Abstract：In order to provide a rapid, selectivity and very high sensitivity method for the determination of zearaleone(ZEN), a competitive indirect time-resolved fluoroimmunoassay(TRFIA) was used. An immunogen of ZEA-oxime-BSA conjugate coated onto the microtitre plate competes with ZEN standard controls or free ZEN in the sample for anti-ZEN antibody. A goat antirat IgG-Eu3+ conjugate was used to enable detection. The suitability of the assay for quantification of ZEN was also studied. Results showed the limit of detection of the assay to be 0.01μg/L(10ppt) for indirect competitive TRFIA formats. The assay range was 0.01-20 μg/L. The concentration of ZEN that is required for 20%, 50% and 80% binding inhibition (ED20, ED50, ED80) were 0.156±0.035 μg/L, 0.634±0.091 μg/L and 2.595±0.274 μg/L, respectively. Cross-reactivity of Zearalanol was 15.16%. The inter- and intra-assay variability of the ZEN-TRFIA were 7.2% and 14.6%, respectively. The mean recovery of ZEN from corn samples was 94.4%. The kit can be stored at 4℃over 6 months. It was shown that the newly developed TRFIA could be applied to detect the ZEN contamination in corn. The ZEN-TRFIA provides very high sensitivity and optimal range, it will be useful to screen ZEN contamination easily, simply and economically when the the number of sanples is large.
