOLOCHIACEAE; BRASSICACEAE; CONVOLVULACEAE; EUPHORBIACEAE; MENISPERMACEAE; POACEAE; and SOLANACEAE. They are recognized by their pungent taste and for causing numbing and salivation.

Analysis of gabapentin in serum and plasma by solid-phase extraction and gas chromatography-mass spectrometry for therapeutic drug monitoring. (1/5623)

A simple method for the determination of gabapentin (Neurontin) is described. The method uses solid-phase extraction by disk column and derivatization followed by gas chromatographic-mass spectrometric analysis. The single-step derivatization with MTBSTFA produces a t-BDMS derivative of both the carboxylic and amine moieties of the molecule. Each step of the procedure was optimized to assure reliable performance of the method. The assay limit of detection was 0.1 microg/mL with a linear range from 1.0 to 35 microg/mL. Within-run (n = 3) and between-run (n = 40) coefficients of variation were less than 8.2 and 15.9%, respectively. The method has proven reliable in routine production for more than a year, producing clean chromatography with unique ion fragments, consistent ion mass ratios, and no interferences. Statistical analysis of the gabapentin concentrations measured in 1020 random specimens over a 2-month period showed a mean concentration of 6.07 microg/mL with a standard deviation of 5.28. (+info)

Solid-phase microextraction for cannabinoids analysis in hair and its possible application to other drugs. (2/5623)

This paper describes the application of solid-phase microextraction (SPME) to cannabis testing in hair. Fifty milligrams of hair was washed with petroleum ether, hydrolyzed with NaOH, neutralized, deuterated internal standard was added and directly submitted to SPME. The SPME was analyzed by GC-MS. The limit of detection was 0.1 ng/mg for cannabinol (CBN) and delta9-tetrahydrocannabinol (THC) and 0.2 ng/mg for cannabidiol (CBD). THC was detected in a range spanning from 0.1 to 0.7 ng/mg. CBD concentrations ranged from 0.7 to 14.1 ng/mg, and CBN concentrations ranged from 0.4 to 0.7 ng/mg. The effectiveness of different decontamination procedures was also studied on passively contaminated hair. The proposed method is also suitable for the analysis of methadone in hair; cocaine and cocaethylene can be detected in hair with SPME extraction after enzymatic hydrolysis. (+info)

Highly sensitive quantitation of methamphetamine by time-resolved fluoroimmunoassay using a new europium chelate as a label. (3/5623)

A simple and highly sensitive time-resolved fluoroimmunoassay of methamphetamine (MA) using a new fluorescent europium chelate (BHHCT-Eu3+) as a label is described. Two variations of competitive immunoassay were attempted. In the first (one-step) assay, microtiter plates coated with anti-MA were used, and the new label was bound to a conjugate of bovine serum albumin and N-(4-aminobutyl)-MA (MA-BSA). In the second (two-step) assay, instead of the labeled MA-BSA, biotinylated MA-BSA and BHHCT-Eu3+-labeled streptavidin-BSA were used. The lowest measurable concentrations of MA for the one-step and the two-step methods were 1 ng/mL (25 pg/assay) and 1 pg/mL (25 fg/assay), respectively. These were 10 to 1000 times superior to the detection limits of MA in any other immunoassay. Intra-assay coefficient of variation was approximately 2-8% at eight different concentrations (n = 4). Analysis of 34 urine samples with the new method and conventional gas chromatography showed a good correlation (r = 0.954). The high detectability of the present assay also enabled segmental hair analysis with a few centimeters of a hair. (+info)

Cocaine metabolite kinetics in the newborn. (4/5623)

The study goal was to determine the half-life elimination of cocaine and benzoylecgonine (BZE) in the newborn. Three 0.3-mL blood samples were collected during the first day of life. Urine was collected once daily. Cocaine and BZE concentrations were determined by gas chromatography-mass spectrometry. An extraction method was developed for measuring low concentrations of cocaine and BZE in small (0.1 mL) blood samples. Cocaine had a half-life of 11.6 h in one subject. The half-life of BZE during the first day of life, based on blood data in 13 subjects, was 16 h (95% confidence interval [CI], 12.8 to 21.4 h). The half-life of BZE during the first week of life, based on urine data in 16 subjects, was 11.2 h (95% CI, 10.1 to 11.8 h). The novel extraction method for small blood sample volumes should be applicable to other basic drugs. (+info)

The urinary elimination profiles of diazepam and its metabolites, nordiazepam, temazepam, and oxazepam, in the equine after a 10-mg intramuscular dose. (5/5623)

A method for the extraction of diazepam and its metabolites (nordiazepam, temazepam, and oxazepam) from equine urine and serum and their quantitation and confirmation by liquid chromatography-tandem mass spectrometry is presented. Valium, a formulation of diazepam, was administered at a dose of 10 mg intramuscularly to four standard-bred mares. Diazepam is extensively metabolized in the horse to nordiazepam, temazepam, and oxazepam. Diazepam urinary concentrations were found to be less than 6 ng/mL. Nordiazepam was found to be mainly in its glucuronide-conjugated form and was measured out to a collection time of 53-55 h. Oxazepam and temazepam were entirely conjugated, and their urinary concentrations were measured out to collection times of 121 h and 77-79 h, respectively. Diazepam and nordiazepam were measured in equine postadministration serum out to collection times of 6 and 54 h, respectively. Oxazepam and temazepam were not detected in postadministration serum. (+info)

Semiautomated preparation of 3,5,6-trichloro-2-pyridinol in human urine using a Zymate XP laboratory robot with quantitative determination by gas chromatography-negative-ion chemical ionization mass spectrometry. (6/5623)

A rapid and sensitive semiautomated method was developed for quantitation of the chlorpyrifos metabolite 3,5,6-trichloro-2-pyridinol (TCP) in human urine. A Zymark Zymate XP laboratory robotics system was used to mix urine samples, transfer aliquots, add the stable-isotope-labeled TCP internal standard (13C2- or 13C2,15N-), and liberate conjugates of TCP from urine via acid hydrolysis. Samples were manually extracted into toluene, derivatized, and analyzed by gas chromatography-negative-ion chemical ionization mass spectrometry. Determination of the metabolic TCP was performed by selected ion monitoring of the dichloropyridinol fragment ions: m/z 161 for TCP and m/z 165 for 13C2-TCP or m/z 168 for 13C2,15N-TCP. Interday precision and accuracy were demonstrated over 3 years of analyses using the 13C2-TCP internal standard, with an average recovery from fortified urine samples of 93+/-12% (N = 54, concentration range 1-140 ng/mL). The method was found to be linear over the range of 0.5 to 200 ng/mL, and the limit of detection for TCP in urine was estimated to be 0.2 ng/mL with a limit of quantitation of 1 ng/mL. The effect of solids distribution on the concentration of TCP in the thawed urine samples was examined, and the results indicated that homogeneous distribution is critical for quantitation. The precision and accuracy of the automated method with respect to the transfer of homgeneous urine aliquots and delivery of internal standard yielded equivalent or improved results over the manual techniques. Overall, this method is more simple than existing methodologies, and it yields results with improved precision, accuracy, and sensitivity over previously developed methods. (+info)

Determination of pyrolysis products of smoked methamphetamine mixed with tobacco by tandem mass spectrometry. (7/5623)

This study examines the pyrolysis products of smoked methamphetamine mixed with tobacco that was trapped with a C8 adsorbent cartridge and then detected by gas chromatography-tandem mass spectrometry. According to the results, the mainstream smoke contains 2-methylpropyl-benzene, 2-chloropropyl-benzene, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, 3-ethyl-phenol, methamphetamine, dimethylamphetamine, hydroquinone, 3-methyl-5-(1-methylethyl)-methylcarbamate phenol, N-methyl-N-(2-phenylethyl)-acetamide, 4-(3-hydroxy-1-butenyl)-3,5,5-trimethyl-2-cyclohexene-1-one, propanoic acid, N-acetylmethamphetamine, phenyl ester, and furfurylmethylamphetamine. In addition, the compounds in sidestream smoke are 2-propenyl benzene, phenylacetone, methamphetamine, dimethylamphetamine, benzyl methyl ketoxime, 3,4-dihydro-2-naphthalenone, N-folmyamphetamine, N-acetylamphetamine, bibenzyl, N-folmylmethamphetamine, N-acetylmethamphetamine, N-propionymethamphetamine, and furfurylmethylamphetamine. Moreover, the presence of methamphetamine promotes the oxidation of the tobacco components. (+info)

Identification and quantification of cocaine N-oxide: a thermally labile metabolite of cocaine. (8/5623)

In this article, we report the identification and quantitation of cocaine N-oxide (CNO), a thermally labile oxidative metabolite, from both animal and human samples. The concentration of CNO is similar to the concentrations of cocaine in the samples analyzed. The technique used for the determination of CNO in this study is liquid chromatography-electrospray ionization mass spectrometry, which is necessary because CNO is converted to cocaine upon heating. This includes simple heating of aqueous solutions to temperatures in excess of 100 degrees C and analysis by gas chromatography-mass spectrometry (GC-MS), in which CNO is converted to cocaine in the injection port. The thermal conversion of CNO to cocaine is estimated to cause an over-reporting of cocaine levels by 10-20% when using GC-MS. (+info)

Capillary electrophoresis-mass spectrometry Ion-mobility spectrometry-mass spectrometry Liquid chromatography-mass spectrometry ... Gas chromatography-mass spectrometry (GC-MS) is an analytical method that combines the features of gas-chromatography and mass ... "Gas chromatography-mass spectrometry with supersonic molecular beams". Journal of Mass Spectrometry. 43 (2): 141-63. Bibcode: ... Gas Chromatography and Mass Spectrometry: A Practical Guide. Academic Press. ISBN 978-0-08-092015-3. Jones M. "Gas ...

