Results 171 to 180 of about 145,241 (196)

Quantification of Carbonate by Gas Chromatography−Mass Spectrometry

Analytical Chemistry, 2010
Carbon dioxide and carbonates are widely distributed in nature, are constituents of inorganic and organic matter, and are essential in vegetable and animal organisms. CO(2) is the principal greenhouse gas in the atmosphere. In human blood, CO(2)/HCO(3)(-) is an important buffering system.
Kristine Chobanyan-Jürgens, Dimitrios Tsikas   +1 more
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Pyrolysis/gas chromatography/mass spectrometry of lignocellulose

Rapid Communications in Mass Spectrometry, 1995
AbstractThe use of pyrolysis/gas chromatography/mass spectrometry (PY/GC/MS) to determine the molecular composition of lignocellulose is reviewed and the technique illustrated with applications on some novel systems. Constituents and structural arrangement of lignocellulosic polymers in plant cell wall are briefly described.
Guido C. Galletti, Paola Bocchini
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Gas chromatography-mass spectrometry combinations

Journal of Physics E: Scientific Instruments, 1980
Modern systems consist of 3 units: gas chromatography, mass spectrometry and data systems. The authors consider the operation of the 3 units independently and show the power of the combined system and its modes of operation.
A M Greenway, C F Simpson
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Gas chromatography—mass spectrometry

1990
Combined gas chromatography—mass spectrometry (GC—MS) is probably the most comprehensive instrumental analytical technique available to the scientist in food analysis at present. The technique is well established in food science, and a predominant area of application is in food safety, where reliable information on food contaminants, e.g.
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Gas chromatography/mass spectrometry of catechol estrogens

Steroids, 1992
Catecholestrogens (CCEs), namely 2- or 4-hydroxyestradiol and hydroxyestrone, are highly polar, reactive, and extremely labile estrogen metabolites in many experimental conditions. For these reasons, indirect assay methods mainly have been used. Some experimental evidence suggests that CCEs are synthesized and biologically active mostly in target cells.
Felice Rosati, L. Polito, Luigi Castagnetta, Orazia M. Granata, G. P. Cartoni, F. Arcuri   +5 more
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Gas chromatography — mass spectrometry of catechol estrogens

Steroids, 1974
Abstract The gas chromatographic and mass spectrometric properties of 19 catechol estrogens and catechol estrogen methyl ethers are reported. The gas chromatographic behaviour of the TMS-derivatives on the stationary phases OV-1, OV-3, OV-7, and OV-17 is examined and correlated with their molecular weight, shape, and polarity. The characteristic mass
Lothar Siekmann, H.-O. Hoppen
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Gas Chromatography/Mass Spectrometry

1986
Abstract Gas chromatography/mass spectrometry (GC/MS) is useful in analyzing mixtures of organic compounds. This article commences with a description of the principles of mass spectrometry and gas chromatography. It provides information on the procedures of mass spectrum interpretation, and describes the experimental procedure of and ...
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Gas chromatography/mass spectrometry of bacterial amines

Biological Mass Spectrometry, 1985
Bacterial amines were examined by gas chromatography/mass spectrometry. Under electron impact all trifluoroacetamides exhibited peaks at m/z 69 due to [CF3]+. Many trifluoroacetamides also showed peaks at m/z 97 corresponding to the [COCF3]+ ion fragment.
D. B. Drucker, A. Tavakkol, J. M. Wilson
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Capillary gas chromatography-mass spectrometry of ecdysteroids

Journal of Chromatography A, 1987
Fully trimethylsilylated ecdysteroids have been analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) using flexible fused-silica capillary columns. Best results were obtained using columns coated with cross-bonded apolar (OV-1 type) stationary phases.
Richard P. Evershed, Huw H. Rees, Julian G. Mercer   +2 more
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Gas chromatography-mass spectrometry of Alternaria mycotoxins

Journal of Chromatography A, 1997
Heptafluorobutyrate (HFB) derivatives have not previously been used for GC of Alternaria mycotoxins. Capillary (0.5 micron film) GC-mass spectrometry (MS) showed that full and partial derivatives of alternariol (AOH), alternariol monomethyl ether (AME) and altenuene (ALT); a structurally uncharacterized derivative of altertoxin I (ALTX-I); and a tris ...
Shriniwas R. Kanhere, Dorcas Weber, Peter M. Scott   +2 more
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