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)
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.
A 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)
Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.
Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.
Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.
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)
Chromatographic techniques in which the mobile phase is a liquid.
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
The sum of the weight of all the atoms in a molecule.
A type of ion exchange chromatography using diethylaminoethyl cellulose (DEAE-CELLULOSE) as a positively charged resin. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
A method of gel filtration chromatography using agarose, the non-ionic component of agar, for the separation of compounds with molecular weights up to several million.
The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
Elements that constitute group 18 (formerly the zero group) of the periodic table. They are gases that generally do not react chemically.
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 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.
Measurement of oxygen and carbon dioxide in the blood.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The rate dynamics in chemical or physical systems.
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.
An analytical technique for resolution of a chemical mixture into its component compounds. Compounds are separated on an adsorbent paper (stationary phase) by their varied degree of solubility/mobility in the eluting solvent (mobile phase).
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A combustible, gaseous mixture of low-molecular weight PARAFFIN hydrocarbons, generated below the surface of the earth. It contains mostly METHANE and ETHANE with small amounts of PROPANE; BUTANES; and higher hydrocarbons, and sometimes NITROGEN; CARBON DIOXIDE; HYDROGEN SULFIDE; and HELIUM. (from McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
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)
A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
A 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 composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.
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.
The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES. Carbohydrates are composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n.
A severe condition resulting from bacteria invading healthy muscle from adjacent traumatized muscle or soft tissue. The infection originates in a wound contaminated with bacteria of the genus CLOSTRIDIUM. C. perfringens accounts for the majority of cases (over eighty percent), while C. noyvi, C. septicum, and C. histolyticum cause most of the other cases.
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)
Electrophoresis in which a pH gradient is established in a gel medium and proteins migrate until they reach the site (or focus) at which the pH is equal to their isoelectric point.
A method of separation of two or more substances by repeated distribution between two immiscible liquid phases that move past each other in opposite directions. It is a form of liquid-liquid chromatography. (Stedman, 25th ed)
A series of steps taken in order to conduct research.
Areas of the earth where hydrocarbon deposits of PETROLEUM and/or NATURAL GAS are located.
A hybrid separation technique combining both chromatographic and electrophoretic separation principles. While the method was invented to separate neutral species, it can also be applied to charged molecules such as small peptides.
The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.
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.
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).
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.
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.
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 chemical and physical integrity of a pharmaceutical product.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
The pH in solutions of proteins and related compounds at which the dipolar ions are at a maximum.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
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)
The process of cleaving a chemical compound by the addition of a molecule of water.
A basis of value established for the measure of quantity, weight, extent or quality, e.g. weight standards, standard solutions, methods, techniques, and procedures used in diagnosis and therapy.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC
Proteins prepared by recombinant DNA technology.
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
Pyrolysis of organic compounds at the temperature of a hydrogen-air flame to produce ionic intermediates which can be collected and the resulting ion current measured by gas chromatography.
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
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.
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)
Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
A group of compounds with the general formula M10(PO4)6(OH)2, where M is barium, strontium, or calcium. The compounds are the principal mineral in phosphorite deposits, biological tissue, human bones, and teeth. They are also used as an anticaking agent and polymer catalysts. (Grant & Hackh's Chemical Dictionary, 5th ed)
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
Severe irritant and vesicant of skin, eyes, and lungs. It may cause blindness and lethal lung edema and was formerly used as a war gas. The substance has been proposed as a cytostatic and for treatment of psoriasis. It has been listed as a known carcinogen in the Fourth Annual Report on Carcinogens (NTP-85-002, 1985) (Merck, 11th ed).
The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
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.
Compounds in which a methyl group is attached to the cyano moiety.
Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.
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.
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 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.
Concentration or quantity that is derived from the smallest measure that can be detected with reasonable certainty for a given analytical procedure.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
The characteristic 3-dimensional shape of a carbohydrate.
Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)
A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.
Presence of warmth or heat or a temperature notably higher than an accustomed norm.
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
Proteins found in any species of bacterium.
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.
Elements of limited time intervals, contributing to particular results or situations.
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
The 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.
Helium. A noble gas with the atomic symbol He, atomic number 2, and atomic weight 4.003. It is a colorless, odorless, tasteless gas that is not combustible and does not support combustion. It was first detected in the sun and is now obtained from natural gas. Medically it is used as a diluent for other gases, being especially useful with oxygen in the treatment of certain cases of respiratory obstruction, and as a vehicle for general anesthetics. (Dorland, 27th ed)
The formation of a solid in a solution as a result of a chemical reaction or the aggregation of soluble substances into complexes large enough to fall out of solution.
Sulfuric acid diammonium salt. It is used in CHEMICAL FRACTIONATION of proteins.
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.
Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.
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.
Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.
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).
Established cell cultures that have the potential to propagate indefinitely.
High-molecular-weight insoluble polymers that contain functional cationic groups capable of undergoing exchange reactions with anions.
The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
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 phase transition from liquid state to gas state, which is affected by Raoult's law. It can be accomplished by fractional distillation.
Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Transport proteins that carry specific substances in the blood or across cell membranes.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Methodologies used for the isolation, identification, detection, and quantitation of chemical substances.
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.
Proteins which contain carbohydrate groups attached covalently to the polypeptide chain. The protein moiety is the predominant group with the carbohydrate making up only a small percentage of the total weight.
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.
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.
Any compound containing one or more monosaccharide residues bound by a glycosidic linkage to a hydrophobic moiety such as an acylglycerol (see GLYCERIDES), a sphingoid, a ceramide (CERAMIDES) (N-acylsphingoid) or a prenyl phosphate. (From IUPAC's webpage)
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.
Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.
A CHROMATOGRAPHY method using supercritical fluid, usually carbon dioxide under very high pressure (around 73 atmospheres or 1070 psi at room temperature) as the mobile phase. Other solvents are sometimes added as modifiers. This is used both for analytical (SFC) and extraction (SFE) purposes.
The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.
The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.
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.
A species of gram-positive, coccoid bacteria isolated from skin lesions, blood, inflammatory exudates, and the upper respiratory tract of humans. It is a group A hemolytic Streptococcus that can cause SCARLET FEVER and RHEUMATIC FEVER.
Centrifugation with a centrifuge that develops centrifugal fields of more than 100,000 times gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.
Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.
An electrochemical process in which macromolecules or colloidal particles with a net electric charge migrate in a solution under the influence of an electric current.
Pesticides or their breakdown products remaining in the environment following their normal use or accidental contamination.
The extent to which an enzyme retains its structural conformation or its activity when subjected to storage, isolation, and purification or various other physical or chemical manipulations, including proteolytic enzymes and heat.
Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.
Organic compounds that have a relatively high VAPOR PRESSURE at room temperature.
The mineral component of bones and teeth; it has been used therapeutically as a prosthetic aid and in the prevention and treatment of osteoporosis.
Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.
A very strong halogenated derivative of acetic acid. It is used in acid catalyzed reactions, especially those where an ester is cleaved in peptide synthesis.
The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.
Oligosaccharides containing two monosaccharide units linked by a glycosidic bond.
Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.
Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and nonsugar component (aglycone) are formed. (From Dorland, 28th ed; From Miall's Dictionary of Chemistry, 5th ed)
Simple sugars, carbohydrates which cannot be decomposed by hydrolysis. They are colorless crystalline substances with a sweet taste and have the same general formula CnH2nOn. (From Dorland, 28th ed)
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
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.
Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.
A technique that combines protein electrophoresis and double immunodiffusion. In this procedure proteins are first separated by gel electrophoresis (usually agarose), then made visible by immunodiffusion of specific antibodies. A distinct elliptical precipitin arc results for each protein detectable by the antisera.
Cyanogen bromide (CNBr). A compound used in molecular biology to digest some proteins and as a coupling reagent for phosphoroamidate or pyrophosphate internucleotide bonds in DNA duplexes.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Inorganic salts of sulfuric acid.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.
Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.
Antibodies produced by a single clone of cells.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
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)
Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.
Electrophoresis in which discontinuities in both the voltage and pH gradients are introduced by using buffers of different composition and pH in the different parts of the gel column. The term 'disc' was originally used as an abbreviation for 'discontinuous' referring to the buffers employed, and does not have anything to do with the shape of the separated zones.
The systematic study of the complete complement of proteins (PROTEOME) of organisms.
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)
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.
Measurement of the intensity and quality of fluorescence.
A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.
The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.
A hexose or fermentable monosaccharide and isomer of glucose from manna, the ash Fraxinus ornus and related plants. (From Grant & Hackh's Chemical Dictionary, 5th ed & Random House Unabridged Dictionary, 2d ed)
The separation of particles from a suspension by passage through a filter with very fine pores. In ultrafiltration the separation is accomplished by convective transport; in DIALYSIS separation relies instead upon differential diffusion. Ultrafiltration occurs naturally and is a laboratory procedure. Artificial ultrafiltration of the blood is referred to as HEMOFILTRATION or HEMODIAFILTRATION (if combined with HEMODIALYSIS).
Six-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives. Various polyneuropathies are caused by hexane poisoning.
Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.
An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. Deficiency of galactosyl-1-phosphate uridyltransferase (GALACTOSE-1-PHOSPHATE URIDYL-TRANSFERASE DEFICIENCY DISEASE) causes an error in galactose metabolism called GALACTOSEMIA, resulting in elevations of galactose in the blood.
The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.
Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.
Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.
The application of medical knowledge to questions of law.
A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.
A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.
Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.
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.
Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.
A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
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)
Serum that contains antibodies. It is obtained from an animal that has been immunized either by ANTIGEN injection or infection with microorganisms containing the antigen.
Apparatus for removing exhaled or leaked anesthetic gases or other volatile agents, thus reducing the exposure of operating room personnel to such agents, as well as preventing the buildup of potentially explosive mixtures in operating rooms or laboratories.
Protein or glycoprotein substances of plant origin that bind to sugar moieties in cell walls or membranes. Some carbohydrate-metabolizing proteins (ENZYMES) from PLANTS also bind to carbohydrates, however they are not considered lectins. Many plant lectins change the physiology of the membrane of BLOOD CELLS to cause agglutination, mitosis, or other biochemical changes. They may play a role in plant defense mechanisms.
Plants whose roots, leaves, seeds, bark, or other constituent parts possess therapeutic, tonic, purgative, curative or other pharmacologic attributes, when administered to man or animals.
The presence of organisms, or any foreign material that makes a drug preparation impure.
A group of naturally occurring N-and O-acyl derivatives of the deoxyamino sugar neuraminic acid. They are ubiquitously distributed in many tissues.
A genus of bacteria that form a nonfragmented aerial mycelium. Many species have been identified with some being pathogenic. This genus is responsible for producing a majority of the ANTI-BACTERIAL AGENTS of practical value.
Measurement and evaluation of the components of substances to be taken as FOOD.
A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.
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.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.

The gas-liquid chromatograph and the electron capture detection in equine drug testing. (1/4089)

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

Research and identification of tranquillizers - use of retention index. (2/4089)

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

Less common "doping" agents and substances encountered during routine screening for drugs. (3/4089)

The chromatographic and spectroscopic properties of several unusual substances which have been detected in the "alkaloidal" chloroform extract from racehorse urine and saliva samples are reported. Some of these substances have been identified by combined gas chromatography-mass spectrometry and the source of the substance is stated where this is known. Other substances whose identity is not known have been detected and their mass spectra show characteristic amine fragments. The occurrence of these unidentified substances is more frequent in aged urine samples and it would therefore appear that they are associated with putrefaction.  (+info)

Solid-phase microextraction and GC-ECD of benzophenones for detection of benzodiazepines in urine. (4/4089)

Benzodiazepines are common drugs that cause intoxication. Benzodiazepines and their metabolites can be converted by hydrolysis in acid to the corresponding benzophenones, which are easier to be separated from matrices because of their hydrophobic properties. In this study, a new separation technique called solid-phase microextraction (SPME), which can integrate extraction, concentration, sampling and sample introduction into one single procedure, has been employed to extract the products of benzodiazepines from urine after acid hydrolysis. The extracts were determined by gas chromatography with electron-capture detection (GC-ECD). The hydrolysis conditions were optimized by a statistic orthogonal design. Factors influencing direct-immersion (DI)-SPME process were also checked and chosen experimentally. The method was evaluated with spiked human urine samples. The recoveries of nine benzodiazepines ranged from 1 to 25%, with the highest for oxazolam and the lowest for bromazepam. The calibration curves were linear from 10 to 500 ng/mL for oxazolam, haloxazolam, flunitrazepam, nimetazepam, and clonazepam and from 20 to 1000 ng/mL for the others except bromazepam. The detection limits were 2-20 ng/mL for most drugs tested. The intraday and interday coefficients of variation of the developed method were within 10 and 17%, respectively. In addition, the utility of the method was confirmed by determining two ingested benzodiazepines (flunitrazepam and oxazolam) in a volunteer's urine; urine flunitrazepam was still detectable 32 h after a therapeutic dose (1.2 mg) of the drug. Finally, the DI-SPME was compared with the conventional liquid-liquid extraction with regard to detection limits and extraction efficiency of the analytes. By DI-SPME, more amounts of analytes could be introduced into GC column than by conventional liquid-liquid extraction, and thus lower detection limits of the analytes were reached, although benzophenone recoveries by DI-SPME were rather low.  (+info)

Gas-liquid chromatography of the heptafluorobutyrate derivatives of the O-methyl-glycosides on capillary columns: a method for the quantitative determination of the monosaccharide composition of glycoproteins and glycolipids. (5/4089)