https://en.wikipedia.org/wiki/Gas_chromatography–mass_spectrometry

"Hyphenation of aqueous liquid chromatography to pyrolysis-gas chromatography and mass spectrometry for the comprehensive ... Pyrolysis-gas chromatography-mass spectrometry is a method of chemical analysis in which the sample is heated to decomposition ... "Derivatization in mass spectrometry --7. On-line derivatisation/degradation". European Journal of Mass Spectrometry. 12 (1): 1- ... to produce smaller molecules that are separated by gas chromatography and detected using mass spectrometry. Pyrolysis is the ...

https://en.wikipedia.org/wiki/Pyrolysis–gas_chromatography–mass_spectrometry

Gohlke, R. S.; McLafferty, F. W. (1993). "Early gas chromatography/mass spectrometry". J. Am. Soc. Mass Spectrom. 4 (5): 367- ... "Gas Chromatography-Mass Spectrometry". American Chemical Society. Retrieved 19 Nov 2019. Gohlke, R. S. (1959). "Time-of-Flight ... 1959 Researchers at Dow Chemical interface a gas chromatograph to a mass spectrometer. 1964 British Mass Spectrometry Society ... History of Mass Spectrometry - Pioneers - University of New South Wales Sydney Five Mass Spectrometry Nobel Prize Pioneers - ...

https://en.wikipedia.org/wiki/History_of_mass_spectrometry

"Early Gas Chromatography/Mass Spectrometry". Journal of the American Society for Mass Spectrometry. 4 (5): 367-371. doi:10.1016 ... These include high-performance liquid chromatography, gas chromatography-mass spectrometry, atomic absorption spectroscopy, ... "Gas Chromatography-Mass Spectrometry". American Chemical Society. Retrieved 19 Nov 2019. Gohlke, Roland S.; McLafferty, Fred W ... the most important advancements in forensic chemistry came in 1955 with the invention of gas chromatography-mass spectrometry ( ...

https://en.wikipedia.org/wiki/Forensic_chemistry

"Gas Chromatography-Mass Spectrometry". American Chemical Society. Retrieved 19 Nov 2019. Poole, Colin; Jennings, Walter (2012 ... Others introduced mass spectrometers to gas chromatography in the late 1950s. The work of Martin and Synge also set the stage ... "Milestones in the Development of Gas Chromatography". Gas Chromatography. Elsevier. p. 2. ISBN 9780123855404. Lesney, Mark S. ( ... Martin, in collaboration with Anthony T. James, went on to develop gas chromatography (GC; the principles of which Martin and ...

https://en.wikipedia.org/wiki/History_of_chromatography

"Gas Chromatography-Mass Spectrometry". American Chemical Society. Retrieved 19 Nov 2019. "Bendix Forms Aviation Firm". St ... Harrington of Bendix Aviation in the 1950s led to the combination of gas chromatography and mass spectrometry, and the ... development of Gas chromatography-mass spectrometry instrumentation. Beginning in the 1960s, Bendix produced scientific ... Criteria were met for hostile and non-hostile environments that provided seals against liquids and gasses. In 1971, Bendix ...

https://en.wikipedia.org/wiki/Bendix_Corporation

"Gas Chromatography-Mass Spectrometry". American Chemical Society. Retrieved 19 Nov 2019. National Historic Chemical Landmarks ( ... in Chemistry Steroid Medicines and Upjohn Innovation Gas Chromatography-Mass Spectrometry, Midland, Michigan Mann, Benjamin W ... now owned by the Massachusetts Institute of Technology) in Cambridge, Massachusetts. The discovery and isolation of phytochrome ... "Neil Bartlett and Reactive Noble Gases". National Historic Chemical Landmarks. American Chemical Society. Archived from the ...

https://en.wikipedia.org/wiki/National_Historic_Chemical_Landmarks

"Gas Chromatography-Mass Spectrometry". American Chemical Society. Archived from the original on April 6, 2020. Retrieved ... was an American pioneer in the development of gas chromatography-mass spectrometry equipment (GC/MS). Finnigan founded the ... An EPA manual for organic analysis using gas chromatography - mass spectrometry. Environmental Protection Agency. pp. 2, 4. ... The Encyclopedia of Mass Spectrometry Volume 9: Historical Perspectives, Part B: Notable People in Mass Spectrometry. Elsevier ...

https://en.wikipedia.org/wiki/Robert_E._Finnigan

"Gas Chromatography-Mass Spectrometry". American Chemical Society. Retrieved 19 November 2019. D.Sc, F. W. Aston M. A. (1 ... KM Downard (2007). "Francis William Aston - the man behind the mass spectrograph". European Journal of Mass Spectrometry. 13 (3 ... 1922 Mass Spectra and Isotopes Aston biography from Cambridge History of Mass Spectrometry - Pioneers (CS1: Julian-Gregorian ... The British Mass Spectrometry Society awards the Aston Medal in his honour. "Francis W. Aston - Biographical". NobelPrize.org. ...

https://en.wikipedia.org/wiki/Francis_William_Aston

ISBN 978-1-60774-172-5. Linskens, Hans-Ferdinand; Jackson, John F. (2012-12-06). Gas Chromatography/Mass Spectrometry. Springer ...

https://en.wikipedia.org/wiki/Kabuse_tea

Gas chromatography-mass spectrometry Capillary electrophoresis-mass spectrometry Ion-mobility spectrometry-mass spectrometry de ... "Combined liquid chromatography mass spectrometry. Part I. Coupling by means of a moving belt interface". Mass Spectrometry ... "Combined liquid chromatography mass spectrometry. Part III. Applications of thermospray". Mass Spectrometry Reviews. 11 (1): 3- ... Mass Spectrom. 7: 858. Baldwin, M. A.; McLafferty, F. W. (1973). "Liquid chromatography-mass spectrometry interface-I: The ...

https://en.wikipedia.org/wiki/Liquid_chromatography–mass_spectrometry

"Early gas chromatography/mass spectrometry". Journal of the American Society for Mass Spectrometry. 4 (5): 367-371. doi:10.1021 ... Mass chromatogram Mass spectral interpretation Mass spectrum analysis Tandem mass spectrometry McLafferty FW (1 January 1993). ... Principles and application of electron-based dissociation in mass spectrometry-based analysis of protein structure" (PDF). Mass ... Tandem mass spectrometry-generated fragmentation is typically made in the collision zone (post-source fragmentation) of a ...

https://en.wikipedia.org/wiki/Fragmentation_(mass_spectrometry)

"Early gas chromatography/mass spectrometry". Journal of the American Society for Mass Spectrometry. 4 (5): 367-71. doi:10.1016/ ... "Time-of-Flight Mass Spectrometry and Gas-Liquid Partition Chromatography". Analytical Chemistry. 31 (4): 535-541. doi:10.1021/ ...

https://en.wikipedia.org/wiki/Food_physical_chemistry

Using gas chromatography and mass spectrometry. (E,E) 9,12-octadecadienoic acid, methyl ester, 9-Octadecenoic acid(Z)-,methyl ...

https://en.wikipedia.org/wiki/Iris_halophila_var._sogdiana

... gas chromatography - mass spectrometry; ICP-MS, inductively coupled plasma - mass spectrometry; CO, carbon monoxide, VOC, ... ultra-performance liquid chromatography-mass spectrometry; HPLC-DAD-MMI-MS, high performance liquid chromatography-diode array ... Abbreviations: TSNA, tobacco specific nitrosoamines; LC-MS, liquid chromatography-mass spectrometry; MAO-A and B, ... In physics, a vapor is a substance in the gas phase whereas an aerosol is a suspension of tiny particles of liquid, solid or ...

https://en.wikipedia.org/wiki/Composition_of_electronic_cigarette_aerosol

Gas Chromatography, Infrared Spectrometry or Mass Spectrometry is used in combination with the color test to identify the type ... Lehrer, M. (1998). "The role of gas chromatography/mass spectrometry. Instrumental techniques in forensic urine drug testing". ... and identifying human remains of victims from mass disasters or missing person cases. It is also used to link suspects or ... Mass surveillance Privacy Surveillance Trace evidence Questioned Document Examination "Can DNA Demand a Verdict". Learn ...

https://en.wikipedia.org/wiki/Forensic_identification

"Gas Chromatography Mass Spectrometry (GC-MS) Information , Thermo Fisher Scientific - US". www.thermofisher.com. Retrieved 2018 ... in 1971 after they demonstrated that gas chromatography-mass spectrometry (GC-MS) could be used to measure compounds present in ... Dettmer, Katja; Aronov, Pavel A.; Hammock, Bruce D. (2007). "Mass spectrometry-based metabolomics". Mass Spectrometry Reviews. ... Dettmer K, Aronov PA, Hammock BD (2007). "Mass spectrometry-based metabolomics". Mass Spectrometry Reviews. 26 (1): 51-78. ...

https://en.wikipedia.org/wiki/Metabolomics

Gas chromatography-mass spectrometry (MGAK) for atmospheric analysis. Developed by Russia. Power source The science and ... The payload mass is about 45 kg and consists of the following instruments (plus an instrument interface and memory unit (BIP ...

https://en.wikipedia.org/wiki/Kazachok

Garcia, Antonia; Barbas, Coral (2011). Metz, Thomas O. (ed.). Gas Chromatography-Mass Spectrometry (GC-MS)-Based Metabolomics. ... A Study via Mass Spectrometry and NMR Spectroscopy". Analytical Chemistry. 92 (19): 12891-12899. doi:10.1021/acs.analchem. ... "Quality assurance procedures for mass spectrometry untargeted metabolomics. a review". Journal of Pharmaceutical and Biomedical ... Journal of Chromatography A. 1032 (1): 299-304. doi:10.1016/j.chroma.2003.09.028. ISSN 0021-9673. Marı́n, A.; Garcı́a, E.; ...

