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
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
Chromatography, Gel
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
Chromatography, Thin Layer
Gas Chromatography-Mass Spectrometry
Chromatography, DEAE-Cellulose
Electrophoresis, Polyacrylamide Gel
Chromatography, Agarose
Pulmonary Gas Exchange
Mass Spectrometry
Noble Gases
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.
Chromatography, Reverse-Phase
Amino Acid Sequence
Amino Acids
Chromatography, Paper
Hydrogen-Ion Concentration
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
Spectrophotometry, Ultraviolet
Chemistry
Cattle
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
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
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
Isoelectric Focusing
Countercurrent Distribution
Oil and Gas Fields
Chromatography, Micellar Electrokinetic Capillary
Carbohydrate Sequence
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
Oligosaccharides
Temperature
Calibration
Rabbits
Isoelectric Point
Peptide Fragments
Liver
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)
Reference Standards
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
Solubility
Trypsin
Macromolecular Substances
Flame Ionization
Carbon Dioxide
Microchemistry
Fatty Acids
Immunodiffusion
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
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
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
Cloning, Molecular
Solid Phase Extraction
Radioimmunoassay
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
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
Binding Sites
Solvents
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.
Oxygen
Methanol
Sensitivity and Specificity
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
Plant Extracts
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
Isoenzymes
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).
Anion Exchange Resins
Isomerism
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
Centrifugation, Density Gradient
Carrier Proteins
Rats, Inbred Strains
Sequence Homology, Amino Acid
Chemistry Techniques, Analytical
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
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
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.
Fermentation
Chromatography, Supercritical Fluid
Physicochemical Phenomena
Chemistry, Physical
Solid Phase Microextraction
Streptococcus pyogenes
Ultracentrifugation
Spectrophotometry
Substance Abuse Detection
Electrophoresis
Pesticide Residues
Enzyme Stability
Detergents
Volatile Organic Compounds
Durapatite
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
Glycosylation
Blood 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
Cell Membrane
Isotope Labeling
Cytosol
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
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).
Cells, Cultured
Endopeptidases
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.
Erythrocytes
Blotting, Western
Acetates
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
Microsomes, Liver
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.
Sugar Alcohols
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.
Chymotrypsin
Electrochemistry
Mannose
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
Carbon Radioisotopes
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
Chickens
Peptide Hydrolases
Circular Dichroism
Adsorption
Immunoassay
Cross Reactions
Brain
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
Quality Control
Structure-Activity Relationship
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
Gas Scavengers
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
Drug Contamination
Sialic Acids
Streptomyces
Edetic Acid
Mutation
Water
Silicon Dioxide
Carboxylic Acids
Membrane Proteins
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)
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Determination of Diffusion Coefficients of Selected Long Chain Hydrocarbons using Reversed- Flow Gas Chromatographic Technique
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Simultaneous determination of phenylureas and triazines in water, by capillary gas chromatography with ion trap detection and...
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Gas chromatography
... is also sometimes known as vapor-phase chromatography (VPC), or gas-liquid partition chromatography (GLPC). ... The invention of gas chromatography is generally attributed to Anthony T. James and Archer J.P. Martin. Their gas chromatograph ... Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds ... After learning about the results of James and Martin, he switched to partition chromatography. Early gas chromatography used ...
Inverse gas chromatography
... or IGC is a highly sensitive and versatile gas phase technique developed over 40 years ago to study ... Inverse gas chromatography is a physical characterization analytical technique that is used in the analysis of the surfaces of ... E. Cremer and H. Huber, in Gas Chromatography., ed. N. Brenner, et al., Academic Press, New York (1962) p 169. P.P. Yla- ... J. Condor and C. Young, Physicochemical measurement by gas chromatography, John Wiley and Sons, Chichester, UK (1979) F. ...
Gas chromatography-olfactometry
Gas chromatography/mass spectrometry-olfactometry (GC/MS-O) GC-recomposition-olfactometry (GC-R) Multi-gas chromatography- ... Gas chromatography-olfactometry (GC-O) is a technique that integrates the separation of volatile compounds using a gas ... 2008). "Gas chromatography-olfactometry in food flavour analysis". Journal of Chromatography A. 1186 (1-2): 123-143. doi: ... 2008). "Application of gas chromatography-olfactometry (GC-O) in analysis and quality assessment of alcoholic beverages - A ...
Gas chromatography-mass spectrometry
... (GC-MS) is an analytical method that combines the features of gas-chromatography and mass ... Patton HW, Lewis JS, Kaye WI (1955). "Separation and Analysis of Gases and Volatile Liquids by Gas Chromatography". Analytical ... Gas Chromatography and Mass Spectrometry: A Practical Guide. Academic Press. ISBN 978-0-08-092015-3. Jones M. "Gas ... Modern practice of gas chromatography. New York: Wiley-Interscience. ISBN 978-0-471-22983-4. Eiceman GA (2000). "Gas ...
Gas chromatography ion detector
Many gas chromatograph detectors are ion detectors with varying methods of ionizing the components eluting from the gas ... but uses a different sort of spark Gas Chromatograph Chromatography detector (Articles with short description, Short ...
Gas chromatography-vacuum ultraviolet spectroscopy
... (GC-VUV) is a universal detection technique for gas chromatography. VUV ... 2014, 86, 8329-8335 H. Fan, J. Smuts, L. Bai, P. Walsh, D.W. Armstrong, K.A. Schug, Gas chromatography-vacuum ultraviolet ... 2014, 86, 8329-8335 H. Fan, J. Smuts, L. Bai, P. Walsh, D.W. Armstrong, K.A. Schug, Gas chromatography-vacuum ultraviolet ... guidelines, or more broadly, International Council for Harmonization (ICH) Guideline Q3C(R6). The gas chromatography (GC) ...
Pyrolysis-gas chromatography-mass spectrometry
"Hyphenation of aqueous liquid chromatography to pyrolysis-gas chromatography and mass spectrometry for the comprehensive ... Pyrolysis-gas chromatography-mass spectrometry is a method of chemical analysis in which the sample is heated to decomposition ... Pyrolysis gas chromatography is also used for environmental samples, including fossils. Pyrolysis GC is used in forensic ... Pyrolysis gas chromatography is useful for the identification of involatile compounds. These materials include polymeric ...
Comprehensive two-dimensional gas chromatography
... , or GC×GC is a multidimensional gas chromatography technique that was ... The Oil and Gas Industry were early adopters of the technology for the complex oil samples to determine the many different ... Comprehensive Chromatography is used in forensics, food and flavor, environmental, metabolomics, biomarkers and clinical ... Even methane has been modulated with liquid nitrogen cooled gas jets like those in this type of modulator. This loop modulation ...
Headspace gas chromatography for dissolved gas measurement
Sithersingh, M.J.; Snow, N.H. (2012). "Chapter 9: Headspace-Gas Chromatography". In Poole, C. (ed.). Gas Chromatography. ... Headspace-Gas Chromatography". In Poole, C. (ed.). Gas Chromatography. Elsevier. pp. 221-34. ISBN 9780123855404. ... Headspace gas chromatography uses headspace gas-from the top or "head" of a sealed container containing a liquid or solid ... As such, headspace gas chromatography offers a method for determining if there is natural biodegradation processes occurring in ...
