中文摘要：

为快速准确检测土壤中21种低浓度多氯联苯（PCBs）的含量，建立了以丙酮-正己烷（1：1，V/V）为萃取剂超声提取，四通道色谱分离仪对提取液进行分离和净化的前处理方法。采用氮吹法将前处理的样品浓缩至50斗L以下，以PCB54作为内标。利用气相色谱一郇Ni微电子捕获检测器（GC—ECD）进行定量测定。土壤中21种PCBs的回收率为68．6％～102．3％，相对标准偏差为2．2％．9．9％，方法检出限为1．21—4．67μg/kg。采用所建方法对长江三角洲地区经长期植物修复后的PCBs污染土壤和无污染的农田土壤进行检测，结果显示，修复后的土壤PCBs总量为99．884-3．97μg/kg，无污染农田土壤PCBs总量为69．01±2．19μg／kg。

英文摘要：

A quick method for the determination of low levels of 21 polychlorinated biphenyls （PCBs） in soil samples was established under the condition of quality assurance/quality control （QA/QC）. PCBs in micro soil samples were extracted with a mixture of hexane - acetone （ 1 ： 1, V/V） by ultra-phonic technique, and then were purified by four-channel purification chromatograph, which was developed independently in our laboratory. Extracts were concentrated to 50 μL under a gentle nitrogen stream and detected by GC-ECD with the internal standard PCB 54. The recoveries rates, RSD （relative standard deviations） and MDL（ method detection limits） for 21 PCBs were 68.6% ~ 102. 3% , 2. 2% - 9.9% , and 1.21 - 4.67 μg/kg, respectively, which met the demands for US EPA PCBs recoveries. PCBs contaminated soil after long-term phytoremediation in the Yangtze River Delta and non-contaminated farmland soil in the same area were detected by this method. The total concentrations of PCBs in two soil samoles were 99.88 ± 3.97 μg/kg and 69.01 ± 2. 19μg/kg respectively.