https://en.wikipedia.org/wiki/Coral_Barbas

"Plasma hydroxyurea determined by gas chromatography-mass spectrometry". Journal of Chromatography B. 877 (4): 446-450. doi: ...

https://en.wikipedia.org/wiki/Hydroxycarbamide

... using gas chromatography-mass spectrometry and trimethylsilyl derivatives". Industrial Crops and Products. 108: 36-43. doi: ... The remaining waxy mass is known as a concrete. The concrete is then mixed with alcohol which dissolves the aromatic ... Because CO 2 is gas at normal atmospheric pressure, it leaves no trace of itself in the final product. The equipment for CO 2 ... Under normal pressure CO 2 changes directly from a solid to a gas in a process known as sublimation.) The supercritical fluid ...

https://en.wikipedia.org/wiki/Rose_oil

These included mass spectrometry and gas chromatography instruments. They have since divested these products to Scion ... laboratory gas chromatography (GC), and GC-triple quadrupole mass spectrometer (originally designed by Bear Instruments and ... Later, the company would expand their product range with MRI, FTIR and FT-Raman spectrometers and with mass spectrometers. In ... It is headquartered in Billerica, Massachusetts, and is the publicly traded parent company of Bruker Scientific Instruments ( ...

https://en.wikipedia.org/wiki/Bruker

Gas or liquid chromatography and mass spectrometry (e.g. LC-MS/MS) achieves greater specificity than immunoassays. Measurement ...

https://en.wikipedia.org/wiki/17α-Hydroxyprogesterone

Sterol levels are measured by gas chromatography-mass spectrometry. Genetic screening for Conradi-Hünermann syndrome via the ...

https://en.wikipedia.org/wiki/Conradi–Hünermann_syndrome

Analysis using gas chromatography and mass spectrometry has been used to identify bioactive compounds in essential oils. These ... Adams, Robert P. (2007). Identification of Essential Oil Components by Gas Chromatography/Mass Spectrometry. Barrett, S. " ... ISBN 0-12-227055-X.[page needed] Cather, JC; MacKnet, MR; Menter, MA (2000). "Hyperpigmented macules and streaks". Proceedings ...

https://en.wikipedia.org/wiki/Aromatherapy

They used gas chromatography and gas chromatography/mass spectrometry methods. It was found that the flowers of Iris kerneriana ...

https://en.wikipedia.org/wiki/Iris_kerneriana

"Cinnamaldehyde content in foods determined by gas chromatography-mass spectrometry". Journal of Agricultural and Food Chemistry ... Ma, W.-B.; Feng, J.-T.; Jiang, Z.-L.; Zhang, X. (2014). "Fumigant Activity of 6 Selected Essential Oil Compounds and Combined ...

https://en.wikipedia.org/wiki/Cinnamaldehyde

"Sperm whale oil analysis by gas chromatography and mass spectrometry". Journal of the American Oil Chemists' Society. 50 (6): ... Alkoxy-Acyl Combinations in the Wax Esters from Winterized Sperm Whale Oil by Gas Chromatography-Mass Spectrometry Information ... causing it to congeal into a spongy and viscous mass. The congealed matter was then loaded into wool sacks and placed in a ...

https://en.wikipedia.org/wiki/Sperm_oil

Niessen, Wilfried M.A. (2001). Current Practice of gas chromatography-mass spectrometry (1 ed.). pp. 55-94. Chosson, P; Lanau, ... The techniques typically used includes gas chromatography and mass spectrometry. Petroleum biomarkers are highly important in ... "Petroleum biomarkers analyzed by atmospheric gas chromatography-tandem mass spectroscopy" (PDF). Waters. Osadetz, K.G; ... Most biomarkers also usually have high molecular mass. Some examples of biomarkers found in petroleum are pristane, triterpanes ...

https://en.wikipedia.org/wiki/Biomarker_(petroleum)

"A pyrolysis gas chromatography mass spectrometry study of the actinomyceteStreptomyces longisporoflavus". Biological Mass ... Boston, MA: Springer US. ISBN 1-4757-2085-8. Hopwood, David A., ed. (2009). Complex enzymes in microbial natural product ... Spectrometry. 2 (5): 261-265. doi:10.1002/bms.1200020504. Doddrell, David M.; Laue, Ernest D.; Leeper, Finian J.; Staunton, ...

https://en.wikipedia.org/wiki/Streptomyces_longisporoflavus

... modern gymnosperm resins as well as in the rock record are separated and characterized by gas chromatography-mass spectrometry ... MS-MS analysis has been used to elucidate fragmentation mechanisms for mass spectrum peaks of interest. Mass spectra for ... GC-MS). Because polar functional groups reduce molecular volatility and make separation by gas chromatography difficult, ...

https://en.wikipedia.org/wiki/Abietane

Gas chromatography/mass spectrometry analysis has revealed that A. dracunculus oil contains predominantly phenylpropanoids such ... Louis, MO & Harvard University Herbaria, Cambridge, MA. Lin, Yourun; Humphries, Christopher J.; Gilbert, Michael G. "Artemisia ... Louis, MO & Harvard University Herbaria, Cambridge, MA. "Artemisia dracunculus L.". Flora of Pakistan. Missouri Botanical ...

https://en.wikipedia.org/wiki/Tarragon

A New Highly Sensitive Approach for Liquid Chromatography/Mass Spectrometry of Small and Large Molecules". Analytical Chemistry ... a New Atmospheric Pressure MALDI Method for Producing Highly Charged Gas-phase Ions of Peptides and Proteins Directly from ... Trimpin, Sarah (2015). ""Magic" Ionization Mass Spectrometry". Journal of the American Society for Mass Spectrometry. 27 (1): 4 ... In mass spectrometry, matrix-assisted ionization (also inlet ionization) is a low fragmentation (soft) ionization technique ...

https://en.wikipedia.org/wiki/Matrix-assisted_ionization

... the first application of liquid chromatography-mass spectrometry-mass spectrometry (LC-MS-MS) was demonstrated on the TAGA 6000 ... The first SCIEX product, introduced in 1979, was the TAGA (Trace Atmospheric Gas Analyzer) quadrupole mass spectrometer system ... "Determination of sulfa drugs in biological fluids by liquid chromatography/mass spectrometry/mass spectrometry". Analytical ... "Atmospheric Pressure Ion Evaporation-Mass Spectrometry". International Journal of Mass Spectrometry and Ion Physics. 50: 331- ...

https://en.wikipedia.org/wiki/SCIEX

One of the first to use gas chromatography, mass spectrometry and thin layer chromatography in flavor research, Patton proved, ...

https://en.wikipedia.org/wiki/Stuart_Patton

and ion microscopy (SIMS) but not gas chromatography. This definition also appears in some mass spectrometry texts. There are ... "resolving power in mass spectrometry". doi:10.1351/goldbook.R05321 Biemann, Klaus (1962). Mass Spectrometry: Organic Chemical ... Fundamentals of contemporary mass spectrometry. Chichester: John Wiley & Sons. ISBN 978-0-471-68229-5. (Mass spectrometry). ... In mass spectrometry, resolution is a measure of the ability to distinguish two peaks of slightly different mass-to-charge ...

https://en.wikipedia.org/wiki/Resolution_(mass_spectrometry)

... and Gas chromatography-mass spectrometry (GCMS) analyses. The API gravity of the oils ranges from 35° to 62° and sulfur ... The zone of wet gas generation is in the 1.1-1.4% Ro range, whereas the primary zone of dry gas generation (main gas window) ... Continuous-type accumulations include fractured shale and fractured limestone oil and gas, basin-centered gas, coal bed gas, ... of gas, and 500 million barrels (79×10^6 m3) of natural gas liquids. Cumulative gas production from the Barnett Shale for the ...

https://en.wikipedia.org/wiki/Bend_Arch–Fort_Worth_Basin

Yu, J.; Baeten, A.; Citrowske, S. "Quantification of Tentatively Identified Extractables and Leachables with Mass Spectrometry ... It is paired with a flame ionization detector (FID) in a gas chromatograph (GC) to improve the sensitivity of the FID and give ... Watanabe, T., Kato, K., Matsumoto, N., and Maeda, T., Chromatography, 27 (2006) 1-7. Watanabe, T., Kato, K., Matsumoto, N., and ... The Polyarc reactor requires a supply of hydrogen and air to operate, which can be split from the gases that supply the FID. ...

https://en.wikipedia.org/wiki/Polyarc_reactor

... Residues in Vegetables Using Dispersive-SPE Sample Preparation Combined with Gas Chromatography-Mass Spectrometry ...

https://en.wikipedia.org/wiki/Dichlofluanid

... library using liquid chromatography with photodiode array spectrophotometry detector and gas chromatography-mass spectrometry ...

https://en.wikipedia.org/wiki/4-Acetoxy-MiPT

... cutoffs were 50 ng/mL for an initial immunoassay test and 15 ng/mL for a confirmatory gas chromatography-mass spectrometry test ... and Massachusetts. A major US insurance company[which?] states that "there are no widely accepted methods for detecting ...

https://en.wikipedia.org/wiki/Cannabis_and_impaired_driving

For metabolite profiling, gas chromatography-mass spectrometry is used to find flavonoids such as quercetin. Compounds can then ... They are generally isolated and measured through the use of chromatography and mass spectrometry techniques. Additionally, the ... Chemical compounds are then derived through various chromatography and mass spectrometry separations. However, extraction ... be further differentiated using reversed-phase high-performance liquid chromatography-mass spectrometry. When it comes to ...

