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Degradation of urine samples and its influence on the 13 C/ 12 C ratios of excreted steroids
Author(s) -
Piper Thomas,
Geyer Hans,
Schänzer Wilhelm
Publication year - 2010
Publication title -
drug testing and analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.065
H-Index - 54
eISSN - 1942-7611
pISSN - 1942-7603
DOI - 10.1002/dta.219
Subject(s) - epitestosterone , androsterone , chemistry , urine , etiocholanolone , chromatography , dehydrogenation , testosterone (patch) , dehydroepiandrosterone , degradation (telecommunications) , steroid , radiochemistry , endocrinology , androgen , organic chemistry , biochemistry , hormone , medicine , telecommunications , computer science , catalysis
The degradation processes in deficiently stored urine samples are well investigated regarding steroid concentrations and diagnostic ratios, such as the quotient of testosterone divided by epitestosterone. In contrast, nothing is known about the influence on carbon isotope ratios (CIR) by inappropriate storage conditions. In general, it is assumed that degradation, i.e. deconjugation or dehydrogenation, does not change CIR and thus CIR can be used in cases where the steroid profile turns out to be invalid. Therefore, the CIR of urinary steroids was investigated in different urine samples during the course of degradation over a time period of six months. Several steroids excreted as glucuronides (androsterone (A), etiocholanolone (E), testosterone, pregnanediol (PD) and 5α‐ and 5β‐androstane‐3α,17β‐diol) or sulfo‐conjugated (A, E and androst‐5‐ene‐3β,17β‐diol (5EN17b)) were investigated together with their unconjugated correspondents (A, E, PD and 5EN17b) and the main dehydrogenation products (5α‐ and 5β‐androstane‐3,17‐dion and androst‐4‐ene‐3,17‐dion). For this purpose, the exiting methods for CIR determination were extended and validated. In addition, the urinary concentrations of all investigated steroids were monitored. Particular attention was paid to dehydroepiandrosterone conjugated and unconjugated together with its degradation product 3α,5‐cyclo‐5α‐androstan‐6β‐ol‐17‐one as here the strongest influence on CIR was expected. Copyright © 2010 John Wiley & Sons, Ltd.