We have developed a method involving the formation of hepta-fluorobutyrate derivatives of O-methyl-glycosides liberated from glycoproteins and glycolipids following methanolysis. The stable derivatives of the most common monosaccharides of these glycoconjugates (Ara, Rha, Xyl, Fuc, Gal, Man, Glc, GlcNAc, GalNAc, Neu5Ac, KDN) can be separated and quantitatively and reproducibly determined with a high degree of sensitivity level (down to 25 pmol) in the presence of lysine as an internal standard. The GlcNAc residue bound to Asn in N-glycans is quantitatively recovered as two peaks. The latter were easily distinguished from the other GlcNAc residues of N-glycans, thus allowing a considerable improvement of the data on structure of N-glycans obtained from a single carbohydrate analysis. The most common contaminants present in buffers commonly used for the isolation of soluble or membrane-bound glycoproteins (SDS, Triton X-100, DOC, TRIS, glycine, and polyacrylamide or salts, as well as monosaccharide constituents of proteoglycans or degradation products of nucleic acids) do not interfere with these determinations. A carbohydrate analysis of glycoproteins isolated from a SDS/PAGE gel or from PDVF membranes can be performed on microgram amounts without significant interferences. Since fatty acid methyl esters and sphingosine derivatives are separated from the monosaccharide peaks, the complete composition of gangliosides can be achieved in a single step starting from less than 1 microg of the initial compound purified by preparative Silicagel TLC. Using electron impact ionization mass spectrometry, reporter ions for the different classes of O-methyl-glycosides (pentoses, deoxy-hexoses, hexoses, hexosamines, uronic acids, sialic acid, and KDN) allow the identification of these compounds in very complex mixtures. The mass of each compound can be determined in the chemical ionization mode and detection of positive or negative ions. This method presents a considerable improvement compared to those using TMS derivatives. Indeed the heptafluorobutyrate derivatives are stable, and acylation of amino groups is complete. Moreover, there is no interference with contaminants and the separation between fatty acid methyl-esters and O-methyl glycosides is achieved.  (+info)

Methodological issues in biomonitoring of low level exposure to benzene. (6/4089)

Data from a pilot study on unmetabolized benzene and trans,trans muconic acid (t,t-MA) excretion in filling station attendants and unexposed controls were used to afford methodological issues in the biomonitoring of low benzene exposures (around 0.1 ppm). Urinary concentrations of benzene and t,t-MA were measured by dynamic head-space capillary GC/FID and HPLC, respectively. The accuracy of the HPLC determination of t,t-MA was assessed in terms of inter- and intra-method reliability. The adequacy of urinary t,t-MA and benzene as biological markers of low benzene exposure was evaluated by analysing the relationship between personal exposure to benzene and biomarker excretion. Filling station attendants excreted significantly higher amounts of benzene, but not of t,t-MA, than controls. Adjusting for occupational benzene exposure, smokers excreted significantly higher amounts of t,t-MA, but not of unmetabolized benzene, than nonsmokers. A comparative analysis of the present and previously published biomonitoring surveys showed a good inter-study agreement regarding the amount of t,t-MA and unmetabolized benzene excreted (about 0.1-0.2 mg/l and 1-2 micrograms/l, respectively) per unit of exposure (0.1 ppm). For each biomarker, based on the distribution of parameters observed in the pilot study, we calculated the minimum sample size required to estimate the population mean with given confidence and precision.  (+info)

The structure of a glycopeptide (GP-II) isolated from Rhizopus saccharogenic amylase. (7/4089)

Mild alkaline treatment of glycopeptide (GP-II) resulted in the loss of 1 mole of serine and 5 moles of threonine per mole of GP-II, suggesting the presence of O-glycosyl bonds between 1 serine and 5 threonine residues and carbohydrate chains. Treatment of GP-II with alkaline borohydride released only disaccharide. Methylation studies of the carbohydrate moiety gave 2,3,4,6-tetra-O-methyl and 2,4,6-tri-O-methyl derivatives of mannose in a ratio of approximately 1:1. In addition, one step of Smith degradation resulted in the loss of about 6 residues of mannose per mole of GP-II. Moreover, alpha-mannosidase [EC] liberated about 6 residles of mannose per mole of GP-II. On the basis of these data, the structure of the carbohydrate moiety of GP-II was confirmed to be 3-O-alpha-mannosylmannose. The amino- and carboxyl-terminal amino acids of GP-II were determined to be threonine and serine, respectively. On reductive cleavage of N-proline bonds with metallic sodium in liquid ammonia, 2 moles of alanine per mole of GP-II were lost. From the compositions of three fragments isolated from the reductive cleavage products, the amino acid sequence of the peptide portion of GP-II was determined. Based on these data, a probable structure was proposed for GP-II.  (+info)

Cellular fatty acids and metabolic products of Pseudomonas species obtained from clinical specimens. (8/4089)

The cellular fatty acid composition of 112 reference strains and clinical isolates of Pseudomonas species was determined by gas-liquid chromatography (GLC). The presence and relative amounts of cyclopropane, hydroxy, and branched-chain fatty acids were distinguishing features of these strains. Determination of short-chain fatty acids extracted from spent growth media provided an additional means for identifying some strains. Our results show that clinical isolates of pseudomonads can be divided into eight distinct GLC groups. The procedures were especially useful for distinguishing glucose-nonoxidizing pseudomonads, which are difficult to identify by conventional criteria. Since the GLC procedures are simple, rapid, and highly reproducible, they are useful in diagnostic laboratories that process large numbers of cultures. Coupled with selected conventional tests, the analysis of short-chain and cellular fatty acids can be very useful for rapid screening of clinical isolates of Pseudomonas species.  (+info)

