郑州空气颗粒物中PAHs的碳同位素特征及来源  

Carbon isotope characteristics of polycyclic aromatic hydrocarbons in atmospheric particles and their source analysis in urban area of Zhengzhou City

作　　者：彭林[1,2] 李剑[3] 朱坦[1] 白志鹏[1] 徐永昌[4] 冯银厂[1] 

机构地区：[1]南开大学环境科学与工程学院 [2]太原理工大学矿业工程学院,山西太原030024 [3]中国石油勘探开发研究院廊坊分院 [4]中国科学院兰州地质研究所

出　　处：《中国环境科学》2005年第1期106-109,共4页China Environmental Science

基　　金：国家自然科学基金资助项目(20307006);南开大学创新基金资助项目

摘　　要：研究了郑州城区空气颗粒物中多环芳烃(PAHs)的稳定碳同位素组成特征并对其来源进行了解析.气相色谱/燃烧系统/同位素质谱(GC/C/IRMS)分析表明,PAHs 的δ13C 值在非采暖季为-29.4‰^-23.4‰,采暖季为-30.0‰^-24.2‰,随着分子量的增大,PAHs 中 13C 降低.统计表明不同采样点的样品中的 PAHs 的δ13C 区别不明显(0.1‰<σ<0.8‰).两个季节中,三环和四环多芳香烃化合物荧蒽、芘和苯并(a)蒽的δ13C没有明显的区别,其范围为-24.5‰^-23.4‰,但是,五环和六环芳烃的δ13C 值有明显差异.随着分子量的增大,采暖季环境空气颗粒物中 PAHs的碳同位素比值变小的程度比非采暖季的大.采暖季的苯并(a)芘、茚并(1,2,3-cd)芘、苯并(ghi)苝的δ13C 值分别为-26.6‰、-30.0‰和-28.1‰,而非采暖季为-24.5‰、-29.4‰和-26.3‰.利用二元复合同位素模型,估算了不同季节机动车尾气和煤的燃烧对郑州城区苯并(a)芘的贡献.在非采暖季机动车尾气排放的贡献率为 70%,在采暖季贡献率为 50%,煤的燃烧对六环化合物的贡献高于机动车排放的贡献.The stable carbon isotopic compositions characteristics of polycyclic aromatic hydrocarbons (PAHs) in atmospheric particle and their source analysis in the urban area of Zhengzhou were studied. Gas chromatogram combustion system isotope mass spectra (GC/C/IRMS) analysis showed that δ13C values of PAHs in non-heating season were -2.94% - -2.34%; and in heating season were -3.00% - -2.42%. 13C in PAHs lowered with increasing molecular weight. Statistic results showed that δ13C values of atmospheric PAHs are similar in the samples of different sampling site differed not obviously (0.01% less than or equal σ less than or equal 0.08%). δ13C values of 3,4-ring polycyclic aromatic compounds (fluoranthene, pyrene, and benzo[a]anthracene) were not different obviously in these two seasons, ranged -2.45% - -2.34%. But δ13C value of 5,6-ring PAHs emerged marked difference. With the increase of molecular weight, the PAHs in the particles depleted in 13C in heating season more than in no-heating season. δ13C values of benzo[a]pyrene, indeno[l,2,3-cd]pyrene, and benzo[ghi] perylene were -2.66% - -3.00% and -2.81% in heating season, respectively, and -2.45% - -2.94% and -2.63% in no-heating season, respectively. Utilizing binary compound isotope model, the contribution of benzo(a) pyrene in urban area of Zhengzhou from automobile exhausts and coal combustion in different seasons was calculated. The exhausts contribution in no-heating season was 70% and 50% in heating season; but the 6 ring compounds distribution from coal combustion was higher than that from the exhausts.

关 键 词：碳同位素 多环芳烃 空气颗粒物 源解析 郑州 

分 类 号：X511[环境科学与工程—环境工程]