https://en.wikipedia.org/wiki/Biogenic_substance

"Ultrasonic nebulization extraction coupled with headspace single drop microextraction and gas chromatography-mass spectrometry ...

https://en.wikipedia.org/wiki/Beta-Pinene

... yohimbe bark with ultra-performance liquid chromatography coupled with ion mobility quadrupole time-of-flight mass spectrometry ... Betz JM, White KD, der Marderosian AH (1995). "Gas chromatographic determination of yohimbine in commercial yohimbe products". ... However, in 1972, Effler and Effler using modern analytical techniques, including mass spectrometry, UV absorption, IR ... Rapid Communications in Mass Spectrometry. 25 (18): 2591-602. Bibcode:2011RCMS...25.2591S. doi:10.1002/rcm.5158. PMID 23657953 ...

https://en.wikipedia.org/wiki/Yohimbine

... breast milk and tissues by gas chromatography-mass spectrometry using selected ion monitoring". Journal of Chromatography B. ...

https://en.wikipedia.org/wiki/Primidone

... identification of anabasine by gas-chromatography/mass spectrometry". Journal of Forensic Sciences. 45 (3): 736-41. doi:10.1520 ...

https://en.wikipedia.org/wiki/Streptosolen

For example, using mass spectrometry on plant protein mixtures would result in multiple intense RuBisCO subunit peaks that ... affinity chromatography, and aggregation using DTT, though these methods are more time-consuming and less efficient when ... since these reactions require CO2 to pass by gas exchange through these openings. Evaporation through the upper side of a leaf ... With the mass convergent evolution of the C4-fixation pathway in a diversity of plant lineages, ancestral C3-type RuBisCO ...

https://en.wikipedia.org/wiki/RuBisCO

... emission spectroscopy Inductively coupled plasma atomic emission spectroscopy Inductively coupled plasma mass spectrometry LBOZ ... By running an affinity chromatography, B-Galactosidase can be isolated and tested by reacting collected samples with ONPG and ... or gases. Although many biochemicals are colored, as in, they absorb visible light and therefore can be measured by ...

https://en.wikipedia.org/wiki/Spectrophotometry

... of indigoid compounds present in archaeological Maya blue by pyrolysis-silylation-gas chromatography-mass spectrometry. Journal ... MA: Interlink Publishing Group. ISBN 978-1-56656-795-4. "Chicanná Ruins." Locogringo. N.p., n.d. Web. 26 Feb. 2015. . Potter, ...

https://en.wikipedia.org/wiki/Chicanná

"Gas Chromatography-Mass Spectrometry". American Chemical Society. Retrieved 19 November 2019. "Nobel Winner Archer Martin Dies ... "Gas-Liquid Chromatography: A Technique for the Analysis and Identification of Volatile Materials" reported the discovery of gas ... He developed partition chromatography whilst working on the separation of amino acids, and later developed gas-liquid ... JAMES, AT; MARTIN, AJ (1954). "Gas-liquid chromatography; a technique for the analysis and identification of volatile materials ...

https://en.wikipedia.org/wiki/Archer_Martin

... chromatography and imaging methods". Rapid Communications in Mass Spectrometry. 28 (16): 1779-1791. doi:10.1002/rcm.6960. ISSN ... the gas-phase acidity of the protonated water clusters and the gas-phase basicity of the analyte molecule are of crucial ... "Paint Spray Mass Spectrometry for the Detection of Additives from Polymers on Conducting Surfaces". Mass Spectrometry Letters. ... "Mass spectrometry imaging under ambient conditions". Mass Spectrometry Reviews. 32 (3): 218-243. Bibcode:2013MSRv...32..218W. ...

https://en.wikipedia.org/wiki/Ambient_ionization

Thermal desorption for gas chromatography, in: Gas Chromatography, ed. C.F. Poole, Elsevier, 2012, chapter 10, pp. 235-289; ... Journal of Mass Spectrometry. 2004 (39): 233-254. doi:10.1002/jms.606. PMID 15039931. A.-L. Sunesson, Passive sampling in ... MDHS 80, Laboratory method using diffusive solid sorbent tubes, thermal desorption and gas chromatography, UK Health & Safety ... Purge-and-trap - A flow of gas is bubbled through an aqueous sample (a beverage or aqueous extract), and the gas stream then ...

https://en.wikipedia.org/wiki/Analytical_thermal_desorption

... as measured in urine measured via gas chromatography-mass spectrometry. Ultrasonography is the primary means for assessing ... Virilization of genitalia with voice deepening, development of muscle mass occur at puberty in affected males and height is not ... and inguinal/labial mass. For apparent male genitalia: nonpalpable testes, micropenis, isolated perineal hypospadias, or mild ...

https://en.wikipedia.org/wiki/5α-Reductase_2_deficiency

... microextraction and gas chromatography/mass spectrometry or high-performance liquid chromatography/mass spectrometry". ... and ion trap gas chromatography-mass spectrometry". Journal of Chromatography A. 777 (2): 275-282. doi:10.1016/S0021-9673(97) ... in Water and Human Saliva by Solid-Phase Microextraction and Quadrupole Ion Trap Gas Chromatography/Mass Spectrometry". ... from Purdue University where she worked on gas phase ion chemistry using mass spectrometry. Following her Ph.D. she was a ...

https://en.wikipedia.org/wiki/Jennifer_S._Brodbelt

... by gas chromatography/mass spectrometry and liquid chromatography/quadrupole time-of-flight mass spectrometry". Rapid ... plasma or urine by gas chromatography-mass spectrometry or liquid chromatography-mass spectrometry to confirm a diagnosis of ... Journal of Mass Spectrometry. 45 (12): 1426-42. Bibcode:2010JMSp...45.1426M. doi:10.1002/jms.1859. PMID 21053377. Baselt RC ( ... In the USA, products containing MDPV and labeled as bath salts were sold as recreational drugs in gas stations, similar to the ...

https://en.wikipedia.org/wiki/Methylenedioxypyrovalerone

The related concept of equivalent mass had been in use at least a century earlier. Developments in mass spectrometry led to the ... In a mixture of gases, the partial pressure of each component is proportional to its molar ratio. The history of the mole is ... Journal of Chromatography. 559 (1-2): 237-246. doi:10.1016/0021-9673(91)80074-Q. PMID 1761625. History of National Mole Day ... Standard unit of mass for atomic-scale chemical species Molecular mass - Mass of a given molecule in daltons Molar mass - Mass ...

https://en.wikipedia.org/wiki/Mole_(unit)

... pig fat by means of stable isotope dilution analysis-headspace solid-phase microextraction-gas chromatography/mass spectrometry ...

https://en.wikipedia.org/wiki/3β-Androstenol

... which before the introduction of the Gas Chromatography-Mass Spectrometry assay, could not be identified in athletes' samples. ...

https://en.wikipedia.org/wiki/Jeff_Michels

... is also commonly used as a polar stationary phase for gas chromatography, as well as a heat transfer fluid ... PEG is often used (as an internal calibration compound) in mass spectrometry experiments, with its characteristic fragmentation ... Mw and Mn can be measured by mass spectrometry. PEGylation is the act of covalently coupling a PEG structure to another larger ... PEO to polymers with a molecular mass above 20,000 g/mol, and POE to a polymer of any molecular mass. PEGs are prepared by ...

https://en.wikipedia.org/wiki/Polyethylene_glycol

Volatile aromatic and alihatic hydrocarbons were detected by GC/MS using a GS-Q column with the intratracheal gas ... Intratracheal gas analysis was carried out by gas chromatography/mass spectrometry (GC/MS) in 20 burned body cases (13 males ... Intratracheal Gas Analysis for Volatile Substances by Gas chromatography/Mass Spectrometry-Application to Forensic Autopsies. ... Intratracheal gas analysis was carried out by gas chromatography/mass spectrometry (GC/MS) in 20 burned body cases (13 males ...

https://www.astm.org/jfs14918j.html

In the work described in this thesis, gas-liquid chromatography (GLC) and combined gas chromatography-mass spectrometry (GC-MS ... derivative in stabilising steroidal dihydroxyacetones for gas chromatography was investigated for fourteen representative ... O-Butyloximes and O-pentyloximes proved to be useful in this respect by virtue of their structurally informative mass spectra ... A number of other derivatives which have been described previously for the gas-phase separation of corticosteroids were also ...

https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.795762

... and diapers by gas chromatography/mass spectrometry. Download Prime PubMed App to iPhone, iPad, or Android ... CocaineGas Chromatography-Mass SpectrometryHumansIndicator Dilution TechniquesInfant CareInfant, NewbornMeconiumSensitivity and ... Measurement of cocaine and metabolites in urine, meconium, and diapers by gas chromatography/mass spectrometry. Ann Clin Lab ... Measurement of Cocaine and Metabolites in Urine, Meconium, and Diapers By Gas Chromatography/mass Spectrometry. Ann Clin Lab ...

https://www.unboundmedicine.com/medline/citation/8239486/Measurement_of_cocaine_and_metabolites_in_urine_meconium_and_diapers_by_gas_chromatography/mass_spectrometry_

Improving Qualitative Synthetic Cathinone Identification by Gas Chromatography/Mass Spectrometry (GC/MS) Using Cold Electron ...

https://www.aafs.org/research/improving-qualitative-synthetic-cathinone-identification-gas-chromatographymass

The chemical components were characterized by gas chromatography coupled to mass spectrometry, which revealed β-copaen-4-α-ol ( ... Article Gas chromatography coupled to mass spectrometry (GC-MS) characterization and evaluation of antibacterial bioactivities ... Gas chromatography coupled to mass spectrometry (GC-MS) characterization and evaluation of antibacterial bioactivities of the ... Gas chromatography coupled to mass spectrometry (GC-MS) characterization and evaluation of antibacterial bioactivities of the ...

