German Sport University Cologne, Institute of Biochemistry, Am Sportpark Müngersdorf 6, 50933 Köln, Germany.
Drug Test Anal. 2009 Feb;1(2):65-72. doi: 10.1002/dta.15.
In order to detect the misuse of endogenous anabolic steroids such as testosterone by athletes a total of n = 1734 suspicious urine samples were investigated by gas chromatography/combustion/isotope ratio mass spectrometry throughout the years 2005, 2006 and 2007. The (13)C/(12)C ratio of a target substance (androsterone, a testosterone metabolite) was compared to the (13)C/(12)C ratio of an endogenous reference compound (11beta-hydroxyandrosterone).N = 1340 samples were investigated due to elevated testosterone/epitestosterone ratios, with n = 87 (6.5%) exceptional findings regarding their isotopic ratios. An additional n = 164 samples were investigated because of elevated dehydroepiandrosterone concentrations, with n = 2 (1.2%) exceptional findings. The remainder were subjected to isotope ratio analysis because of elevated androsterone levels or because this was requested by sports federations.Significant differences between female and male samples were found for the (13)C/(12)C ratios of androsterone and 11beta-hydroxyandrosterone but not for samples taken in or out of competition.A further n = 645 samples originating from other World Anti-Doping Agency accredited laboratories, mainly throughout Europe as well as South America, South Africa and Southeast Asia, were investigated. The (13)C/(12)C ratios of the urinary steroids differ significantly for each geographical region, reflecting the dietary status of the individuals.The system stability over time has been tested by repeated injections of a standard solution and repeated processing of frozen stored blank urine. Despite a drift over time in absolute (13)C/(12)C ratios, no significant change in the difference of (13)C/(12)C (11beta-hydroxyandrosterone) minus (13)C/(12)C (androsterone) could be observed.
为了检测运动员是否滥用内源性合成代谢类固醇（如睾酮），我们在 2005 年、2006 年和 2007 年期间使用气相色谱/燃烧/同位素比质谱法对总共 1734 份可疑尿液样本进行了研究。目标物质（雄酮，一种睾酮代谢物）的 (13)C/(12)C 比值与内源性参考化合物（11β-羟基雄酮）的 (13)C/(12)C 比值进行了比较。由于睾酮/表睾酮比值升高，对 1340 个样本进行了研究，其中 87 个（6.5%）样本的同位素比值异常。由于脱氢表雄酮浓度升高，对另外 164 个样本进行了研究，其中 2 个（1.2%）样本的同位素比值异常。其余样本是由于雄酮水平升高或体育联合会要求进行同位素比分析。我们发现，在雄酮和 11β-羟基雄酮的 (13)C/(12)C 比值方面，男女样本之间存在显著差异，但在比赛内外采集的样本之间没有差异。我们还对来自其他世界反兴奋剂机构认可的实验室（主要来自欧洲以及南美、南非和东南亚）的另外 645 个样本进行了研究。每个地理区域的尿液类固醇的 (13)C/(12)C 比值存在显著差异，反映了个体的饮食状况。我们通过重复注射标准溶液和重复处理冷冻储存的空白尿液来测试系统的时间稳定性。尽管 (13)C/(12)C 比值随时间存在漂移，但 (11β-羟基雄酮)减去 (13)C/(12)C（雄酮）的 (13)C/(12)C 差值没有观察到显著变化。