Pellizzari, E., Bunch, J. E., Bursey, J. T., Berkley, R. E., Sawicki, E., & Krost, K. (1976). Estimation of N-Nitrosodimethylamine Levels in Ambient Air by Capillary Gas-Liquid Chromatography/Mass Spectrometry. Analytical Letters, 9, 579 ...
A method is described for the gas chromatographic-electron-capture detection determination of alkenes via on-column bromination reactions. Pyridinium bromide perbromide (PBPB) was used as the Br2 source, and a cholesterol-glass beads mixture, treated with methanol, was used to remove excess Br2. The optimum ratio of cholesterol to glass beads was found to be 1:10, at which 93% of the bromine released from PBPB can be removed, without removal of the derivitized analytes. The conversion efficiency of alkene to the brominated derivative is extremely low (less than 2%) for ethene, whereas for propene and 1-butene it is 41 and 79%, respectively. For C3---C5 alkenes, this method is 200-300 times more sensitive than analysis of the underivitized analytes by using conventional flame ionization detection.. ...
Article High Resolution Detailed Hydrocarbon Analyses by Capillary Column Gas Chromatography. In the petrochemical industry, samples such as petroleum naphthas and gasolines routinely must be quantitatively separated into their individual components....
An interlaboratory study was organised to validate the preliminary CEN method PrEN 12673: Water Quality - Gas Chromatographic determination of some selected chlorophenols in water. This intercomparison study on three types of water - drinking water, surface water and waste water - comprised a total of nine samples: a high-level, low-level and blank for each of the three types of water. The level of sample was based on the water quality objectives. The variation of the samples with respect to homogeneity and stability of the components appeared after extensive testing to be negligible in comparison with the variation between the results of the participants. In this data set about 7% of the data were detected as statistical outliers and subsequently rejected. For the remaining data set the relative standard deviations for repeatability varied between 5% and 25% and reproducibility between 25% and 55%. Both these ranges comply with the general variation in interlaboratory studies as found by ...
Fatty acids are a widely studied group of lipids of sufficient taxonomic diversity to be useful in defining microbial community structure. The extraordinary resolution of glass capillary gas-liquid chromatography can be utilized to separate and tentatively identify large numbers of fatty acid methyl esters derived from the lipids of estuarine detritus and marine benthic microbiota without the bias of selective methods requiring culture or recovery of the microbes. The gas-liquid chromatographic analyses are both reproducible and highly sensitive, and the recovery of fatty acids is quantitative. The analyses can be automated, and the diagnostic technique of mass spectral fragmentation analysis can be readily applied. Splitless injection on glass capillary gas chromatographic columns detected by mass spectral selective ion monitoring provides an ultrasensitive and definitive monitoring system. Reciprocal mixtures of bacteria and fungi, when extracted and analyzed, showed progressive changes of ...
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D6229 - 06(2010) Standard Test Method for Trace Benzene in Hydrocarbon Solvents by Capillary Gas Chromatography , benzene content, capillary GC, gas chromatography, hydrocarbon solvents, Benzene--paints/related coatings/materials, Capillary gas chromatography, Gas chromatography (GC)--paints/related coatings/materials, Hydrocarbon solvents, Trace elements--paints/related coatings/materials,
TY - JOUR. T1 - The analysis of polyunsaturated fatty acids in meat by capillary gas‐liquid chromatography. AU - Sinclair, Andrew J.. AU - Slattery, William J.. AU - ODea, Kerin. PY - 1982/1/1. Y1 - 1982/1/1. N2 - Polyunsaturated fatty acids (PUFA) of lean meat from domesticated and wild ruminants (cattle, sheep, goat, sambar deer and buffalo) and non‐ruminants (pig, horse and kangaroo) have been examined by capillary gas‐liquid chromatography. Ten different PUFA were found in all specimens with linoleic acid accounting for at least 50% of the total, and arachidonic and linolenic acids being the next most abundant. The total PUFA content for the ruminants ranged from 9 % in beef to 31 % in sambar deer and for the non‐ruminants from 25 % in pig to 43 % in horse. In all species the meat phospholipids (PL) were rich in PUFA (range 24-46% of PL fatty acids), whereas the triglycerides were relatively more saturated (PUFA content range 2-17%). Overall, horse and kangaroo meat had the ...
TY - JOUR. T1 - Whey-protein-coated peanuts assessed by sensory evaluation and static headspace gas chromatography. AU - Lee, S. Y.. AU - Trezza, T. A.. AU - Guinard, J. X.. AU - Krochta, J. M.. PY - 2002/1/1. Y1 - 2002/1/1. N2 - Lipid oxidation is one of the leading causes of deterioration in peanuts. Oxygen concentration plays an important role in oxidation. Oxygen uptake can be impeded by specialized packaging systems or an edible coating, which in turn will decrease the rate of lipid oxidation. Four different formulations of whey-proteinrbased coatings were used to coat the peanuts. The peanut samples were stored in duplicate at 40°C, 50°C, and 60°C, each for storage times of 0, 5, 15, and 45 d. Descriptive analysis results revealed that the rancidity was significantly lower for whey-protein-coated peanuts than for uncoated peanuts. This finding was also confirmed by static headspace GC analysis.. AB - Lipid oxidation is one of the leading causes of deterioration in peanuts. Oxygen ...
China Gas Chromatograph for White Plasticizer with Fid, Find details about China Gas Chromatograph, Chromatograph from Gas Chromatograph for White Plasticizer with Fid - Labmen Instrument Technology Limited
A gas liquid chromatography system for the analysis of complex mixtures of fatty and resin acids has been developed. On 30-40 m long, 0.3 mm ID glass capillary columns coated with 1,4-butanediol succi
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Gas chromatography analysis. Researcher with a gas chromatography machine and autosampler. The machine into which samples are being loaded is a TurboMatrix 650 ATD autosampler. It handles and processes the gas chromatography samples automatically using a process called thermal desorption. Photographed as part of work carried out by the UKs Health and Safety Laboratory (HSL). - Stock Image C026/0582
High molecular weight (HMW) hydrocarbons (defined herein as C35+ compounds) are difficult to characterise by conventional analytical methods. Very few studies have reported precise and reproducible quantification of such compounds in fossil fuels. Nonetheless, such components have important effects on the physical and biological fate of fossil fuels in the geosphere. For example, the phase behaviour of waxy gas condensates is significantly affected by the varying proportions of HMW compounds. Similarly HMW compounds are amongst the most resistant petroleum components to biodegradation. The current study reports the development of reproducible quantitative high temperature capillary gas chromatography (HTCGC) methods for studying both these aspects of the chemistry of HMW hydrocarbons. In addition those hydrocarbons which remain unresolved when analysed by gas chromatography (so called unresolved complex mixtures UCMs) are also studied. UCMs may account for a large portion of the hydrocarbons in ...
TY - JOUR. T1 - Isotopic precision for a lead species (PbEt4) using capillary gas chromatography coupled to inductively coupled plasma-multicollector mass spectrometry. AU - Krupp, Eva Maria. AU - Pecheyran, C AU - Pinaly, H AU - Motelica-Heino, M AU - Koller, D AU - Young, S M M AU - Brenner, I B AU - Donard, O F X PY - 2001/7/31. Y1 - 2001/7/31. N2 - Precision and accuracy of lead isotope ratios of a volatile lead species (PbEt4) were determined by coupling a capillary GC to a magnetic sector multicollector ICP-MS. PbEt4 was prepared by ethylation of a certified lead isotope solution (NIST SRM 981). Coupling was achieved by a transfer line, which allowed simultaneous introduction of a thallium standard solution to correct for mass discrimination. Seven isotopes (Hg-202, Tl-203, Pb-204, Tl-205, Pb-206, Pb-207, Pb-208) were monitored simultaneously with a transient resolution of 50 ms. Pb isotope ratios for the PbEt4 peaks were calculated using transient peak integrals of each isotope signal. ...
TY - CONF. T1 - Principles and Advantages of Programmed Temperature Vaporising (PTV) Injectors for Capillary Gas Chromatography: Large volume injection and other Applications. AU - Janssen, J.G.M.. PY - 1997. Y1 - 1997. M3 - Other. T2 - conference; Shell Houston; 1997-09-01; 1997-09-01. Y2 - 1 September 1997 through 1 September 1997. ER - ...
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You may also wish to search for items by Krupcik. 26 matching references were found. Soják, L.; Krupcík, J.; Janák, J., Gas chromatography of all C15-C18 linear alkenes on capillary columns with very high resolution power, J. Chromatogr., 1980, 195, 1, 43-64, . [all data] Krupcik, J.; Leclercq, P.A.; Garaj, J.; Masaryk, J., Analysis of Divalent Metal Dialkyldithiocarbamates by Gas Chromatography and Mass Spectrometry, J. Chromatogr., 1979, 171, 285-304, . [all data] Matisova, E.; Krupcik, J.; Cellar, P.; Garaj, J., Quantitative Analysis of Hydrocarbons in Gasolines by Capillary Gas-Liquid Chromatography. I. Isothermal Analysis, J. Chromatogr., 1984, 303, 151-163, . [all data] Krupcik, J.; Repka, D.; Benicka, E.; Hevesi, T.; Nolte, J.; Paschold, B.; Mayer, H., Use of Retention Temperatures for the Identification of Phenols Separated on OV-1701 Capillary ...
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Gas liquid chromatography was employed to detect lactic acid in the cerebrospinal fluid of patients suspected of having bacterial meningitis. The technique was found to be both rapid and reliable. Differentiation between aseptic, purulent, and partially treated bacterial meningitis was readily achieved. The effectiveness of therapy in bacterial meningitis was indicated by a rapid fall in the concentration of lactic acid.
Gas chromatographic determination of the fatty acids in the seeds of cottonseed (Gossypium sp.) showed linoleic, palmitic, oleic, and stearic acids, with linoleic acid being the major component. Changes in the composition of fatty acids during various stages of germination were measured in the cotyledons and in the roots. A decrease in the content of all the fatty acids and an 8-fold increase in the moisture content of the cotyledons were observed during the 10 days of germination. There were no significant changes in the fatty acid contents of the roots with the exception of those in linoleic acid which increased by 50% during 4-10 days of germination. The possible significance of these changes is discussed. ...
Helium vs. hydrogen as a carrier gas in capillary Gas ChromatographyTrade NewsAfter the expense of a new gas chromatograph, the last thing any chemist wa...
The main sources of error in chromatographic analysis are described, particular attention being drawn to variable bias. This is one of the major potential sources as it is not easily detected. A...
You may also wish to search for items by Uralets, V. and Uralets. 7 matching references were found. Golovnya, R.V.; Uralets, V.P.; Kuzmenko, T.E., Characterization of fatty acid methyl esters by gas chromatography on siloxane liquid phases, J. Chromatogr., 1976, 121, 1, 118-121, . [all data] Rodchenkov, G.M.; Uralets, V.P.; Semenov, V.A.; Leclercq, P.A., Analysis of Dexamethasone, Triamcinolone, and Their Metabolites in Human Urine by Microcolumn Liquid and Capillary Gas Chromatography Mass Spectrometry, J. Hi. Res. Chromatogr. Chromatogr. Comm., 1988, 11, 3, 283-288, . [all data] Uralets, V.P.; Semenova, V.A.; Yakushin, M.A.; Semenov, V.A., Analysis of anabolic steroids in body fluids by capillary gas chromatography with a two-channel detection system and a computer, J. Chromatogr., 1983, 279, 695-707, . [all data] Rodchenkov, G.M.; Uralets, V.P.; Semenov, V.A., ...
A method is described for the adsorption on charcoal and desorption with carbon-disulfide (75150) for gas chromatographic determination of 2-butanone (78933). Data are given on the principle, range and sensitivity, interference, precision, accuracy, advantages and disadvantages of the method. Also described are the apparatus, reagents and procedure used; analysis of samples; determination of desor
biological samples. J. Chromatogr. 246, 81-87. 2. ANDERSON, R.L. (1983): Toxicity of fenvalerate and permethrin to several non- target aquatic invertebrates. Environ. Entamol. 11, 1251-1257. 3. ARGAUER, R.J., K.J. ELLER, M. P. RICHARD and T. BROWN RICHARD (1997): Determining ten synthetic pyrethroids in lettuce and ground meat by using ion-trap mass spectrometry and electron capture gas chromatography. J. Agric. Food Chem. 45, 180-184. 4. ARGAUER, R.J., K.I. ELLER, M.A. IBRAHIM and R.J. BROWN (1995): Determining propoxur and other carbamates in meat using HPLC fluorescence and gas chromatography/ion-trap mass spectrometry after supercritical fluid extraction. J. Agric. Food Chem. 43, 2774-2778. 5. BRAUN, H.E. and J. STANEK (1982): Application of the AOAC multi-residue method to determination of synthetic pyrethroid residues in celery and animal products. J. AOAC. 65, 685-689. 6. CHEN, Z. M. and Y. H. WANG (1996): Chromatographic methods for the determination of pyrethroid pesticide residues in ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
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Docosahexaenoic acid (DHA) in infant formula at concentrations based on worldwide human milk has resulted in circulating red blood cell (RBC) lipids related to visual and cognitive development. In this study, infants received study formula (17mg DHA/100kcal) with a commercially-available (Control: n=140; DHASCO®) or alternative (DHASCO®-B: n=127) DHA single cell oil from 14 to 120 days of age. No significant group differences were detected for growth rates by gender through 120 days of age. Blood fatty acids at 120 days of age were assessed by capillary column gas chromatography in a participant subset (Control: n=34; DHASCO-B: n=27). The 90% confidence interval (91-104%) for the group mean (geometric) total RBC DHA (µg/mL) ratio fell within the pre-specified equivalence limit (80-125%), establishing study formula equivalence with respect to DHA. This study demonstrated infant formula with DHASCO-B was safe, well-tolerated, and associated with normal growth. Furthermore, DHASCO and DHASCO-B ...
Agarwal N, Kewalramani N, Kamra D N, Agarwal D K and Nath K 1991 Hydrolytic enzymes of buffalo rumen: comparison of cell free fluid, bacterial and protozoal fractions. Buffalo Journal 7: 203-207. AOAC (Association of Official Analytical Chemists) 1995 Official Methods of Analysis, 16th edition; AOAC: Arlington, VA, USA. Bradford M M 1976 A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Analytical Biochemistry 72: 248-254. Cottyn B G and Boucque C V 1968 Rapid method for the gas-chromatographic determination of volatile fatty acids in rumen fluid. Journal of Agriculture and Food Chemistry 16: 105-107. Dehority B A 2005 Ciliate protozoa. In Methods in Gut Microbial Ecology for Ruminants, edited by H P S Makker and C S Mc Sweeney, IAEA, pp 67-78 ...
A new method for sampling and chemical analysis of alphacypermethrin in workplace air has been described. Air samples were taken using a glass tube filled with silica gel with chemically bounded octadecyl phase. Chromatographic determinations were conducted using an HP-5 capillary column (10 m x 0.53 mm) and an electron-capture detector. Alphacypermethrin recovery was 100.15%. The calculated detection limit for a 60-L air sample was 0.0001 mg/m3 ...
Learn how headspace analysis and GC/MS analysis helped the FDA identify and quantify the carcinogen Benzene in soft drinks in a blog from Innovatech Labs.
TY - JOUR. T1 - Optimization of temperature programming in gas chromatography with respect to separation time. II. Optimization of the individual temperature programme substrategies. AU - Bartu, V.. AU - Wicar, S.. AU - Scherpenzeel, G.J.. AU - Leclercq, P.A.. PY - 1986. Y1 - 1986. N2 - The temperature programme optimization substrategies for a mixture with non-intersecting retention time approximation functions are described. For mixtures of compounds whose elution functions intersect, the determination of strategies for possible solutions and of the corresponding substrategies for temperature programme optimization is derived. Heuristic methods for the minimization of the retention times of the most difficult to separate component pairs are presented. Further, the calculation of retention times and peak widths for optimization purposes is discussed.. AB - The temperature programme optimization substrategies for a mixture with non-intersecting retention time approximation functions are ...
