中文摘要：

2007年3月采集上海市农村及郊区36个表层土壤样品,采用气相色谱法对土壤中的多氯联苯（PCBs）残留进行了分析,揭示了土壤中PCBs的残留水平、分布、组成特征及来源。结果表明,试区土壤中共检出62种PCB,总浓度最高2530ng·kg-1,最低71.7ng·kg-1,平均含量534ng·kg-1。较高污染浓度主要是编号为BS2、SJ6、JS4和FX4的土壤样品,但从整体采样区域来看,其污染可能主要来源于城区污染导致的区域大气沉降或是全球大气传输所致。上海农村及郊区土壤PCBs污染物以Tri-CBs和Tetra-CBs为主,主要以工业Aroclor1242来源为主。相关性分析显示,土壤中PCBs与TOC具有显著相关性,尤其是对于挥发性较强的低氯代PCBs,表明TOC是影响上海市土壤中PCBs持留的重要因素之一。聚类分析显示,部分采样点PCBs污染与工业品使用有关,但可能还存在其他来源。

英文摘要：

A new random sampling strategy was adopted to examine the PCBs in the agricultural lands nearby Shanghai and a total of 36 surface soil samples were collected from rice,bean,cotton and vegetable soils in the October of 2007.The concentrations of 144 polychlorinated biphenyls（PCBs）in the soil samples were determined by using gas chromatography equipped with 63Ni micro-electron capture detector（GC-μECD）.On basis of the analytical data of 62 PCB congeners,it was certified that the total concentrations of identified PCBs ranged from 71.7 to 2 530 ng·kg-1 with means of 534 ng·kg-1.According to the compositional profiles of soil PCBs homologues,the higher proportions of low chlorinated（Tri-CBs and Tetra-CBs）were observed.The results indicated that PCB15＋13,PCB22,PCB66,PCB44 and PCB153 were the most dominant congeners among the identified PCBs with regard to the concentrations and detection frequencies.The high levels of PCBs were detected in soil samples taken from the agricultural field BS2,SJ6,JS4 and FX4,respectively.PCBs homologues analysis revealed that PCBs in the study areas might be originated from Aroclor1242.The correlation analysis showed that there was a relatively good correlation among the individual PCBs and soil TOC,suggesting the important influence of soil TOC on PCBs contamination.