title: Determination of the exogenous character of testosterone in bovine urine by gas chromatography-combustion-isotope ratio mass spectrometry.
abstract: A new approach was developed in order to control testosterone abuse in animal production. A gas chromatographic-combustion-isotope ratio mass spectrometric (GC-C-IRMS) method was used to distinguish the exogenous character from the endogenous character of the main metabolites of testosterone (epitestosterone and etiocholanolone) in cattle urine. This method is based on a comparison between the carbon isotope ratio (13C/12C) of testosterone metabolites and those of testosterone endogenous precursors. After urinary steroid purification, extracts were acetylated with acetic anhydride and injected into the GC-C-IRMS system. In order to validate the method, testosterone enanthate was administered to a 4 year old cow. The 13C/12C isotope ratios of testosterone exogenous metabolites appeared to be significantly different to the 13C/12C precursor ratios and were detected until 3 weeks after the anabolic administration. These preliminary results appear to be promising for the difficult control of natural hormones in livestock.
authors.affiliation: LDH-LNR, Ecole Nationale Vétérinaire (Ministère de l'Agriculture), Nantes, France.
authors.forename: V
authors.initials: V
authors.lastname: Ferchaud
authors.forename: B
authors.initials: B
authors.lastname: Le Bizec
authors.forename: F
authors.initials: F
authors.lastname: Monteau
authors.forename: F
authors.initials: F
authors.lastname: André
mesh_terms: D045930:Anabolic Agents / Q000652:urine*; D000818:Animals; D002417:Cattle / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D013739:Testosterone / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000378:metabolism / Q000652:urine*
chemical_list: D045930:Anabolic Agents; D013739:Testosterone; C004648:testosterone enanthate