https://www.degruyter.com/document/doi/10.1515/znc-2020-0045/html

We propose a new quantitative gas chromatographymass spectrometry with isotope dilution (GC-ID-MS) method for the simultaneous ... Reference intervals of urinary steroid metabolites using gas chromatography-mass spectrometry in Chinese adults. *A. Chan, N. ... Gas Chromatography-Mass Spectrometry Measurement of 6β-OH-Cortisol/Cortisol Ratio in Human Urine: A Specific Marker of ... inproceedings{Luceri2001GasCS, title={Gas Chromatography-Mass Spectrometry Measurement of 6$\beta$-OH-Cortisol/Cortisol Ratio ...

https://www.semanticscholar.org/paper/Gas-Chromatography-Mass-Spectrometry-Measurement-of-Luceri-Fattori/cb91ff81dd4c40048e2ff904d5b7304127bdd776

Gas Chromatography Mass Spectrometry (GC/MS) - Agilent 240 Ion Trap Gas Chromatography Mass Spectrometry (GC/MS) - Agilent 240 ... Gas Chromatography Mass Spectrometry (GC/MS) - Agilent 240 Ion Trap Gas Chromatography Mass Spectrometry (GC/MS) - Agilent 240 ... Spectrometry & Spectroscopy, Chromotography Gas Chromatography Mass Spectrometry (GC/MS) - Agilent Technologies 7890B GC - 240 ... Standard Operating Procedure: Gas Chromatography Mass Spectrometry (GC/MS) - Agilent Technologies 7890B GC - 240 Ion Trap MS ...

https://www.buffalo.edu/shared-facilities-equip/facilities-equipment/SearchEquipment/function.host.html/content/shared/www/shared-facilities-equip/equipment-list/GCMS.detail.html

... mass spectrometry (GC/MS) is the marriage of two analytical methods into a versatile technique for the identification of ... Gas Chromatography / Mass Spectrometry (GCMS). HomeHAMMGas Chromatography / Mass Spectrometry (GCMS) ... Gas Chromatography / Mass Spectrometry (GCMS). HomeHAMMGas Chromatography / Mass Spectrometry (GCMS) ... Gas chromatography / mass spectrometry (GC/MS) is the marriage of two analytical methods into a versatile technique for the ...

https://www.mee-inc.com/hamm/gas-chromatography-mass-spectrometry-gcms/

Gas chromatography-mass spectrometry analyses of fatty acid methyl esters from marine algae. Alfahmawi, Rawan Khalil Hasan ...

https://bora.uib.no/bora-xmlui/handle/1956/20401?locale-attribute=en

Can gas chromatography combustion isotope ratio mass spectrometry be used to quantify organic compound abundance?. Title. Can ... Printed from /publications/can-gas-chromatography-combustion-isotope-ratio-mass-spectrometry-be-used-quantify on 29/11/22 12:06 ... gas chromatography combustion isotope ratio mass spectrometry be used to quantify organic compound abundance?. ... can-gas-chromatography-combustion-isotope-ratio-mass-spectrometry-be-used-quantify. ...

https://www.hutton.ac.uk/publications/can-gas-chromatography-combustion-isotope-ratio-mass-spectrometry-be-used-quantify

... of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry. In: ... of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry. Journal ... of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry. Journal ... of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry., ...

https://research.vu.nl/en/publications/fatty-acid-profiling-of-raw-human-plasma-and-whole-blood-using-di

... of an air bubble into a solvent droplet is proposed for fully automated bubble-in-drop microextraction-gas chromatography-mass ... Liquid Chromatography (LC/HPLC)Gas Chromatography (GC)Sample PreparationMass SpectrometryPharmaceutical AnalysisEnvironmental ... View MoreLiquid Chromatography (LC/HPLC)Gas Chromatography (GC)Sample PreparationMass SpectrometryPharmaceutical Analysis ... Development of Fully Automated Bubble-in-Drop Microextraction-Gas Chromatography-Mass Spectrometry of Organochlorine Pesticides ...

https://www.chromatographyonline.com/view/development-fully-automated-bubble-drop-microextraction-gas-chromatography-mass-spectrometry-organ-1

Gas chromatography/Fourier transform infrared/mass spectrometry coupling : a tool for Li-ion battery safety field investigation ... Gas chromatography/Fourier transform infrared/mass spectrometry coupling : a tool for Li-ion battery safety field investigation ... Sie sind hier:Gas chromatography/Fourier transform infrared/mass spectrometry coupling : a tool for Li-ion battery safety field ... Sie sind hier: Gas chromatography/Fourier transform infrared/mass spectrometry coupling : a tool for Li-ion battery safety ...

https://www.isea.rwth-aachen.de/go/id/ojpu/file/824246

Development of headspace solid phase microextraction gas chromatography mass spectrometry method for analysis of volatile ... Development of headspace solid phase microextraction gas chromatography mass spectrometry method for analysis of volatile ... The purpose of this thesis work was to develop a headspace solid phase microextraction gas chromatography mass spectrometry (HS ... Septum in crimp cap ensured a gas tight seal for the vial, giving lower RSD values and larger AUC compared to the other ...

https://www.essays.se/essay/09bad6c219/

A comparative metabolomic analysis was conducted on Saccharomyces cerevisiae cells with and without patulin treatment using gas ... chromatography-mass spectrometry-based approach. A total of 72 metabolites were detected and compared, including 16 amino acids ... was conducted on Saccharomyces cerevisiae cells with and without patulin treatment using gas chromatography-mass spectrometry- ... metabolomic analysis of Saccharomyces cerevisiae during the degradation of patulin using gas chromatography-mass spectrometry. ...

https://profils-profiles.science.gc.ca/en/publication/comparative-metabolomic-analysis-saccharomyces-cerevisiae-during-degradation-patulin

Quantitative Determination of Chlorpyrifos and Penconazole Residues in Grapes Using Gas Chromatography/Mass Spectrometry ... Quantitative Determination of Chlorpyrifos and Penconazole Residues in Grapes Using Gas Chromatography/Mass Spectrometry ... Quantitative Determination of Chlorpyrifos and Penconazole Residues in Grapes Using Gas Chromatography/Mass Spectrometry . ... Gas chromatorgraphy /mass spectrometry (GC/MS) was used to determine the residue levels. Results obtained have indicated the ...

https://www.medwelljournals.com/abstract/?doi=jftech.2005.284.289

Quantitative analysis of catecholamines and their metabolites in human urine by gas chromatography - mass spectrometry as a ... Quantitative analysis of catecholamines and their metabolites in human urine by gas chromatography - mass spectrometry as a ... Four different gas chromatographic - mass spectrometric methods were developed for the analysis of the catecholamines and their ... It was the aim of this work to develop a gas chromatographic - mass spectrometric (GC-MS) method that allow for the ...

https://repository.up.ac.za/handle/2263/22790

Mass spectrometry, coupled with chromatographic separations such as Gas chromatography (GC-MS) is normally used for direct ... The present study focuses on the analysis of the methanol extract of Equisetum arvense by Gas Chromatography-Mass Spectrometry ... Equisetum arvense, Bioactive compounds, Gas Chromatography-Mass Spectrometry. INTRODUCTION: Herbal medicine, as a major part of ... DETERMINATION OF BIOACTIVE COMPOUNDS OF EQUISETUM ARVENSE BY GAS CHROMATOGRAPHY-MASS SPECTROMETRY METHOD. HTML Full Text ...

https://ijpjournal.com/bft-article/determination-of-bioactive-compounds-of-equisetum-arvense-by-gas-chromatography-mass-spectrometry-method/?view=fulltext

Gas Chromatography-Mass Spectrometry Ions Limit Of Detection Nitrobenzenes Particulate Matter Reproducibility Of Results Tandem ... Sensitive and selective gas chromatography-tandem mass spectrometry method for the detection of nitrobenzene in tobacco smoke. ... Sensitive and selective gas chromatography-tandem mass spectrometry method for the detection of nitrobenzene in tobacco smoke ... Title : Sensitive and selective gas chromatography-tandem mass spectrometry method for the detection of nitrobenzene in tobacco ...

https://stacks.cdc.gov/view/cdc/59718

keywords = "Corn, Gas chromatography-mass spectrometry, Gel permeation chromatography, Triadimefon, Triadimenol-a, Triadimenol- ... triadimenol-b in corn by gel permeation chromatography and gas chromatography/mass spectrometry. Fenxi Huaxue, 33(10), 1442- ... triadimenol-b in corn by gel permeation chromatography and gas chromatography/mass spectrometry, Fenxi Huaxue, vol. 33, no. 10 ... triadimenol-b in corn by gel permeation chromatography and gas chromatography/mass spectrometry. In: Fenxi Huaxue. 2005 ; Vol. ...

https://researchwith.montclair.edu/en/publications/determination-of-residual-triadimefon-triadimenol-a-triadimenol-b

... analysis of distillation fractions by gas chromatography-mass spectrometry method Download Download PDF ...

https://www.lmaleidykla.lt/ojs/index.php/chemija/article/view/4546/3724

Determination of p-tert-octylphenol in blood and tissues by gas chromatography coupled with mass spectrometry ... A sensitive and reproducible procedure using gas chromatography coupled with mass spectrometry is described for the ... Determination of p-tert-octylphenol in blood and tissues by gas chromatography coupled with mass spectrometry Journal of ... Samples were then analyzed by a gas chromatograph equipped with a mass spectrometer (single ion monitoring) with a Varian VF- ...

https://espace.inrs.ca/id/eprint/1779/

... gas chromatography-mass spectrometry Remove constraint Subject: gas chromatography-mass spectrometry Subject term biomass ... In this study, Miscanthus biomass samples were analyzed using pyrolysis/two-dimensional gas chromatography/mass spectrometry ( ... Miscanthus; acetic acid; biomass; gas chromatography-mass spectrometry; guaiacol; heat treatment; nuclear magnetic resonance ...

