Abstract: Analysis of Clenbuterol and Its Metabolite in Urine of Rats by GC/MSXu Youxuan;Wang Shan; Shen Li;Wu Yun;Zhang Chang jiu;Zhu Shaotang (China Doping Control Center,National Research institute of Sports Medicine,Beijing 100029,China)Received 1993-05-05 Abstract:The methods were established for the analysis of clenbuterol and. its metabolite. 3 mg of clenbuterol hydrochloride to & rats,the urine samples were extrated with diethylether-isopropanol and derivatized with MSTFA/NH4I. N-dealkylated clenbuterol was identified and the excretion curves of clenbuterol and its metabolite were obtained.Keywords: clenbuterol, metabolite, GC/MS