Abstract:In this work, chloramphenicol (CAP) as the research object, by optimizing the reaction conditions, an indirect competitive enzyme-linked immunosorbent assay(ic-ELISA) for CAP was constructed and applied to the detection of CAP residues in aquatic products. The optimal working conditions of the constructed ic-ELISA were 0.05 μg/well coating amount of CAP-OVA, coating conditions at 4 ℃ for 14 h, 0.5% nonfat milk powder as blocking solution, and the dilution ratio of CAP antibody was 1∶16 000. The results showed that the sensitivity(IC50) of the constructed ic-ELISA method was 4.88 μg/mL, and the detection limit (IC15) was 0.29 μg/mL. The cross-reaction rate of the chloramphenicol structural analogs and similar antibiotics were less than 0.1%. The spiked recovery experiments of 5.0, 10.0, 20.0 μg/kg in Larimichthys crocea, razor clam and bullfrog were carried out, and the recovery rates were within 83.90%-100.73%, and the intraday and interday coefficients of variation (CV) for this method ranged from 2.28% to 6.96%. The detection results were in good agreement with that of LC-MS/MS. The ic-ELISA of CAP in this study was simple to operate and has high sensitivity. It could be applied to the rapid quantitative detection of CAP residues in various aquatic products, and provide technical reference for ic-ELISA of other small molecule hazards. And it is also an indirect competitive enzyme-linked immunosorbent assay for the construction of the method provides technical reference.