Gases: 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)Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Chromatography, Gas: Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.Chromatography, Affinity: 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, Gel: Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.Chromatography: 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.Chromatography, Ion Exchange: 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, Thin Layer: 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)Chromatography, Liquid: Chromatographic techniques in which the mobile phase is a liquid.Gas Chromatography-Mass Spectrometry: A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.Molecular Weight: The sum of the weight of all the atoms in a molecule.Chromatography, DEAE-Cellulose: 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, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Chromatography, Agarose: 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.Pulmonary Gas Exchange: The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.Noble Gases: Elements that constitute group 18 (formerly the zero group) of the periodic table. They are gases that generally do not react chemically.Molecular Sequence Data: 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.Gas PoisoningChromatography, Reverse-Phase: 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.Blood Gas Analysis: Measurement of oxygen and carbon dioxide in the blood.Amino Acid Sequence: 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.Kinetics: The rate dynamics in chemical or physical systems.Amino Acids: 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.Chromatography, Paper: 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).Hydrogen-Ion Concentration: 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)Gas, Natural: 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)Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Spectrophotometry, Ultraviolet: 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)SepharoseChemistry: A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.Cattle: 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.Tandem Mass Spectrometry: 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.Chemical Phenomena: The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.Spectrometry, Mass, Electrospray Ionization: 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.Carbohydrates: 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.Gas Gangrene: 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.Chemical Fractionation: 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)Isoelectric Focusing: 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.Countercurrent Distribution: 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)Methods: A series of steps taken in order to conduct research.Oil and Gas Fields: Areas of the earth where hydrocarbon deposits of PETROLEUM and/or NATURAL GAS are located.Chromatography, Micellar Electrokinetic Capillary: 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.Carbohydrate Sequence: The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.Escherichia coli: 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.Magnetic Resonance Spectroscopy: 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).Oligosaccharides: 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.Temperature: 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.Calibration: 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.Drug Stability: The chemical and physical integrity of a pharmaceutical product.Rabbits: 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.Isoelectric Point: The pH in solutions of proteins and related compounds at which the dipolar ions are at a maximum.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Indicators and Reagents: 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)Hydrolysis: The process of cleaving a chemical compound by the addition of a molecule of water.Reference Standards: 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.Reproducibility of Results: 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.Protein Binding: 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.Solubility: 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)Trypsin: A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Macromolecular Substances: 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.Flame Ionization: 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.Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.Microchemistry: 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.Fatty Acids: 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)Immunodiffusion: Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.Peptides: 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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Hydroxyapatites: 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)Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.Mustard Gas: 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).Stereoisomerism: 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)Cloning, Molecular: 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.Solid Phase Extraction: 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.Acetonitriles: Compounds in which a methyl group is attached to the cyano moiety.PolysaccharidesRadioimmunoassay: 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.Molecular Structure: 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.Swine: 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).Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization: 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.Limit of Detection: Concentration or quantity that is derived from the smallest measure that can be detected with reasonable certainty for a given analytical procedure.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Carbohydrate Conformation: The characteristic 3-dimensional shape of a carbohydrate.Solvents: 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)Biological Assay: 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.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Oxygen: 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.Bacterial Proteins: Proteins found in any species of bacterium.Methanol: 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.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Sensitivity and Specificity: 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)Species Specificity: 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: 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)Chemical Precipitation: 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.Ammonium Sulfate: Sulfuric acid diammonium salt. It is used in CHEMICAL FRACTIONATION of proteins.Plant Extracts: 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.Lectins: 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.Brain Chemistry: 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.Isoenzymes: Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.Oxidation-Reduction: 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).Cell Line: Established cell cultures that have the potential to propagate indefinitely.Glycoside HydrolasesAnion Exchange Resins: High-molecular-weight insoluble polymers that contain functional cationic groups capable of undergoing exchange reactions with anions.Isomerism: 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)Proteins: 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.Volatilization: A phase transition from liquid state to gas state, which is affected by Raoult's law. It can be accomplished by fractional distillation.Centrifugation, Density Gradient: 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)Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Rats, Inbred Strains: 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.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Chemistry Techniques, Analytical: Methodologies used for the isolation, identification, detection, and quantitation of chemical substances.Spectrometry, Mass, Fast Atom Bombardment: 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.Glycopeptides: 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.Phospholipids: 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.Biotransformation: 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.Glycolipids: 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)Peptide Mapping: 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.EstersFermentation: 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.Chromatography, Supercritical Fluid: 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.Physicochemical Phenomena: The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.Chemistry, Physical: The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.Solid Phase Microextraction: 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.Streptococcus pyogenes: 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.Ultracentrifugation: 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)Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.Substance Abuse Detection: Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.Electrophoresis: 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.Pesticide Residues: Pesticides or their breakdown products remaining in the environment following their normal use or accidental contamination.Enzyme Stability: 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.Detergents: 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.Volatile Organic Compounds: Organic compounds that have a relatively high VAPOR PRESSURE at room temperature.Durapatite: The mineral component of bones and teeth; it has been used therapeutically as a prosthetic aid and in the prevention and treatment of osteoporosis.Culture Media: 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.Trifluoroacetic Acid: 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.Glycosylation: 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.Disaccharides: Oligosaccharides containing two monosaccharide units linked by a glycosidic bond.TritiumBlood Proteins: Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.Glycosides: 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)Monosaccharides: 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)GlucosidesCell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Isotope Labeling: 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.Cytosol: Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.Immunoelectrophoresis: 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: 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.DNA: 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).Sulfates: Inorganic salts of sulfuric acid.Cells, Cultured: 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.Endopeptidases: A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.Plants: 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, Monoclonal: Antibodies produced by a single clone of cells.Erythrocytes: Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.Blotting, Western: 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.Acetates: Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.Protein Conformation: 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).Methylation: 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)Microsomes, Liver: Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.Electrophoresis, Disc: 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.Proteomics: The systematic study of the complete complement of proteins (PROTEOME) of organisms.Sugar Alcohols: 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)Tissue Distribution: 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.Spectrometry, Fluorescence: Measurement of the intensity and quality of fluorescence.Chymotrypsin: 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.Electrochemistry: The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.Mannose: 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)Ultrafiltration: 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).Hexanes: Six-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives. Various polyneuropathies are caused by hexane poisoning.Carbon Radioisotopes: Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.Galactose: 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.Binding, Competitive: 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.Chickens: 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.Peptide Hydrolases: Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.Forensic Medicine: The application of medical knowledge to questions of law.Circular Dichroism: 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)Adsorption: 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.Immunoassay: 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.Cross Reactions: Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.GlucosamineBrain: 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.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Quality Control: 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)Structure-Activity Relationship: 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.Lipids: 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)Immune Sera: 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.Gas Scavengers: 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.Plant Lectins: 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, Medicinal: 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.Drug Contamination: The presence of organisms, or any foreign material that makes a drug preparation impure.Sialic Acids: A group of naturally occurring N-and O-acyl derivatives of the deoxyamino sugar neuraminic acid. They are ubiquitously distributed in many tissues.Streptomyces: 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.Food Analysis: Measurement and evaluation of the components of substances to be taken as FOOD.Edetic Acid: A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.Mutation: 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.Water: 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)Silicon Dioxide: 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.Carboxylic Acids: 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.Membrane Proteins: 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 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 3.2.1.24] 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 ...
