提出了气相色谱法测定土壤中莠去津和3种有机磷农药敌敌畏、甲拌磷和乐果的含量的方法。样品经粉碎后用丙酮-二氯甲烷(1+1)混合溶剂经加速溶剂萃取仪在60 ℃静态萃取10 min。采用Rtx-1701色谱柱分离,火焰光度检测器测定3种有机磷农药;采用Rtx-CLP II色谱柱分离,电子捕获检测器测定莠去津。结果表明:加速溶剂萃取比超声提取法处理样品的回收率高。敌敌畏、甲拌磷、乐果和莠去津的检出限(3S/N)分别为0.08,0.07,0.09,0.40 μg·kg-1。以空白土壤样品为基体,进行加标回收试验,回收率在82.0%~106.0%之间,相对标准偏差(n=7)在10.5%~16.9%之间。

The contents of atrazine and three organophosphorus pesticides, i.e., dichlorophos, phorate and dimethoate, in soil were determined by GC. The sample was crushed and extracted statically with mixed solvent of acetone+dichloromethane (1+1) at 60 ℃ for 10 min. The Rtx-1701 column and flame photometric detector were used for separation and determination of the 3 organophosphorus pesticides; and Rtx-CLP II column and electron capture detector were used for separation and determination of atrazine. It was found that recovery of accelerated solvent extraction was better than ultrasonic extraction. Detection limits (3S/N) of the method were found 0.08 μg·kg-1 for dichlorophos, 0.07 μg·kg-1 for phorate, 0.09 μg·kg-1 for dimethoate, 0.40 μg·kg-1 for atrazine. Using blank sample of soil as matrix, test for recovery was made by standard addition method, and values of recovery obtained were in the range of 82.0%-106.0%, with values of RSD′s (n=7) in the range of 10.5%-16.9%.