title: Use of isotope ratio mass spectrometry to differentiate between endogenous steroids and synthetic homologues in cattle: a review.
abstract: Although substantial technical advances have been achieved during the past decades to extend and facilitate the analysis of growth promoters in cattle, the detection of abuse of synthetic analogs of naturally occurring hormones has remained a challenging issue. When it became clear that the exogenous origin of steroid hormones could be traced based on the (13)C/(12)C isotope ratio of the substances, GC/C/IRMS has been successfully implemented to this aim since the end of the past century. However, due to the costly character of the instrumental setup, the susceptibility of the equipment to errors and the complex and time consuming sample preparation, this method is up until now only applied by a limited number of laboratories. In this review, the general principles as well as the practical application of GC/C/IRMS to differentiate between endogenous steroids and exogenously synthesized homologous compounds in cattle will be discussed in detail, and will be placed next to other existing and to be developed methods based on isotope ratio mass spectrometry. Finally, the link will be made with the field of sports doping, where GC/C/IRMS has been established within the World Anti-Doping Agency (WADA) approved methods as the official technique to differentiate between exogenous and endogenous steroids over the past few years.
authors.affiliation: Federal Agency for the Safety of the Food Chain, Directorate General Laboratories, Brussels, Belgium. Geert.janssens@favv.be
authors.forename: Geert
authors.initials: G
authors.lastname: Janssens
authors.forename: Dirk
authors.initials: D
authors.lastname: Courtheyn
authors.forename: Sven
authors.initials: S
authors.lastname: Mangelinckx
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Prévost
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Bichon
authors.forename: Fabrice
authors.initials: F
authors.lastname: Monteau
authors.forename: Geert
authors.initials: G
authors.lastname: De Poorter
authors.forename: Norbert
authors.initials: N
authors.lastname: De Kimpe
authors.forename: Bruno
authors.initials: B
authors.lastname: Le Bizec
mesh_terms: D045930:Anabolic Agents / Q000652:urine*; D000818:Animals; D002247:Carbon Isotopes; D002417:Cattle; D004300:Doping in Sports / Q000517:prevention & control; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D012015:Reference Standards; D012016:Reference Values; D013256:Steroids / Q000652:urine*; D015813:Substance Abuse Detection / Q000295:instrumentation / Q000379:methods* / Q000592:standards
chemical_list: D045930:Anabolic Agents; D002247:Carbon Isotopes; D013256:Steroids