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Improved method of detection of testosterone abuse by gas chromatography/combustion/isotope ratio mass spectrometry analysis of urinary steroids
Author(s) -
Aguilera Rodrigue,
Becchi Michel,
Casabianca Hervé,
Hatton Caroline K.,
Catlin Don H.,
Starcevic Borislav,
Pope Harrison G.
Publication year - 1996
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/(sici)1096-9888(199602)31:2<169::aid-jms276>3.0.co;2-i
Subject(s) - chemistry , epitestosterone , isotope ratio mass spectrometry , urine , chromatography , gas chromatography , mass spectrometry , gas chromatography–mass spectrometry , testosterone (patch) , isotopes of carbon , medicine , androgen , environmental chemistry , biochemistry , total organic carbon , hormone
The current approach to detection of doping with testosterone is based on measuring the testosterone to epitestosterone ratio (T/E) in urine by gas chromatography/mass spectrometry. The median T/E for healthy males who have not used T is about 1.0. In a single urine, a T/E lower than six leads to a negative report even though it does not exclude T administration. A value greater than six indicates possible T administration or a naturally elevated ratio. It has been shown previously that the carbon isotope ratio of urinary T changes after T administration. In this study a potential confirmation method for T abuse was optimized. Gas chromatography/combustion/carbon isotope ratio mass spectrometry (GC/C/IRMS) was used to analyze two T precursors (cholesterol and 5‐androstane‐3β,17β‐diol) and two T metabolites (5α‐ and 5β‐androstane‐3α,17β‐diol) in addition to T itself in each of 25 blind urines collected from eight healthy men before, during or after T administration. The carbon isotope ratios of T and the metabolites were lower after T administration. The relationships among the variables were studied using multivariate analysis and beginning with principal components analysis; cluster analysis revealed that the data are composed of two clusters, and classified the samples obtained after T administration in one cluster and the remainder in the other; discriminant analysis correctly identified T users. The measurement of carbon isotope ratios of urinary androgens is comparable to the T/E > 6 test and continues to show promise for resolving cases where doping with T is suspected.