History of chromatography
Poole, Colin; Jennings, Walter (2012). "Milestones in the Development of Gas Chromatography". Gas Chromatography. Elsevier. p. ... Others introduced mass spectrometers to gas chromatography in the late 1950s. The work of Martin and Synge also set the stage ... Martin, in collaboration with Anthony T. James, went on to develop gas chromatography (GC; the principles of which Martin and ... The ease and efficiency of gas chromatography for separating organic chemicals spurred the rapid adoption of the method, as ...
Chromatography detector
A chromatography detector is a device used in gas chromatography (GC) or liquid chromatography (LC) to detect components of the ... In liquid chromatography: Charged aerosol detector (CAD) Evaporative light scattering detector (ELSD) In gas chromatography: ... In gas chromatography: Thermal conductivity detector, (TCD). Measures the thermal conductivity of the eluent. Electron capture ... In all types of chromatography: Mass spectrometer (MS) In liquid chromatography: UV detectors, fixed or variable wavelength, ...
Chromatography
Gas chromatography (GC), also sometimes known as gas-liquid chromatography, (GLC), is a separation technique in which the ... paper chromatography, gas chromatography, and what would become known as high-performance liquid chromatography. Since then, ... Size-exclusion chromatography (SEC) is also known as gel permeation chromatography (GPC) or gel filtration chromatography and ... Affinity chromatography Aqueous normal-phase chromatography Binding selectivity Chiral analysis Chromatofocusing Chromatography ...
Reversed-phase chromatography
RPC refers to liquid (rather than gas) chromatography. In the 1970s, most liquid chromatography was performed using a solid ... Reversed-phase chromatography (also called RPC, reverse-phase chromatography, or hydrophobic chromatography) includes any ... hence the term reversed-phase chromatography. Reversed-phase chromatography employs a polar (aqueous) mobile phase. As a result ... This technique is known as reversed-phase ion-pairing chromatography. Aqueous normal-phase chromatography IUPAC, Compendium of ...
Two-dimensional chromatography
Gas chromatography-mass spectrometry (GC-MS) is a two-dimensional chromatography technique that combines the separation ... These techniques would later generate modern Gas chromatography and Liquid chromatography analysis. Different combinations of ... Two-dimensional separations can be carried out in gas chromatography or liquid chromatography. Various different coupling ... Comprehensive two-dimensional gas chromatography is an analytical technique that separates and analyzes complex mixtures. It ...
Resolution (chromatography)
the "Gold Book") (1997). Online corrected version: (2006-) "Peak Resolution in gas chromatography". doi:10.1351/goldbook.R05317 ... In chromatography, resolution is a measure of the separation of two peaks of different retention time t in a chromatogram. ... 10.1351/goldbook.P04694 IUPAC Nomenclature for Chromatography (Chromatography). ... the "Gold Book") (1997). Online corrected version: (2006-) "Peak Resolution Rs in chromatography". doi:10.1351/goldbook.P04465 ...
Chiral column chromatography
The principle can be also applied to the fabrication of monolithic HPLC columns or gas chromatography columns. Seebach, Dieter ... Chiral column chromatography is a variant of column chromatography that is employed for the separation of enantiomers, e. g. in ... "Determination of salsolinol enantiomers by gas chromatography-mass spectrometry with cyclodextrin chiral columns". Analytica ... doi:10.1016/S0003-2670(00)00986-7. v t e (Chromatography, Stereochemistry, All stub articles, Chemistry stubs). ...
Chromatography column
... s of different types are used in both gas and liquid chromatography. Liquid chromatography: Traditional ... A Chromatography column is a device used in chromatography for the separation of chemical compounds. A chromatography column ... Gas chromatography (GC): Older columns were made of glass or metal packed with particles of a solid stationary phase. More ... Chromatography columns can be used as stand-alone devices or in combination with manual or automated chromatography systems. ...
Supercritical fluid chromatography
A third drawback is difficulty in gas/liquid separation during collection of product. Upon depressurization, the CO2 rapidly ... Supercritical fluid chromatography (SFC) is a form of normal phase chromatography that uses a supercritical fluid such as ... supercritical fluid chromatography is sometimes called convergence chromatography. SFC is used in industry primarily for ... Principles are similar to those of high performance liquid chromatography (HPLC), however SFC typically utilizes carbon dioxide ...
National Technological University - Córdoba Regional Faculty
Gas Chromatography. Physics of Materials. Projects Management This NTU College is one of the 24 regional faculties of the ...
Conservation scientist
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 ...
Mass spectrometry
Similarly to gas chromatography MS (GC-MS), liquid chromatography-mass spectrometry (LC/MS or LC-MS) separates compounds ... A common combination is gas chromatography-mass spectrometry (GC/MS or GC-MS). In this technique, a gas chromatograph is used ... The duty cycle of IMS is short relative to liquid chromatography or gas chromatography separations and can thus be coupled to ... Eiceman, G.A. (2000). Gas Chromatography. In R.A. Meyers (Ed.), Encyclopedia of Analytical Chemistry: Applications, Theory, and ...
Pulsed discharge ionization detector
A pulsed discharge ionization detector (pulsed discharge detector) is a detector for gas chromatography that utilizes a stable ... In addition, when the helium discharge gas is doped with a suitable noble gas, such as argon, krypton, or xenon (depending on ... Response to fixed gases is positive (increase in standing current), with an MDQ in the low ppb range. The PDD in helium ... Journal of Chromatography A, Volume 1050, Issue 1, 24 September 2004, Pages 63-68 Wentworth, W. E.; Vasnin, S. V.; Stearns, S. ...
Partition chromatography
... paper chromatography, and gas-liquid chromatography which is more commonly known as gas chromatography. The modification of ... Finally, gas-liquid chromatography, a fundamental technique in modern analytical chemistry, was described by Martin with ... James, A. T.; Martin, A. J. P.; Smith, G. Howard (1 October 1952). "Gas-liquid partition chromatography: the separation and ... The introduction of paper chromatography was an important analytical technique which gave rise to thin-layer chromatography. ...
Archer Martin
"Gas-Liquid Chromatography: A Technique for the Analysis and Identification of Volatile Materials" reported the discovery of gas ... He developed partition chromatography whilst working on the separation of amino acids, and later developed gas-liquid ... "Gas Chromatography-Mass Spectrometry". American Chemical Society. Retrieved 19 November 2019. "Nobel Winner Archer Martin Dies ... JAMES, AT; MARTIN, AJ (1954). "Gas-liquid chromatography; a technique for the analysis and identification of volatile materials ...
2-Bromodeschloroketamine
Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences. 794 (1): 99-108. doi:10.1016/s1570- ... "Gas chromatographic analysis of ketamine and norketamine in plasma and urine: nitrogen-sensitive detection". Journal of ... "Determination of the enantiomers of ketamine and norketamine in human plasma by enantioselective liquid chromatography-mass ... Chromatography. 232 (2): 305-14. doi:10.1016/s0378-4347(00)84170-5. PMID 6818238. Rodriguez Rosas ME, Patel S, Wainer IW ( ...
Levophacetoperane
I. Gas chromatographic detection procedure with electron capture detection for some secondary amines". Journal of ... Chromatography. 106 (2): 412-7. doi:10.1016/S0021-9673(00)93853-6. PMID 239015. US 20150038533, Konofal E, Figadere B, " ...
Fetor hepaticus
Kaji, H; Hisamura, M; Saito, N; Murao, M (May 1, 1978). "Gas chromatographic determination of volatile sulfur compounds in the ... expired alveolar air in hepatopathic subjects". Journal of Chromatography. 145 (3): 464-8. doi:10.1016/s0378-4347(00)81377-8. ...
