Results 211 to 220 of about 185,893 (258)

Introduction to Gas Chromatography-Mass Spectrometry

2013
Gas chromatography-mass spectrometry (GC-MS) is a technique of pivotal importance for the analysis of hormones in biological fluids. In consequence, it has gained relevance in clinical and endocrinological laboratories, providing reference analytical methods.
Alberto, Sánchez-Guijo, Michaela F, Hartmann, Stefan A, Wudy   +2 more
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Integrated gas chromatography-mass spectrometry

Quarterly Reviews of Biophysics, 1973
Mass spectrometric analysis of organic compounds was in the early 1950s done mostly for quantitative determination of petroleum products. The use of the mass spectrometer for qualitative analysis of solid organic material samples was shown by O'Neil & Wier (1951) and since then a continuous increase in mass spectrometric studies of different ...
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Gas chromatography-mass spectrometry

1982
The complexity and wide range of organic acids present in urine, and other biological fluids, makes their quantification and positive identification a difficult problem. Although chromatographic characteristics of individual compounds, such as retention data on gas, liquid and thin-layer chromatography, are extremely useful indicators of probable ...
R. A. Chalmers, A. M. Lawson
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Applications of Hadamard Transform to Gas Chromatography/Mass Spectrometry and Liquid Chromatography/Mass Spectrometry

Analytical Chemistry, 2008
Successful application of the Hadamard transform (HT) technique to gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) is described. Novel sample injection devices were developed to achieve multiple sample injections in both GC and LC instruments. Air pressure was controlled by an electromagnetic valve in GC,
Cheng-Huang, Lin, Takashi, Kaneta, Hung-Ming, Chen, Wen-Xiong, Chen, Hung-Wei, Chang, Ju-Tsung, Liu   +5 more
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Characterisation of beeswax in works of art by gas chromatography–mass spectrometry and pyrolysis–gas chromatography–mass spectrometry procedures

Journal of Chromatography A, 2004
Pyrolysis (Py) with in situ derivatisation with hexamethyldisilazane-gas chroma-break tography-mass spectrometry (GC-MS) and a gas chromatography-mass spectrometry procedure based on microwave-assisted saponification were used to identify the organic components in small sized beeswax samples.
BONADUCE, ILARIA, COLOMBINI, MARIA PERLA
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Pyrolysis/gas chromatography/mass spectrometry of lignocellulose

Rapid Communications in Mass Spectrometry, 1995
Abstract The 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.
G C, Galletti, P, Bocchini
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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.
Dimitrios, Tsikas, Kristine, Chobanyan-Jürgens   +1 more
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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.
L A, Castagnetta, O M, Granata, F P, Arcuri, L M, Polito, F, Rosati, G P, Cartoni   +5 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 ...
P M, Scott, D, Weber, S R, Kanhere
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