在各种蔬菜的多种残留农药的检测中,蔬菜的基体常对农药的检测带来严重干扰.试样的预处理选用了较为简单的乙腈萃取法,以避免造成农药的损失.有机含磷农药的GC检测采用FPD检测器,而有机含氯农药及菊酯类农药用GC-ECD检测器,为了使被测农药能与干扰物质达到更好的分离,采用了具有不同极性的两个色谱柱.尽管如此,有时仍可能获得假结果(例如假阳性结果等).为此进一步采用GC与MS联用的检测措施,使上述问题得以澄清.按所提出的方法,使多种共存的农药的检测,在准确性及可靠性方面得到很大提高.

In the detection of various residual pesticides in different kinds of vegetables,serious interferences due to the vegetable matrix were encountered frequently.A simple pretreatment of vegetable samples by extraction with acetonitrile was adopted in order to avoid loss of pesticides.Organo-phosphorus pesticides were determined in an aliquot of the extract by GC with FPD,and organochlorine pecticides as well as pyrethroids by GC with ECD.Two chromatographic columns with different polarity were used in GC-analysis to obtain a better separation of the interfering substances from the objective pesticides.Even then,pseudo results were sometimes obtained.As a further measure,GC-MS was applied to clear the obscurity.By the proposed method,the accuracy and reliability of the detection of residual pesticides were greatly increased.