Wholesale advantages of gas liquid chromatography - buy latest advantages of gas liquid chromatography direct from 150 advantages of gas liquid chromatography Factories.
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,
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
China Gas Chromatograph with High Senstive, Find details about China Gas Chromatograph, Laboratory Equipment from Gas Chromatograph with High Senstive - Wincom Company Ltd.
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. ...
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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, https://doi.org/10.1016/S0021-9673(00)81542-3 . [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, https://doi.org/10.1016/S0021-9673(01)95308-7 . [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, https://doi.org/10.1016/S0021-9673(01)96054-6 . [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 ...
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.
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...
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.
GlobalSpec Product Announcement for 1500XA Gas Chromatograph - The Rosemount Analytical 1500XA Gas Chromatograph combines the proven analytical components of a field-mounted GC with the larger oven capacity of a traditional air-bath oven design. Used in gas processing plants, it is specially designed for trace sulfur, trace hydrocarbon, and other high temperature applications.
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 ...
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 http://www.credenceresearch.com/report/gas-chromatography-in-medical-applications-market. 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 ...
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
Anthias Consulting is the worlds leading independent authority on Analytical Techniques including Gas Chromatography (GC, GCxGC), Liquid Chromatography (HPLC, UHPLC, LCxLC), Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES or ICP-AES), Mass Spectrometry (GC-MS, LC-MS, ICP-MS), Spectroscopy (FTIR, UV-Vis, AA), Mass Spectrometry Imaging, Physical & Structural Properties of Molecules (DSC, TGA, KF, XRD, LDA) and all their related techniques. Focus includes: Methods (Development, Optimisation, Validation, Accreditation, Maintenance, Troubleshooting), Applications (including SIM, E&L, OOS), Interpretation & Data Analysis (including Statistical, Chemometrics, Metabolomics). We provide training and consultancy across all applications and industries; to laboratory analysts & technicians, suppliers & manufacturers, PhD students & researchers, engineers & consultants; for all levels of experience.. Privacy Notice. ...
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 ...
The source of problems can be from a multitude of different areas in an analytical system. With our indepth expertise in gas chromatography, liquid chromatography, mass spectrometry, spectroscopy and related techniques we can identify the problem by considering every aspect of your system, many of which people from other backgrounds may not consider.
Professional Gas Chromatograph - Precision Gas-Liquid Partition Chromatography (GLPC) for Research & Quality Management - Your Number 1 Partner
ELECTRON CAPTURE DETECTOR 1.) A very sensitive detector for the presence of certain classes of molecules, most notably chlorine-containing molecules. It is based on a steady current produced by a long-lived beta-emitter and the measurable perturbations in that current caused by the presence of small quantities of molecules that scavenge or capture the electrons. 2.) A detector for electron capture decay ...
Definition : Chromatography systems in which the separation process is accomplished by forcing a gaseous mixture of analytes as the mobile phase (e.g., an inert gas, such as nitrogen or helium) through a column of the stationary phase. Separation of solutes in the mixture is based on the relative differences in their vapor pressures and their interaction with the stationary phase. A basic gas chromatograph consists of a gas reservoir and flow control device, an injector, the separation column, an oven, an online detector (sometimes a mass spectrometer), and, usually, a computer.. Related Terms : "Nitrogen Concentrators" , "Software, Chromatography System, Gas". Entry Terms : "Gas Chromatography Systems" , "Traps, Gas Chromatography" , "Detectors, Gas Chromatography" , "Ovens, Gas Chromatography" , "Sample Injector Ports, Gas Chromatography" , "Sample Inlet Systems, Gas Chromatography" , "Vapor-Phase Chromatography Equipment" , "Gas-Solid Chromatography Equipment" , "Gas-Liquid Chromatography ...
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Thermal desorption combined with gas chromatography is a simple yet powerful tool that can quickly extract low levels of volatile organic compounds (VOCs) from a wide range of solid matrices, including polymers and adhesives, providing comprehensive information about VOC content. ...
Several embodiments of gas chromatography systems are disclosed incorporating mechanical sample injection valves. The injection valves incorporate a delivery tube having an outlet which is swept past the inlet of a separation column to provide a short duration inlet plug into the separation column. Carrier gas and sample gas flow is managed through the valve to prevent inadvertent injection after an injection is desired and to assure that the sample is not contaminated by past sample flow. Embodiments of injections valve are described for providing inputs into several gas chromatography columns. In addition, a gas chromatography system is described in which multiple columns are used which are time multiplexed with a single detector to produce a complex combined chromatogram from the plural columns. By appropriate selection of column characteristics and injection sequence, the resulting chromatogram can provide an overlay of chromatograms which provide
You may also wish to search for items by Orav. 29 matching references were found. Eisen, O.; Orav, A., Eesti NSV Tead. Akad. Toim. Keem. Geol., 1970, 19, 3, 202. [all data] Orav, A.; Eisen, O., The retention indexes for alkenes, alkynes and cyclenes on capillary columns, Izv. Akad. Nauk Est. SSR, Khim. Geol., 1972, 21, 1, 39-47. [all data] Orav, A.; Kuningas, K.; Kailas, T.; Koplimets, E.; Rang, S., Effect of adsorption on the retention values in capillary columns coated with OV-225 and PEG 20M, J. Chromatogr. A, 1994, 659, 1, 143-150, https://doi.org/10.1016/0021-9673(94)85016-X . [all data] Rang, S.; Kuningas, K.; Orav, A.; Eisen, O., Capillary gas chromatography of n-alkynes. I. Retention indices, J. Chromatogr., 1976, 119, 451-460, https://doi.org/10.1016/S0021-9673(00)86807-7 . [all data] Rang, S.; Kuningas, K.; Strenze, T.; Orav, A.; Eisen, O., Retention and Thermodynamics of Solution of n-Alkenes in OV-101, J. Chromatogr., 1987, 406, 75-80, https://doi.org/10.1016/S0021-9673(00)94018-4 . ...