https://pubag.nal.usda.gov/?f%5Bjournal_facet%5D%5B%5D=Energy+%26+Fuels&f%5Bpublication_year_rev_facet%5D%5B%5D=7983-2017&f%5Bsubject_facet%5D%5B%5D=biomass&f%5Bsubject_facet%5D%5B%5D=gas+chromatography-mass+spectrometry&f%5Bsubject_term%5D%5B%5D=biomass&per_page=50&q=%22Emerson%2C+Rachel+M.%22&search_field=author&sort=title

Quantification of 5-(hydroxymethyl)uracil in DNA by gas chromatography/mass spectrometry: Problems and solutions. Chemical ... Dive into the research topics of Quantification of 5-(hydroxymethyl)uracil in DNA by gas chromatography/mass spectrometry: ... Quantification of 5-(hydroxymethyl)uracil in DNA by gas chromatography/mass spectrometry : Problems and solutions. / LaFrancois ... title = "Quantification of 5-(hydroxymethyl)uracil in DNA by gas chromatography/mass spectrometry: Problems and solutions", ...

https://researchexperts.utmb.edu/en/publications/quantification-of-5-hydroxymethyluracil-in-dna-by-gas-chromatogra

Gas Chromatography��Mass Spectrometry documents. Free PDF Download. ... Gas Chromatography��Mass Spectrometry. GUIA DE PRÁCTICA de BIOQUIMICA. Chromatography / Dna / Ph / Restriction Enzyme / ... Gas Chromatography��Mass Spectrometry. ... Obesity / Adipose Tissue / Chronic Condition / Body Mass Index ...

https://kupdf.net/category/Gas%20Chromatography%EF%BF%BD%EF%BF%BD%EF%BF%BDMass%20Spectrometry

Environ Sci Technol 34(9):1856-1861.Norman KNT, Leonard K [2000]. Gas chromatography-mass spectrometry determination of ... EPA [1996]. Method 7580: White phosphorus (P4) by solvent extraction and gas chromatography. Cincinnati, OH: U.S. Enironmental ... EPA [1996]. Method 7580: White phosphorus (P4) by solvent extraction and gas chromatography. Cincinnati, OH: U.S. Environmental ... A NIOSH-certified CBRN tight-fitting APR with a canister-type gas mask or CBRN PAPR for air levels greater than AEGL-2. ...

https://www.cdc.gov/niosh/ershdb/emergencyresponsecard_29750025.html

In this regard, we comprehensively review the current state-of-the-art ethylene gas sensors and detecting technologies, ... printable optically colorimetric sensor arrays to a wide range of nanostructured chemiresistive gas sensors (including the ... covering from preconcentrator-equipped gas chromatographic systems, Fourier transform infrared technology, photonic crystal ... The real-time detecting and monitoring of ethylene gas molecules could benefit the agricultural, horticultural and healthcare ...

https://www.mdpi.com/1996-1944/15/17/5813

DFBA was partitioned into hexane and then quantified by gas chromatography-mass spectrometry (GC-MS). The method was validated ... Trace levels of compounds showing chromatographic and mass spectral features consistent with hydrazine were identified at very ... Analysis of hydrazine in smokeless tobacco products by gas chromatography-mass spectrometry. *Kevin McAdam. 1, ... Analysis of hydrazine in smokeless tobacco products by gas chromatography-mass spectrometry ...

https://bmcchem.biomedcentral.com/articles/10.1186/s13065-015-0089-0

Gas chromatography-Mass spectrometry analysis of essential oil revealed the presence of eugenol (88.20 %) as major compound ... Identification of essential oil components by gas chromatography/ mass spectrometry, 4th Edition. Allured Publ., Carol Stream, ... from the aerial flowering parts were obtained by hydrodistillation and analyzed by Gas Chromatography - Mass Spectrometry. ... Analysis of fatty acid composition of Nyctanthes arbortristis Linn bark by gas liquid chromatography ...

https://www.researchgate.net/publication/237067600_Chemical_composition_and_biological_activities_of_essential_Oil_from_leaf_and_bark_of_Nyctanthesarbor-tristis_L_from_Nepal

Simple and sensitive high-performance liquid chromatography method for simultaneous determination of urinary free cortisol and 6beta-hydroxycortisol in routine practice. (semanticscholar.org)
high performance liquid chromatography - taste dilution analysis. (www.csiro.au)
Cannabinoids are a specific chemical class found in cannabis that are produced in the glandular trichomes of the plant and can be analyzed via high performance liquid chromatography (HPLC). (labmanager.com)

The purpose of this thesis work was to develop a headspace solid phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) method to detect volatile organic compounds (VOCs) in board samples and to statistically investigate potential correlation between chromatographic data and flavor data obtained from a trained panel. (essays.se)
We have developed a method that incorporates small molecule separation based on laser desorption with 80 capture on a solid-phase microextraction (SPME) fiber for injection into a gas chromatography/mass spectrometry 81 (GCMS) system. (lsu.edu)
Ethnic Agave alcoholic beverages such as raicilla, sisal, tequila, mezcal, bacanora, sotol and pulque have been analyzed by gas chromatography and headspace solid-phase microextraction- gas chromatography-mass spectrometry (HS-SPME-GC-MS). There were 105 compounds identified, eleven were classified as major compounds and the others were classified as minor compounds. (com.hr)

The first on-line coupling of gas chromatography to a mass spectrometer was reported in the late 1950s. (wikipedia.org)
In 1964, Electronic Associates, Inc. (EAI), a leading U.S. supplier of analog computers, began development of a computer controlled quadrupole mass spectrometer under the direction of Robert E. Finnigan. (wikipedia.org)
The GC-MS is composed of two major building blocks: the gas chromatograph and the mass spectrometer. (wikipedia.org)
The molecules are retained by the column and then elute (come off) from the column at different times (called the retention time), and this allows the mass spectrometer downstream to capture, ionize, accelerate, deflect, and detect the ionized molecules separately. (wikipedia.org)
The mass spectrometer does this by breaking each molecule into ionized fragments and detecting these fragments using their mass-to-charge ratio. (wikipedia.org)
Sometimes two different molecules can also have a similar pattern of ionized fragments in a mass spectrometer (mass spectrum). (wikipedia.org)
Combining the two processes reduces the possibility of error, as it is extremely unlikely that two different molecules will behave in the same way in both a gas chromatograph and a mass spectrometer. (wikipedia.org)
The Agilent 240 Ion Trap mass spectrometer (MS), combined with the Agilent 7890B GC, delivers exceptional performance and unsurpassed flexibility with both MS and GC options. (buffalo.edu)
As a sample constituent elutes from the GC column, it enters the ionization chamber of the mass spectrometer where the molecules are ionized, typically by electron impact. (mee-inc.com)
Samples were then analyzed by a gas chromatograph equipped with a mass spectrometer (single ion monitoring) with a Varian VF-5ms capillary column. (inrs.ca)
With the triple quadrupole mass spectrometer organic traces can be identified and quantified in the pg range. (rms-foundation.ch)
Similarly, several types of mass analyzers such as magnetic sector, quadrupole, ion-trap, or time of flight (TOF) can be used, depending on continuous or pulsed mode detection, Mass spectrometer can work in both full scan and selective ion monitoring (SIM) modes. (infinitalab.com)
Analyses were carried out on a gas chromatograph coupled with an ion trap mass spectrometer operated in electron ionization and methanol positive chemical ionization. (archives-ouvertes.fr)
Urine steroid profiles were assessed with a gas chromatograph-mass spectrometer Shimadzu GCMS-QP2020. (almclinmed.ru)
Headspace was transferred to an evacuated canister and quantitatively analyzed for 20 VOCs as well as tentatively identified compounds using a preconcentrator/gas chromatography/ mass spectrometer system. (cdc.gov)
3. Triple quadrupole mass spectrometer (Quattro Premier XE, Micromass now Waters) equipped with a 1100 LC-system (Agilent). (fz-borstel.de)
4. Triple quadrupole mass spectrometer (XEVO TQ-MS, Waters) equipped with a 1100 LC-System (Agilent). (fz-borstel.de)
An LC/MS system contains an HPLC as described above but instead of a non-selective UV detector, the detector is a mass spectrometer. (labmanager.com)
Photographed in 2012, chemist Jennifer Roberts, of the Chemical Exposure & Monitoring Branch of the Division of Applied Research and Technology (DART), was performing a manual injection on a gas chromatograph-mass spectrometer (GC-MS), while inside the Gas Chromatography-Mass Spectrometry Lab, in Cincinnati, Ohio. (cdc.gov)

A fast-screening dispersive liquid-liquid microextraction-gas chromatography-mass spectrometry method applied to the determination of efavirenz in human plasma samples. (harvard.edu)

The assay procedure involved trimethylsilyl (TMS) derivatization of CBD and the internal standard delta-6-tetrahydrocannabinol (THC), capillary column gas chromatography, ion trap mass spectroscopy in positive ion chemical ionization mode using isobutane, and calculations of CBD levels based on peak ion intensity of the 387 M + H peak of delta-6-THC-TMS and the 459 M + H peak of CBD-2TMS. (nih.gov)
In this work, we develop a Fourier transform infrared spectroscopy-based method to measure the gas-phase dynamics occurring during atomic layer deposition of hafnium oxide using tetrakis (ethylmethylamido) hafnium and water vapor. (nist.gov)
This paper discusses the use of high-precision direct absorption spectroscopy to realize amount of substance standards for ozone (O3), a reactive species which cannot be delivered through traditional gravimetrically based gas cylinder standards. (nist.gov)
Validated by GC-MS (gas chromatography-mass spectrometry) and FTIR (Fourier transform infrared spectroscopy). (nativeremedies.com)