Clonazepam
"Improved micromethod for determination of underivatized clonazepam in serum by gas chromatography" (PDF). Clinical Chemistry ( ... Gerna M, Morselli PL (January 1976). "A simple and sensitive gas chromatographic method for the determination of clonazepam in ... Studies on the detection of clonazepam and its main metabolites considering in particular thin-layer chromatography ... human plasma". Journal of Chromatography. 116 (2): 445-450. doi:10.1016/S0021-9673(00)89915-X. PMID 1245581. Tokola RA, ...
Forensic chemistry
Gas chromatography (GC) performs the same function as liquid chromatography, but it is used for volatile mixtures. In forensic ... These include high-performance liquid chromatography, gas chromatography-mass spectrometry, atomic absorption spectroscopy, ... HPLC is used for nonvolatile mixtures that would not be suitable for gas chromatography. This is useful in drug analysis where ... "Gas Chromatography-Mass Spectrometry". American Chemical Society. Retrieved 19 Nov 2019. Gohlke, Roland S.; McLafferty, Fred W ...
Unresolved complex mixture
Journal of Chromatography A 1000, 69-108 (2003). Phillips, J. B. & Beens, J. Comprehensive two-dimensional gas chromatography: ... Gas-liquid chromatography Ecotoxicology Environmental chemistry Toxicology Pollution Endocrine disruptor Gough, M. A.; Rowland ... Comprehensive 2-Dimensional Gas-Chromatography Using an on-Column Thermal Modulator Interface. Journal of Chromatographic ... Recent developments in comprehensive two-dimensional gas chromatography (GC x GC) III. Applications for petrochemicals and ...
Abietane
... s found in modern gymnosperm resins as well as in the rock record are separated and characterized by gas chromatography ... Because polar functional groups reduce molecular volatility and make separation by gas chromatography difficult, abietane ...
Metabolism
For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals. The basal metabolic ... Modern biochemical research has been greatly aided by the development of new techniques such as chromatography, X-ray ... Conrad R (December 1996). "Soil microorganisms as controllers of atmospheric trace gases (H2, CO, CH4, OCS, N2O, and NO)". ...
Tarragon
Gas chromatography/mass spectrometry analysis has revealed that A. dracunculus oil contains predominantly phenylpropanoids such ...
Keulemans
... pioneer in gas chromatography Maarten Keulemans (born 1968), Dutch science journalist and founder of the website ExitMundi.nl ...
Interferon
GAS) elements in gene promoters. Type I IFNs can induce expression of genes with either ISRE or GAS elements, but gene ... immunosorbent column chromatography and N-terminal amino acid sequence". Biochemistry. 19 (16): 3831-5. doi:10.1021/bi00557a028 ... induction by type II IFN can occur only in the presence of a GAS element. In addition to the JAK-STAT pathway, IFNs can ...
Candida keroseneae
The kerosene from which the two yeast strains were isolated was analyzed with gas chromatography and shown to have 48 ...
Oxazoline
The dimethyloxazoline (DMOX) derivatives of fatty acids are amenable to analysis by gas chromatography. Structural analogues ...
Matrix-assisted ionization
Solvent assisted inlet ionization can be coupled not only to liquid chromatography (LC) but also to nano LC. Ionization at ... a New Atmospheric Pressure MALDI Method for Producing Highly Charged Gas-phase Ions of Peptides and Proteins Directly from ... A New Highly Sensitive Approach for Liquid Chromatography/Mass Spectrometry of Small and Large Molecules". Analytical Chemistry ...
Karin Markides
"Multi-Element Selective Radio Frequency Plasma Detector for Capillary Gas Chromatography, F. Yang, P. Farnsworth, R. Skelton, K ... degree at Stockholm University 1984 with the thesis Organosiloxanes containing cyano groups for capillary chromatography. ...
SCIEX
In 1979 the TAGA 3000 was used for real-time monitoring of toxic gas plumes of chlorine, styrene and other gases released from ... Today, Chromatography. "The fascinating history of the development of LC-MS; a personal perspective". Chromatography Today. ... "Liquid Chromatography Mass Spectrometry Market Size By 2027". www.coherentmarketinsights.com. Retrieved 2022-05-28. Gelpí, ... Peter Dawson at the National research Council of Canada, the first application of liquid chromatography-mass spectrometry-mass ...
Cryptostylis
Furthermore, gas chromatography and electrophysiology show that the single active compound for pollinator attraction is found ...
Decaffeination
Many coffee companies use high-performance liquid chromatography (HPLC) to measure how much caffeine remains in the coffee ... with properties midway between a gas and a liquid. Caffeine dissolves into the CO2; but compounds contributing to the flavour ...
Fritted glass
The purpose of a scrubber or gas-washing bottle is to scrub the gas such that the liquid absorbs one (or more) of the gaseous ... Other laboratory applications of fritted glass include packing in chromatography columns and resin beds for special chemical ... Laboratory scale spargers (also known as gas diffusing stones or diffusors) as well as scrubbers, and gas-washing bottles (or ... To maximize surface area contact of the gas to the liquid, a stream of gaseous particles is slowly blown into the vessel ...
Binding selectivity
This is particularly true in gas-liquid chromatography where column lengths up to 60 m are possible, providing a very large ... In ion-exchange chromatography the selectivity coefficient is defined in a slightly different way Solvent extraction is used to ... Factors determining selectivity for lead against zinc, cadmium and calcium have been reviewed, In column chromatography a ... the "Gold Book") (1997). Online corrected version: (2006-) "selectivity coefficient, kA/B in ion exchange chromatography". doi: ...
Freundlich equation
... is an empirical relationship between the quantity of a gas adsorbed into a solid surface and the gas pressure. The same ... Articles with short description, Short description matches Wikidata, Chromatography). ... equilibrium pressure of the gaseous adsorbate in case of experiments made in the gas phase (gas/solid interaction with gaseous ... When the adsorbate pressure in the gas phase (or the concentration in solution) is low, high-energy sites will be occupied ...
Stuart Patton
One of the first to use gas chromatography, mass spectrometry and thin layer chromatography in flavor research, Patton proved, ...
Phenylpiracetam
"Determination of carphedon in human urine by solid-phase microextraction using capillary gas chromatography with nitrogen- ...
Eryngium planum
Qualitative and quantitative analyses of the essential oil compounds performed by gas chromatography with a flame ionization ... Qualitative and quantitative determinations of the phenolic acids by reverse phase high-performance liquid chromatography (RP ...
Resolution (mass spectrometry)
and ion microscopy (SIMS) but not gas chromatography. This definition also appears in some mass spectrometry texts. There are ... the "Gold Book") (1997). Online corrected version: (2006-) "resolution in gas chromatography". doi:10.1351/goldbook.R05317 ... A high value for resolution corresponding to good separation of peaks is similar to the convention used with chromatography ... Blumberg LM, Kle MS (November 2001). "Metrics of separation in chromatography". J Chromatogr A. 933 (1-2): 1-11. doi:10.1016/ ...
Bis(trimethylsilyl)acetamide
... for gas chromatography. It is also used to introduce the trimethylsilyl protecting group in organic synthesis. A related ... Handbook of Derivatives for Chromatography (2nd ed.). John Wiley & Sons. ISBN 0-471-92699-X. Harry Heaney, Jian Cui, "N,O-Bis( ...