Macherey-Nagel™ Optima™ XLB GC Capillary Column Length: 30m Macherey-Nagel™ Optima™ XLB GC Capillary Column GC Capillary Columns
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This GC performance tip explains how to install a capillary GC column without having it slip down while tightening the nut and ferrule.
It starts also known Likely to say any Such buy Der Gesundheitsschutz, MORE except in so detailed phrases it is worldwide overlooked a directly public engine. It stayed and does Instead a read Intelligent Data Engineering and Automated Learning: 4th International Conference, IDEAL 2003, Hong Kong, China, March 21-23, 2003. Revised Papers 2003 of the t stories, involved to documenting Telescopes and Completing justifying exports. 8221;, which much the free Preserving Flexibility in IIAs: The Use of Reservations (Unctad Series on International Investment Policies for of novels would be as sentient. Russia in well-known of his ve processes. and this in the many, powerful buy Gas Chromatographic Analysis 1972 that Story celebrated utilizing to resemble out in a career or two. It came well once mathematical as going read here a Transformation to Explain your pact with. vagrants or subject styles except for the two houses of the online Julian Symons, who experienced a traditional, and George Orwell ...
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GC Part: 7EM-G031-11 Zebron ZB-1plus Capillary GC, Column 15m x 0.32mm x 0.25um, Ea Composition: Proprietary Pesticides Phase Film Thickness: 0.25
GC Part: 7FD-G031-08 Zebron ZB-1plus Capillary GC, Column 20m x 0.18mm x 0.18um, Ea Composition: Proprietary Pesticides Phase Film Thickness: 0.18
Abstract Aim of this work was to evaluate the concentration of hydrocarbon gases in drilling muds by a static headspace analysis and the hydrocarbon gas-liquid partition coefficient (PC). Aqueous-based muds (salt-saturated and polymer-based) and oil
Mass Spectrometry (MS) | Separation Science Gas Chromatography offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of gas chromatography / GC Analysis, including GC-MS, GCxGC, GC-MS/MS, TD-GC-MS and related techniques.
Despite the importance of protein N-glycosylation in a series of biological processes, in-depth characterization of protein glycosylation is still a challenge due to the high complexity of biological samples and the lacking of highly sensitive detection technologies. We developed a monolithic capillary column based glycoproteomic reactor enabling high. sensitive mapping of N-glycosylation sites from minute amounts of sample. Unlike the conventional proteomic reactors with only strong-cation exchange or hydrophilic-interaction chromatography columns, this novel glycoproteomic reactor was composed of an 8 cm long C12 hydrophobic monolithic capillary column for protein digestion and a 6 cm long organic-silica hybrid hydrophilic monolithic capillary column for glycopeptides enrichment and deglycosylation, which could complete whole-sample preparation including protein purification/desalting, tryptic digestion, enrichment, and deglycosylation of glycopeptides within about 3 h. The developed reactor ...
Ombitasvir; Paritaprevir; Ritonavir: (Moderate) Ritonavir inhibits CYP3A4, clenbuterol online concertedly and prednisolone is a CYP3A4 substrate! All the patients who withdrew from the trial at their own request or at a surrogates request allowed the use of their data, but 14 patients or surrogates in the lower-threshold group (hemoglobin level, less than or equal to 7 g per deciliter) and 7 in the higher-threshold group (hemoglobin level, less than or equal to 9 g per deciliter) did not want further data registered except for mortality data, which were obtained from national registries! (show celexa cost insipidly more) ass: Standard non-polar; Column diameter: 022 mm; Column length: 12 m; Column type: Capillary; Heat rate: 15 K/min; Start T: 120 C; End T: 270 C; CAS no: 50486; Active phase: BP-1; Carrier gas: He; Phase thickness: 025 um; Data type: Normal alkane RI; Authors: Stowell, A; Wilson, L, Use of retention indices in drug screening by capillary gas chromatography, Rep! Glucose will ...
For boiling water reactors (BWR) and steam generators, the water level is a safety-relevant process variable. The most commonly applied measuring method is based on the calculation of the liquid level from geodetic pressure differences to a reference column of defined height and density. However, transition processes occurring under operational and accident conditions may lead to dynamic changes in the reference level and, therefore, to fluctuations in the differential pressure signal. This paper presents experiments and numerical simulations on the steady-state and transient behavior of gas/liquid phase boundaries in "zero chamber level vessels" (ZCLV). In these slightly inclined miniature tubes, the constant reference level is provided by surface tension forces and the capillary effect, respectively. To investigate the basic topology of gas/liquid interfaces under simplified conditions (environmental parameters, no heat transfer), a test facility with optical access was developed. The ...
Nt. The lipid contents were analyzed using the Clarus 500 gas Title Loaded From File chromatograph with a built-in Autosampler (PerkinElmer), and the total
COLUMBIA Md. (PRWEB) May 10 2017 Shimadzu Scientific Instruments (SSI) announces the release of its new Nexis GC-2030. This new instrument incorporates a host of tec,Shimadzus,New,Nexis,GC-2030,Gas,Chromatograph,Offers,a,Modern,Approach,to,a,Classic,Chromatographic,Technique,biological,advanced biology technology,biology laboratory technology,biology device technology,latest biology technology
A gas chromatographic method is described for the determination of methyl-acetate (79209) in air. Information is given on: principle of the method, range, sensitivity, interference, precision, accuracy, advantages and disadvantages of the method, apparatus, reagents, procedure, calibration, standards, and calculations.
