Abstract
A multi-residue analysis was developed to discern oestrogens (17 beta-oestradiol or zeranol) used as anabolic drugs and diethylstilboestrol (DES) from the mycotoxins zearalenone and zearalenol. A mixture of 17 beta-oestradiol, oestrone, DES, zeranol, zearalenol, zearalenone and zearalanone was analysed using a 5 micron silica column with gradient elution from hexane to hexane:methanol:2-propanol, 40:45:15 (v/v) and ultraviolet detection at 280 nm. Only six peaks were obtained since zearalenone and zearalanone had identical elution times. Minimum detectabilities were 5-10 ng for the standards. Chicken muscle tissues (2.5 g) were extracted with acetone:water (95:5, v/v). The extracts were spiked with oestradiol and zeranol at 50, 100 or 200 ppb; and DES or zearalenone at 50 ppb; cleaned-up through dual columns of basic alumina and phosphate exchanged AGMP-1 resin and analysed by high-performance liquid chromatography with ultraviolet detection (HPLC-UV). Minimum detectability was 10 ng for oestradiol, zeranol, DES or zearalenone when tissues were spiked at 50 ppb. Recoveries were greater than or equal to 86%, greater than or equal to 83%, 60% and 100% for oestradiol, zeranol, DES and zearalenone, respectively.