应用稳定碳同位素组成特征研究环境空气颗粒物中多环芳烃的来源

Origin of Atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) in Two Chinese Cities Using Compound-Specific Stable Carbon Isotopic Analysis

采集了乌鲁木齐市与郑州市非采暖季的环境空气颗粒物 ,用二氯甲烷做溶剂提取、硅胶柱层分离出多环芳烃样品 .用气相色谱 /燃烧系统 /同位素质谱测定了多环芳烃单化合物的稳定碳同位素组成 .结果表明 :这 2个城市的TSP与PM10 中多环芳烃单化合物稳定碳同位素组成相比较没有明显的区别 ;两城市的颗粒物样品中 ,分子量较小菲、蒽、荧蒽、芘和苯并 (e)芘的稳定碳同位素组成没有明显的区别 ,平均值范围为 - 2 3 4‰～ - 2 4 8‰ ,分子量较大的多环芳烃的δ13 C出现了明显差异 ,乌鲁木齐市环境空气颗粒物中多环芳烃单化合物的δ13 C随着其分子量的增大比郑州市更贫13 C ,乌鲁木齐市的环境空气颗粒物中的苯并 (a)芘、茚并 (1,2 ,3 cd)芘、苯并 (ghi)的δ13 C值分别为 - 2 8 3‰、- 31 8‰和 - 30 2‰ ,郑州市为 - 2 4 4‰、- 2 9 4‰和 - 2 6 3‰ .结合对两城市燃煤量和机动车拥有量的对比分析 ,本研究认为 :在非采暖季 ,这两个城市环境空气颗粒物中多环芳烃的污染主要是以煤的炭化、气化、燃烧以及机动车尾气为主的复合型污染 ,而机动车尾气对郑州市环境空气颗粒物中分子量较高的多环芳烃的贡献高于乌鲁木齐市 。

Origin of atmospheric polycyclic aromatic hydrocarbons (PAHs) in total suspended particulate (TSP) and particulate matter ten (PM 10) collected in non-heating seasons in urban areas of Urumchi and Zhengzhou, China were discussed on the base of carbon isotopic compositions of individual compounds. Carbon isotope ratios were measured with type of GC-C-MS and uncertainty is less than 0.6‰. δ 13C values of atmospheric PAHs in Urumchi range from -23.6‰ to -32.1‰ and from -22.5‰ to -31.0‰ in Zhengzhou. δ ...