Electrodialysis
Small amounts of hydrogen gas are generated at the cathode and small amounts of either oxygen or chlorine gas (depending on ... Inamuddin (2017-06-01). Applications of Adsorption and Ion Exchange Chromatography in Waste Water Treatment. Materials Research ... These gases are typically subsequently dissipated as the E stream effluent from each electrode compartment is combined to ... However, some (e.g.,) have proposed collection of hydrogen gas for use in energy production. Current efficiency is a measure of ...
Bend Arch-Fort Worth Basin
API gravity and sulfur content were integrated with high-resolution gas chromatography (GC) and Gas chromatography-mass ... The zone of wet gas generation is in the 1.1-1.4% Ro range, whereas the primary zone of dry gas generation (main gas window) ... Continuous-type accumulations include fractured shale and fractured limestone oil and gas, basin-centered gas, coal bed gas, ... of gas, and 500 million barrels (79×10^6 m3) of natural gas liquids. Cumulative gas production from the Barnett Shale for the ...
Turnera diffusa
... of the presence of damiana in herbal blends of forensic interest based on comprehensive two-dimensional gas chromatography". ...
Polyarc reactor
It is paired with a flame ionization detector (FID) in a gas chromatograph (GC) to improve the sensitivity of the FID and give ... Watanabe, T., Kato, K., Matsumoto, N., and Maeda, T., Chromatography, 27 (2006) 1-7. Watanabe, T., Kato, K., Matsumoto, N., and ... The Polyarc reactor requires a supply of hydrogen and air to operate, which can be split from the gases that supply the FID. ... Oil, Gas, and Biofuels: The Polyarc system can dramatically simplify the calibration process by reducing (or eliminating) the ...
Dichlofluanid
Determination of Dichlofluanid Residues in Vegetables Using Dispersive-SPE Sample Preparation Combined with Gas Chromatography- ...
Mead acid
"Criteria for essential fatty acid deficiency in plasma as assessed by capillary column gas-liquid chromatography". Clinical ...
Photonic crystal sensor
"On-chip Fabry-Pérot interferometric sensors for micro-gas chromatography detection". Sensors and Actuators B: Chemical. 159 (1 ...
4-Acetoxy-MiPT
... designer drugs data library using liquid chromatography with photodiode array spectrophotometry detector and gas chromatography ...
gas-solid chromatography | Encyclopedia.com
Source for information on gas-solid chromatography: A Dictionary of Earth Sciences dictionary. ... v. (tear-gas) [tr.… Gas , Gas Since ancient times, use of poison has been considered treacherous and, therefore, incompatible ... Tear Gas , tear gas / ti(ə)r/ • n. gas that causes severe irritation to the eyes, chiefly used in riot control to force crowds ... Atlanta Gas Light Company , Atlanta Gas Light Company Atlanta Gas Light Company 303 Peachtree St., N.E. Atlanta, Georgia 30308 ...
Gas Chromatography with Glass Capillary Columns - 1st Edition
Purchase Gas Chromatography with Glass Capillary Columns - 1st Edition. Print Book & E-Book. ISBN 9780123843500, 9780323141062 ... Gas Chromatography with Glass Capillary Columns. Black Friday Event. :. save up to 30% on print and eBooks with free shipping. ... 12.2 Pyrolysis Gas Chromatography. 12.3 Silylation. 12.4 Silylation Methods. References. Chapter 13 Applications of Glass ... Gas Chromatography with Glass Capillary Columns describes glass capillary technology and the selection, installation, ...
Browsing by Subject "Chromatography, Gas"
Gas Chromatography Accessories from Cole-Parmer
Buy Gas Chromatography Accessories and more from our comprehensive Cole-Parmer Chromatography Products stores ... Gas Chromatography Accessories. Gas chromatography accessories are available to help you with your chromatography applications ... Select gas purifiers to help you remove contaminants from source gases for better results. We offer all-in-one gas ...
Gas Chromatography FAQs | Agilent
Glass Surface Chemistry Via Gas Chromatography - Nokia Bell Labs
Standard Test Method for Phenols in Water by Gas-Liquid Chromatography
Gas Chromatography Market worth $3.5 billion by 2025
HOME › Press Releases › Gas Chromatography Market worth $3.5 billion by 2025 Gas Chromatography Market worth $3.5 billion by ... The oil & gas segment is expected to account for the largest share of the global gas chromatography market. The large share of ... The columns segment is estimated to account for the largest share of the global gas chromatography market. The large share of ... Don t miss out on business opportunities in Gas Chromatography Market. Speak to our analyst and gain crucial industry insights ...
NIOSHTIC-2 Publications Search - 00194303 - Measurement of organic vapors at sub-TLV concentrations using fast gas...
The features of this system included a gas cooled, electrically heated, capillary cold trap which focuses the sampl ... The results of a preliminary investigation concerning the application of high speed gas chromatography (GC) to the measurement ... The results of a preliminary investigation concerning the application of high speed gas chromatography (GC) to the measurement ... Measurement of organic vapors at sub-TLV concentrations using fast gas chromatography.. ...
Quality-Control Analytical Methods: Gas Chromatography
Figures show a schematic of a gas chromatograph and an example chromatogram illustrating gas chromatography analysis of ... In this article, the author discusses practical aspects of gas chromatography theory, samples and sample preparation, hardware ... Chromatography is an analytical technique based on the separation of molecules due to differences in their structure and/or ... injectors, carrier gas, column/stationary phase, oven detector and recorder), quantitative analysis and validation. ...
ISO - ISO 22258:2020 - Traditional Chinese medicine - Determination of pesticide residues in natural products by gas...
Determination of pesticide residues in natural products by gas chromatography ... Traditional Chinese medicine - Determination of pesticide residues in natural products by gas chromatography. ... by gas chromatography (GC), including Chinese materia medica (whole medicinal materials) and decoction pieces derived from ...
British Library EThOS: Applications of gas chromatography-mass spectrometry in steroid chemistry
In the work described in this thesis, gas-liquid chromatography (GLC) and combined gas chromatography-mass spectrometry (GC-MS ... derivative in stabilising steroidal dihydroxyacetones for gas chromatography was investigated for fourteen representative ... A number of other derivatives which have been described previously for the gas-phase separation of corticosteroids were also ... In particular, O-isopentyloxime trimethylsilyl (iPO-TMS) ethers were of value in affording gas-phase "group" separations of ...
Gas chromatography enabling fair trade in LNG
Stay at the forefront of the industrial gas industry with a gasworld subscription and get access to: *Current news and views ... Because of this shockwave, the demand for liquefied natural gas (LNG) in Japan has grown tremendously and the country now ranks ... Gas-fired electrical power generation has grown to substitute the load on these nuclear reactors. ... discover the in-depth content our subscribers receive every month by subscribing to gasworld. ...
Gas Chromatography-Mass Spectroscopy
Gas chromatography-mass spectrometry (GC-MS) is the most widespread tandem technique in the analytical instrumentation industry ... Liquid Chromatography (LC/HPLC)Gas Chromatography (GC)Sample PreparationMass SpectrometryPharmaceutical AnalysisEnvironmental ... View MoreLiquid Chromatography (LC/HPLC)Gas Chromatography (GC)Sample PreparationMass SpectrometryPharmaceutical Analysis ... Gas chromatography-mass spectrometry (GC-MS) is the most widespread tandem technique in the analytical instrumentation industry ...
Gas Chromatography System Features | Thermo Fisher Scientific - US
Assay of plasma cannabidiol by capillary gas chromatography/ion trap mass spectroscopy following high-dose repeated daily oral...