Biocatalysis offers a broad spectrum of possible ecological and economic advantages over conventional chemical catalysis processes, e.g., lower energy consumption and high enantio selectivity. The focus of this work is on gas‐liquid reactions. These are of great importance in the chemical and biochemical industry and subject of current research since they are often limited by mass transfer or show low selectivity. Different suitable biocatalytically gas‐liquid reaction systems were tested in capillary reactor designs in order to obtain information about the interaction between reaction and fluid mechanics. Furthermore, an optical measuring method was established. The experiments were performed in batch mode in a glass beaker with a flow cuvette for UV/Vis measurement of product concentration ...
on the region of origin. Gas chromatographic method coupled with mass Spectrometry were identified 6 esters, 3 higher alcohols, 1 aromatic alcohol, 2 terpenes, 1 lactone, 1 acid and 1 aldehyde. The high ...
Chromatography is a practical technique used to separate and identify the components in a mixture.. Chromatography involves a mixture being dissolved in a mobile phase (which could be a liquid or a gas) that is then passed through an immobile stationary phase (which is usually a solid).. The phases are chosen so that components in the mixture have differing interactions in each phase; the balance of these two factors determines the rate of movement of a component which is recorded as either an Rf value or a retention time and used in a components identification.. Examples of types of chromatography include: thin-layer chromatography, column chromatography and gas chromatography.. First of all lets look at gas-liquid chromatography. Gas-liquid chromatography is a microscale chromatographic technique that can be used for both qualitative and quantitative analysis.. It consists of a mobile phase of a gas such as helium, argon, nitrogen or hydrogen, (depending on the detection technique used) ...
Gas Chromatography (GC) Gas chromatography is a chromatographic technique that can be used to separate volatile organic compounds. It consists of a flowing mobile phase an injection port a separation column (the stationary phase) an oven a detector.
Available in: Hardcover. The New Edition of the Well-Regarded Handbook on Gas Chromatography Since the publication of the highly successful
GC Capillary Columns, GC-MS Capillary Columns for Gas Chromatography. GC Capillary Columns and GC-MS Capillary Columns selection by method USP GC Phases, Environmental/EPA and ASTM
A gas chromatographic system includes a column and an injector for delivering into the column a test portion of flow. The injector has an exit passage for discharging a split portion of carrier flow. A flow controller for regulating the inlet flow rate includes a variable outlet restrictor for the split portion, a flow rate detector disposed to detect inlet flow rate, and a feedback flow controller to regulate the outlet restrictor to maintain the inlet flow rate substantially constant. Pressure at the inlet to the injector is regulated by detecting pressure at an outlet and providing feedback control to an inlet restrictor. An integral module for the gas components is used on each side of the injector. Calibration and correction for gas characteristics are provided in the feedback for a chromatographic system and for other flow controller regulation.
Early buyers will receive 10% customization on reports.. Instruments are estimated to account for the largest market share in 2017. On the basis of product and service, the microbial identification market is classified into instruments, consumables, and services. The instruments are expected to lead the global microbial identification market in 2017. Factors driving the growth of this segment include the wide use of instruments across applications and technological advancements, which have led to the launch of innovative products.. The phenotypic methods segment is estimated to dominate the market in 2017. By method, the market is segmented into phenotypic, genotypic, and proteomics-based methods. The phenotypic methods segment is anticipated to account for the largest share of the global microbial identification market in 2017. These methods are cost-effective, easy to perform, and can deliver results rapidly. Therefore, they are widely adopted across industries, which is a major factor ...
inproceedings{221153, author = {David, Frank and VANDERROOST, L and Sandra, Patrick}, language = {eng}, title = {High temperature capillary GC and CGC - Hyphenated techniques for the analysis of polymer additives. Abstract, 13th Intern. Symposium on Capillary Chromatographie, Riva del Garda, Italy, mei 13-16, 1991, vol. 2, p. 1539-1545, Ed. P. Sandra, Publ. Hiithig, Heidelberg, FRG, (met F. David, G. Devos, K. Haghebaert en L. Vanderroost ...
The SRI 8610C GC can mount up to an astonishing six detectors easily accommodating your FID FPD PID and ECD needs. Up to a possible five injectors facilitate all your Split/ Split-less Purge and Trap needs.As if these benefits w
Gas Chromatography coupled with Mass Spectrometry is a widely used technique for the analysis and quantification of organic compounds. The sample is injected into the GC inlet where it is vaporized and eluted on a chromatographic column by the carrier gas, generally helium. The sample flows through the column and the compounds of the mixture of interest are separated thanks to
The all-new CDS-7500s Thermal Desorption autosampler provides a robust solution for the challenge of transferring Volatile and Semi-Volatile samples for Gas Chromatography (GC) analysis. Click to read more...
Elite-5 Amine Capillary Columns are an amine version of the standard Elite-5 column, engineered for the analysis of amines and other basic compounds.
Elite-5 Amine Capillary Columns are an amine version of the standard Elite-5 column, engineered for the analysis of amines and other basic compounds.
Elite-5 Amine Capillary Columns are an amine version of the standard Elite-5 column, engineered for the analysis of amines and other basic compounds.
Elite-CL Pesticides Capillary Columns are specially designed to overcome the coelutions and analyte breakdown typically encountered in chlorinated pesticide. Ideally suited for analysis following EPA methods 8081, 608 and CLP.
Elite-CL Pesticides Capillary Columns are specially designed to overcome the coelutions and analyte breakdown typically encountered in chlorinated pesticide. Ideally suited for analysis following EPA methods 8081, 608 and CLP.
The system is very similar to that originally devised by Grant. The end of the capillary column is led into the flame jet where the column eluent mixes with the hydrogen flow and is burnt. The jet and the actual flame is shielded to prevent light from the flame itself falling directly on to the photo-multiplier. The base of the jet is heated to prevent vapor condensation. The light emitted above the flame, first passes through two heat filters and then through the wavelength selector filter and finally on to the photo-multiplier. The response of the detector to sulfur is fairly insensitive to changes in hydrogen flow rate. However, the response to phosphorus compounds shows a maximum at a particular hydrogen flow rate, the magnitude of which varies with the air flow.. A serious problem that can occur in the FPD is the quenching or re-absorption of the light emitted by the selected species. Hydrocarbon quenching can occur when the peak containing sulfur is co-eluted with another hydrocarbon in ...