D5317 - 98(2017) Standard Test Method for Determination of Chlorinated Organic Acid Compounds in Water by Gas Chromatography with an Electron Capture Detector , electron capture, gas chromatography, herbicides, organic acid,,
The latest market report published by Credence Research, Inc. Gas Chromatography In Medical Applications Market - Growth, Future Prospects, Competitive Analysis, 2017 - 2025, the global gas chromatography in medical applications market was valued at US$ 2,486.94 Mn in 2016, and is expected to reach US$ 4,381.11 Mn by 2025 expanding at a CAGR of 6.25 % from 2017 to 2025.. Browse the full report Gas Chromatography In Medical Applications Market - Growth, Future Prospects, Competitive Analysis, 2017 - 2025 at Market Insights. Gas chromatography is a matured market and provides tremendous opportunity for innovations in the design and operation aspects of gas chromatography. Challenges faced by many lab managers operating gas chromatography are insidious leaks and column trimming. Frequent innovations (Agilent Technologies) has resulted in replacing nuts and ferrules which earlier made connections for flow ...
This course looks at analytical columns for gas chromatography in detail, GC Detectors, mass spectrometry principles and the data generated; the types of mass spectrometers available that are hyphenated to GC; their vacuum systems, ionisation techniques, mass filters and detectors.
Sigma-Aldrich offers a number of SUPELCOWAX® 10 Capillary GC Column products. View information & documentation regarding SUPELCOWAX® 10 Capillary GC Column, including CAS, MSDS & more.
The 4-day Comprehensive GC Training course introduces the fundamental theory of GC along with the operation, maintenance and troubleshooting of the Thermo TRACE Gas Chromatograph using Xcalibur software.
Common oven temperatures (such as terms: cool oven, very slow oven, slow oven, moderate oven, hot oven, fast oven, etc.) are set to control the effects of baking in an oven, for various lengths of time. The various standard phrases to describe oven temperatures include words such as cool to hot or very slow to fast. For example, a cool oven has temperature set to 90°C (200°F), and a slow oven has a temperature range from 150-160°C (300-325°F). A moderate oven has a range of 180-190°C (350-375°F), and a hot oven has temperature set to 200-230°C (400-450°F). A fast oven has a range of 230-260°C (450-500°F) for the typical temperature. Conversion of units Gas Mark (Regulo) SI Units SI Units: Temperature, U.S. National Institute of Standards and Technology (NIST), U.S. Commerce Department, February 11, 2011, web: NIST-Temp: accessed 2011-03-26 ...
oven temperature off MY hotpoint RGB745 gas ovens temperature is off, sometimes as much as 200 degrees. It seems - Hotpoint RGB745 Gas Kitchen Range question
article{47fc4f1e-2c18-4477-8507-2504703b8b7e, abstract = {,p,Despite the maturity reached by targeted proteomic strategies, reliable and standardized protocols are urgently needed to enhance reproducibility among different laboratories and analytical platforms, facilitating a more widespread use in biomedical research. To achieve this goal, the use of dimensionless relative retention times (iRT), defined on the basis of peptide standard retention times (RT), has lately emerged as a powerful tool. The robustness, reproducibility and utility of this strategy were examined for the first time in a multicentric setting, involving 28 laboratories that included 24 of the Spanish network of proteomics laboratories (ProteoRed-ISCIII). According to the results obtained in this study, dimensionless retention time values (iRTs) demonstrated to be a useful tool for transferring and sharing peptide retention times across different chromatographic set-ups both intra- and inter-laboratories. iRT values also ...
A gas chromatograph having a carrier gas feed for a pressure-controlled feeding of a carrier gas stream, which feed leads to a sample applicator having preliminary separation which is connected to a b
Gas chromatography, first established in the 1950′s, is a mature analytical technique with many established applications. Therefore, it is probable that documented methods or journal articles exist stating which stationary phases have successfully been used for a given application. Today, GC is the preferred chromatographic technique in the environmental, petroleum, chemical, flavor & fragrance, and forensic industries. In the biofuel, agriculture, food & beverage, cosmetic and personal care/cleaning product, and clinical industries, its frequency of use is equal to other chromatographic techniques. It is used for specific chromatographic applications in the industrial hygiene, pharmaceutical, and life science industries.We have identified the GC columns that are routinely used in the various industries. These are conveniently arranged by industry, and then application within that industry, to simplify the process of selecting the proper phase. First, follow the link that matches your
Journal of Chemistry is a peer-reviewed, Open Access journal that publishes original research articles as well as review articles on all aspects of fundamental and applied chemistry.
The program offers a wide array of research equipment and facilities, including the following: Hewlett Packard gas chromatograph (mass spectral detector) with HP headspace injector; Hewlett Packard gas chromatograph (FID) with Tek-Mar headspace injector; Hewlett Packard HP Chemstation analytical software; Gow-Mac gas chromatograph (TCD); Hewlett Packard gas chromatograph (FPD); Neotronics Electronic Nose 4000; -70C freezer; deionized and distilled water equipment; Kjeldahl nitrogen analyzers; BYK-Gardner Spectrocolorimeter; Seward stomacher 400 laboratory blender; colony counters; rapid PCR analytical equipment; HPLC-MS sensory analysis facility; a food-science teaching laboratory; state-of-the-art culinary preparation equipment and bench research facilities.. Once in the program, you will have access to the research facilities of several departments, including the Department of Agricultural and Biological Engineering, the Department of Animal and Veterinary Sciences, the Department of Food ...
ASTM-E260 Standard Practice for Packed Column Gas Chromatography - gas chromatography; GC; packed columns ; Chemical analysis; Gas chromatography (GC); Gases; Organic chemicals; Packed column gas chromatography; Supercritical fluid chromatography (SFC); Vaporizable organic/inorganic mixtures
Tauro-7 alpha, 12 alpha-dihydroxy-5 beta-cholanic acid has been used as internal standard in the gas-liquid chromatographic analysis of bile acid methyl ester acetates. The advantage of this compound over other internal standards is that its use takes into account the hydrolysis rate of the bile acids. The entire procedure is monitored by thin-layer chromatography, gas-liquid chromatography, and by radioactivity measurement and zonal scanning.
Shellie, Robert, Mondello, Luigi, Dugo, Giovanni and Marriott, Philip 2004, Enantioselective gas chromatographic analysis of monoterpenes in essential oils of the family Myrtaceae, Flavour and fragrance journal, vol. 19, no. 6, Nov/Dec, pp. 582-585, doi: 10.1002/ffj.1368. ...
Detectors for use with capillary columns must have high sensitivities due to the limited sample size that can be used whith such columns. In addition, due to the very small peak volumes produced by the column, the sensing volume must also be extremely small. As the flame ionization detector (FID) is mass sensitive as opposed to concentration sensitive (see book 4 of this series for the meaning of mass and concentration sensitivity) the dilution by hydrogen does not effect the detector response. Thus, the FID has both the high sensitivity and the small sensor volume that is necessary and is, consequently, ideal for use with capillary columns. The nitrogen phosphorous detector (NPD) is also appropriate for capillary columns (the function of which is very similar to that of the FID) for the same reason. The micro-argon detector employs a scavenger flow which also, in effect, reduces the sensor volume, so this detector can also be used with capillary columns. The FID and the NPD detector will be ...
Jet Contact Spring for External Igniter and Auto-Ignite Flame Ionization Detector (FID) for the PerkinElmer AutoSystem/AutoSystem XL, and the Nitrogen Phosphorus Detector (NPD) for the PerkinElmer Series/Sigma 2000 Series GCs
Jet Contact Spring for External Igniter and Auto-Ignite Flame Ionization Detector (FID) for the PerkinElmer AutoSystem/AutoSystem XL, and the Nitrogen Phosphorus Detector (NPD) for the PerkinElmer Series/Sigma 2000 Series GCs
The intrinsically safe, portable MicroFID II Flame Ionization Detector (FID) is designed for HAZMAT detection, confined space entry and soil gas monitoring. MicroFID II provides measurements over a wide range of VOCs, including methane. Its operating range of 0.1 ppm to 50,000 ppm helps better define the severity of the hot zone. When sampling in an unknown, potentially explosive environment, responders can be confident the area can be safely entered with measurement information provided by the instrument ...
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GC-FID/TCD. Gas Chromatograph-Flame Ionization Detector / Thermal Conductivity Detector. Location: ER-4006. This Agilent 6890A GC is equipped with a FID and TCD in series. Sample introduction is via a Gerstel Multi Purpose Sampler, which can handle both liquid and gaseous samples. The GC-FID/TCD is mainly used for the quantification of permanent gases, such as CO2, H2, and CH4.. GC-FID/ECD. Gas Chromatograph-Flame Ionization Detector / Electron Capture Detector. Location: ER-4006. This GC is an Agilent 6890A model with a FID and ECD in parallel. It is used with a Gerstel Multi Purpose Sampler, which can handle both liquid and gaseous samples. This GC is mainly used for quantification of fatty acids (as methyl esters) and of hydrocarbons, and for headspace analysis of volatile organic contaminants (e.g. BTEX) in aqueous solutions. It is also used in combination with the preparative fraction collector.. Preparative Fraction Collector. Location: ER-4006. The GC-FID/ECD is interfaced with a Gerstel ...
Volatile fatty acids produced in Robertsons cooked meat medium by a range of clinically relevant anaerobes were compared by gas liquid chromatography with those produced in blood agar. The same volatile fatty acid profiles were obtained in both media, although the concentration of acids was lower in blood agar. We conclude that detection of volatile fatty acids from a pure culture of an organism on solid medium is practicable and offers advantages over the conventional technique.. ...
TY - JOUR. T1 - Microscale preparation of pentafluorobenzyl esters. Electron-capture gas chromatographic detection of indole-3-acetic acid from plants. AU - Epstein, Ephraim. AU - D. Cohen, Jerry. N1 - Funding Information: Pulsed positive/negative-ion MS data were provided by Dr. R. W. K. Chapman, Finnigan Corporation, 1383 Piccard Dr., Suite 100, Rockville, MD 20850, U.S.A., and Ms. A. Schulze, Ms. P. J. Hall and Ms. S. D. Cohen assisted with GC-SIM-MS. This work was supported by U.S.-Israel Binational Agricultural Research and Development grant I-5-79 to E.E. and to Dr. R. S. Bandurski and, in part, by National Science Foundation grant PCM 79-04637 and National Aeronautics and Space Administration grant NAGW-97, ORD25796 to Dr. R. S. Bandurki. This is contribution No. E-306, 1980 series, from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel and is Journal article 9723 from the Michigan Agricultural Experiment Station.. PY - 1981/5/22. Y1 - 1981/5/22. N2 - A ...
This study was conducted at the Horticulture Department of Cukurova University, Adana, Turkey, in 2010 to determine the volatile aroma compounds of Morchella mushroom. Fresh samples of Morchella esculenta (Sample 1) and Morchella elata (Sample 2) were collected from Canakkale (Sample 1) and Mersin (Sample 2) provinces in Turkey in the spring of 2010. Volatile aroma compounds were analyzed by headspace gas chromatography mass spectrometry (HS-GC/MS). A total of 31 aroma compounds were identified in the 2 analyzed samples: 7 alcohols, 7 esters, 7 ketones, 3 acids, 2 aldehydes, 1 terpene, phenol, 1-propanamine, geranyl linalool, and quinoline. Seventeen aroma components were identified in Sample 1, and 18 compounds were found in Sample 2. Phenol was determined as the major aroma compound in both Sample 1 and Sample 2, at 50.888% and 58.293% content, respectively. Alcohols, especially 1-octen-3-ol, were detected as the second major aroma components in Sample 1 and Sample 2, at 15.500% and 5.660% ...
Starch index and internal ethylene were measured on a total of 10 fruit per orchard each year. Soluble solids concentration was measured using a handheld temperature-compensated refractometer (Fisher Scientific, Nepean, Ontario, Canada) on fruit in Ontario, but not in Maine. Starch staining with iodine was measured using a visual rating in which 1 = all starch remaining and 8 = no starch (Blanpied and Silsby, 1992). To measure internal ethylene concentration (IEC) in Maine, a 25-mm-long stainless steel needle with a syringe was inserted through the calyx end to remove 1 mL of gas, which was injected into a gas chromatograph with a flame ionization detector (Shimadzu GC-8A, Kyoto, Japan). The gas chromatograph was fitted with a 450 × 3-mm stainless steel column packed with activated alumina. Operating conditions were as follows: oven temperature was 80 °C, injector temperature was 200 °C, and flame ionization detector temperature was 200 °C. IEC was measured in Ontario by withdrawing a 3-mL ...
A method is described for the absorption on charcoal and desorption with carbon-disulfide for gas chromatographic determination of 1,1- dichloro-1-nitroethane (594729) in the air. Data are given on the principle, range and sensitivity, precision, accuracy, advantages and disadvantages of the method. Also described are the apparatus, reagents and procedure used; analysis of samples; interferences;
QP-2010s Gas Chromatograph/Mass Spectrometer from Shimadzu,Shimadzus GCMS-QP2010s Gas Chromatograph/Mass Spectrometer, utilizing many of the high-end features of the GCMS-QP2010 Plus, offers high throughput and excellent productivity, providing users with an excellent performance-to-cost ratio. Like the GCMS-QP2010 Plus, the GCMS-QP2010s features patented,biological,biology supply,biology supplies,biology product
An automatic flow injection (FIA) and two possible reference gas chromatographic (liquid and headspace sampling GC) methods including appropriate sample preparation were developed and validated for determination of acetone in milk. The methods were tested by preserved raw milk samples. The FIA results were compared with data obtained by GC determinations. It was found that FIA procedure is suitable for rapid automated measurement of acetone in the range of 0-5 mmol l-1 in milk, therefore it is a promising analytical method for ketosis monitoring in dairy farms. ...
The GC-FID (Gas Chromatograph - Flame Ionization Detector) works by injecting a sample into a column (tube) which is then heated in an oven. The evolution from the stationary phase (solid or liquid) to the mobile phase (gas) is measured as it moves through the column and the flame ionization detector. This technique measures the amount of each compound found in the sample, and our software delivers the results as peaks on a graph as they are reflected at varying temperatures over time. The area under the curve is measured and compared to the calibration, resulting in accurately quantified testing.. ...
Public tender in Salisbury. Supply of two Agilent 7890B Series gas chromatography mass spectrometry flame photometric detection systems. Supply of two Agilent 7890B Series gas chromatography mass spectrometry flame photometric detection systems. voluntary ex ante transparency notice