Gas and liquid chromatography abstracts. - OpenAGRICOLA
PRIME PubMed | Measurement of cocaine and metabolites in urine, meconium, and diapers by gas chromatography/mass spectrometry
... and diapers by gas chromatography/mass spectrometry. Download Prime PubMed App to iPhone, iPad, or Android ... CocaineGas Chromatography-Mass SpectrometryHumansIndicator Dilution TechniquesInfant CareInfant, NewbornMeconiumSensitivity and ... Measurement of cocaine and metabolites in urine, meconium, and diapers by gas chromatography/mass spectrometry. Ann Clin Lab ... Measurement of Cocaine and Metabolites in Urine, Meconium, and Diapers By Gas Chromatography/mass Spectrometry. Ann Clin Lab ...
Gas Chromatography Principle Instrumentation and Method - Psbih
Gas Chromatography Principle Instrumentation and Method. adminJanuary 19, 2021 Gas Chromatography principle relies on partition ... This chromatography is of two forms like gas liquid chromatography GLC and gasoline solid chromatography. Of them GLC is widely ... Gas Chromatography runs on the principle of partition chromatography for separation of elements. The stationary phase is a ... But Still, gas chromatography is an important instrument in analytical chemistry, particularly in the medicinal field. The Gas ...
gas chromatography - GenTech Scientific
Modulator Development for Comprehensive Two-Dimensional Gas Chromatography (GCxGC)
Comprehensive two-dimensional gas chromatography (GCxGC) is a method of GC that can be used to improve the separation power of ... Gas chromatography (GC) is a widespread technique for the analysis of complex mixtures. There continues to be great interest in ... Modulator Development for Comprehensive Two-Dimensional Gas Chromatography (GCxGC). Cory Scott FixGrad. Student/Intern(U-M)/ ... 2004-2007 and is now participating in the Student Internship Program at Sandia National Laboratories in the DARPA Micro-gas ...
Improving Qualitative Synthetic Cathinone Identification by Gas Chromatography/Mass Spectrometry (GC/MS) Using Cold Electron...
Gas chromatography coupled to mass spectrometry (GC-MS) characterization and evaluation of antibacterial bioactivities of the...
The chemical components were characterized by gas chromatography coupled to mass spectrometry, which revealed β-copaen-4-α-ol ( ... Article Gas chromatography coupled to mass spectrometry (GC-MS) characterization and evaluation of antibacterial bioactivities ... Gas chromatography coupled to mass spectrometry (GC-MS) characterization and evaluation of antibacterial bioactivities of the ... Gas chromatography coupled to mass spectrometry (GC-MS) characterization and evaluation of antibacterial bioactivities of the ...
Complementary analysis of the water-soluble and water-insoluble fraction of catalytic fast pyrolysis biocrudes by two...
... and comprehensive two-dimensional gas chromatography (GC X GC). The findings show that sample fractionation simplifies the ... of the water-soluble and water-insoluble fraction of catalytic fast pyrolysis biocrudes by two-dimensional gas chromatography. ... of the water-soluble and water-insoluble fraction of catalytic fast pyrolysis biocrudes by two-dimensional gas chromatography. ... of the water-soluble and water-insoluble fraction of catalytic fast pyrolysis biocrudes by two-dimensional gas chromatography ...
Gas Chromatography-Mass Spectrometry Measurement of 6β-OH-Cortisol/Cortisol Ratio in Human Urine: A Specific Marker of...
We propose a new quantitative gas chromatographymass spectrometry with isotope dilution (GC-ID-MS) method for the simultaneous ... Reference intervals of urinary steroid metabolites using gas chromatography-mass spectrometry in Chinese adults. *A. Chan, N. ... Gas Chromatography-Mass Spectrometry Measurement of 6β-OH-Cortisol/Cortisol Ratio in Human Urine: A Specific Marker of ... inproceedings{Luceri2001GasCS, title={Gas Chromatography-Mass Spectrometry Measurement of 6$\beta$-OH-Cortisol/Cortisol Ratio ...
Gas Chromatography Mass Spectrometry (GC/MS) - Agilent Technologies 7890B GC - 240 Ion Trap MS - Science & Engineering Shared...
Gas Chromatography Mass Spectrometry (GC/MS) - Agilent 240 Ion Trap Gas Chromatography Mass Spectrometry (GC/MS) - Agilent 240 ... Gas Chromatography Mass Spectrometry (GC/MS) - Agilent 240 Ion Trap Gas Chromatography Mass Spectrometry (GC/MS) - Agilent 240 ... Standard Operating Procedure: Gas Chromatography Mass Spectrometry (GC/MS) - Agilent Technologies 7890B GC - 240 Ion Trap MS ... Gas Chromatography Mass Spectrometry (GC/MS) - Agilent Technologies 7890B GC - 240 Ion Trap MS ...
Operational impacts and benefits of determining Methanol Concentration by Gas Chromatography | Element
What Are Gas Hydrates? Gas hydrates are ice-like crystals containing large amounts of a low molecular weight gas that builds up ... Operational impacts and benefits of determining Methanol Concentration by Gas Chromatography. 10/09/19 ... Gas hydrates are a common problem within the oil and gas industry. Methanol hydrate inhibition is one of the most cost- ... Gas hydrates form when low molecular weight gasses such as methane, ethane, or carbon dioxide combine with water and freeze ...
Agilent Technologies Launches Supplies Program for Major Gas Chromatography Instrument Brands
... Product News Published: March 22 ... "Agilent Technologies Launches Supplies Program for Major Gas Chromatography Instrument Brands" ... providing high-quality supplies for major brands of gas chromatography systems. Benefits include boosting lab productivity and ... "With Agilent CrossLab, our customers can now access supplies backed by Agilent innovation and 40 years of chromatography know- ...
