Screening procedures for clenbuterol residue determination in bovine urine and liver matrices using enzyme-linked immunosorbent assay and liquid chromatography Original Research Article

The suitability of analytical protocols for simultaneous determination of clenbuterol (CL) by ELISA and liquid chromatography (LC) was investigated. Clenbuterol spiked bovine urine and liver samples were treated with aqueous and organic solutions followed by clean-up by solid phase extraction (SPE). The determination of clenbuterol in prepared solutions was performed by a commercial ELISA test (R-Biofarm) and by LC with UV detection. The optimal conditions for liver were obtained when CL was isolated by a mixture of ethyl acetate–isopropanol (7:3 (v/v)) and purified by a mixed mode SPE column. However, additional purification with perchloric acid should be used to decrease the interference from matrices. For urine samples, the optimal conditions were obtained after dilution of the sample with borate buffer (pH 8.5), and clean-up by mixed mode SPE. The recoveries of CL were >80% from both matrices. The procedures were useful for clenbuterol screening by ELISA as well as by LC.