一种商品化酶抑制-比色法快速检测农药残留试剂盒对10种有机磷农药的敏感性测定

Sensitivity testing of 10 organophosphorus pesticides by a commercial enzyme inhibition-colorimetry test kit for rapid detection of pesticide residues

目的了解酶抑制-比色法快速检测试剂盒对不同农药的敏感性。方法通过使用一种商品化酶抑制-比色法试剂盒对敌敌畏等10种农药残留分别迚行5个浓度的测定,用抑制率和农药浓度的常用对数拟合回归曲线,同时计算对应的IC50和IC10。结果商品化的酶抑制-比色法试剂盒不是对所有的有机磷农药都敏感,即不是蔬菜中的所有的有机磷农药用酶抑制法都可以测定出来;该试剂盒对10种农药残留的敏感性依照敌敌畏、敌百虫、辛硫磷、喹硫磷、巴胺磷的顺序依次降低;试剂盒对地虫磷、杀螟硫磷、乐果、甲基嘧啶磷、倍硫磷不敏感,该试剂盒对含有浓度为3mg/kg以下的这些农药的样品没有响应。结论建议在日常检测中只要抑制率高于10%的样品建议复检,同时使用色谱、质谱定性定量。

Objective To understand the sensitivity of enzyme inhibition-colorimetry rapid detection kit to different pesticides.Methods Five concentrations of 10 pesticide residues,such as dichlorvos,were measured by using a commercial enzyme inhibition-colorimetry kit.The regression curves were fitted with the logarithm of inhibition rate and pesticide concentration,and the corresponding IC50 and IC10 were calculated at the same time.Results Commercial enzyme inhibition-colorimetry kit was not sensitive to all organophosphorus pesticides.That was not all organophosphorus pesticides in vegetables could be determined by enzyme inhibition method.The sensitivity of the kit to 10 pesticide residues was reduced in the order of dichlorvos,trichlorfon,phoxim,quetiphos and paramiphos.The kit was not sensitive to phoxim,cythion,dimethoate,pyrimiphos,and phoxiphos.The kit did not respond to samples containing these pesticides at concentrations up to 3 mg/kg.Conclusion It is suggested that the samples whose inhibition rate is higher than 10%should be re-examined in daily detection,and then be qualitatively and quantitatively analyzed by chromatography and mass spectrometry.