ICP-MS is very sensitive and has limited matrix effects when used as an element-specific detector for GC in order to identify volatile metal or metalloid species, GC-MS is not very sensitive or selective in the electron ionization (EI) mode, but provides molecular information about volatile species. In this work, an ion trap EI-MS-MS and an ICP-MS system were used as two different detectors for the same GC system to provide complementary information about volatile organometallic species in the complex matrices of landfill and sewage sludge fermentation gases. A simple robust GC separation method with cryotrapping was adequate for the separation of the different metal(loid) containing volatile compounds, and was directly coupled to the ICP-MS system, In addition, gas samples from this GC system were collected in evacuated vials. These fractions were further separated on a capillary column and detected in an ion trap mass spectrometer. For the first time, parent ions, fragmentation patterns, ...
New Gas Chromatography Mass Spectrometry (GC-MS) Systems | GMI, Dont waste your money on your next Gas Chromatography System purchase. Download GMIs Gas Chromatography Guide and become an expert on acquiring excellent quality equipment by learning how to:   Select the right system based on expected throughput. Differentiate sample introduction systems to suit your required injection techniques. Pick out the proper GC Column for your Gas Chromatograph equipment. Choose between detector types according to selectivity or dependency. Dont waste your time and money on the wrong equipment. Download the guide today, click here.   Browse through and learn more about a specific New Gas Chromatography, Detector or System by clicking on the product name below. For any inquiries and/or concerns, just contact our new lab equipment experts via our hotline at 1-800-745-2710 or email us at [email protected]
With the aim to reinforce laboratory competence in the field of testing the quality of fish from aquaculture, a study on the precision of fatty acid (FA) analyses in fish meat and fish feed was undertaken. Different methods were performed in laboratories. In situ transesterification method and extraction of lipids from the fish were followed by capillary gas chromatography with flame ionization detection. The reproducibility (R) values of the majority of FAs were less than 3% of their absolute values. Differences in calculating ionization detector response factors and/or autoxidation caused by faulty sample-handling could lead to variation in quantification of FAs in fish, especially for FA C22:6n-3. Statistical analysis showed a significant correlation between the two laboratories quantifications of FAs in fish and fish feed (Pearsons correlation coefficient; r = 0.987, r = 0.994, and r = 0.997; for fish Z [trout], fish Š [rainbow trout], and fish feed, respectively). Overall, adequate ...
A review on the use of packed capillary columns in gas chromatography (GC) is presented. Several articles on the invention of packed capillary columns have been published, as well as on the progress and the development of this technology. Practical applications by this technique have also been studied, especially in the period from 1996 and onwards. A recently developed technique, solvating gas chromatography (SGC), which uses CO2 as the mobile phase combined with a high inlet pressure, has received specific focus.. The use of packed capillary columns in GC has also been evaluated. The technique used to pack these columns has been developed from a similar technology, which have been used for packing of columns, achieving very good separations, for both supercritical fluid chromatography (SFC) and high performance liquid chromatography (HPLC). In the present work, the possibilities of using packed capillary columns in GC, without applying a higher inlet pressure than 5 bar, has been explored. A ...
A piece of equipment used in gas chromatography that uses a flame to decompose the neutral solute molecules into charged particles, then measures any changes in conductivity ...
The aim of this thesis was to investigate distributions of 32 volatile chlorinated and/or brominated halocarbons that are currently believed to be present in the tropical upper troposphere and stratosphere and to contribute to stratospheric ozone depletion and also to global warming. For this purpose an analytical system was established, which is capable to measure ultra-low concentrated atmospheric trace gases. A quadrupole Mass Spectrometric (MS) Detector was attached to an existing Gas Chromatograph with pre-concentration system and Electron Capture Detector (ECD). The characterisation of the chromatographic system was significantly enhanced by the subsequent identification of 48 additional volatile organic compounds. Furthermore a Gaussian fit algorithm, which was developed in the workgroup, was applied to the chromatographic signals. This algorithm was proven to reflect peaks quantitatively and to enhance the performance of the integration process - especially the reproducibilities for ...
Browse our extensive catalog of new & used Gas Liquid Chromatograph Equipment for sale or auction. Find any required new, refurbished or used Gas Liquid Chromatograph Equipment or device.
Browse our extensive catalog of new & used Gas Liquid Chromatograph Equipment for sale or auction. Find any required new, refurbished or used Gas Liquid Chromatograph Equipment or device.
This report includes the estimation of market size for value (million USD) and volume (K Units). Both top-down and bottom-up approaches have been used to estimate and validate the market size of Gas Chromatography (GC) market, to estimate the size of various other dependent submarkets in the overall market. Key players in the market have been identified through secondary research, and their market shares have been determined through primary and secondary research. All percentage shares, splits, and breakdowns have been determined using secondary sources and verified primary sources.. Some Major Points from Table of Contents:. Chapter 1. Research Methodology & Data Sources. Chapter 2. Executive Summary. Chapter 3. Gas Chromatography (GC) Market: Industry Analysis. Chapter 4. Gas Chromatography (GC) Market: Product Insights. Chapter 5. Gas Chromatography (GC) Market: Application Insights. Chapter 6. Gas Chromatography (GC) Market: Regional Insights. Chapter 7. Gas Chromatography (GC) Market: ...
Pipet 100.0 mg of standard solution or sample solution into a glass tube fitted with a screw cap and add 100.0 mg of internal standard solution. Remove the water by lyophilization and dissolve the residue in 1.0 ml of pyridine. Add 4 mg O-benzyl-hydroxylamine hydrochloride, and cap the tube and set it aside for 12 h at room temperature. Then, add 1 ml of N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) and heat to 80º for 12 h shaking occasionally and allow to cool. Inject 1 µl portions of these solutions directly into a gas chromatograph under the following operating conditions with helium as carrier gas (initial flow rate: approx. 1 ml/min at 80º and 1 atm; split flow: 25 ml/min):. Column: Fused silica HT-8 (25 m x 0.22 mm x 0.25 µm), or equivalent. Injector: Programmed temperature vaporizer: 30º; 270º/min to 300º (49 min). Detector: Flame ionization detector; 360º. Temperature program: 80º (3 min); 10º/min 80º (3 min); 10º/min to 210º; 5º/min to 350º (6 min). Approximate ...
Significant findings. Conventional chemical analyses for volatile insect pheromones usually involve the use of a gas chromatograph (GC). The GC separates individual chemical components in the complex mixture. Each separate compound is then usually quantified using a flame ionization detector (FID). This detector basically burns and ionizes all the carbon in each separated chemical component. This method of analysis requires a relatively large chemical concentration to acquire a good signal for quantitation. Besides being insensitive, this form of ionization detection is nonspecific and not useful for assessing very low but bioactively significant pheromone concentrations that result in mating disruption in apple and pear orchard air.. Our preliminary method development findings using the GC/MS/CI show that both the electron impact (EI) and chemical ionization (CI) modes on the mass spectrometer have greatly enhanced sensitivity for codlemone quantitation compared to conventional GC/FID ...
ENGLISH ABSTRACT: Even capillary gas chromatography does not always give complete separation of the components of complex mixtures. During the last few decades several two-dimensional gas chromatographic techniques were ...
Analusis, a European journal on Analytical Chemistry, is published under the auspices of the Société Française de Chimie, the Société de Chimie Industrielle and the Gesellschaft Deutscher Chemiker
Quality Environmental Test Chambers manufacturers & exporter - buy Hplc Gas Chromatograph Mass Spectrometry Analyzer Machine GLPC / GC from China manufacturer.
However, the most interesting parts of this exhibition, as of Lovelocks new book A Rough Ride to the Future (Allen Lane, 2014) dont have anything to do with Gaia or climate change. They are about Lovelock the inventor. This is what makes Lovelocks career not merely productive and interesting but remarkable. He has invented over a hundred useful devices, including the electron capture detector that enabled him to detect small traces of chlorofluorocarbon (CFC) gases in the atmosphere in the late 1960s, leading to a realization that these industrial reagents (used as refrigerants) were gradually accumulating and could, once they reached the frigid stratosphere over the poles, undergo chemical reactions that destroy ozone, the planets protective screen against harmful ultraviolet radiation from the sun. Lovelock also claims to have invented the first microwave oven, which he used to defrost hamsters frozen for experiments during his early stint at the Medical Research Council. Several of these ...
However, the most interesting parts of this exhibition, as of Lovelocks new book A Rough Ride to the Future (Allen Lane, 2014) dont have anything to do with Gaia or climate change. They are about Lovelock the inventor. This is what makes Lovelocks career not merely productive and interesting but remarkable. He has invented over a hundred useful devices, including the electron capture detector that enabled him to detect small traces of chlorofluorocarbon (CFC) gases in the atmosphere in the late 1960s, leading to a realization that these industrial reagents (used as refrigerants) were gradually accumulating and could, once they reached the frigid stratosphere over the poles, undergo chemical reactions that destroy ozone, the planets protective screen against harmful ultraviolet radiation from the sun. Lovelock also claims to have invented the first microwave oven, which he used to defrost hamsters frozen for experiments during his early stint at the Medical Research Council. Several of these ...
In this application note a completely automated method for analyzing and quantifying VOCs in food packaging materials is presented. The combination of sample preparation steps and an analytical step in the same sequence allows high accuracy in quantification, high sample throughput, and minimizes error-prone manual manipulations. Detection and quantification are performed by means of a gas chromatograph (GC) coupled with a single quadrupole mass spectrometer (MS).
In this application note a completely automated method for analyzing and quantifying VOCs in food packaging materials is presented. The combination of sample preparation steps and an analytical step in the same sequence allows high accuracy in quantification, high sample throughput, and minimizes error-prone manual manipulations. Detection and quantification are performed by means of a gas chromatograph (GC) coupled with a single quadrupole mass spectrometer (MS).
0159]1. Cynthia Q Sun et al (Chemico-Biological Interactions 140 (2002), pp 185-198). [0160]2. R. Corinne Sprong et al (Antimicrobial Agents and Chemotherapy, April 2001, pp 1298-1301). [0161]3. Schuster et al (Pharmacology and Therapeutics in Dentistry 5: pp 25-33; 1980) [0162]4. Gudmundur Bergsson et al (Antimicrobial Agents and Chemotherapy, November 2001, pp 3209-3212). [0163]5. Yong-Ching Yang et al. J. Chin. Inst. Chem. Engrs., Vol 34, No 6, 617-623. A Process for Synthesis of High Purity Monglyceride [0164]6. Catrienus DeJong and Herman T. Badings 1990. Determination of free fatty acids in milk and cheese, procedures for extraction, clean up and capillary gas chromatographic analysis. Journal of high resolution chromatography, Vol. 13, February 1990. Pages 94-98. [0165]7. Halldor Thormar et al (Antimicrobial Agents and Chemotherapy; January 1987, pp 27-31) This author reports the growth inhibitory properties of various free fatty acids against Enterococci, which are gram-positive, and ...
The Thermo Scientific TVA-1000B Toxic Vapor Analyzer is the only over- the shoulder portable vapor analyzer that offers both Flame Ionization Detection (FID) and Photo Ionization Detection (PID) in a single, easy-to-use instrument.
2D-GC allows for more precise separation of polar components (cyclical hydrocarbons, aromatic compounds and FAME) from the non-polar paraffins. For comparing the results from 2D-GC gas chromatography, standardized methods such as DIN EN 12916 (aromatic distribution in diesel fuels), ASTM D 2887 (simulated distillation), DIN EN 14078 (FAME-content) as well as DIN EN 14331 (methyl ester distribution in FAME-blends) can be consulted.. 2-dimensional gas chromatography analysis is available globally. Test samples can be easily shipped to the laboratory for prompt handling from European and global clients.. ...
BACKGROUND: The chemical composition of Amazonian fish is extremely variable, being influenced by the season and the type and amount of food. A special interest in the fish oil composition has been developed owing to the presence of essential fatty acids, since this is directly related to human health. This study aimed to investigate the fatty acid composition (FAC) of the total lipid (TL), neutral lipid (NL) and phospholipid (PL) fractions of the dorsal muscle and orbital cavity of farmed and wild matrinxã in the Amazon area captured in different seasons. RESULTS: Fatty acids (FA) were analysed by high-resolution gas chromatography/mass spectrometry. Sixty-five FA were detected in the TL, 66 in the NL and 55 in the PL. The main FA found in farmed and wild fish were oleic, palmitic, stearic and linoleic acids. No distinctions in the quality or quantity of these fractions between dorsal muscle and orbital cavity were found. CONCLUSION: The season had a significant influence on the TL and FAC. ...
Short-chain fatty acids (SCFAs) are gut microbiota metabolites recognized for their beneficial effects on the host organism. In this study, a simple and rapid sample preparation method combined to SCFAs analysis by direct injection and gas chromatography coupled with flame ionization detection (GC-FID), for the determination and quantification of eight SCFAs (acetic, propionic, i-butyric, butyric ...
Short-chain fatty acids (SCFAs) are gut microbiota metabolites recognized for their beneficial effects on the host organism. In this study, a simple and rapid sample preparation method combined to SCFAs analysis by direct injection and gas chromatography coupled with flame ionization detection (GC-FID), for the determination and quantification of eight SCFAs (acetic, propionic, i-butyric, butyric ...
... is also sometimes known as vapor-phase chromatography (VPC), or gas-liquid partition chromatography (GLPC). ... The invention of gas chromatography is generally attributed to Anthony T. James and Archer J.P. Martin. Their gas chromatograph ... Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds ... After learning about the results of James and Martin, he switched to partition chromatography. Early gas chromatography used ...
... or IGC is a highly sensitive and versatile gas phase technique developed over 40 years ago to study ... Inverse gas chromatography is a physical characterization analytical technique that is used in the analysis of the surfaces of ... E. Cremer and H. Huber, in Gas Chromatography., ed. N. Brenner, et al., Academic Press, New York (1962) p 169. P.P. Yla- ... J. Condor and C. Young, Physicochemical measurement by gas chromatography, John Wiley and Sons, Chichester, UK (1979) F. ...
Gas chromatography/mass spectrometry-olfactometry (GC/MS-O) GC-recomposition-olfactometry (GC-R) Multi-gas chromatography- ... Gas chromatography-olfactometry (GC-O) is a technique that integrates the separation of volatile compounds using a gas ... 2008). "Gas chromatography-olfactometry in food flavour analysis". Journal of Chromatography A. 1186 (1-2): 123-143. doi: ... 2008). "Application of gas chromatography-olfactometry (GC-O) in analysis and quality assessment of alcoholic beverages - A ...
