Development of an enzyme linked immunosorbent assay for the determination of phenothiazine drugs in meat and animal feeds.

In this study, 2-chlorophenothiazine was used to synthesize a hapten for production of monoclonal antibody. The obtained monoclonal antibody showed high crossreactivities to chlorpromazine, promethazine and perphenazine, and showed low crossreactivities to acepromazine and fluphenazine. After evaluation of three coating antigens, a heterologous competitive indirect enzyme linked immunosorbent assay was developed to determine the five phenothiazines in animal feeds and the residues of chlorpromazine, promethazine and perphenazine in meat. The crossreactivities to the five analytes were in a range of 2.4%-98%. The limits of detection for the five drugs in feeds were in a range of 0.1-3.0 μg g, and that for chlorpromazine, promethazine and perphenazine in meat were in a range of 0.5-0.8 ng g. Their recoveries from standards fortified blank samples (chicken, pork and feeds) were in a range of 74.1%-96.5% with coefficients of variation of 6.4%-15.1%. Therefore, this method could be used as a rapid screen tool to determine phenothiazine drugs in animal feeds and animal derived foods.