农用地土壤中六六六和滴滴涕8种有机氯农药测定的脱水前处理研究

Research on Dehydration of Agricultural Soil Extract During BHCs and DDTs Deter- mination

新鲜农用地土壤经快速溶剂萃取后,萃取溶液中含有水分。建立了采用快速溶剂萃取-气相色谱法测定农用地土壤中六六六和滴滴涕农药残留的方法,在加速溶剂萃取液中加入纯水,用减压蒸馏法将丙酮和正己烷去除,用正己烷液液萃取剩下的溶液,浓缩净化后进气相色谱仪检测。方法检出限为4.90×10^(-3)~4.80×10^(-2) mg/kg,曲线的相关系数均>0.999,方法加标回收率为76.2%~91.2%,相对标准偏差为1.2%~6.1%。该方法准确可靠,可用于实际农用地土壤中六六六和滴滴涕的测定。

After rapid solvent extraction of fresh agricultural soil,the extraction solution contains water.A rapid solvent extraction-gas chromatography method was established for the determination of BHCs and DDTs residues in agricultural soil.Pure water was added to the accelerated solvent extraction solution,acetone and n-hexane were removed by vacuum distillation,and the remaining solution was extracted by n-hexane using liquid-liquid extraction,after concentrated and purified,the extract was then detected by gas chromatography.The detection limits were 4.90×10^(-3)~4.80×10^(-2) mg/kg,and the correlation coefficients were greater than 0.999.The recoveries were 76.2%~91.2%,and the relative standard deviations were 1.2%~6.1%.The method is accurate and reliable,and can be used for the determination of BHCs and DDTs in soil of actual agricultural land.