天津市区表层土壤中多氯联苯的污染特征

用GC/ECD分析、GCMS验证的方法测定了天津市区41个表层(0～10 cm)土壤样品中84种PCB异构体.结果表明:w(PCBs)为0.82～8.86 ngg,平均值为3.56 ngg,其中工业区>路边绿化带>公园.7种PCB指示异构体的浓度(以w计)范围为0.08～2.05 ngg,占总量的22.89%,与w(PCBs)具有较好的相关性(R=0.74,P<0.000 1).5氯联苯和3氯联苯是主要的异构体,分别占总量的28.30%和22.14%.浓度位居前10位的异构体分别是PCB3128、PCB201、PCB6、PCB84、PCB92、PCB101、PCB1632、PCB89、PCB180和PCB1213.主成分分析显示,国产变压器油与电容器油、Aro1242、Aro1248、Aro1254、A30和KC300以及现有工业的排放是天津市区表层土壤中PCBs的主要来源.

Pollution Characteristics of Polychlorinated Biphenyls in Surface Soils from Tianjin Urban Area

Eighty-four PCB congeners in 41 surface soil samples(0-10 cm) from the urban area of Tianjin were analyzed by GC/ECD and GC/MS.The results showed that Σ84PCBs for the 41 samples ranged from 0.82 to 8.86 ng/g,with anaverage value of 3.56 ng/g.Total PCB concentrations in soil from the industrial area were the highest,followed by those in soils from the roadside green belt and garden sites.The sum of concentrations of the seven indicator PCBs ranged from 0.08 to 2.05 ng/g,accounting for 22.89% of total PCB concentration,and it was also well correlated with the total PCB concentration(R=0.74,P<0.0001).Tri-and penta-CBs were the predominant homologues,accounting for 22.14% and 28.30% of total PCB concentrations,respectively.The top ten congeners with the highest concentrations were PCB31/28,PCB201,PCB6,PCB84,PCB92,PCB101,PCB16/32,PCB89,PCB180 and PCB12/13.Principal component analysis showed that Chinese transformer and capacitor oils,Aro1242,Aro1248,Aro1254,A30 and KC300,as well as emissions from some industries,were the main sources of PCBs in Tianjin urban soils.