酶抑制法测定多种有机磷农药残留试验

采用酶抑制法测定50种有机磷农药的检出限,并进行酶活性减退试验,结果表明:(1)敌敌畏和对氧磷的检出限较低,速灭磷、二溴磷、喹硫磷、敌百虫、辛硫磷、除线磷、甲胺磷和甲基毒死蜱的检出限相对较高,其它40种农药的检出限更高;(2)配制好的酶在9℃的冰箱中保存,其活性并不随着时间的推移而降低,但是每天测试的酶活性都有一定差别;(3)用酶抑制法测定农药残留重现性不好;(4)与酶、显色剂和底物反应的提取液的浓度影响酶抑制法测定农残的结果。

The Test of Various Organophosphate Pesticides with Enzyme Inhibition Method

The detection limits of 50 organophosphate pesticides were determined by means of enzyme inhibition method, and the impairment test of enzyme activity was also done. The results showed：The detection limits of DDVP and paraoxon were low？ the detection limits of mevinphos, dibrom, quinalphos, dipterex, phoxim, dichlofenthion, methamidophos, and chlorpyrifos-methyl were relatively higher？the detection limits of the others were much higher. It was also found that the activity of the made-up enzyme stored in refrigerator with -9℃temperature didn’t reduce as time went by, and in every test, the activity of the enzyme had certain difference. At last, the repeatability of the determination of pesticides was bad when tested by means of enzyme inhibition method, and the determination results were also influenced by the concentration of the extracts which reacted with enzyme, chromogenic agent and substrates.