A chemiluminescent immunoassay for zeranol and its metabolites

A sensitive immunoassay is presented for the detection of the xenobiotic oestrogenic growth promotor zeranol (Ralgro) and the mycotoxin zearalanone. The detection is based on chemiluminescence using a zeranol-isoluminol conjugate. A lowest detectable amount of 2-5 pg zeranol per tube was achieved. The bovine zeranol metabolites zearalanone and taleranol can also be determined, and this has been shown in a metabolic pilot study of zeranol in veal calves. This study indicates that taleranol is a major metabolite in male veal calves, in contrast to zearalanone which is known to be the major metabolite in adult cattle.