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

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

彭林1,白志鹏1,朱坦1,徐永昌2,李剑3,冯银厂1

(1.南开大学环境科学与工程学院,天津　300071;2.中国科学院兰州地质研究所,兰州　730000;3.中国石油勘探开发研究

院廊坊分院,廊坊　065007)

摘要: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PM 10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-2314‰～-2418‰,分子量较大的多环芳烃的δ13C 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δ13C 随着其分子量的增大比郑州市更贫13C ,乌鲁木齐市的环境空气颗粒物中的苯并(a )芘、茚并(1,2,32cd )芘、苯并(ghi ) 的δ13C 值分别为-2813‰、-3118‰和-3012‰,郑州市为-2414‰、

-2914‰和-2613‰.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,煤的燃烧对乌鲁木齐市环境空气颗粒物中分子量较高的多环芳烃的贡献高于郑州市.

关键词:稳定碳同位素;多环芳烃;TSP ;PM 10;郑州;乌鲁木齐

中图分类号:X131.1　文献标识码:A 文章编号:025023301(2004)增刊20016205

基金项目:国家自然基金资助项目(20307006)教育部“跨世纪优秀人

才培养计划”基金项目(2002248)

作者简介:彭林(1966～),女,南开大学博士生,副教授,主要从事环

境中有机污染物来源与环境空气颗粒物来源方面的研究.E 2mail :plin123@

Origin of Atmospheric Polycyclic Aromatic H ydrocarbons (PAH s)in Two Chinese Cities Using Compound 2Specif ic Stable C arbon Isotopic Analysis

PEN G Lin 1,BAI Zhi 2peng 1,ZHU Tan 1,XU Y ong 2chang 2,L I Jian 3,FEN G Y in 2chang 1

(1.College of Environmental Sciences and Engineering ,Nankai University ,Tianjin 300071,China ;2.K ey Laboratory of G as G eochemisstry ,Lanzhou Institute of G eology ,Chinese Academy of Sciences ,Lanzhou 730000,China ;ngfang ,Research In 2stitute of Petroleum Exploration &Development ,Langfang 065007,China )

Abstract :Origin of atmospheric polycyclic aromatic hydrocarbons (PAHs )in total sus pended particulate (TSP )and particulate matter ten (PM 10)collected in non 2heating 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 2C 2MS and uncertainty is less than 016‰.δ13C values of atmospheric PAHs in Urumchi range from -2316‰to -3211‰and from -2215‰to -3110‰in Zhengzhou.δ13C values of PAHs in TSP are similar to those in PM 10in the two urban areas.δ13C values of low 2weight molecules

(pyrene ,fluoranthene ,benzo [e]pyrene etc.)in PAHs from the two cities are similar ,and the mean value of δ13

C ranged from

-2314‰to -2418‰.However ,δ13

C values of high 2weight molecules in PAHs evidently differentiate each other.The individual compounds of atmos pheric PAHs in Urumchi are more depleted in 13C with increasing molecular weight in PAH than those in Zhengzhou.δ13C values of benzo [a ]pyrene ,indeno (1,2,32cd )pyrene and benzo (ghi )perylene in Urumchi were -2813‰,-3118‰and -3012‰,respectively ,which are similar to those of the corresponding molecules in coal combustion particles.The val 2ues of those three compounds in Zhengzhou ,however ,were -2414‰,-2914‰and -2613‰,res pectively ,being similar to those from coal carbonization and automobile exhausts.Our data ,incorporated with the analysis upon the consumption of coal and amount of motor vehicles ,indicate that PAHs were controlled by coal carbonization ,coal combustion and automobile exhausts in two cities ,and contribution of automobile exhausts to PAHs of weight molecular in Zhengzhou is larger than that in Urumchi in no 2heating sea 2son ,while contribution of coal combustion to PAHs of weight molecular in Urumchi is larger than that in Zhengzhou in no 2heating season.

K ey w ords :carbon isotope ;polycyclic aromatic hydrocarbons ;TSP ;PM 10;Urumchi ;Zhengzhou

空气颗粒物中存在的多环芳烃(PAHs )主要来源于化石燃料的不完全燃烧,还有少量的PAHs 来源于植物和微生物的内源性合成、森林及草原自然起火、火山活动和一些矿物成分[1].判别空气颗粒

第25卷增刊2004年6月

环 境 科 学ENV IRONM EN TAL SCIENCE

Vol.25,Sup.J une ,2004