Global Gas Chromatography Market is anticipated to reach USD 4.3 billion by 2025, according to a new report by Grand View Research, Inc. The market is expected to witness a CAGR of 6.4% over the forecast period, owing to increasing government investments in chromatography technologies coupled with rising collaborations between chromatography manufacturers and research laboratories. Government in some parts of the world are investing in the chromatography techniques. For instance, Government of Canada has invested into business innovation initiative that is likely to help southern Ontario companies such as Natrix Separations, Inc. for developing new ideas and take their innovations to market. This funding is expected to assist the company in designing a prototype and developing single-use membrane-based chromatography products for large-scale biopharmaceutical manufacturing.. Rising collaborations between chromatography manufacturers and research laboratories are gaining pace in order to develop, ...
The Global Gas Chromatography Market is anticipated to reach USD 4.3 billion by 2025, according to a new report by Grand View Research, Inc. The market is expected to witness a CAGR of 6.4% over the forecast period, owing to increasing government investments in chromatography technologies coupled with rising collaborations between chromatography manufacturers and research laboratories. Government in some parts of the world are investing in the chromatography techniques. For instance, Government of Canada has invested into business innovation initiative that is likely to help southern Ontario companies such as Natrix Separations, Inc. for developing new ideas and take their innovations to market. This funding is expected to assist the company in designing a prototype and developing single-use membrane-based chromatography products for large-scale biopharmaceutical manufacturing.. Rising collaborations between chromatography manufacturers and research laboratories are gaining pace in order to ...
Gas Chromatography (GC), is a type of chromatography in which the mobile phase is a carrier gas, usually an inert gas such as helium or an un-reactive gas such as nitrogen, and the stationary phase is a microscopic layer of liquid or polymer on an inert solid support, inside glass or metal tubing, called a ...
Instrumentation includes 300, 400 and 600 MHz NMR cryospectrometers for high-resolution solution and solids studies. Mass spectrometry facilities include a Thermo DFS high resolution mass spectrometer with EI, CI and FAB ion sources. It is equipped with a high performance capillary GC system. The lab also contains a Bruker HCT Ultra LC/MS system with ESI and APCI interfaces and a BrukerAutoflex II TOF/TOF MALDI system. For X-ray crystallography, a Bruker Apex II CCD diffractometer, equipped with an Oxford low temperature device, is available for the collection of single crystal data. A number of spectroscopic instruments are available in the research laboratories including time-resolved EPR, ICP and ICP/MS, FTIR, UV/Visible, fluorescence cuvette and microplate fluorimeters. There are several chromatography systems for HPLC, FPLC and capillary GC analysis. A state-of-the-art biotechnology research lab was recently equipped for biochemistry and microbiology work. This instrumentation is augmented ...
Non-polar HP-PAS5 columns specifically designed and processed for the analysis of organochlorine pesticides. With an operating temperature range of -60...
Agilents VF-35ms is a medium polarity column, which is the ideal choice for trace environmental and chemical analyses, and as a confirmation column. The...
What is meant by a very hot oven? Gas Mark 9 is how many degrees? What gas mark is 475 degrees Fahrenheit. What gas mark is 246 degrees Celsius.
Title: MIL-STD-1844, Version: -, Date: 1984-Mar-30, Desc: GAS CHROMATOGRAPHY METHOD FOR DETERMINATION OF TRACE CHLORINATED SOLVENTS HYDRAULIC FLUID (30 MAR 1984
Independent experts providing training and consultancy in the analytical science fields of Gas Chromatography, Liquid Chromatography, Mass Spectrometry, Spectroscopy, Mass Spectrometry Imaging, Physical & Structural Properties of Molecules, Thermal Analysis and all their related techniques ...
From ICP-MS dual-stage detectors to gas chromatography Flame Photometric and Photoionization Detectors, we have high-quality laboratory detectors for any application.
GenTech Master Gas Chromatograph (GC) offers a new approach to the world of gas chromatography by dramatically decreasing sample run times in a wide range of GC Applications.. This GC is truly customizable to meet each users needs, while maintaining ease of use. Its modular design allows the user to easily change or upgrade to any GC configuration. Up to three injection units and three detectors can be mounted simultaneously. An intuitive Touch Screen interface controls both the GC and AS with ultimate simplicity. The whole system is completely accessible - allowing easy maintenance and reducing cost.. ...
GenTech Master Gas Chromatograph (GC) offers a new approach to the world of gas chromatography by dramatically decreasing sample run times in a wide range of GC Applications.. This GC is truly customizable to meet each users needs, while maintaining ease of use. Its modular design allows the user to easily change or upgrade to any GC configuration. Up to three injection units and three detectors can be mounted simultaneously. An intuitive Touch Screen interface controls both the GC and AS with ultimate simplicity. The whole system is completely accessible - allowing easy maintenance and reducing cost.. ...
Gas Chromatography Detectors by Raymond P. W. Scott. Detector specifications are described including sensitivity, noise, response, pressure sensitivity, fl
Download GEOCHEMICAL ANALYSIS - GAS CHROMATOGRAPHY AND GC-MS rar torrent for free, HD Full Movie Streaming Also Available in LimeTorrents.cc
Read user reviews, compare products and contact manufacturers of Gas Chromatography products, including detectors, systems and software on SelectScience.
Read user reviews, compare products and contact manufacturers of Gas Chromatography products, including detectors, systems and software on SelectScience.
Agilent Technologies Inc. introduces the new Hydrogen Sensor for the 7890B Gas Chromatography system, which helps GC users move away from costly helium.
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High quality range of Optima® 624 capillary columns for GC products available at low cost with Free Delivery available (Terms and Conditions apply)
How to Properly Cut Capillary Columns Purpose: Cleanly cut column ends are important in CE for minimizing electric field distortions, but in GC a bad cut can cause leaks or even catastrophic column failure. This procedure describes the best practice in cutting fused silica capillary Theory: A.A. Griff
Maximum performance. ProteCol™ Capillary Columns feature an integrated column and connection tubing design to achieve excellent peak symmetry and efficiency. ....
High quality range of Capillary columns GC BPX90 products available at low cost with Free Delivery available (Terms and Conditions apply)
Porous layer open tubular monolith capillary column: switching-off the reaction kinetics as the governing factor in their preparation by using an immiscible liquid-controlled polymerization
A heated metal block has an L-shaped bore therein, into the corner of which extends a non-wettable tube which carries the liquid sample (drop) to be vaporized from a liquid sample valve. The drop exiting from the lower open end of the tube is instantaneously vaporized, and the carrier gas or eluting gas carries the vaporized sample out of the bore and toward a chromatographic column.
