Development of Enzyme Linked Immunoassay with High Specificity to Clenbuterol

A derivative of clenbuterol(CL),2-(1-(4-amino-3,5-dichlorophenyl)-2-(tert-butylamino) ethoxy) acetic acid,was synthesized and conjugated to bovine serum albumin(BSA) as immunogen by active ester method.The specific anti-CL antibody was generated by immunizing New Zealand rabbits,and thereby the direct competitive enzyme linked immunosorbent assay(dc-ELISA) was developed.The linear concentration of the method ranged from 1.0 to 10-4 mg/L,and the detection limit was 0.13 μg/L.The recoveries of CL from bovine urine determined by dc-ELISA were in the range of 90.05%-115.89% and 80.50%-112.37% with relative standard deviation of 7.1% and 12.6%(n = 10) at the spiked level of 10.0 μg/L and 1.0 μg/L,respectively.The results of antibody specificity determination showed that the cross-reactivity rate of anti-CL antibody to salbutamol was lower than 0.3%.