... (GC-MS) is an analytical method that combines the features of gas-chromatography and mass ... Patton HW, Lewis JS, Kaye WI (1955). "Separation and Analysis of Gases and Volatile Liquids by Gas Chromatography". Analytical ... Gas Chromatography and Mass Spectrometry: A Practical Guide. Academic Press. ISBN 978-0-08-092015-3. Jones M. "Gas ... Modern practice of gas chromatography. New York: Wiley-Interscience. ISBN 978-0-471-22983-4. Eiceman GA (2000). "Gas ...
Many gas chromatograph detectors are ion detectors with varying methods of ionizing the components eluting from the gas ... but uses a different sort of spark Gas Chromatograph Chromatography detector (Articles with short description, Short ...
... (GC-VUV) is a universal detection technique for gas chromatography. VUV ... 2014, 86, 8329-8335 H. Fan, J. Smuts, L. Bai, P. Walsh, D.W. Armstrong, K.A. Schug, Gas chromatography-vacuum ultraviolet ... 2014, 86, 8329-8335 H. Fan, J. Smuts, L. Bai, P. Walsh, D.W. Armstrong, K.A. Schug, Gas chromatography-vacuum ultraviolet ... guidelines, or more broadly, International Council for Harmonization (ICH) Guideline Q3C(R6). The gas chromatography (GC) ...
"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 ... Pyrolysis gas chromatography is also used for environmental samples, including fossils. Pyrolysis GC is used in forensic ... Pyrolysis gas chromatography is useful for the identification of involatile compounds. These materials include polymeric ...
... , or GC×GC is a multidimensional gas chromatography technique that was ... The Oil and Gas Industry were early adopters of the technology for the complex oil samples to determine the many different ... Comprehensive Chromatography is used in forensics, food and flavor, environmental, metabolomics, biomarkers and clinical ... Even methane has been modulated with liquid nitrogen cooled gas jets like those in this type of modulator. This loop modulation ...
Sithersingh, M.J.; Snow, N.H. (2012). "Chapter 9: Headspace-Gas Chromatography". In Poole, C. (ed.). Gas Chromatography. ... Headspace-Gas Chromatography". In Poole, C. (ed.). Gas Chromatography. Elsevier. pp. 221-34. ISBN 9780123855404. ... Headspace gas chromatography uses headspace gas-from the top or "head" of a sealed container containing a liquid or solid ... As such, headspace gas chromatography offers a method for determining if there is natural biodegradation processes occurring in ...
Poole, Colin; Jennings, Walter (2012). "Milestones in the Development of Gas Chromatography". Gas Chromatography. Elsevier. p. ... Others introduced mass spectrometers to gas chromatography in the late 1950s. The work of Martin and Synge also set the stage ... Martin, in collaboration with Anthony T. James, went on to develop gas chromatography (GC; the principles of which Martin and ... The ease and efficiency of gas chromatography for separating organic chemicals spurred the rapid adoption of the method, as ...
A chromatography detector is a device used in gas chromatography (GC) or liquid chromatography (LC) to detect components of the ... In liquid chromatography: Charged aerosol detector (CAD) Evaporative light scattering detector (ELSD) In gas chromatography: ... In gas chromatography: Thermal conductivity detector, (TCD). Measures the thermal conductivity of the eluent. Electron capture ... In all types of chromatography: Mass spectrometer (MS) In liquid chromatography: UV detectors, fixed or variable wavelength, ...
Gas chromatography (GC), also sometimes known as gas-liquid chromatography, (GLC), is a separation technique in which the ... paper chromatography, gas chromatography, and what would become known as high-performance liquid chromatography. Since then, ... Size-exclusion chromatography (SEC) is also known as gel permeation chromatography (GPC) or gel filtration chromatography and ... Affinity chromatography Aqueous normal-phase chromatography Binding selectivity Chiral analysis Chromatofocusing Chromatography ...
RPC refers to liquid (rather than gas) chromatography. In the 1970s, most liquid chromatography was performed using a solid ... Reversed-phase chromatography (also called RPC, reverse-phase chromatography, or hydrophobic chromatography) includes any ... hence the term reversed-phase chromatography. Reversed-phase chromatography employs a polar (aqueous) mobile phase. As a result ... This technique is known as reversed-phase ion-pairing chromatography. Aqueous normal-phase chromatography IUPAC, Compendium of ...
Gas chromatography-mass spectrometry (GC-MS) is a two-dimensional chromatography technique that combines the separation ... These techniques would later generate modern Gas chromatography and Liquid chromatography analysis. Different combinations of ... Two-dimensional separations can be carried out in gas chromatography or liquid chromatography. Various different coupling ... Comprehensive two-dimensional gas chromatography is an analytical technique that separates and analyzes complex mixtures. It ...
the "Gold Book") (1997). Online corrected version: (2006-) "Peak Resolution in gas chromatography". doi:10.1351/goldbook.R05317 ... In chromatography, resolution is a measure of the separation of two peaks of different retention time t in a chromatogram. ... 10.1351/goldbook.P04694 IUPAC Nomenclature for Chromatography (Chromatography). ... the "Gold Book") (1997). Online corrected version: (2006-) "Peak Resolution Rs in chromatography". doi:10.1351/goldbook.P04465 ...
The principle can be also applied to the fabrication of monolithic HPLC columns or gas chromatography columns. Seebach, Dieter ... Chiral column chromatography is a variant of column chromatography that is employed for the separation of enantiomers, e. g. in ... "Determination of salsolinol enantiomers by gas chromatography-mass spectrometry with cyclodextrin chiral columns". Analytica ... doi:10.1016/S0003-2670(00)00986-7. v t e (Chromatography, Stereochemistry, All stub articles, Chemistry stubs). ...
... s of different types are used in both gas and liquid chromatography. Liquid chromatography: Traditional ... A Chromatography column is a device used in chromatography for the separation of chemical compounds. A chromatography column ... Gas chromatography (GC): Older columns were made of glass or metal packed with particles of a solid stationary phase. More ... Chromatography columns can be used as stand-alone devices or in combination with manual or automated chromatography systems. ...
A third drawback is difficulty in gas/liquid separation during collection of product. Upon depressurization, the CO2 rapidly ... Supercritical fluid chromatography (SFC) is a form of normal phase chromatography that uses a supercritical fluid such as ... supercritical fluid chromatography is sometimes called convergence chromatography. SFC is used in industry primarily for ... Principles are similar to those of high performance liquid chromatography (HPLC), however SFC typically utilizes carbon dioxide ...
Gas Chromatography. Physics of Materials. Projects Management This NTU College is one of the 24 regional faculties of the ...
Gas chromatography-mass spectrometry (GC-MS): Combines gas chromatography (which uses gas "to separate complex mixtures of ... Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS): Combines gas chromatography and mass spectrometry on a heated sample ... 2014). Chromatography. Retrieved April 19, 2014. CAMEO. (2014).Gas chromatography. Retrieved April 19, 2014. National Gallery ... The heat decomposes the sample, producing smaller molecules to be separated by the gas chromatography and detected by the mass ...
Similarly to gas chromatography MS (GC-MS), liquid chromatography-mass spectrometry (LC/MS or LC-MS) separates compounds ... A common combination is gas chromatography-mass spectrometry (GC/MS or GC-MS). In this technique, a gas chromatograph is used ... The duty cycle of IMS is short relative to liquid chromatography or gas chromatography separations and can thus be coupled to ... Eiceman, G.A. (2000). Gas Chromatography. In R.A. Meyers (Ed.), Encyclopedia of Analytical Chemistry: Applications, Theory, and ...
A pulsed discharge ionization detector (pulsed discharge detector) is a detector for gas chromatography that utilizes a stable ... In addition, when the helium discharge gas is doped with a suitable noble gas, such as argon, krypton, or xenon (depending on ... Response to fixed gases is positive (increase in standing current), with an MDQ in the low ppb range. The PDD in helium ... Journal of Chromatography A, Volume 1050, Issue 1, 24 September 2004, Pages 63-68 Wentworth, W. E.; Vasnin, S. V.; Stearns, S. ...
... paper chromatography, and gas-liquid chromatography which is more commonly known as gas chromatography. The modification of ... Finally, gas-liquid chromatography, a fundamental technique in modern analytical chemistry, was described by Martin with ... James, A. T.; Martin, A. J. P.; Smith, G. Howard (1 October 1952). "Gas-liquid partition chromatography: the separation and ... The introduction of paper chromatography was an important analytical technique which gave rise to thin-layer chromatography. ...
"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 ... "Gas Chromatography-Mass Spectrometry". American Chemical Society. Retrieved 19 November 2019. "Nobel Winner Archer Martin Dies ... JAMES, AT; MARTIN, AJ (1954). "Gas-liquid chromatography; a technique for the analysis and identification of volatile materials ...
Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences. 794 (1): 99-108. doi:10.1016/s1570- ... "Gas chromatographic analysis of ketamine and norketamine in plasma and urine: nitrogen-sensitive detection". Journal of ... "Determination of the enantiomers of ketamine and norketamine in human plasma by enantioselective liquid chromatography-mass ... Chromatography. 232 (2): 305-14. doi:10.1016/s0378-4347(00)84170-5. PMID 6818238. Rodriguez Rosas ME, Patel S, Wainer IW ( ...
I. Gas chromatographic detection procedure with electron capture detection for some secondary amines". Journal of ... Chromatography. 106 (2): 412-7. doi:10.1016/S0021-9673(00)93853-6. PMID 239015. US 20150038533, Konofal E, Figadere B, " ...
Kaji, H; Hisamura, M; Saito, N; Murao, M (May 1, 1978). "Gas chromatographic determination of volatile sulfur compounds in the ... expired alveolar air in hepatopathic subjects". Journal of Chromatography. 145 (3): 464-8. doi:10.1016/s0378-4347(00)81377-8. ...
"Improved micromethod for determination of underivatized clonazepam in serum by gas chromatography" (PDF). Clinical Chemistry ( ... Gerna M, Morselli PL (January 1976). "A simple and sensitive gas chromatographic method for the determination of clonazepam in ... Studies on the detection of clonazepam and its main metabolites considering in particular thin-layer chromatography ... human plasma". Journal of Chromatography. 116 (2): 445-450. doi:10.1016/S0021-9673(00)89915-X. PMID 1245581. Tokola RA, ...
Gas chromatography (GC) performs the same function as liquid chromatography, but it is used for volatile mixtures. In forensic ... These include high-performance liquid chromatography, gas chromatography-mass spectrometry, atomic absorption spectroscopy, ... HPLC is used for nonvolatile mixtures that would not be suitable for gas chromatography. This is useful in drug analysis where ... "Gas Chromatography-Mass Spectrometry". American Chemical Society. Retrieved 19 Nov 2019. Gohlke, Roland S.; McLafferty, Fred W ...
Journal of Chromatography A 1000, 69-108 (2003). Phillips, J. B. & Beens, J. Comprehensive two-dimensional gas chromatography: ... Gas-liquid chromatography Ecotoxicology Environmental chemistry Toxicology Pollution Endocrine disruptor Gough, M. A.; Rowland ... Comprehensive 2-Dimensional Gas-Chromatography Using an on-Column Thermal Modulator Interface. Journal of Chromatographic ... Recent developments in comprehensive two-dimensional gas chromatography (GC x GC) III. Applications for petrochemicals and ...
... s found in modern gymnosperm resins as well as in the rock record are separated and characterized by gas chromatography ... Because polar functional groups reduce molecular volatility and make separation by gas chromatography difficult, abietane ...
For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals. The basal metabolic ... Modern biochemical research has been greatly aided by the development of new techniques such as chromatography, X-ray ... Conrad R (December 1996). "Soil microorganisms as controllers of atmospheric trace gases (H2, CO, CH4, OCS, N2O, and NO)". ...
Gas chromatography/mass spectrometry analysis has revealed that A. dracunculus oil contains predominantly phenylpropanoids such ...
... pioneer in gas chromatography Maarten Keulemans (born 1968), Dutch science journalist and founder of the website ...
GAS) elements in gene promoters. Type I IFNs can induce expression of genes with either ISRE or GAS elements, but gene ... immunosorbent column chromatography and N-terminal amino acid sequence". Biochemistry. 19 (16): 3831-5. doi:10.1021/bi00557a028 ... induction by type II IFN can occur only in the presence of a GAS element. In addition to the JAK-STAT pathway, IFNs can ...
The kerosene from which the two yeast strains were isolated was analyzed with gas chromatography and shown to have 48 ...
The dimethyloxazoline (DMOX) derivatives of fatty acids are amenable to analysis by gas chromatography. Structural analogues ...
Solvent assisted inlet ionization can be coupled not only to liquid chromatography (LC) but also to nano LC. Ionization at ... a New Atmospheric Pressure MALDI Method for Producing Highly Charged Gas-phase Ions of Peptides and Proteins Directly from ... A New Highly Sensitive Approach for Liquid Chromatography/Mass Spectrometry of Small and Large Molecules". Analytical Chemistry ...
"Multi-Element Selective Radio Frequency Plasma Detector for Capillary Gas Chromatography, F. Yang, P. Farnsworth, R. Skelton, K ... degree at Stockholm University 1984 with the thesis Organosiloxanes containing cyano groups for capillary chromatography. ...
In 1979 the TAGA 3000 was used for real-time monitoring of toxic gas plumes of chlorine, styrene and other gases released from ... Today, Chromatography. "The fascinating history of the development of LC-MS; a personal perspective". Chromatography Today. ... "Liquid Chromatography Mass Spectrometry Market Size By 2027". Retrieved 2022-05-28. Gelpí, ... Peter Dawson at the National research Council of Canada, the first application of liquid chromatography-mass spectrometry-mass ...
Furthermore, gas chromatography and electrophysiology show that the single active compound for pollinator attraction is found ...
Many coffee companies use high-performance liquid chromatography (HPLC) to measure how much caffeine remains in the coffee ... with properties midway between a gas and a liquid. Caffeine dissolves into the CO2; but compounds contributing to the flavour ...
The purpose of a scrubber or gas-washing bottle is to scrub the gas such that the liquid absorbs one (or more) of the gaseous ... Other laboratory applications of fritted glass include packing in chromatography columns and resin beds for special chemical ... Laboratory scale spargers (also known as gas diffusing stones or diffusors) as well as scrubbers, and gas-washing bottles (or ... To maximize surface area contact of the gas to the liquid, a stream of gaseous particles is slowly blown into the vessel ...
This is particularly true in gas-liquid chromatography where column lengths up to 60 m are possible, providing a very large ... In ion-exchange chromatography the selectivity coefficient is defined in a slightly different way Solvent extraction is used to ... Factors determining selectivity for lead against zinc, cadmium and calcium have been reviewed, In column chromatography a ... the "Gold Book") (1997). Online corrected version: (2006-) "selectivity coefficient, kA/B in ion exchange chromatography". doi: ...
... is an empirical relationship between the quantity of a gas adsorbed into a solid surface and the gas pressure. The same ... Articles with short description, Short description matches Wikidata, Chromatography). ... equilibrium pressure of the gaseous adsorbate in case of experiments made in the gas phase (gas/solid interaction with gaseous ... When the adsorbate pressure in the gas phase (or the concentration in solution) is low, high-energy sites will be occupied ...
One of the first to use gas chromatography, mass spectrometry and thin layer chromatography in flavor research, Patton proved, ...
"Determination of carphedon in human urine by solid-phase microextraction using capillary gas chromatography with nitrogen- ...
