表面活性剂对检测蔬菜中残留农药的植物酯酶方法的作用

On the Effect of Surfactants on the Plant-Esterase Method for Testing of Residual Pesticides in Vegetables

摘要: 在所测试的5种表面活性剂(OP、CTMAB、CPC、SLS及SDS)中,阴离子表面活性剂、十二烷基硫酸钠(SDS),对被植物酯酶催化的显色反应呈现显著的增加灵敏度和稳定性的作用.而此显色反应因有机磷农药的存在而受到抑制,显色反应灵敏度的增加幅度达70%左右,对影响显色反应的各种因素作了较深入的试验并对其反应条件作了优化.所提出的方法已应用于小青菜中残留敌敌畏农药的测定,并在此样品的基础上对方法的精密度及回收率作了试验,测得其相对标准偏差(n=6)为0.87%,平均回收率为111%.

Abstract: Among 5 surfactants (including OP,CTMAB,CPC,SLS and SDS) tested,the anion surfactant,sodium dodecyl sulfate (SDS) was found to have significant enhancement effect on sensitivity and stability of the plant-esterase catalyzed color reaction,which was inhibitated by the presence of organo-phosphorus pesticides.Extent of increasing in sensitivity of the color reaction was found to be about 70%.Various factors affecting the color reaction were studied and optimized.The proposed method was tested for its precision and recovery in the determination of dichlorvos in a sample of Chinese cabbage,and the results of RSD′s (n=6) and average recovery obtained were 0.87% and 111% respectively.