Carbon isotope ratio determination and investigation of seized testosterone preparations.

In the present study, the content of a number of black market testosterone products collected in Austria has been analyzed. Additionally, (13) C/(12) C ratios were measured for testosterone in the products after cleavage of the testosterone ester. The aim was to determine whether some of these products had similar (13) C/(12) C ratios to those normally found for endogenous testosterone, which could prevent a positive isotopic ratio mass spectrometric (IRMS) finding in doping control. Moreover, it was investigated to what extent the preparations contained the masking agent epitestosterone, in order to lower the testosterone/epitestosterone (T/E) ratio in urinary steroid profiles. Out of 30 analyzed products, the declared ingredients differed from the actual content in 10 cases. Epitestosterone, however, could not be found in any of the products. The products displayed δ(13)C(VPDB) values between -23.6 and -29.4‰. For more than half of these products, the values were within a range reported for endogenous urinary steroids.