Qualitative and quantitative analyses of the essential oil compounds performed by gas chromatography with a flame ionization ... Qualitative and quantitative determinations of the phenolic acids by reverse phase high-performance liquid chromatography (RP ...
and ion microscopy (SIMS) but not gas chromatography. This definition also appears in some mass spectrometry texts. There are ... the "Gold Book") (1997). Online corrected version: (2006-) "resolution in gas chromatography". doi:10.1351/goldbook.R05317 ... A high value for resolution corresponding to good separation of peaks is similar to the convention used with chromatography ... Blumberg LM, Kle MS (November 2001). "Metrics of separation in chromatography". J Chromatogr A. 933 (1-2): 1-11. doi:10.1016/ ...
... for gas chromatography. It is also used to introduce the trimethylsilyl protecting group in organic synthesis. A related ... Handbook of Derivatives for Chromatography (2nd ed.). John Wiley & Sons. ISBN 0-471-92699-X. Harry Heaney, Jian Cui, "N,O-Bis( ...
Small amounts of hydrogen gas are generated at the cathode and small amounts of either oxygen or chlorine gas (depending on ... Inamuddin (2017-06-01). Applications of Adsorption and Ion Exchange Chromatography in Waste Water Treatment. Materials Research ... These gases are typically subsequently dissipated as the E stream effluent from each electrode compartment is combined to ... However, some (e.g.,) have proposed collection of hydrogen gas for use in energy production. Current efficiency is a measure of ...
API gravity and sulfur content were integrated with high-resolution gas chromatography (GC) and Gas chromatography-mass ... 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 ...
... of the presence of damiana in herbal blends of forensic interest based on comprehensive two-dimensional gas chromatography". ...
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. ... Oil, Gas, and Biofuels: The Polyarc system can dramatically simplify the calibration process by reducing (or eliminating) the ...
Determination of Dichlofluanid Residues in Vegetables Using Dispersive-SPE Sample Preparation Combined with Gas Chromatography- ...
"Criteria for essential fatty acid deficiency in plasma as assessed by capillary column gas-liquid chromatography". Clinical ...
"On-chip Fabry-Pérot interferometric sensors for micro-gas chromatography detection". Sensors and Actuators B: Chemical. 159 (1 ...
... designer drugs data library using liquid chromatography with photodiode array spectrophotometry detector and gas chromatography ...
Source for information on gas-solid chromatography: A Dictionary of Earth Sciences dictionary. ... v. (tear-gas) [tr.… Gas , Gas Since ancient times, use of poison has been considered treacherous and, therefore, incompatible ... Tear Gas , tear gas / ti(ə)r/ • n. gas that causes severe irritation to the eyes, chiefly used in riot control to force crowds ... Atlanta Gas Light Company , Atlanta Gas Light Company Atlanta Gas Light Company 303 Peachtree St., N.E. Atlanta, Georgia 30308 ...
Purchase Gas Chromatography with Glass Capillary Columns - 1st Edition. Print Book & E-Book. ISBN 9780123843500, 9780323141062 ... Gas Chromatography with Glass Capillary Columns. Black Friday Event. :. save up to 30% on print and eBooks with free shipping. ... 12.2 Pyrolysis Gas Chromatography. 12.3 Silylation. 12.4 Silylation Methods. References. Chapter 13 Applications of Glass ... Gas Chromatography with Glass Capillary Columns describes glass capillary technology and the selection, installation, ...
Viala, A; Estadieu, M; Durand, A; Cano, J. P; Rougemont, A; Delmont, J; World Health Organization (‎Organisation mondiale de la Santé, 1978)‎ ...
Buy Gas Chromatography Accessories and more from our comprehensive Cole-Parmer Chromatography Products stores ... Gas Chromatography Accessories. Gas chromatography accessories are available to help you with your chromatography applications ... Select gas purifiers to help you remove contaminants from source gases for better results. We offer all-in-one gas ...
Mass spectrometry, chromatography, spectroscopy, software, dissolution, sample handling and vacuum technologies courses ...
Nokia sites use cookies to improve and personalize your experience and to display advertisements. The sites may also include cookies from third parties. By using this site, you consent to the use of cookies. Learn more ...
Scope1.1 This test method covers a direct aqueous injection procedure for the gas-liquid chromatographic determination of ... 1.1 This test method covers a direct aqueous injection procedure for the gas-liquid chromatographic determination of phenols, ...
HOME › Press Releases › Gas Chromatography Market worth $3.5 billion by 2025 Gas Chromatography Market worth $3.5 billion by ... The oil & gas segment is expected to account for the largest share of the global gas chromatography market. The large share of ... The columns segment is estimated to account for the largest share of the global gas chromatography market. The large share of ... Don t miss out on business opportunities in Gas Chromatography Market. Speak to our analyst and gain crucial industry insights ...
The features of this system included a gas cooled, electrically heated, capillary cold trap which focuses the sampl ... The results of a preliminary investigation concerning the application of high speed gas chromatography (GC) to the measurement ... The results of a preliminary investigation concerning the application of high speed gas chromatography (GC) to the measurement ... Measurement of organic vapors at sub-TLV concentrations using fast gas chromatography.. ...
Figures show a schematic of a gas chromatograph and an example chromatogram illustrating gas chromatography analysis of ... In this article, the author discusses practical aspects of gas chromatography theory, samples and sample preparation, hardware ... Chromatography is an analytical technique based on the separation of molecules due to differences in their structure and/or ... injectors, carrier gas, column/stationary phase, oven detector and recorder), quantitative analysis and validation. ...
Determination of pesticide residues in natural products by gas chromatography ... Traditional Chinese medicine - Determination of pesticide residues in natural products by gas chromatography. ... by gas chromatography (GC), including Chinese materia medica (whole medicinal materials) and decoction pieces derived from ...
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 ... A number of other derivatives which have been described previously for the gas-phase separation of corticosteroids were also ... In particular, O-isopentyloxime trimethylsilyl (iPO-TMS) ethers were of value in affording gas-phase "group" separations of ...
Stay at the forefront of the industrial gas industry with a gasworld subscription and get access to: *Current news and views ... Because of this shockwave, the demand for liquefied natural gas (LNG) in Japan has grown tremendously and the country now ranks ... Gas-fired electrical power generation has grown to substitute the load on these nuclear reactors. ... discover the in-depth content our subscribers receive every month by subscribing to gasworld. ...
Gas chromatography-mass spectrometry (GC-MS) is the most widespread tandem technique in the analytical instrumentation industry ... Liquid Chromatography (LC/HPLC)Gas Chromatography (GC)Sample PreparationMass SpectrometryPharmaceutical AnalysisEnvironmental ... View MoreLiquid Chromatography (LC/HPLC)Gas Chromatography (GC)Sample PreparationMass SpectrometryPharmaceutical Analysis ... Gas chromatography-mass spectrometry (GC-MS) is the most widespread tandem technique in the analytical instrumentation industry ...
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Assay of plasma cannabidiol by capillary gas chromatography/ion trap mass spectroscopy following high-dose repeated daily oral ... capillary column gas chromatography, ion trap mass spectroscopy in positive ion chemical ionization mode using isobutane, and ...
Gas and liquid chromatography abstracts.. Other Authors:. Institute of Petroleum (Great Britain). Gas Chromatography Discussion ...
... 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 ...
Gas Chromatography Principle Instrumentation and Method. adminJanuary 19, 2021 Gas Chromatography principle relies on partition ... This chromatography is of two forms like gas liquid chromatography GLC and gasoline solid chromatography. Of them GLC is widely ... Gas Chromatography runs on the principle of partition chromatography for separation of elements. The stationary phase is a ... But Still, gas chromatography is an important instrument in analytical chemistry, particularly in the medicinal field. The Gas ...
Why Carrier Gasses Are Important in Gas Chromatography November 21, 2022. * An Overview of the Different Types of Toxicology ... Scientific customer of the month customerspotlight environmental food safety forensics forensic science gas chromatography GC ...
Comprehensive two-dimensional gas chromatography (GCxGC) is a method of GC that can be used to improve the separation power of ... Gas chromatography (GC) is a widespread technique for the analysis of complex mixtures. There continues to be great interest in ... Modulator Development for Comprehensive Two-Dimensional Gas Chromatography (GCxGC). Cory Scott FixGrad. Student/Intern(U-M)/ ... 2004-2007 and is now participating in the Student Internship Program at Sandia National Laboratories in the DARPA Micro-gas ...
Improving Qualitative Synthetic Cathinone Identification by Gas Chromatography/Mass Spectrometry (GC/MS) Using Cold Electron ...
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 ...
... and comprehensive two-dimensional gas chromatography (GC X GC). The findings show that sample fractionation simplifies the ... of the water-soluble and water-insoluble fraction of catalytic fast pyrolysis biocrudes by two-dimensional gas chromatography. ... of the water-soluble and water-insoluble fraction of catalytic fast pyrolysis biocrudes by two-dimensional gas chromatography. ... of the water-soluble and water-insoluble fraction of catalytic fast pyrolysis biocrudes by two-dimensional gas chromatography ...
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 ...
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 ... Standard Operating Procedure: Gas Chromatography Mass Spectrometry (GC/MS) - Agilent Technologies 7890B GC - 240 Ion Trap MS ... Gas Chromatography Mass Spectrometry (GC/MS) - Agilent Technologies 7890B GC - 240 Ion Trap MS ...
What Are Gas Hydrates? Gas hydrates are ice-like crystals containing large amounts of a low molecular weight gas that builds up ... Operational impacts and benefits of determining Methanol Concentration by Gas Chromatography. 10/09/19 ... Gas hydrates are a common problem within the oil and gas industry. Methanol hydrate inhibition is one of the most cost- ... Gas hydrates form when low molecular weight gasses such as methane, ethane, or carbon dioxide combine with water and freeze ...
... Product News Published: March 22 ... "Agilent Technologies Launches Supplies Program for Major Gas Chromatography Instrument Brands" ... providing high-quality supplies for major brands of gas chromatography systems. Benefits include boosting lab productivity and ... "With Agilent CrossLab, our customers can now access supplies backed by Agilent innovation and 40 years of chromatography know- ...
  • The phytocomponents of the methanol extract of Equisetum arvense were investigated by using Gas Chromatography-Mass spectrometry, while the mass spectra of the compounds found in the extract were matched with the National Institute of Standards and Technology Library. (
  • In the work described in this thesis, gas-liquid chromatography (GLC) and combined gas chromatography-mass spectrometry (GC-MS) were applied to the analysis of steroids of biological significance, with particular interest centring on the corticosteroid family. (
  • The primary method that has been used to analyze for 2,4,6-trinitrotoluene and/or its metabolites in blood and urine is high-performance liquid chromatography (HPLC)/mass spectrometry (MS) (Yinon and Hwang 1985b, 1986b, 1986c, 1987). (
  • Figures show a schematic of a gas chromatograph and an example chromatogram illustrating gas chromatography analysis of menthol with decanol used as an internal standard. (
  • The Agilent 7890B is a state-of-art gas chromatograph (GC) that provides superior performance for all GC applications with the use of advanced electronic pneumatic control (EPC) modules and high performance GC oven temperature control. (
  • The carbon-disulfide was adsorbed on charcoal tubes, eluted with benzene , and quantitated with a gas chromatograph equipped with a sulfur flame photometric detector. (
  • GCMSsolution is the workstation software for Shimadzu GCMS-TQ series gas chromatograph mass spectrometers. (
  • Agilent Technologies, Inc., has introduced the Agilent CrossLab supplies portfolio, providing high-quality supplies for major brands of gas chromatography systems. (
  • With Agilent CrossLab, our customers can now access supplies backed by Agilent innovation and 40 years of chromatography know-how, for multiple instrument brands," said Cikui Liang, business manager, Agilent Chemistries and Supplies Division. (
  • Chromatographic analysis was carried out on an Agilent 6890N gas chromatography system equipped with 5973 series mass selective detector, 7673 series autosampler and chemstation (Agilent Technologies, Palo Alto, CA). HP-5 MS column with 0.25 μm film thickness (30 m × 0.25 mm I.D., USA) was used for separation. (
  • Through its website, GenTech offers a number of refurbished liquid and gas chromatography and mass spectrometry instruments for rent from makers including Thermo Fisher Scientific , AB Sciex, and Agilent Technologies. (
  • Comprehensive two-dimensional gas chromatography (GCxGC) is a method of GC that can be used to improve the separation power of a GC system drastically, and much effort has gone into developing improved modulators, a key component of the GCxGC system. (
  • In this study, we perform a comprehensive characterization of five biocrude samples from loblolly pine (pinus taeda), produced under different CFP conditions, by fractionation, automatic precolumn derivatization, and comprehensive two-dimensional gas chromatography (GC X GC). (
  • 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. (
  • 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). (
  • Can gas chromatography combustion isotope ratio mass spectrometry be used to quantify organic compound abundance? (
  • Quantification of glyphosate and other organophosphorus compounds in human urine via ion chromatography isotope dilution tandem mass spectrometry. (
  • The chapters that follow focus on general considerations in column attachment, measurement of column efficiency, and retention behavior of carrier gas, along with the operating temperature of the column, the choice of carrier gas, and carrier gas velocity. (
  • Measurement of organic vapors at sub-TLV concentrations using fast gas chromatography. (
  • The results of a preliminary investigation concerning the application of high speed gas chromatography (GC) to the measurement of aromatic vapors of toluene (108883), benzene (71432), and xylene (1330207) in air at threshold limit value (TLV) and sub/TLV concentrations were reported. (
  • A separate chapter discusses the importance of temperature and carrier gas flow rate in the measurement of HSP, of amorphous materials. (
  • The purpose of this investigation was to 1) compare the performance of proton nuclear magnetic resonance spectroscopy to gas chromatography head-space analysis in the measurement of serum isopropanol and its metabolite, acetone, obtained during a simulated overdose, and 2) compare pharmacokinetic parameters obtained using the two analytical techniques. (
  • [1] Standalone FIDs can also be used in applications such as landfill gas monitoring , fugitive emissions monitoring and internal combustion engine emissions measurement [2] in stationary or portable instruments. (
  • GC)/electron capture detection (ECD) and thin-layer chromatography (TLC)/densitometry have also been used to detect 2,4,6-trinitrotoluene and/or its metabolites in urine. (
  • 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. (
  • Four different gas chromatographic - mass spectrometric methods were developed for the analysis of the catecholamines and their metabolites and are discussed in detail. (
