气相色谱法同时测定土壤中毒死蜱、乙草胺和丁草胺残留量

通过改进样品前处理方法及加标回收验证试验,建立以乙腈为提取剂,超声快速提取,固相萃取净化,氮吹浓缩,气相色谱仪ECD检测器测定土壤中毒死蜱、乙草胺、丁草胺残留量的方法。研究结果表明,土壤中毒死蜱、乙草胺、丁草胺在0.05mg.L-1、0.1mg.L-1和0.5 mg.L-13种添加水平下平均回收率分别是毒死蜱110.7%、99.1%、96.6%,乙草胺96.6%、97.94%、100.5%,丁草胺91.8%、93.0%、93.9%;变异系数范围分别为6.2%～10.3%,7.9%～10.4%和5.9%～9.6%;最低检测浓度分别为0.0008 mg.kg-1,0.0036 mg.kg-1和0.0029 mg.kg-1。该方法准确度、精密度高,重现性好,能达到农药残留量检测要求。

Determination of Residue of Chlorpyrifos,Acetochlor and Butachlor in Soil by GAS Chromatography

By pretreatment improvement and recoveries test,a method for determination of chlorpyrifos,acetochlor and butachlor in soil samples,which were rapidly extracted by ultrasonic with acetonitrile as extractant,purified by solid phase extraction,concentrated by nitrogen-blowing,and determined by GC ECD detector was established.When adding chlorpyrifos,acetochlor and butachlor at concentration of 0.05mg·L^-1、 0.1 mg·L^-1 and 0.5 mg·L^-1,the average recoveries for the chlorpyrifos were 110.7%,99.1%,96.6%,acetochlor were 96.6%,97.94%,100.5%,butachlor were 91.8%,93.0%,93.9%.The relative standard deviation of chlorpyrifos,acetochlor and butachlor ranged from 6.2% to 10.3%,7.9% to 10.4% and 5.9% to 9.6%.The limits of detection were 0.0008mg·kg^-1,0.0036mg·kg^-1 and 0.0029mg·kg^-1,respectively.The method is accuracy,precision and reproducibility,which meet the requirement of pesticide residue testing.