Systematic Error in Gas Chromatography-Mass Spectrometry–Based Quantification of Hydrolyzed Urinary Steroids
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چکیده
منابع مشابه
Systematic error in gas chromatography-mass spectrometry-based quantification of hydrolyzed urinary steroids.
Gas chromatography-mass spectrometry-based metabolite profiling can lead to an understanding of various disease mechanisms as well as to identifying new diagnostic biomarkers by comparing the metabolites related in quantification. However, the unexpected transformation of urinary steroids during enzymatic hydrolysis with Helix pomatia could result in an underestimation or overestimation of thei...
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The excretion of fecal neutral steroids was studied in six normocholesterolemic subjects and one hypercholesterolemic subject fed a standardized diet supplemented with butter fat or corn oil. The neutral steroids in the diets and in feces were identified by gas-liquid chromatography combined with mass spectrometric analyses of the chromatographic effluents. The three main sterols in the diets w...
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Numerous methods are available for measuring urinary steroids in evaluating endocrine dysfunctions. Measurements of these particular steroids, or groups of them, usually involve tedious isolation methods, corrections for interferences and losses of the steroid, and (or) expensive reagents. We show how gas-liquid chromatography provides a rapid, sensitive, and direct method for several steroid m...
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Cross reacting antibodies can cause an overestimation of the results of immunoassays. Therefore, alternative methods are needed for the accurate quantification of steroids. Gas chromatography combined with isotope-dilution mass spectrometry (GC-IDMS) is developed to quantify urinary active androgens, testosterone, epitestosterone and dihydrotestosterone, which are clinically relevant androgens ...
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ژورنال
عنوان ژورنال: Cancer Epidemiology Biomarkers & Prevention
سال: 2010
ISSN: 1055-9965,1538-7755
DOI: 10.1158/1055-9965.epi-09-0581