  • In this article, the author discusses practical aspects of gas chromatography theory, samples and sample preparation, hardware (injectors, carrier gas, column/stationary phase, oven detector and recorder), quantitative analysis and validation. (
  • Gas Chromatography-micro Electron Capture Detector (GC-ECD) is a technique used to analyse halogenated compounds and is primarily used in the environmental, forensic and pharmaceutical markets. (
  • Analysis of dissolved gases by headspace sampling gas chromatography with column and detector switching. (
  • Schematic of a flame ionization detector for gas chromatography. (
  • A flame ionization detector (FID) is a scientific instrument that measures analytes in a gas stream. (
  • It is frequently used as a detector in gas chromatography . (
  • This makes the detector sensitive to the mass rather than the concentration, which is useful because the response of the detector is not greatly affected by changes in the carrier gas flow rate. (
  • abstract = "Gas chromatography (GC) has in recent times become an important tool for the fatty acid profiling of human blood and plasma. (
  • Experiment #7: Column Chromatography of Food Dye Arianne Jan D. Tuozo Mr. Carlos Edward B. Santos October 12, 2015 Abstract Column chromatography is the separation of mixture's components through a column. (
  • The Principle in gas chromatography entails separation of volatile parts of the sample based on their partition co-efficient. (
  • This type of chromatography was primarily designed to evaluate volatile substances like fatty acids, essential oils, etc. (
  • You can imagine the need to convert into a gas phase would be inconvenient to say the least for the testing of volatile compounds! (
  • Gas chromatography / mass spectrometry (GC/MS) is the marriage of two analytical methods into a versatile technique for the identification of complex volatile materials. (
  • The instrument also includes a heated injection port to vaporize all volatile constituents of the sample and an oven to keep the constituents in gas form as they pass through the column. (
  • Analysis of volatile phenols in alcoholic beverage by ethylene glycol-polydimethylsiloxane based stir bar sorptive extraction and gas chromatography-mass spectrometry. (
  • 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. (
  • Headspace volatile profiles were determined using gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and aroma of fruiting body extracts were sensorially assessed. (
  • For the analysis of explosives Particularly, gas chromatography is better suited since, the mixture or compound is not required to be converted into a gas phase. (
  • Gas chromatography (GC) is a widespread technique for the analysis of complex mixtures. (
  • Gas chromatography (GC) effectively separates the different constituents of the sample for subsequent analysis and identification by mass spectrometry (MS). (
  • Currently, there are no simple methods for the quantitative analysis of carboxylic acids via gas chromatography. (
  • The present study focuses on the analysis of the methanol extract of Equisetum arvense by Gas Chromatography-Mass Spectrometry. (
  • Mass spectrometry, coupled with chromatographic separations such as Gas chromatography (GC-MS) is normally used for direct analysis of components existing in traditional medicines and medicinal plants. (
  • A total of 21 compounds were identified in the gas chromatography-mass spectrometry analysis of the ethyl acetate fraction in which 14 of the identified compounds are recognized for their pharmacological potential in the literature . (
  • Fingerprinting commercial products as well as Bt deposited in public collections was accomplished using a technique known as Cellular Fatty Acid analysis, based on Gas-Liquid Chromatography (GLC). (
  • The TD-30 was developed as the optimal solution for gas and materials analysis. (
  • The Associate Research Chemist performs research on jet fuel technology with emphasis on fuel testing techniques such as density, viscosity, dielectric constant, trace metals concentrations, etc, as well as chemical analysis techniques such as gas chromatography and high performance liquid chromatography. (
  • Resulting sera were analyzed by gas chromatography head-space analysis and proton nuclear magnetic resonance spectroscopy for determination of isopropanol and acetone concentrations. (
  • A correlation between concentrations quantitated by gas chromatography head-space analysis versus proton nuclear magnetic resonance spectroscopy was determined using linear regression. (
  • Proton nuclear magnetic resonance spectroscopy can be used to rapidly quantitate serum isopropanol and acetone concentrations in the same sample when gas chromatography head-space analysis is unavailable. (
  • 32. Spahl W, Budzikiewicz H. Qualitative analysis of dental resin composites by gas and liquid chromatography/mass spectrometry. (
  • Plasma FA analysis is performed using gas chromatography. (
  • CARRIER_GAS He, flow rate 1.5 ml/min. (
  • Advantages and Disadvantages of Substitution of Helium as Carrier Gas in Gas Chromatography by Hydrogen. (
  • The different rates between desorption and adsorption are applied in the chromatography methods for separation of mixtures. (
  • Download and please the download Gas Adsorption onto your non-commercial color. (
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  • Inverse Gas Chromatography (IGC), is an adsorption-based technique providing a versatile framework for the investigation of interfacial phenomena. (
  • 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. (
  • Equalization of tanks can result in a high volume of off-gassed vapors when a tank hatch is opened. (
  • Hydrocarbon gases and vapors (HGVs) and associated oxygen displacement were the primary or contributory factors in these fatalities. (
  • Workers in all operations during oil and natural gas exploration and production may be exposed to H 2 S. This blog provides an update on fatalities, injuries, and exposures associated with hazardous gases and vapors (HGVs and H 2 S) in the oil and gas extraction industry, and alerts employers to exposures that can occur while working around oil and gas process fluids. (
  • NIOSH has conducted surveillance of worker fatalities and severe injuries in the oil and gas extraction industry, including those that may be associated with exposure to or ignition of hazardous gases and vapors. (
  • NIOSH researchers sought to determine the number of fatalities and hospitalizations with known or potential exposure to hazardous gases and vapors as well as fires and explosions while working around process fluids, including waste water, flowback, petroleum condensate, or crude oil. (
  • Three workers died of sudden cardiac death with potential exposures to hazardous gases and vapors, two workers died due to fire/explosions, two workers died due to hydrogen sulfide poisoning, and one worker died due to HGV exposures. (
  • 1.1 This test method covers a direct aqueous injection procedure for the gas-liquid chromatographic determination of phenols, cresols, and mono- and di-chlorophenols in water. (
  • This document specifies the method of determination of pesticide residues in natural products used in traditional Chinese medicine (TCM) by gas chromatography (GC), including Chinese materia medica (whole medicinal materials) and decoction pieces derived from plants. (
  • Simple and sensitive high-performance liquid chromatography method for simultaneous determination of urinary free cortisol and 6beta-hydroxycortisol in routine practice. (
  • This preliminary study presents a new method for the determination of dissolved gases in sea-water. (
  • This standard specifies a method for the determination of the boiling range distribution of petroleum products by gas chromatography using flame ionization or thermal conductivity detection. (
  • Jönsson, BA & Skarping, G 1991, ' Method for the biological monitoring of hexahydrophthalic anhydride by the determination of hexahydrophthalic acid in urine using gas chromatography and selected-ion monitoring ', Journal of Chromatography A , vol. 572, no. 1-2, pp. 117-131. (
  • In this regard, we comprehensively review the current state-of-the-art ethylene gas sensors and detecting technologies, covering from preconcentrator-equipped gas chromatographic systems, Fourier transform infrared technology, photonic crystal fiber-enhanced Raman spectroscopy, surface acoustic wave and photoacoustic sensors, printable optically colorimetric sensor arrays to a wide range of nanostructured chemiresistive gas sensors (including the potentiometric and amperometric-type FET-, CNT- and metal oxide-based sensors). (
  • A charcoal sampling method and a gas chromatographic analytical procedure for carbon disulfide. (
  • The sample is injected into the injection point and can be transported by the cell gas to the column. (
  • In addition to fatality and injury surveillance, NIOSH has conducted additional worker exposure assessments at oil and gas worksites to examine potential hazardous exposures, including oxygen concentration and hazardous and flammable gas and vapor concentrations (HGVs and H 2 S) during various worker activities. (
  • The generation of these ions is proportional to the concentration of organic species in the sample gas stream. (
  • The real-time detecting and monitoring of ethylene gas molecules could benefit the agricultural, horticultural and healthcare industries. (
  • Detection of ethylene glycol by gas chromatography/mass spectrometry. (
  • In addition to HGVs, hydrogen sulfide (H 2 S), a widely recognized hazard in the oil and gas extraction industry, continues to persist as a cause of death among workers 2 . (
  • Hydrogen sulfide is naturally present in some oil and gas deposits and may be produced as a by-product of the desulfurization process of these fuels. (
  • 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. (
  • Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry. (
  • 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. (
  • The urine was worked-up by liquid-solid extraction, esterified with boron trifluoride-methanol, and analysed by capillary gas chromatography and selected-ion monitoring. (
  • The large share of this segment can primarily be attributed to factors such as improved gas chromatography columns for the petroleum industry. (
  • The large share of this segment can be attributed to increasing crude & shale oil production and improved gas chromatography columns for the petroleum industry. (
  • Element's analytical procedures conform to the Gas Processors Association (GPA), American Standard Test Methods (ASTM), and the American Petroleum Institute (API) protocols. (
  • Gas chromatography/Fourier transform infrared/mass spectrometry coupling : a tool for Li-ion bat. (
  • The mobile phase can be any inert gas, but is typically helium. (
  • IMSEAR at SEARO: Simultaneous detection of strychnine and brucine in biological matrix by gas chromatography-mass spectroscopy. (
  • A new gas chromatography-mass spectroscopy (GC-MS) method is being presented for the separation and detection of strychnine and brucine, alkaloids of Strychnos nux vomica in a single run. (
  • The firm is developing a shoebox-size gas chromatography instrument that could be used for routine screenings and critical illness detection and monitoring. (
  • Gas hydrates form when low molecular weight gasses such as methane, ethane, or carbon dioxide combine with water and freeze into a solid. (
  • Chromatography is an analytical technique based on the separation of molecules due to differences in their structure and/or composition. (
  • Gas Chromatography principle relies on partition based separation of elements. (
  • Gas Chromatography runs on the principle of partition chromatography for separation of elements. (
  • The separation of fatty acid was done using gas chromatography. (
  • We offer all-in-one gas purifications systems to efficiently remove oxygen, water, sulfur compounds, and hydrocarbons. (
  • Chromatography is a way of separating two or more chemical compounds. (
  • The current study aimed to assess the pharmacological potential of Justicia adhatoda by evaluating the presence of biologically active compounds using the gas chromatography-mass spectrometry approach and to undertake biological activities for the effectiveness of the present compounds using standard tests. (
  • But Still, gas chromatography is an important instrument in analytical chemistry, particularly in the medicinal field. (
  • Gas Chromatography with Glass Capillary Columns describes glass capillary technology and the selection, installation, evaluation, and use of glass open tubular columns for gas chromatography. (
  • This reference material is intended primarily for students and researchers interested in gas chromatography with glass capillary columns. (
  • The columns segment is estimated to account for the largest share of the global gas chromatography market. (
  • Bruker has significantly expanded its Gas Chromatography offering with the release of the GC CARE Gas Chromatography columns. (
  • This book also looks at the factors that affect column stability, materials of restricted volatility, and some applications of glass capillary gas chromatography. (
  • The features of this system included a gas cooled, electrically heated, capillary cold trap which focuses the sample as an extremely narrow band in the front of the column. (
  • The Gas is set to flow at a constant rate from the cylinder on to the liquid coating impregnated on a solid support in a column. (
  • The element that partitioned into gas comes from the column and can be detected by the sensor. (
  • The sample is carried through the column by the mobile phase, typically an inert gas. (
  • Before proceeding with the column chromatography itself, a proper solvent system must be chosen among the different solvents. (
  • Gas and liquid chromatography abstracts. (
  • This chromatography is of two forms like gas liquid chromatography GLC and gasoline solid chromatography. (
  • The stationary phase is a liquid coating supported over a predetermined period while the mobile phase is an inert and stable gas. (
  • Thus, the title as Gas-Liquid chromatography. (
  • High performance liquid chromatography has a broader array of uses than conventional gas chromatography. (
  • These include gas, high pressure liquid, or ion exchange chromatography. (
  • Most of lipids in co-extractives were removed by liquid-liquid extraction and gel permeation chromatography. (
  • 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. (
  • In particular, O-isopentyloxime trimethylsilyl (iPO-TMS) ethers were of value in affording gas-phase "group" separations of keto- from hydroxysteroids. (
  • Gas chromatography is a popular method for the identification and quantification of organic mixtures. (
  • 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. (
  • Select gas purifiers to help you remove contaminants from source gases for better results. (
  • At a time when the world is forced to go digital more than ever before just to stay connected, discover the in-depth content our subscribers receive every month by subscribing to gas world. (
  • The pesticides were finally determined by gas chromatography/mass spectrometry in selective-ion Monitor (SIM) simultaneously. (
  • Gas chromatography-mass spectrometry (GC-MS) is the most widespread tandem technique in the analytical instrumentation industry. (
  • He was involved with the WIMS program from 2004-2007 and is now participating in the Student Internship Program at Sandia National Laboratories in the DARPA Micro-gas Analyzer initiative while finishing his thesis. (
  • Chemical studies by gas chromatography of extracted material show a preponderance of cholesterol esters. (
  • The esterification of a representative library of simple carboxylic acids using SOMS, along with spectral data collected from proton nuclear magnetic resonance spectroscopy and a proof of concept experiment using gas chromatography were utilized to validate the hypothesis set forth in this project. (
  • This experiment uses the TLC chromatography technique to identify the presence of acetylsalicylic and Acetaminophen in analgesic drugs (Tylenol and Anacin). (
  • A previous NIOSH report (2016) 1 described the death of nine oil and gas extraction workers that occurred during gauging or sampling activities at open thief hatches on crude oil storage tanks. (
  • The federal Occupational Safety and Health Administration (OSHA) severe injury data set provides a source to identify severe non-fatal incidents among oil and gas extraction workers. (