RAPID ANALYSIS OF BETA-AGONISTS IN URINE BY THERMOSPRAY TANDEM MASS-SPECTROMETRY

A method is described for the analysis of beta-agonists in urine of ca ttle. The method uses solid-phase extraction (SPE), followed by analys is of the resulting extract by flow injection thermospray tandem mass spectrometry (TSP-MS-MS). Sample preparation is performed using a mixe d-bed SPE procedure using a sorbent having both hydrophobic and ionic properties. MS-MS analysis following thermospray ionization, is perfor med in single-reaction monitoring parent mode. In that way isotope dil ution can be used for quantitation of clenbuterol. Data are presented on precision and accuracy for clenbuterol and related compounds. Furth ermore, data acquisition was performed in full-scan neutral loss mode to indicate the suitability of flow injection analysis (FIA)-TSP-MS-MS for exploratory analysis. Detection of beta-agonists in this mode is based on the presence of the N-tert.-butyl-beta-ethanolamino moiety an d, in that respect, detection of known as well as unknown compounds ha ving this moiety will take place. This feature is exemplified by the a nalysis of samples containing several compounds.