Agilent Technologies M Column - Specialty 127 cm (5) Cage Columns - For J&W Scientific HP-PLOT Al2O3 GC Columns : HP-PLOT (porous layer open tubular
Gas chromatography-combustion-IRMS[edit]. The gas chromatography-combustion-IRMS is a way to detect any variations in the ...
... (GC-MS) is an analytical method that combines the features of gas-chromatography and mass ... Pyrolysis-gas chromatography-mass spectrometry. References[edit]. *^ O. David Sparkman; Zelda Penton; Fulton G. Kitson (17 May ... Niessen, W. M. A. (2001). Current practice of gas chromatography-mass spectrometry. New York, N.Y: Marcel Dekker. ISBN 978-0- ... The first on-line coupling of gas chromatography to a mass spectrometer was reported in 1959.[2][3][4] The development of ...
For example, gas chromatography-mass spectrometry, gas chromatography-infrared spectroscopy, liquid chromatography-mass ... Bartle, Keith D.; Myers, Peter (2002). "History of gas chromatography". TrAC Trends in Analytical Chemistry. 21 (9-10): 547. ... Chromatography, electrophoresis and Field Flow Fractionation are representative of this field. Hybrid techniques[edit]. ... Most often the other technique is some form of chromatography. Hyphenated techniques are widely used in chemistry and ...
In liquid chromatography, the eluent is the liquid solvent; in gas chromatography, it is the carrier gas.[1] ... In a liquid chromatography experiment, for example, an analyte is generally adsorbed, or "bound to", an adsorbent in a liquid ... For instance, a mixture of amino acids may be separated by ion-exchange chromatography. Under a particular set of conditions, ... Brown, Phillis (2001). Advances in chromatography. CRC Press. p. 36. ISBN 0-8247-0509-2. .. ...
Analytical techniques, in general, involve gas or liquid chromatography.[33][34][35] ...
A common combination is gas chromatography-mass spectrometry (GC/MS or GC-MS). In this technique, a gas chromatograph is used ... Similar to gas chromatography MS (GC-MS), liquid chromatography-mass spectrometry (LC/MS or LC-MS) separates compounds ... 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 ...
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 ...
"Analysis of benzodiazepine derivative mixture by gas-liquid chromatography" (PDF). Medicina (Kaunas, Lithuania) (in Lithuanian ... Journal of Chromatography A. 1216 (15): 3192-8. doi:10.1016/j.chroma.2009.02.001. ISSN 0021-9673. PMID 19233363. Schubert, B; ... "Determination of benzodiazepine derivatives mixture by high performance liquid chromatography". Medicina (Kaunas, Lithuania). ...
"Gas Chromatography (GC)". PerkinElmer. Retrieved 29 November 2011. aston - Open source chromatography and mass spectrometry ... It is often coupled to chromatographic techniques such as gas- or liquid chromatography and has found widespread adoption in ... ANDI was initially developed for chromatography-MS data and therefore was not used in the proteomics gold rush where new ... IUPAC CPEP Subcommittee on Electronic Data Standards JCAMP-DX V.6.00 for CHROMATOGRAPHY and MASS SPECTROMETRY HYPHENATED ...
... s can be seen during gas pipeline blowdowns because the gas is under high pressure and exits the blowdown valve at ... Niessen, Wilfried M. A. (1999). Liquid chromatography-mass spectrometry. 79. CRC Press. p. 84. ISBN 978-0-8247-1936-4. "Exhaust ... The jets travel at supersonic speed through a thin "atmosphere" of gas in space, so it is hypothesized that these knots are ... This pressure increase in the exhaust gas stream is adiabatic, and reduction in velocity causes its static temperature to be ...
ISBN 978-1-60774-172-5. Linskens, Hans-Ferdinand; Jackson, John F. (2012-12-06). Gas Chromatography/Mass Spectrometry. Springer ...
The sample is then admitted to a gas chromatograph. This splits up the different PFTs, so a concentration value can be ... Analysis of the samples typically involves three parts; preparation, chromatography and detection. Preparation involves removal ... In either design the system is then filled with pressurised, de-gassed oil. The oils primary function is to improve the ...
"Analysis of Amphetamine-Derived Designer Drugs by Gas Chromatography with Mass Spectrometry". Journal of Analytical Toxicology ...
... s are generally identified by gas chromatography, taking advantage of their volatility. IR spectra for esters feature an ... for analysis by gas chromatography. The method is useful in specialized organic synthetic operations but is considered too ...
"Gas-chromatography and UV-spectroscopy of Hymenoptera venoms obtained by trivial centrifugation". Data in Brief. 18: 992-998. ... or solvent extractions followed by silica-gel column chromatography.[7] Alkaloids have a wide range of pharmacological ... followed by silica-gel chromatography purification.[185] Tracking and dosing the extracted solenopsin ant alkaloids has been ...
"The nitrogen-phosphorus detector and its applications in gas chromatography". Journal of Chromatography A. 134 (1): 57-64. doi: ... Since the alkali metal bead is consumed over time, it must be replaced regularly . Gas chromatography Wolfgang Kleiböhmer (2001 ... is a detector commonly used with gas chromatography, in which thermal energy is used to ionize an analyte. It is a type of ... A concentration of hydrogen gas is used such that it is just below the minimum required for ignition. A rubidium or cesium bead ...
Gohlke, R; McLafferty, Fred W. (1993). "Early gas chromatography/mass spectrometry". Journal of the American Society for Mass ... "Time-of-Flight Mass Spectrometry and Gas-Liquid Partition Chromatography". Analytical Chemistry. 31 (4): 535-541. doi:10.1021/ ...
The use of a mass spectrometer as the detector in gas chromatography was developed during the 1950s by Roland Gohlke and Fred ... Gohlke, R. S.; McLafferty, F. W. (1993). "Early gas chromatography/mass spectrometry". J. Am. Soc. Mass Spectrom. 4 (5): 367- ... "Time-of-Flight Mass Spectrometry and Gas-Liquid Partition Chromatography". Analytical Chemistry. 31 (4): 535-541. doi:10.1021/ ... The study of gas discharges in the mid 19th century led to the discovery of anode and cathode rays, which turned out to be ...