The main advantage of HPLC versus gas chromatography (GC) is the ability to quantify both acidic and neutral forms of cannabinoids without derivatization because high temperatures are not required for the analysis. (labmanager.com)

Gas Chromatography-Tandem Mass spectrometry (GC-MS-MS) couples a Gas Chromatograph (GC) with two Mass Spectrometers to p rovide superior selectivity sensitivity and detail in molecular structure analysis. (infinitalab.com)
Gas Chromatography-Tandem Mass Spectrometry (GC-MS-MS) is a microanalytical technique that provides superior selectivity sensitivity and detail, when compared to GC with a single MS (GC-MS). (infinitalab.com)
Gas chromatography with Tandem Mass Spectrometry (GC-MS-MS ) is a configuration that uses a GC followed by two Mass Spectrometers having the same type of mass analyzers. (infinitalab.com)
To increase confidence in compound identifications, the use of structural fragmentation data collected via tandem mass spectrometry (MS/MS or MS 2 ) is vital. (nature.com)

The advent of highly selective separatory chromatographic methods (LC and GC) increasingly linked to mass spectrometers means that analytical methods are now available for all of the important adrenal cortical hormones, their major precursors and metabolites, and synthetic glucocorticoids. (semanticscholar.org)
It was the aim of this work to develop a gas chromatographic - mass spectrometric (GC-MS) method that allow for the simultaneous analysis of the endogenous catecholamines, their basic and acidic metabolites using a single extraction procedure (which is easy to use and not tedious) with minimal derivatization steps. (up.ac.za)
Four different gas chromatographic - mass spectrometric methods were developed for the analysis of the catecholamines and their metabolites and are discussed in detail. (up.ac.za)
This paper describes a rapid gas chromatographic/mass spectrometric (GC/MS) screening method for the detection of drugs of abuse and/or their metabolites in urine. (unicatt.it)
Currently, major activities include measurements of hormones, inflammatory factors, fatty acids, and endogenous metabolites , analysed by a variety of assays, such as immunoassays, gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS), in samples from large-scale epidemiological studies. (who.int)

Like liquid chromatography-mass spectrometry, it allows analysis and detection even of tiny amounts of a substance. (wikipedia.org)
The technique of "single ion monitoring" (SIM) was applied to the quantitative detection of five representative derivatives of Reichstein's Substance S. The sensitivity with which single, characteristic fragment ions in their mass spectra could be measured varied considerably between derivatives, the limit of detection in the most favourable case (the 17alpha,21-anhydro derivative) being 400 pg. (bl.uk)
There are only few studies evaluating the diagnostic value of gas chromatography-mass spectrometry (GC-MS) for detection of ACC recurrence after surgery. (almclinmed.ru)
Gas chromatography with mass spectrometry (GC/MS) is commonly used for the analysis of water samples, but PFAS compounds pose special problems in sample pretreatment, separation, and detection. (tntech.edu)
The most common approach to terpene analysis is headspace GC with flame ionization detection, mass spectrometry (MS), or both. (labmanager.com)
The use of high-quality standards, reagents, and chromatography consumables is a prerequisite for accurate and reliable testing and detection of terpenes in cannabis crops and cannabis-derived products. (labmanager.com)

e-learning series of 5 GCMS and 9 GC training sessions covering key principles of gas chromatography and mass spectrometry. (ibms.org)

These derivatives were compared with respect to their ease of preparation, stability, retention characteristics and mass spectra. (bl.uk)
Analytical methods were evaluated for measuring cocaine (CO), benzoylecgonine (BE), and ecgonine methyl ester (EME) in urine and methanolic extracts from meconium and diapers by isotope dilution gas chromatography/mass spectrometry (GC/MS). Volatile derivatives of the extracted drugs were generated before GC/MS analysis. (unboundmedicine.com)
Thiazolidine peracetates: carbohydrate derivatives that readily assign cis-, trans-2,3- monosaccharides by gas chromatography - mass spectrometry analysis. (usda.gov)
2. Gas chromatography/mass spectrometry of simple coumarins, 3-phenylpropionic acids and their hydroxy and methoxy derivatives. (rxlist.com)

We propose a new quantitative gas chromatographymass spectrometry with isotope dilution (GC-ID-MS) method for the simultaneous determination of urinary free cortisol (UFC) and 6β-OH-cortisol (6β-OHC). (semanticscholar.org)

Gas chromatography/Fourier transform infrared/mass spectrometry coupling : a tool for Li-ion bat. (rwth-aachen.de)

As a result of the thermal lability of many of these compounds, particularly those possessing the "dihydroxyacetone" side-chain, modification of the basic structure is a prerequisite in any gas-phase analytical procedure. (bl.uk)
Compounds are identified from the mass spectrum by their unique ion fragmentation patterns. (mee-inc.com)
This compound identification analysis is performed by a computerized comparison of the mass spectra for the sample with spectra library for known compounds. (mee-inc.com)
Samples were analyzed using GC, Gas Chromatography-Mass Spectrometry (GC-MS) to identify major and bioactive compounds. (frontiersin.org)
ISO 10638:2010 specifies a qualitative method, using gas chromatography/mass spectrometry, for the identification of antidegradants in raw rubbers, latices, unvulcanized-rubber compounds and vulcanized-rubber products. (iso.org)
Volatile aroma compounds were determined using Headspace Gas Kromotografi Mass Spectrometry (HS-GC/MS) technique. (agrifoodscience.com)
The GC-MS-MS overcomes the limitations of GC with a single MS (GC-MS), when working with complex sample matrices, more sensitive analysis requirements, isomeric compounds not separated by GC and gives additional mass and structural information. (infinitalab.com)
Mass Spectrometry works by ionizing chemical compounds to generate charged ions, with a range of molecular masses, which are then separated based on their mass to charge (m/z) ratios and analyzed by spectrometry principles. (infinitalab.com)
Individual compounds have their own unique mass spectrum since every pure compound always produces the same family of ions. (infinitalab.com)
Gas chromatography-mass spectrometry (GC-MS) analysis was performed to identify the bioactive compounds in the ethylacetate fraction, antioxidant activity was evaluated using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays whilst the total phenolic and flavonoid contents were determined by already adopted protocols. (jomped.org)
Investigate several analytical instrumental methods/approaches/techniques, including but not limited to gas, liquid, and ion chromatographic techniques and spectroscopic techniques for determination of chemical compounds in workplace atmospheres. (cdc.gov)

Since the molecules are measurable by their mass, LC/MS provides highly selective, quantitative results. (labmanager.com)

abstract = "Gas chromatography (GC) has in recent times become an important tool for the fatty acid profiling of human blood and plasma. (vu.nl)

A sensitive and reproducible procedure using gas chromatography coupled with mass spectrometry is described for the determination of p-tert-octylphenol (OP), a persistent degradation product of alkylphenol ethoxylates that binds to the estrogen receptor in blood and tissues. (inrs.ca)

Gas chromatography coupled to mass spectrometry (GC-MS) characterization and evaluation of antibacterial bioactivities of the essential oils from Piper arboreum Aubl. (degruyter.com)
Ultraviolet degradation of procymidone--structural characterization by gas chromatography coupled with mass spectrometry and potential toxicity of photoproducts using in silico tests. (archives-ouvertes.fr)
Collection of plant leaves, preparation of extracts, anti-nutrient analysis, phytochemical screening via crude method and gas chromatography-mass spectrophotometer (GC-MS), isolation and characterization of S. aureus and the antimicrobial activity test were all done using standard protocols. (biomedcentral.com)
Mass spectrometry-based metabolomics plays an important role in clinical research, disease treatment, drug characterization, animal and plant research, agricultural research, and nutrition. (rsc.org)
Omics experiments as well as tandem mass spectrometric experiments for structural characterization are performed in our group. (fz-borstel.de)

The samples for GC/MS can be gases, liquids, or solids. (mee-inc.com)
Gases and liquids can be injected directly into the sample injector. (mee-inc.com)

Prediction of MS/MS spectra en masse and mapping pre-computed spectra to structures and metadata within chemistry databases can enhance identification schemes and enable integration into various software systems and workflows. (nature.com)

The mass spectrometry process normally requires a very pure sample while gas chromatography using a traditional detector (e.g. (wikipedia.org)
The magnetic poles separate the ions by their mass/charge ratio, successively focusing ions with increasing mass onto a detector for counting. (mee-inc.com)

The combination of metabolomics and mass spectrometry is of great significance for the discovery and identification of metabolite biomarkers. (rsc.org)

The positive ions are separated according to their mass by a mass analyzer. (mee-inc.com)
The mass analyzer most commonly used in GC/MS is the quadrapole filter, in which the ions pass by four hyperbolic magnetic poles created by a radio frequency field. (mee-inc.com)
The analyzer scans step-wise through a set range of mass values to evaluate the relative abundance of ions at each mass value. (mee-inc.com)
In a Tandem MS system (MS-MS), the ions (termed precursor ions) that are separated in the first mass analyzer enter a collision cell for further fragmentation The collision cell is filled with a suitable inert gas where collisions between the precursor ions and inert gas molecules are induced by an oscillatory field, causing bond breakage in the precursor ions to form product ions. (infinitalab.com)
The product ions undergo further separation in the second mass analyzer, yielding more information and reducing interferences and background noise. (infinitalab.com)

The gas chromatograph utilizes a capillary column whose properties regarding molecule separation depend on the column's dimensions (length, diameter, film thickness) as well as the phase properties (e.g. 5% phenyl polysiloxane). (wikipedia.org)
In a gas chromatograph, the sample chemical mixture is vaporized, and transported by an inert carrier gas into a column (packed or capillary), containing the solid phase (termed stationary phase). (infinitalab.com)