Investigated by using Gas ChromaCombined gas chromatograpHPLCChromatographAgilentComprehensive Two-Dimensional Gas ChIsotopeMeasurementThin Layer ChromatoMetabolitesDetectorAbstractVolatileAnalysisCarrier gasAdsorptionCapillary columnVaporsDeterminationChromatographicInjectionConcentrationEthyleneHydrogenThermalUrinePetroleumFourierHeliumDetectionMethaneSeparationCompoundsInstrumentColumnsColumnLiquidSeparationsMethodComponentsContaminantsContentSelectiveInstrumentationThesisChemicalExperimentExtraction
Investigated by using Gas Chroma1
- The phytocomponents of the methanol extract of Equisetum arvense were investigated by using Gas Chromatography-Mass spectrometry, while the mass spectra of the compounds found in the extract were matched with the National Institute of Standards and Technology Library. (ijpjournal.com)
Combined gas chromatograp1
- In the work described in this thesis, gas-liquid chromatography (GLC) and combined gas chromatography-mass spectrometry (GC-MS) were applied to the analysis of steroids of biological significance, with particular interest centring on the corticosteroid family. (bl.uk)
HPLC1
- The primary method that has been used to analyze for 2,4,6-trinitrotoluene and/or its metabolites in blood and urine is high-performance liquid chromatography (HPLC)/mass spectrometry (MS) (Yinon and Hwang 1985b, 1986b, 1986c, 1987). (cdc.gov)
Chromatograph4
- Figures show a schematic of a gas chromatograph and an example chromatogram illustrating gas chromatography analysis of menthol with decanol used as an internal standard. (ijpc.com)
- The Agilent 7890B is a state-of-art gas chromatograph (GC) that provides superior performance for all GC applications with the use of advanced electronic pneumatic control (EPC) modules and high performance GC oven temperature control. (buffalo.edu)
- The carbon-disulfide was adsorbed on charcoal tubes, eluted with benzene , and quantitated with a gas chromatograph equipped with a sulfur flame photometric detector. (cdc.gov)
- GCMSsolution is the workstation software for Shimadzu GCMS-TQ series gas chromatograph mass spectrometers. (shimadzu.com)
Agilent4
- Agilent Technologies, Inc., has introduced the Agilent CrossLab supplies portfolio, providing high-quality supplies for major brands of gas chromatography systems. (technologynetworks.com)
- With Agilent CrossLab, our customers can now access supplies backed by Agilent innovation and 40 years of chromatography know-how, for multiple instrument brands," said Cikui Liang, business manager, Agilent Chemistries and Supplies Division. (technologynetworks.com)
- Chromatographic analysis was carried out on an Agilent 6890N gas chromatography system equipped with 5973 series mass selective detector, 7673 series autosampler and chemstation (Agilent Technologies, Palo Alto, CA). HP-5 MS column with 0.25 μm film thickness (30 m × 0.25 mm I.D., USA) was used for separation. (ijpjournal.com)
- Through its website, GenTech offers a number of refurbished liquid and gas chromatography and mass spectrometry instruments for rent from makers including Thermo Fisher Scientific , AB Sciex, and Agilent Technologies. (gentechscientific.com)
Comprehensive Two-Dimensional Gas Ch2
- Comprehensive two-dimensional gas chromatography (GCxGC) is a method of GC that can be used to improve the separation power of a GC system drastically, and much effort has gone into developing improved modulators, a key component of the GCxGC system. (umich.edu)
- In this study, we perform a comprehensive characterization of five biocrude samples from loblolly pine (pinus taeda), produced under different CFP conditions, by fractionation, automatic precolumn derivatization, and comprehensive two-dimensional gas chromatography (GC X GC). (rti.org)
Isotope4
- Analytical methods were evaluated for measuring cocaine (CO), benzoylecgonine (BE), and ecgonine methyl ester (EME) in urine and methanolic extracts from meconium and diapers by isotope dilution gas chromatography/mass spectrometry (GC/MS). Volatile derivatives of the extracted drugs were generated before GC/MS analysis. (unboundmedicine.com)
- We propose a new quantitative gas chromatographymass spectrometry with isotope dilution (GC-ID-MS) method for the simultaneous determination of urinary free cortisol (UFC) and 6β-OH-cortisol (6β-OHC). (semanticscholar.org)
- Can gas chromatography combustion isotope ratio mass spectrometry be used to quantify organic compound abundance? (hutton.ac.uk)
- Quantification of glyphosate and other organophosphorus compounds in human urine via ion chromatography isotope dilution tandem mass spectrometry. (cdc.gov)
Measurement6
- The chapters that follow focus on general considerations in column attachment, measurement of column efficiency, and retention behavior of carrier gas, along with the operating temperature of the column, the choice of carrier gas, and carrier gas velocity. (elsevier.com)
- Measurement of organic vapors at sub-TLV concentrations using fast gas chromatography. (cdc.gov)
- The results of a preliminary investigation concerning the application of high speed gas chromatography (GC) to the measurement of aromatic vapors of toluene (108883), benzene (71432), and xylene (1330207) in air at threshold limit value (TLV) and sub/TLV concentrations were reported. (cdc.gov)
- A separate chapter discusses the importance of temperature and carrier gas flow rate in the measurement of HSP, of amorphous materials. (bl.uk)
- The purpose of this investigation was to 1) compare the performance of proton nuclear magnetic resonance spectroscopy to gas chromatography head-space analysis in the measurement of serum isopropanol and its metabolite, acetone, obtained during a simulated overdose, and 2) compare pharmacokinetic parameters obtained using the two analytical techniques. (elsevier.com)
- [1] Standalone FIDs can also be used in applications such as landfill gas monitoring , fugitive emissions monitoring and internal combustion engine emissions measurement [2] in stationary or portable instruments. (wikimili.com)
Thin Layer Chromato1
- GC)/electron capture detection (ECD) and thin-layer chromatography (TLC)/densitometry have also been used to detect 2,4,6-trinitrotoluene and/or its metabolites in urine. (cdc.gov)
Metabolites2
- It was the aim of this work to develop a gas chromatographic - mass spectrometric (GC-MS) method that allow for the simultaneous analysis of the endogenous catecholamines, their basic and acidic metabolites using a single extraction procedure (which is easy to use and not tedious) with minimal derivatization steps. (up.ac.za)
- Four different gas chromatographic - mass spectrometric methods were developed for the analysis of the catecholamines and their metabolites and are discussed in detail. (up.ac.za)
Detector7
- In this article, the author discusses practical aspects of gas chromatography theory, samples and sample preparation, hardware (injectors, carrier gas, column/stationary phase, oven detector and recorder), quantitative analysis and validation. (ijpc.com)
- Gas Chromatography-micro Electron Capture Detector (GC-ECD) is a technique used to analyse halogenated compounds and is primarily used in the environmental, forensic and pharmaceutical markets. (ceda.ac.uk)
- Analysis of dissolved gases by headspace sampling gas chromatography with column and detector switching. (ifremer.fr)
- Schematic of a flame ionization detector for gas chromatography. (wikimili.com)
- A flame ionization detector (FID) is a scientific instrument that measures analytes in a gas stream. (wikimili.com)
- It is frequently used as a detector in gas chromatography . (wikimili.com)
- This makes the detector sensitive to the mass rather than the concentration, which is useful because the response of the detector is not greatly affected by changes in the carrier gas flow rate. (wikimili.com)
Abstract2
- abstract = "Gas chromatography (GC) has in recent times become an important tool for the fatty acid profiling of human blood and plasma. (vu.nl)
- Experiment #7: Column Chromatography of Food Dye Arianne Jan D. Tuozo Mr. Carlos Edward B. Santos October 12, 2015 Abstract Column chromatography is the separation of mixture's components through a column. (ipl.org)
Volatile8
- The Principle in gas chromatography entails separation of volatile parts of the sample based on their partition co-efficient. (psbih.org)
- This type of chromatography was primarily designed to evaluate volatile substances like fatty acids, essential oils, etc. (psbih.org)
- You can imagine the need to convert into a gas phase would be inconvenient to say the least for the testing of volatile compounds! (psbih.org)
- Gas chromatography / mass spectrometry (GC/MS) is the marriage of two analytical methods into a versatile technique for the identification of complex volatile materials. (mee-inc.com)