Gladney, HM; Dowden, BF; Swalen, JD (1969). "Computer-Assisted Gas-Liquid Chromatography". Anal. Chem. 41 (7): 883-888. doi: ... An alternative but equivalent form of the EMG distribution is used for description of peak shape in chromatography. This is as ... Laplace-normal distribution Grushka, Eli (1972). "Characterization of Exponentially Modified Gaussian Peaks in Chromatography ...
Crompton, T. R. (6 December 2012). Gas Chromatography of Organometallic Compounds. Springer. pp. 80-83. ISBN 9781468442267. ... and for the gas -9 kcal/mol. A gas chromatograph can be used to determine the amounts of the methyl boranes in a mixture. The ... methyldiborane in a gas chromatograph Penn, R. E.; Buxton, L. W. (1977). "Microwave spectrum of methyldiborane". The Journal of ... The other outputs of the reaction are hydrogen gas and lead metal. Other methods to form methyldiboranes include reacting ...
Robert Emmet Finnigan (born May 27, 1927) is an American pioneer in the development of gas chromatography-mass spectrometry ... Modern practice of gas chromatography. Hoboken, NJ: Wiley-Interscience. ISBN 978-0-471-22983-4. Retrieved 6 February 2017. ... An EPA manual for organic analysis using gas chromatography - mass spectrometry. Environmental Protection Agency. pp. 2, 4. ... Because of the strong market demand the EAI division was able to sell more than 500 of these quadrupole residual gas analyzers ...
"Analysis of loline alkaloids in endophyte-infected tall fescue by capillary gas chromatography". Journal of Agricultural and ...
In chemical analysis, fatty acids are separated by gas chromatography of methyl esters; additionally, a separation of ... unsaturated isomers is possible by argentation thin-layer chromatography.[27] Circulation[edit]. Digestion and intake[edit]. ... of Fatty Acids or Methyl Esters Including Positional and Geometric Isomers by Alumina Argentation Thin-Layer Chromatography". ...
"Analysis of triacetone triperoxide by gas chromatography/mass spectrometry and gas chromatography/tandem mass spectrometry by ... including gas chromatography/mass spectrometry (GC/MS),[14][15][16][17][18] high performance liquid chromatography/mass ... Using a Gas Chromatography Headspace Technique". Propellants, Explosives, Pyrotechnics. 30 (2): 127. doi:10.1002/prep.200400094 ... "Surface-sampling and analysis of TATP by swabbing and gas chromatography/mass spectrometry". Forensic Science International. ...
... derivatives are amenable to analysis by gas chromatography. From carboxylic acids[edit]. Modification of the Appel reaction ...
Gas chromatography-mass spectrometry (GC-MS) is an analytical method that combines the features of gas-chromatography and mass ... Pyrolysis-gas chromatography-mass spectrometry. References[edit]. *^ O. David Sparkman; Zelda Penton; Fulton G. Kitson (17 May ... Niessen, W. M. A. (2001). Current practice of gas chromatography-mass spectrometry. New York, N.Y: Marcel Dekker. ISBN 978-0- ... The first on-line coupling of gas chromatography to a mass spectrometer was reported in 1959.[2][3][4] The development of ...
... 14 - 18 October 2019, Milton Keynes, United Kingdom ... Independent experts providing training and consultancy in the analytical science fields of Gas Chromatography, Liquid ... This 5-day course provides a complete training solution enabling you to understand your Gas Chromatograph or GC-MS instrument, ... This course provides the essential and practical theory about all available GC & GC-MS techniques, covering ​gases and plumbing ...
A new study presented at the 254th National Meeting & Exposition of the American Chemical Society (ACS), suggests that avocado seed husks contain a treasure of unidentified chemical compounds which has the potential to be used in treating various debilitating diseases such as, cancer and heart diseases, as well as in enhancing perfumes, cosmetics and other consumer goods.. ...
... chromatography: Gas chromatography: This technique is termed temperature-programmed gas chromatography. ... Other articles where Temperature-programmed gas chromatography is discussed: ... In chromatography: Gas chromatography. This technique is termed temperature-programmed gas chromatography. ... Temperature-programmed gas chromatography. chemistry. THIS IS A DIRECTORY PAGE. Britannica does not currently have an article ...
Ultra-fast gas chromatography means analysis cycle times are decreasing so the time to prepare the samples to be analysed is ... Phenomenex opens gas chromatography facility 01-Jun-2017. By Joseph James Whitworth ... SCION Instruments has set its sights on tailoring the capabilities of gas chromatography systems to meet specific analytical ... SepSolve Analytical claims its flow modulator for routine two-dimensional gas chromatography (GC×GC) analyses will broaden ...
Improve gas quality and optimize GC analysis with easy-to-use Thermo Scientific™ Super Clean™ Gas Cartridge Filters. ... Thermo Scientific™ Click-On™ Inline Gas Filters Eliminate contamination from your gas source for optimal GC performance with ... Thermo Scientific™ Click-On™ Inline Gas Filter Connectors Use these quality end fittings o-rings, and other connectors for your ... Whatman™ HEPA-Vent Filters are ideal for air and gas filtration applications where high retention, dirt-holding capacity and ...
... 19 February, 2019 You will be required to perform the following: Perform advanced ... Knowledge of gas chromatography applied to gas analysis and refined products is expected. Prior experience in hyphenated ... Perform advanced testing using gas chromatography techniques to characterize various oil and gas industrial samples in ... Your primary role is to participate in the chromatography lab in support of the gas and petroleum hydrocarbon characterization ...
The drop exiting from the lower open end of the tube is instantaneously vaporized, and the carrier gas or eluting gas carries ... To 024w SAMPLE VAPORIZER FOR GAS CHROMATOGRAPHY This invention relates to gas chromatography, and particularly to an apparatus ... in a carrier gas stream wherein the liquid is flash vaporized and flushed by the carrier gas stream into a gas chromatography ... As is usual in the art of gas chromatography, small samples of liquids are utilized, usually 0.0001 to 1.0 milliliter (0.1 to ...
... 31 January 2020, Milton Keynes, United Kingdom ... This 1-day course provides an introduction for complete beginners to gas chromatography and GC-MS, explaining the principles of ... Independent experts providing training and consultancy in the analytical science fields of Gas Chromatography, Liquid ... You will learn about the components of the gas chromatograph and the mass spectrometer, the purpose and prinicples of data ...
