Rapid Immunoassay Method for the Determination of Clenbuterol and Salbutamol in Blood

The aim of the study was to evaluate the adequacy of enzyme-linked immunosorbent assay (ELISA) in the post-exposure determination of the -agonists clenbuterol and salbutamol in animal plasma and serum. Experimental guinea pigs (n 20) were treated with two doses (0.25 and 2.5 mg/kg) of clenbuterol (n 10) and salbutamol (n 10) for seven days, whereas the control animal group (n 10) was left untreated. Validation of the applied method yielded acceptable recovery (mean 70) and repeatability rates, showing ELISA to be applicable for the semi-quantitative determination of both analytes in both matrices, preferably in plasma. In both matrices, clenbuterol concentrations were proven to be significantly (14-fold) higher than those of salbutamol. Concentrations of both analytes were higher in plasma than in serum. The application of a 10-fold higher clenbuterol and salbutamol dose (2.5 mg/kg) resulted in concentrations 3- to 4-fold higher for clenbuterol and 2- to 3-fold higher for salbutamol, indicating a different release rate of these two -agonists.