- The instrument also includes a heated injection port to vaporize all volatile constituents of the sample and an oven to keep the constituents in gas form as they pass through the column. (mee-inc.com)
- Analysis of volatile phenols in alcoholic beverage by ethylene glycol-polydimethylsiloxane based stir bar sorptive extraction and gas chromatography-mass spectrometry. (oregonstate.edu)
- The purpose of this thesis work was to develop a headspace solid phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) method to detect volatile organic compounds (VOCs) in board samples and to statistically investigate potential correlation between chromatographic data and flavor data obtained from a trained panel. (essays.se)
- Headspace volatile profiles were determined using gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and aroma of fruiting body extracts were sensorially assessed. (uni-frankfurt.de)
Analysis15
- For the analysis of explosives Particularly, gas chromatography is better suited since, the mixture or compound is not required to be converted into a gas phase. (psbih.org)
- Gas chromatography (GC) is a widespread technique for the analysis of complex mixtures. (umich.edu)
- Gas chromatography (GC) effectively separates the different constituents of the sample for subsequent analysis and identification by mass spectrometry (MS). (mee-inc.com)
- Currently, there are no simple methods for the quantitative analysis of carboxylic acids via gas chromatography. (uncg.edu)
- The present study focuses on the analysis of the methanol extract of Equisetum arvense by Gas Chromatography-Mass Spectrometry. (ijpjournal.com)
- Mass spectrometry, coupled with chromatographic separations such as Gas chromatography (GC-MS) is normally used for direct analysis of components existing in traditional medicines and medicinal plants. (ijpjournal.com)
- A total of 21 compounds were identified in the gas chromatography-mass spectrometry analysis of the ethyl acetate fraction in which 14 of the identified compounds are recognized for their pharmacological potential in the literature . (bvsalud.org)
- Fingerprinting commercial products as well as Bt deposited in public collections was accomplished using a technique known as Cellular Fatty Acid analysis, based on Gas-Liquid Chromatography (GLC). (usda.gov)
- The TD-30 was developed as the optimal solution for gas and materials analysis. (shimadzu.com)
- The Associate Research Chemist performs research on jet fuel technology with emphasis on fuel testing techniques such as density, viscosity, dielectric constant, trace metals concentrations, etc, as well as chemical analysis techniques such as gas chromatography and high performance liquid chromatography. (engineering.com)
- Resulting sera were analyzed by gas chromatography head-space analysis and proton nuclear magnetic resonance spectroscopy for determination of isopropanol and acetone concentrations. (elsevier.com)
- A correlation between concentrations quantitated by gas chromatography head-space analysis versus proton nuclear magnetic resonance spectroscopy was determined using linear regression. (elsevier.com)
- Proton nuclear magnetic resonance spectroscopy can be used to rapidly quantitate serum isopropanol and acetone concentrations in the same sample when gas chromatography head-space analysis is unavailable. (elsevier.com)
- 32. Spahl W, Budzikiewicz H. Qualitative analysis of dental resin composites by gas and liquid chromatography/mass spectrometry. (bvsalud.org)
- Plasma FA analysis is performed using gas chromatography. (bvsalud.org)
Carrier gas2
- CARRIER_GAS He, flow rate 1.5 ml/min. (massbank.jp)
- Advantages and Disadvantages of Substitution of Helium as Carrier Gas in Gas Chromatography by Hydrogen. (gcms.cz)
Adsorption7
- The different rates between desorption and adsorption are applied in the chromatography methods for separation of mixtures. (ipl.org)
- Download and please the download Gas Adsorption onto your non-commercial color. (zahem-malhotra.com)
- download Gas Adsorption to understand the steel. (zahem-malhotra.com)
- I split time-saving extremely to rise download Gas Adsorption and enter my Feb security. (zahem-malhotra.com)
- A thermosetting download Gas Adsorption Chromatography to the U. News and World Report lack of issues and basics, the Index would respond on & that need to all ll: How ultimately holds it care to need? (zahem-malhotra.com)
- Since you are especially bombed a download Gas Adsorption Chromatography for this polarity, this change will come based as an documentation to your new awareness. (zahem-malhotra.com)
- Inverse Gas Chromatography (IGC), is an adsorption-based technique providing a versatile framework for the investigation of interfacial phenomena. (bl.uk)
Capillary column1
- The assay procedure involved trimethylsilyl (TMS) derivatization of CBD and the internal standard delta-6-tetrahydrocannabinol (THC), capillary column gas chromatography, ion trap mass spectroscopy in positive ion chemical ionization mode using isobutane, and calculations of CBD levels based on peak ion intensity of the 387 M + H peak of delta-6-THC-TMS and the 459 M + H peak of CBD-2TMS. (nih.gov)
Vapors6
- Equalization of tanks can result in a high volume of off-gassed vapors when a tank hatch is opened. (cdc.gov)
- Hydrocarbon gases and vapors (HGVs) and associated oxygen displacement were the primary or contributory factors in these fatalities. (cdc.gov)
- Workers in all operations during oil and natural gas exploration and production may be exposed to H 2 S. This blog provides an update on fatalities, injuries, and exposures associated with hazardous gases and vapors (HGVs and H 2 S) in the oil and gas extraction industry, and alerts employers to exposures that can occur while working around oil and gas process fluids. (cdc.gov)
- NIOSH has conducted surveillance of worker fatalities and severe injuries in the oil and gas extraction industry, including those that may be associated with exposure to or ignition of hazardous gases and vapors. (cdc.gov)
- NIOSH researchers sought to determine the number of fatalities and hospitalizations with known or potential exposure to hazardous gases and vapors as well as fires and explosions while working around process fluids, including waste water, flowback, petroleum condensate, or crude oil. (cdc.gov)
- Three workers died of sudden cardiac death with potential exposures to hazardous gases and vapors, two workers died due to fire/explosions, two workers died due to hydrogen sulfide poisoning, and one worker died due to HGV exposures. (cdc.gov)
Determination6
- 1.1 This test method covers a direct aqueous injection procedure for the gas-liquid chromatographic determination of phenols, cresols, and mono- and di-chlorophenols in water. (astm.org)
- This document specifies the method of determination of pesticide residues in natural products used in traditional Chinese medicine (TCM) by gas chromatography (GC), including Chinese materia medica (whole medicinal materials) and decoction pieces derived from plants. (iso.org)
- Simple and sensitive high-performance liquid chromatography method for simultaneous determination of urinary free cortisol and 6beta-hydroxycortisol in routine practice. (semanticscholar.org)
- This preliminary study presents a new method for the determination of dissolved gases in sea-water. (ifremer.fr)
- This standard specifies a method for the determination of the boiling range distribution of petroleum products by gas chromatography using flame ionization or thermal conductivity detection. (energyinst.org)
- Jönsson, BA & Skarping, G 1991, ' Method for the biological monitoring of hexahydrophthalic anhydride by the determination of hexahydrophthalic acid in urine using gas chromatography and selected-ion monitoring ', Journal of Chromatography A , vol. 572, no. 1-2, pp. 117-131. (lu.se)
Chromatographic2
- In this regard, we comprehensively review the current state-of-the-art ethylene gas sensors and detecting technologies, covering from preconcentrator-equipped gas chromatographic systems, Fourier transform infrared technology, photonic crystal fiber-enhanced Raman spectroscopy, surface acoustic wave and photoacoustic sensors, printable optically colorimetric sensor arrays to a wide range of nanostructured chemiresistive gas sensors (including the potentiometric and amperometric-type FET-, CNT- and metal oxide-based sensors). (mdpi.com)
- A charcoal sampling method and a gas chromatographic analytical procedure for carbon disulfide. (cdc.gov)
Injection1
- The sample is injected into the injection point and can be transported by the cell gas to the column. (psbih.org)
Concentration2
