Residue screening for the beta-agonists clenbuterol, salbutamol and cimaterol in urine using enzyme immunoassay and high-performance liquid chromatography.

The antibody for enzyme immunoassay was raised against clenbuterol-diazo-BSA, and salbutamol-carboxymethyl ether-biocytin was used as a label. Procedural blanks from 500 negative urine samples were always less than 0.2 ppb salbutamol or less than 0.02 ppb clenbuterol equivalents, and a residue level of 1 ppb was detected with good reliability. After treatment of veal calves with anabolic dosages, residue levels in urine amounted to 10-200 ppb clenbuterol or salbutamol. beta-Agonists were separated by high-performance liquid chromatography on LiChrospher RP-Select B columns, and acidic methanol-buffer or acetonitrile-buffer mobile phases. Combinations of high-performance liquid chromatography and enzyme immunoassay were used for confirmation.