济南市道路尘中类二噁英类多氯联苯残留情况

摘要

通过采集济南市区主要路段道路尘样品,用气相色谱-电子俘获检测器( GC-ECD)方法分析了济南市区主要路段道路尘中毒性较高的12种类二噁英类多氯联苯( DL-PCBs)的残留情况,并对样品中DL-PCBs的含量、污染水平及同系物的组成进行了详细研究.结果发现,DL-PCBs在各采样点均有检出,残留总浓度在0.20～22.84 ng/g(干重)范围内,平均值为0.0051 ng/kg,同系物PCB81的检出率最高为90％,而同系物PCB189未被检出.计算的毒性当量( TEQ)值显示,对毒性当量贡献最大的是同系物PCB 126,其TEQ值高达117.100 pg/g(干重).由平均残留百分含量较大的同系物结构分析可知,济南市区主要路段道路尘中非邻位氯取代的剧毒类二噁英类PCBs含量相对较大.%By collecting the main road dust samples in Jinan city, the pollutant residues of 12 types of Dioxin-Like Polychlorinated Biphenyls (DL-PCBs) with higher toxicity were quantitatively analyzed using the method of gas chromatography with electron capture detection (GC-ECD). The residual concentration, pollution levels and homologues composition of DL-PCBs were investigated in detail. The detection and analysis results indicated that the others 11 DL-PCBs were detected except PCB169 absent in all samples. The total concentration of DL-PCBs was in the range of 0.20~22.84 ng/g (dry weight) and the average value was 0.0051 ng/kg. The content of PCB81 was the most (90%).The toxic equivalent values (TEQ) showed that the PCB126 had the highest TEQ value, which is 117.100 pg/g (dry weigh). The average residual percentage analysis of homologues showed that the percent of non-ortho chlorine substituted DL-PCBs were relatively large.