太原市大气总悬浮颗粒物中正构烷烃和多环芳烃空间分布及来源分析

Distribution Characteristics and Source Analysis of n-alkanes (C_(14)～C_(31)) and PAHs in Total Suspended Particulates in Urban Area of Taiyuan City

收集了太原市不同功能区的大气总悬浮颗粒物样品,经超声波提取分离得到正构烷烃、多环芳烃,经色谱-质谱分析表明,太原市大气颗粒物中正构烷烃主要来源于化石燃料的燃烧,少量为自然排放源。含量较高的不带取代基的多环芳烃有8种,其年平均浓度为1.50μg/m3,其中苯并(a)芘的年平均浓度为74.7ng/m3。多环芳烃的浓度分布为一电厂化工区>太钢工业区>桃园三巷商业居民区>太行仪表厂文化区。利用三角图与烟尘、汽车尾气样品中的多环芳烃特征相比较,认为太原市大气颗粒物中的多环芳烃主要来源于煤的燃烧。

Total suspended particulates (TSP, airborne particulate matter with aerodynamic diameter smaller than 100 μm) were collected at four sites, which represents different functional zones of Taiyuan City, China. Samples were extracted by purified CH2Cl2.nalkanes and PAHs were separated through packed column and determined by GCMS. The results show that the nalkanes are mainly from combustion of the fossil fuels and others from natural exhausting sources. 8 kinds of PAHs without substituting groups are in higher content with year average concentration of 1.50 μg/m3, in which BaP is 74.7 ng/m3. The concentration distribution of PAHs is: 119.3 ng/m3 in chemical industrial zone, 91.0 ng/m3in industrial zone, 56.4 ng/m3 in commercial and residential zone, 32.0 ng/m3 in sciencetechnical and cultural zone. The ratio (BaP/COR) and triangular plot (CH, BaP+BeP+BkF and COR) are used for the purpose of source apportionment and show that the major source of PAHs is from coal incomplete combustion.