摘要
应用仪器中子活化分析(INAA)及气相色谱质谱联用技术(GC/MS)研究了PUF大气被动采样器采自全国31个点的大气样品中的可萃取有机氯/溴/碘(EOCl/Br/I)和多氯联苯(PCBs)。结果表明,大气中卤素污染物质量浓度最高的点大部分分布在城区,且呈现沿城市到乡村的下降趋势;在交通枢纽地区大气中EOCl的质量浓度要高于远离交通枢纽的采样点,机动车尾气的排放是大气中有机氯污染物的重要来源之一;工业也是大气中有机氯污染物的主要来源。84种PCBs异构体分析结果表明,大气中PCBs主要以低氯代PCBs为主,Cl2-CB占总PCBs的41%,Cl3-CB含量最高,占总量的43%,其余异构体含量随取代氯原子的增加而下降,这种异构体的分布特征与我国所生产和使用的PCBs"指纹谱"非常相近,且PCBs异构体的分布特征没有地域差异,这表明大气环境中PCBs主要来自工业污染,且城市地区是我国大气中PCBs的主要来源。在所有已测定的样品中已知PCBs的氯在总EOCl中的比例不足1.0%,大气中绝大部分的有机氯为未知化合物。
Organic halogens have long been recognized to be severe environmental pollutants,because of their persistence, bioaccumulation and potential hazardous impact on human health. In this study, a large-scale network of 31 passive air sampling sites was used to better understand the atmospheric distributions of organic halogens across China. EOCl, EOBr, EOI, and PCBs in the atmospheric samples were determined by a hybrid NAA method combined with GC-MS. EOCl, EOBr, EOI, and PCBs exhibited a huge urban-rural gradient. The highest values were detected in the areas of high usage and emission, which were linked to the local urbanization with relatively rapid economic development in China. The results clearly indicate that these pollutants mainly come from industrial pollution. Higher EOCl contents in traffic areas state that exhaust emission from vehicle is another main source of organochlorines in air. The relative proportions of the known organochlorines （84 PCB congeners） to total EOCl are less than 1. 0%, which implies that most of EOCl measured in air are unknown. PCBs are dominated by di-CB （mean. 41%） and tri-CB （mean. 43%）. No systematic distribution differences of PCB congeners in the sampling locations are found, which suggest that atmospheric contamination of PCBs in China are still controlled by primary sources, rather than secondary ones.
出处
《核化学与放射化学》
EI
CAS
CSCD
北大核心
2008年第3期146-151,共6页
Journal of Nuclear and Radiochemistry
基金
国家自然科学基金项目(10505023)
国家自然科学基金重大项目(10490180)
中国科学院知识创新工程重要方向性项目(KJCX3.SYW.N3)
中国科学院核分析重点实验室开放基金项目(K117,K127)