Gas chromatography-mass spectrometry (GC-MS) is an analytical method that combines the features of gas-chromatography and mass spectrometry to identify different substances within a test sample. (wikipedia.org)
The burned body in one case showed no presence of volatile substances in the intratracheal gas, nor intratracheal soot, although high concentrations (1 μg/g and more) of volatile substances were detected on the clothes. (astm.org)
Mass spectrometry technology has been applied to various basic disciplines, providing technical support for the discovery and identification of endogenous substances in living organisms. (rsc.org)

Mass Spectrom. (lsu.edu)
Biomed Environ Mass Spectrom 1988;15(8):413-417. (rxlist.com)

It is not possible to make an accurate identification of a particular molecule by gas chromatography or mass spectrometry alone. (wikipedia.org)

The mass spectrometry tool could further improve and develop the exploratory research of the life sciences. (rsc.org)

We utilize liquid chromatography to fractionate and analyse components of complex bacterial extracts and isolation of fractions for structural analysis using NMR and MS (Gisch et al. (fz-borstel.de)
Both extract and fractions underwent a modified form of gas chromatography-mass spectrometry analysis. (naturalnews.com)

In this study, the intentional incorporation of an air bubble into a solvent droplet is proposed for fully automated bubble-in-drop microextraction-gas chromatography-mass spectrometric (BID-GC-MS) analysis of selected organochlorine pesticides as model analytes. (chromatographyonline.com)
ISO 16000-33:2017 specifies the sampling and analysis of phthalates in indoor air and describes the sampling and analysis of phthalates in house dust and in solvent wipe samples of surfaces by means of gas chromatography/mass spectrometry. (iso.org)
1.1 This test method provides a procedure to quantify six phthalates by solvent extraction of plasticized PVC articles followed by analysis of the extract by gas chromatography/mass spectrometry. (techstreet.com)
Residual solvent analysis is performed through headspace gas chromatography/mass spectrometry analysis. (labmanager.com)

Gas chromatography / mass spectrometry (GC/MS) is the marriage of two analytical methods into a versatile technique for the identification of complex volatile materials. (mee-inc.com)
1 Techniques involved in metabolomics methods include nuclear magnetic resonance, mass spectrometry (MS), and chromatography. (rsc.org)

We report the optimized conditions for the synthesis of the derivatized analytes, as well as their GC retention properties and characteristic mass spectrometric fragments. (tntech.edu)
Complex biological lipid extracts are directly analysed using tandem mass spectrometric approaches (Schwudke et al. (fz-borstel.de)

Journal of chromatography. (semanticscholar.org)
Journal of Chromatography A , 1186 , 365-371. (vu.nl)
Journal of Chromatography A, 993 (1-2), 89-102. (mpg.de)

In the present work, a fully automated bubble-in-drop (BID) microextraction approach coupled to gas chromatography-mass spectrometry (GC-MS) for the analysis of three organochlorine pesticides (OCPs), α-hexachlorocyclohexane (HCH), dichlorodiphenyldichloroethane (DDD), and dieldrin (DID) as model analytes in water samples, was developed and evaluated. (chromatographyonline.com)
Samples are separated in a gaseous state and analyzed using their mass/charge ratio. (uwlax.edu)
Samples were analyzed by gas chromatography and mass spectrometry. (cdc.gov)

Development and analytical validation of a gas chromatography-mass spectrometry method for the measurement of sugar probes in canine serum. (tamu.edu)

In 1997, He and Lee reported a concept to perform LLME in a simple apparatus or device (in this case, the commonly used microsyringe), which served as a microseparatory funnel for extraction, before the extract was injected, using the same device, into a gas chromatograph for analysis (4). (chromatographyonline.com)

Ambient mass spectrometry can detect small molecules directly, but complex mixtures can be a challenge. (lsu.edu)
The Mass Spectrometry technique requires a very pure sample and does not work well for mixtures. (infinitalab.com)

e-learning series of 5 training sessions covering key principles of liquid chromatography. (ibms.org)

Gas Chromatography utilizes the principle that intermolecular (physical adsorption) forces between molecules in a gas and a solid surface depend upon the molecular structure and the nature of the solid surface. (infinitalab.com)

The target analytes are extracted by mixing the sample with water and purge with inert gas (e.g. (wikipedia.org)
The sample is carried through the column by the mobile phase, typically an inert gas. (mee-inc.com)
The mobile phase can be any inert gas, but is typically helium. (mee-inc.com)

Gas chromatography (GC) effectively separates the different constituents of the sample for subsequent analysis and identification by mass spectrometry (MS). (mee-inc.com)

Can gas chromatography combustion isotope ratio mass spectrometry be used to quantify organic compound abundance? (hutton.ac.uk)

Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry. (vu.nl)
Dive into the research topics of 'Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry. (vu.nl)

The chemical components were characterized by gas chromatography coupled to mass spectrometry, which revealed β-copaen-4-α-ol (31.38%), spathulenol (25.92%), and germacrene B (21.53%) as major constituents of the essential oils of Piper arboreum, Piper aduncum , and Piper gaudichaudianum , respectively. (degruyter.com)
LaFrancois, CJ, Yu, K & Sowers, LC 1998, ' Quantification of 5-(hydroxymethyl)uracil in DNA by gas chromatography/mass spectrometry: Problems and solutions ', Chemical Research in Toxicology , vol. 11, no. 7, pp. 786-793. (utmb.edu)
Fossil wood that is ca 7 million years old from Bükkábrány (Hungary) was analyzed by thermogravimetry (TG), differential scanning calorimetry (DSC) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) to evaluate alterations of its chemical composition. (sibjforsci.com)

In particular, O-isopentyloxime trimethylsilyl (iPO-TMS) ethers were of value in affording gas-phase "group" separations of keto- from hydroxysteroids. (bl.uk)

Material Identification - The first result from the compiled data is a total-ion chromatogram (TIC), which is a plot of the total mass eluting from the GC and detected by MS as a function of time. (mee-inc.com)
More specific identification of the compound(s) for each band can then be made from the mass spectrum corresponding to the band. (mee-inc.com)
Confident identification of unknown chemicals in high resolution mass spectrometry (HRMS) screening studies requires cohesive workflows and complementary data, tools, and software. (nature.com)
Liquid chromatography mass spectrometry (LC/MS) is used for cannabis and hemp potency testing in scenarios when identification is critical. (labmanager.com)

Liquid chromatography system used for quantitative and qualitative analysis of anions and cations in solution. (uwlax.edu)

Anatomy6

Organisms7

Chemicals and Drugs67

Analytical, Diagnostic and Therapeutic Techniques and Equipment42

Phenomena and Processes27

Disciplines and Occupations5

Anthropology, Education, Sociology and Social Phenomena2

Technology, Industry, Agriculture1

Information Science4

Health Care9

Analysis of gabapentin in serum and plasma by solid-phase extraction and gas chromatography-mass spectrometry for therapeutic drug monitoring. (1/5623)

Solid-phase microextraction for cannabinoids analysis in hair and its possible application to other drugs. (2/5623)

Highly sensitive quantitation of methamphetamine by time-resolved fluoroimmunoassay using a new europium chelate as a label. (3/5623)

Cocaine metabolite kinetics in the newborn. (4/5623)

The urinary elimination profiles of diazepam and its metabolites, nordiazepam, temazepam, and oxazepam, in the equine after a 10-mg intramuscular dose. (5/5623)

Semiautomated preparation of 3,5,6-trichloro-2-pyridinol in human urine using a Zymate XP laboratory robot with quantitative determination by gas chromatography-negative-ion chemical ionization mass spectrometry. (6/5623)

Determination of pyrolysis products of smoked methamphetamine mixed with tobacco by tandem mass spectrometry. (7/5623)

Identification and quantification of cocaine N-oxide: a thermally labile metabolite of cocaine. (8/5623)

Gas Chromatography-Mass Spectrometry

Mass Spectrometry

Chromatography, Gas

Chromatography, Liquid

Chromatography, High Pressure Liquid

Volatile Organic Compounds

Solid Phase Microextraction

Metabolomics

Tandem Mass Spectrometry

Metabolome

Perianal Glands

Spectrometry, Mass, Electrospray Ionization

Oils, Volatile

Volatilization

Ocimum basilicum

Chromatography, Thin Layer

Androstenediols

Acetic Anhydrides

Substance Abuse Detection

Meconium

Deuterium

Doping in Sports

F2-Isoprostanes

Magnetic Resonance Spectroscopy

Fatty Acids

Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Biotransformation

Carboxylic Acids

Hydroxyeicosatetraenoic Acids

Gases

Urinalysis

Reproducibility of Results

Oxidation-Reduction

Esters

Quality Control

Steroids

Methylation

Molecular Structure

Carbohydrate Conformation

Water Pollutants, Chemical

Carbohydrate Sequence

Lipoxygenase

Molecular Sequence Data

Polycyclic Hydrocarbons, Aromatic

Stereoisomerism

Sensitivity and Specificity

Chemistry

Chemical Phenomena

Arachidonic Acids

Arachidonic Acid

Hydrolysis

Proteomics

Dinoprost

Cytochrome P-450 Enzyme System

Fatty Acids, Unsaturated

Biological Markers

Liver

Hexanes

Chromatography, Affinity

Time Factors

Cattle

Chromatography, Ion Exchange

Kinetics

Eucommiaceae

Calibration

Amino Acid Sequence

Lipid Metabolism

Isotope Labeling

Pentanes

Chromatography

8,11,14-Eicosatrienoic Acid

Reference Standards

Proteome

Limit of Detection

Chromatography, Gel

Rhodiola

Breath Tests

Reference Values

Water Pollutants

Flame Ionization