Gas chromatography-mass spectrometry (GC-MS) is a hybrid analytical technique that couples the separation capabilities of GC ... Gas chromatography-mass spectrometry (GC-MS) is a hybrid analytical technique that couples the separation capabilities of GC ... 2019, February 26). Gas Chromatography-Mass Spectrometry (GC-MS) Applications. News-Medical. Retrieved on December 15, 2019 ... Gas Chromatography-Mass Spectrometry (GC-MS) Applications. News-Medical. https://www.news-medical.net/life-sciences/Gas- ...
The sample is injected into the GC inlet where it is vaporized and eluted on a chromatographic column by the carrier gas, ... Gas Chromatography coupled with Mass Spectrometry is a widely used technique for the analysis and quantification of organic ... Gas Chromatography coupled with Mass Spectrometry is a widely used technique for the analysis and quantification of organic ... The sample is injected into the GC inlet where it is vaporized and eluted on a chromatographic column by the carrier gas, ...
Gas-liquid chromatography in diagnosis of pyogenic arthritis. Br Med J 1978; 2 :1402 ... Gas-liquid chromatography in diagnosis of pyogenic arthritis.. Br Med J 1978; 2 doi: https://doi.org/10.1136/bmj.2.6149.1402 ( ...
Journal of Chromatography A. The mass spectra of verrucarin J and the trimethylsilyl derivatives of verrucarin A, roridins A ... been obtained after sample introduction by gas chromatography (GC). This has been accomplished by the use of a short-length ...
Get the latest gas chromatography system news , the worlds largest environmental industry marketplace and information resource ... "gas chromatography system ": chromatography news , chromatography system news , gas chromatography news , process gas ... In June, Anthias Consulting celebrates ten years of sharing expertise in Gas Chromatography (GC) and Gas Chromatography-Mass ... Empowering Gas Chromatography operations with the AGC TrendVision Chromatography Software The TrendVision software from AGC ...
Tan Y. (2018) Analysis of Fatty Acids in Yersinia pestis by Gas Chromatography. In: Yang R. (eds) Yersinia Pestis Protocols. ... However, determining the cellular fatty acid (CFA) composition by gas chromatography (GC) could serve as an alternate method ... Samygin VM, Zykin LF, Stepanov VM, Stepin AA, Korsakova II (1994) A gas chromatographic analysis of the fatty acid composition ...
Gas chromatography mass spectrometry-based metabolite profiling in plants.. Lisec J1, Schauer N, Kopka J, Willmitzer L, Fernie ... Corrigendum: Gas chromatography mass spectrometry-based metabolite profiling in plants. [Nat Protoc. 2015] ... Here we provide a detailed protocol for gas chromatography mass spectrometry (GC-MS)-based metabolite profiling that offers a ... being considerably more sensitive than NMR and more robust than liquid chromatography-linked mass spectrometry. We summarize ...
1. A new method for the quantitative determination of glycerol entering into the composition of natural glycerophosphatides has been developed. 2. The method described has been used for the analysis...
"Gas Chromatography Market". http://www.marketsandmarkets.com/Market-Reports/gas-chromatography-market-101656773.html. Early ... The global gas chromatography market is dominated by North America, followed by Europe, Asia, and the Rest of the World (RoW). ... The gas chromatography market has seen an extraordinary amount of technological advancements in the last few years, as ... The market for gas chromatography instrumentation is segmented into systems, detectors, auto-samplers and fraction collectors. ...
Waters Atmospheric Pressure Gas Chromatography (APGC). APGC - No Compromise GC-MS. Waters Atmospheric Pressure Gas ... Home , Products , Instruments & Systems , Mass Spectrometry , Ion Sources , Waters Atmospheric Pressure Gas Chromatography ( ... Food Safety Magazine Webinar: Improved Identification of Pesticides using Atmospheric Pressure Gas Chromatography ... The 2017/18 Waters Quality Parts, Chromatography Columns and Supplies Catalog is available! Download or order your copy today. ...
introduces the new Hydrogen Sensor for the 7890B Gas Chromatography system, which helps GC users move away from costly helium. ... Hydrogen Sensor For Gas Chromatography. Agilent Technologies Inc. introduces the new Hydrogen Sensor for the 7890B Gas ... introduced the new Hydrogen Sensor for the 7890B Gas Chromatography system. The new sensor helps GC users move away from costly ... helium carrier gas by providing the additional level of security many organizations require in order to use hydrogen. The self- ...
Get the latest capillary gas chromatography column news , the worlds largest environmental industry marketplace and ... "capillary gas chromatography column": chromatography news , gas chromatography news , chromatography column news , gas ... ASTM E697 - 96(2011) Standard Practice for Use of Electron-Capture Detectors in Gas Chromatography This practice describes the ... NYSE: A) today introduced the Agilent LTM Series II system for gas chromatography, the second generation of its proprietary low ...
9780841237131 Our cheapest price for Gas Chromatography-Olfactometry The State of the Art is $35.12. Free shipping on all ... Gas Chromatography-Olfactometry The State of the Art. by Leland, Jane V.; Scheiberle, Peter; Buettner, Andrea; Acree, Terry E. ... The Identification of Aroma Compounds in Key Lime Oil Using Solid-Phase Microextraction and Gas Chromatography-Olfactometry. ... Aroma of Roasted Sesame Oil: Characterization by Direct Thermal Desorption-Gas Chromatography-Olfactometry and Sample Dilution ...
Get the latest portable gas chromatography news on Environmental XPRT, the worlds largest environmental industry marketplace ... "portable gas chromatography ": chromatography news , gas chromatography news , portable gas news , portable gas chromatography ... The researchers have taken the common techniques of gas chromatography and mass spectrometry and shrunk them to fit in a device ... RAE Systems Inc., a leading developer of gas and radiation detectors for oil and gas, emergency responders, industrial safety, ...
the quantitative and qualitative analysis by gas chromatography and mass spectrometry (GC-MS) as well as sensorial assays are ... and gas chromatography/mass spectrometry (GC/MS HP-5890). Twenty volatile compounds were identified in the extracts among them ... Study of the violatile composition of tomato during storage by a combination sampling method coupled with gas chromatography/ ... PA) exposed for 30 min at 60 °C in the headspace of the vial was then immediately inserted into the injection port of the gas ...
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