经粉碎后的土豆样品用水超声提取,取滤液以正辛醇为萃取溶剂进行动态液相微萃取处理,对样品中3种有机磷农药敌敌畏、甲基对硫磷和对硫磷进行富集分离。气相色谱法测定时采用OV-1701毛细管色谱柱分离和火焰光度检测器测定。3种农药的线性范围均在2.0~50.0 μg·g-1之间,检出限(3S/N)依次为0.20,0.46,0.42 μg·g-1。以土豆样品作基体,用标准加入法做回收试验,测得回收率在90.6%~101%之间,相对标准偏差(n=7)在3.2%~5.6%之间。

Smashed potato sample was extracted ultrasonically with water, the filtrate was treated by dynamic liquid phase micro-extraction (DLPME) using n-octanol as extracting agent, to separate and enrich the 3 organophosphorus pesticides, i.e., dichloroas, methylparathion and parathion, which were then determined by GC. OV-1701 capillary column was used in GC separation and flame photometric detection was adopted in the determination. Ranges of linearity for the 3 organophosphorous pesticides were same between 2.0-50.0 μg·g-1, with values of detection limit (3S/N) of 0.20, 0.46, 0.42 μg·g-1 for methylparathion, parathion and dichlorovos respectively. Using potato samples as matrixes, values of recovery found by standard addition method were in the range of 90.6%-101% with RSD′s (n=7) in the range of 3.2%-5.6%.