A method to determine δ13CVPDB-values of trace amounts of boldenone and its main metabolite

For more than 10 years the possibility of endogenous boldenone production in human beings has been discussed. This is an interesting issue for doping control as boldenone is a prohibited substance according to the WADA list. Boldenone (androsta-1,4-dien-17ß–ol-3–one, Bo) is an anabolic steroid known to be used in cattle malt or equine doping for many years. While testing cattle in order to detect the misuse of forbidden growth hormones, it became obvious that false-positive boldenone results may occur due to faecal cross-contamination during sampling. Further investigations demonstrated the capability of different intestinal bacteria to produce enzymes which exhibit ∆1-steroid dehydrogenase activity. Bacteria of this species can also be found in the human intestine. Although Bo is not clinically approved for human application, there were several cases of athletes tested positive for boldenone or its main metabolite 5ß-androst-l-en-17ß-ol-3-one (BM1). By GC/C/IRMS (gas chromatography/combustion/isotope ratio mass spectrometry) it is possible to analyse either Bo or BM1 and to distinguish whether the source is endogenous or exogenous. Both steroids exhibit urinary concentrations between 1-100 ng/mL. To obtain the required amount of steroid a large specimen and an effective method are unavoidable to fulfil the requirements for a reliable IRMS – measurement. The developed method together with first results concerning doping control samples will be presented. Verf.-Referat