花生田环境中毒死蜱的残留行为及安全性评价

目的]研究毒死蜱在花生田环境中的残留消解情况。方法]样品采用有机溶剂振荡提取、弗罗里硅土柱层析净化、GC-ECD测定。结果]毒死蜱在花生植株、花生仁、花生壳和土壤中的平均回收率为80.83%～96.09%,标准偏差2.68%～6.07%,变异系数3.05%～6.90%;毒死蜱的最小检出量为2.0×10-12g,在花生植株、花生仁、花生壳和土壤中的最低检测浓度分别为0.006、0.006、0.006和0.003mg/kg。在安徽、广东的试验结果表明,毒死蜱在花生植株、土壤中的降解半衰期分别为2.64～4.63、6.59～7.15d;15%毒死蜱颗粒剂以5400aig/hm2（1.5倍推荐高剂量）、3600aig/hm2（推荐高剂量）施药剂量,施药1次,采收间隔期为15、21、28d,花生仁、壳、植株中毒死蜱的最终残留量最高分别为0.02、0.82、0.43mg/kg。结论]15%毒死蜱颗粒剂用于防治花生地下害虫,施药剂量不超过3600aig/hm2（推荐高剂量）,施药1次,安全间隔期为28d。

Chlorpyrifos Residue and Behavior in Environment of Peanut Field and Its Safety Evaluation

Objective]The research aimed to study the residue dynamics of chlorpyrifos in peanut and soil.Method] Chlorpyrifos in the samples was extracted with organic solvent,purified with colum chromatography of florisil and detected by capillary gas chromatography with electron capture delector.Result] The average recoveries in plant,peanut kernel,peanut shell and soil were ranged from 80.83% to 96.09%.The standard deviations were from 2.68% to 6.07%,and the coefficients of variation were from 3.05% to 6.90%.The minimum detectable amount of chlorpyrifos standard was 2.0×10-12 g.And the minimum detectable concentrations in plant,peanut kernel,peanut shell and soil were 0.006,0.006,0.006 and 0.003mg/kg,respectively.The test in Anhui and Guangdong Province indicated that the half-lives of chlorpyrifos were from 2.64 to 4.63 days in plant,while in soil were from 6.59 to 7.15 days.The maximum final residues of chlorpyrifos in peanut kernel,shell and plant were 0.02,0.82 and 0.43 mg/kg.Conclusion] 15% GR of chlorpyrifos could be applied to control soil-insect of peanut with the dosage less than 3 600 ai g/hm2 and used one time,and the safety interval was 28 days.