Gas chromatographic/electron impact mass spectrometric selective confirmatory analysis of clenbuterol in human and bovine urine

Abstract

A method for the confirmatory analysis of clenbuterol in human and bovine urine was developed. After a double washing of the acidified sample with tert-butyl methyl ether (only for bovine urine), and a solid-phase extraction with Bond-Elut Certify columns, derivatization was performed with trimethylboroxine. The extract was then analysed by gas chromatography/electron impact mass spectrometry. The advantages of the methylboronate derivative with respect to other derivatives are discussed in terms of chromatographic properties and, above all, of specificity of the electron impact mass spectrum. The method was successfully used for the confirmatory analyses of clenbuterol during the XXV Olympic Games of Barcelona.