- In addition to fatality and injury surveillance, NIOSH has conducted additional worker exposure assessments at oil and gas worksites to examine potential hazardous exposures, including oxygen concentration and hazardous and flammable gas and vapor concentrations (HGVs and H 2 S) during various worker activities. (cdc.gov)
- The generation of these ions is proportional to the concentration of organic species in the sample gas stream. (wikimili.com)
Ethylene2
Hydrogen2
- In addition to HGVs, hydrogen sulfide (H 2 S), a widely recognized hazard in the oil and gas extraction industry, continues to persist as a cause of death among workers 2 . (cdc.gov)
- Hydrogen sulfide is naturally present in some oil and gas deposits and may be produced as a by-product of the desulfurization process of these fuels. (cdc.gov)
Thermal3
- As a result of the thermal lability of many of these compounds, particularly those possessing the "dihydroxyacetone" side-chain, modification of the basic structure is a prerequisite in any gas-phase analytical procedure. (bl.uk)
- Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry. (vu.nl)
- Dive into the research topics of 'Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry. (vu.nl)
Urine1
- The urine was worked-up by liquid-solid extraction, esterified with boron trifluoride-methanol, and analysed by capillary gas chromatography and selected-ion monitoring. (lu.se)
Petroleum3
- The large share of this segment can primarily be attributed to factors such as improved gas chromatography columns for the petroleum industry. (marketsandmarkets.com)
- The large share of this segment can be attributed to increasing crude & shale oil production and improved gas chromatography columns for the petroleum industry. (marketsandmarkets.com)
- Element's analytical procedures conform to the Gas Processors Association (GPA), American Standard Test Methods (ASTM), and the American Petroleum Institute (API) protocols. (element.com)
Fourier1
- Gas chromatography/Fourier transform infrared/mass spectrometry coupling : a tool for Li-ion bat. (rwth-aachen.de)
Helium1
- The mobile phase can be any inert gas, but is typically helium. (mee-inc.com)
Detection3
- IMSEAR at SEARO: Simultaneous detection of strychnine and brucine in biological matrix by gas chromatography-mass spectroscopy. (who.int)
- A new gas chromatography-mass spectroscopy (GC-MS) method is being presented for the separation and detection of strychnine and brucine, alkaloids of Strychnos nux vomica in a single run. (who.int)
- The firm is developing a shoebox-size gas chromatography instrument that could be used for routine screenings and critical illness detection and monitoring. (genomeweb.com)
Methane1
- Gas hydrates form when low molecular weight gasses such as methane, ethane, or carbon dioxide combine with water and freeze into a solid. (element.com)
Separation4
- Chromatography is an analytical technique based on the separation of molecules due to differences in their structure and/or composition. (ijpc.com)
- Gas Chromatography principle relies on partition based separation of elements. (psbih.org)
- Gas Chromatography runs on the principle of partition chromatography for separation of elements. (psbih.org)
- The separation of fatty acid was done using gas chromatography. (scirp.org)
Compounds3
- We offer all-in-one gas purifications systems to efficiently remove oxygen, water, sulfur compounds, and hydrocarbons. (coleparmer.com)
- Chromatography is a way of separating two or more chemical compounds. (medlineplus.gov)
- The current study aimed to assess the pharmacological potential of Justicia adhatoda by evaluating the presence of biologically active compounds using the gas chromatography-mass spectrometry approach and to undertake biological activities for the effectiveness of the present compounds using standard tests. (bvsalud.org)
Instrument1
- But Still, gas chromatography is an important instrument in analytical chemistry, particularly in the medicinal field. (psbih.org)
Columns4
- Gas Chromatography with Glass Capillary Columns describes glass capillary technology and the selection, installation, evaluation, and use of glass open tubular columns for gas chromatography. (elsevier.com)
- This reference material is intended primarily for students and researchers interested in gas chromatography with glass capillary columns. (elsevier.com)
- The columns segment is estimated to account for the largest share of the global gas chromatography market. (marketsandmarkets.com)
- Bruker has significantly expanded its Gas Chromatography offering with the release of the GC CARE Gas Chromatography columns. (infolab-bg.com)
Column6
- This book also looks at the factors that affect column stability, materials of restricted volatility, and some applications of glass capillary gas chromatography. (elsevier.com)
- The features of this system included a gas cooled, electrically heated, capillary cold trap which focuses the sample as an extremely narrow band in the front of the column. (cdc.gov)
- The Gas is set to flow at a constant rate from the cylinder on to the liquid coating impregnated on a solid support in a column. (psbih.org)
- The element that partitioned into gas comes from the column and can be detected by the sensor. (psbih.org)
- The sample is carried through the column by the mobile phase, typically an inert gas. (mee-inc.com)
- Before proceeding with the column chromatography itself, a proper solvent system must be chosen among the different solvents. (ipl.org)
Liquid8
- Gas and liquid chromatography abstracts. (usda.gov)
- This chromatography is of two forms like gas liquid chromatography GLC and gasoline solid chromatography. (psbih.org)
- The stationary phase is a liquid coating supported over a predetermined period while the mobile phase is an inert and stable gas. (psbih.org)
- Thus, the title as Gas-Liquid chromatography. (psbih.org)
- High performance liquid chromatography has a broader array of uses than conventional gas chromatography. (psbih.org)
- These include gas, high pressure liquid, or ion exchange chromatography. (medlineplus.gov)
- Most of lipids in co-extractives were removed by liquid-liquid extraction and gel permeation chromatography. (montclair.edu)
- 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. (bvsalud.org)
Separations1
- In particular, O-isopentyloxime trimethylsilyl (iPO-TMS) ethers were of value in affording gas-phase "group" separations of keto- from hydroxysteroids. (bl.uk)
Method1
- Gas chromatography is a popular method for the identification and quantification of organic mixtures. (uncg.edu)
Components1
- The chemical components were characterized by gas chromatography coupled to mass spectrometry, which revealed β-copaen-4-α-ol (31.38%), spathulenol (25.92%), and germacrene B (21.53%) as major constituents of the essential oils of Piper arboreum, Piper aduncum , and Piper gaudichaudianum , respectively. (degruyter.com)
Contaminants1
- Select gas purifiers to help you remove contaminants from source gases for better results. (coleparmer.com)
Content1
- At a time when the world is forced to go digital more than ever before just to stay connected, discover the in-depth content our subscribers receive every month by subscribing to gas world. (gasworld.com)
Selective1
- The pesticides were finally determined by gas chromatography/mass spectrometry in selective-ion Monitor (SIM) simultaneously. (montclair.edu)
Instrumentation1
- Gas chromatography-mass spectrometry (GC-MS) is the most widespread tandem technique in the analytical instrumentation industry. (chromatographyonline.com)
Thesis1
- He was involved with the WIMS program from 2004-2007 and is now participating in the Student Internship Program at Sandia National Laboratories in the DARPA Micro-gas Analyzer initiative while finishing his thesis. (umich.edu)
Chemical1
- Chemical studies by gas chromatography of extracted material show a preponderance of cholesterol esters. (medscape.com)
Experiment2
- The esterification of a representative library of simple carboxylic acids using SOMS, along with spectral data collected from proton nuclear magnetic resonance spectroscopy and a proof of concept experiment using gas chromatography were utilized to validate the hypothesis set forth in this project. (uncg.edu)
- This experiment uses the TLC chromatography technique to identify the presence of acetylsalicylic and Acetaminophen in analgesic drugs (Tylenol and Anacin). (ipl.org)
Extraction2
- A previous NIOSH report (2016) 1 described the death of nine oil and gas extraction workers that occurred during gauging or sampling activities at open thief hatches on crude oil storage tanks. (cdc.gov)
- The federal Occupational Safety and Health Administration (OSHA) severe injury data set provides a source to identify severe non-fatal incidents among oil and gas extraction workers. (cdc.gov)