我国北方典型城市大气中VOCs的组成及分布特征

从2008年4月到2009年1月,利用前级浓缩-气相色谱/质谱法,对天津市和沈阳市大气中的挥发性有机物及浓度变化进行了采样研究.共监测了108种VOCs,包括卤代烷烃39种、苯系物16种、烯烃12种、烷烃30种、醛酯11种,在天津市检测到挥发性有机污染物中,醛酯56.9%,卤代烷烃13.4%,烷烃13.1%,苯系物12.9%,烯烃2.5%,卤代烯烃1.1%.沈阳市醛酯49.3%,卤代烷烃17.8%,烷烃11.8%,苯系物10.3%,卤代烯烃7.8%,烯烃2.9%.2市VOCs的含量季节变化都是春秋季节大于冬夏季节,在不同季节不同点位的VOCs的总量的变化趋势几乎一致,并且分析了天津市和沈阳市苯系物和卤代烃的的主要组成成分以及主要来源,苯系物的主要成分包括苯、甲苯、乙苯、二甲苯,苯系物的主要来源是汽车尾气,卤代烷烃的主要成分是二氯甲烷和氯乙烯,主要来自于汽车尾气和石油化工.

Composition and distribution of VOCs in the ambient air of typical cities in Northern of China

In order to study the composition and distribution of VOCs in the ambient air in the typical cities in North China,The research was conducted in Tianjin and Shenyang from April 2008 to January 2009,using the method of two-step-concentration-gas sepectrometry /mass(CCD-GC /MS).108 species of VOCs were detected in this study,the main ingredients include 39 species of alkyl halides,16 species of BTEX,12 species of olefins,30 species of alkanes,11 species of aldehydes and esters.The main components of VOCs in Tianjin were aldehyde esters,halogenated hydrocarbons,alkanes,BETX,olefins and halogenated alkenes,which accounted for 56.9%,13.4%,13.1%,12.9%,2.5%and 1.1%,respectively.The main components of VOCs in Shenyang were aldehyde esters,halogenated hydrocarbons,alkanes,BETX,halogenated alkeness and olefin,which accounted for 49.3%,17.8%,11.8%,10.3%,7.8%and2.9%,respectively.There were no significant differences in the total amount of VOCs in each sampling sites in each sampling period.In Tianjin and Shenyang,the components and the main sources of BETX and halogenated hydrocarbons were analysed.The main components of BTEX,which include benzene,toluene,ethylbenzene,xylene,automobile exhaust was the main source of BETX,and the components of halogenated,which include methylene chloride and vinyl chloride,vehicle exhaust and petrochemicals was the main source of halogenated.