GAS-CHROMATOGRAPHIC ELECTRON-IMPACT MASS-SPECTROMETRIC SELECTIVE CONFIRMATORY ANALYSIS OF CLENBUTEROL IN HUMAN AND BOVINE URINE

A method for the confirmatory analysis of clenbuterol in human and bov ine urine was developed. After a double washing of the acidified sampl e with tert-butyl methyl ether (only for bovine urine), and a solid-ph ase extraction with Bond-Elut Certify(R) columns, derivatization was p erformed with trimethylboroxine. The extract was then analysed by gas chromatography/electron impact mass spectrometry. The advantages of th e methylboronate derivative with respect to other derivatives are disc ussed in terms of chromatographic properties and, above all, of specif icity of the electron impact mass spectrum. The method was successfull y used for the confirmatory analyses of clenbuterol during the XXV Oly mpic Games of Barcelona.