APPLICATION OF A SEQUENTIAL ANALYTICAL PROCEDURE FOR THE DETECTION OFTHE BETA-AGONIST BROMBUTEROL IN BOVINE URINE SAMPLES

The multistep analytical procedure routinely applied in our laboratory for the detection of the aryl amine beta-agonists clenbuterol, mabute rol and mapenterol in bovine matrices has been extended to the analysi s in urine samples of brombuterol, a new clenbuterol-like compound. In the screening steps, the urine samples were first enzyme-linked immun osorbent assay (ELISA)-tested, then the positive samples were analyzed by thin-layer chromatography (TLC) and the beta-agonists detected wit h the Bratton-Marshall color reaction. The TLC spots corresponding to the suspected compounds were scraped off the plates, collected and ext racted separately with methanol. The beta-agonists in the extracts wer e detected by HPLC-Vis (limits of detection: 0.5 ng/g). In the confirm atory step the presence and the concentration of the compounds of inte rest in the samples were established by GC-MS with two different ioniz ation techniques, EI and CI (limits of detection: 1.0 ng/g). The use o f this procedure has made possible the detection of brombuterol in off icially sampled bovine urine.