2．5％溴氰菊酯油在大白菜上硇残留消髓动态砜究

为研究2．5％溴氰菊酯乳油在大白菜和土壤中的残留消解动态，对大白菜和土壤喷施相应药剂后进行取样。样品经石油醚或石油彬丙酮（V／V1：1）提取，液液分配净化，用气相色谱电子捕获检测器检测。溴氰菊酯在白菜中的平均回收率在104．09％-112．28％之间，变异系数为2．66％-4．35％；在土壤中的平均回收率在103．67％-108．80％之间，变异系数为1．66％-3．45％，准确度和精密度均达到了《农药残留试验准则》的规定。消解动态试验和最终残留试验结果表明：溴氰菊酯在白菜和土壤中的消解较快，在白菜和土壤中的丰衰期分别为6．7d和6．4d。当溴氰菊酯分别在高剂量和低剂量下施药三次和四次后。药后21d收获白菜和土壤中的残留量均低于最低检出浓度（LOD）。

The Dynamics of 2.5 % Deltamethrin EC Residue Disappearance in Cabbage and Soil

To determine the dynamics of deltamethrin residue disappearance, cabbage and soil samples were collected after dehamethrin application on cabbage and soil. Samples were extracted with petroleum ether or petroleum ether/acetone （ V/V 1 ： 1 ） and cleaned up by liquid extraction, followed by residue determination using GC - ECD. This method is that the recover rate was 104.09% to 112.28%, and the RSD was 2.66 to 4.35 for cabbage; the recover rate was 103. 67% to 108.80%, and the RSD was 1.66 to 3.45 for soil. This way has reached the requirement of The Guideline on Pesticide Residues Trials. As a result, Deltamethrin decomposed quickly in cabbage and soil, with half-lives of 6.7 d and 6.4 d respectively, when dehamethrin of high dosage and low dosage was applied 3 and 4 times on cabbage and soil, detectable residues were less than LOD in cabbage and soil 21 d after the last application.