北京市海淀区大气PM10中正构烷烃的分布研究

利用索氏抽提与层析柱前处理以及气相色谱/质谱联用技术(GC-MS)等方法检测了2004～2005年北京市海淀区采样点大气PM10中的正构烷烃.实验数据表明,正构烷烃的碳数分布范围在nC11～nC32之间,相对含量较大的范围为nC16～nC29,且随碳数递增,正构烷烃以等间距顺序出峰,秋季和夏季的色谱图基线比较平稳,UCM鼓包峰较小,冬季有不明显的UCM鼓包峰,春季有明显的UCM鼓包峰,23≤Cmax＜27,1＜CPI＜3,(nC21+nC22)/(nC28+nC29)值除冬季以外,春季、夏季和秋季的平均值均小于1.表明北京市海淀区2004～2005年大气PM10中均检测出丰富的正构烷烃,正构烷烃主要来自高等植物等现代生物和化石燃料(石油、煤等)的不完全燃烧双重来源.

Distribution Research of n-alkanes in PM10 on Haidian District in Beijing

N-alkanes from the PM10 in Northwest urban District of Beijing during 2004 and 2005 were analyzed by Soxhlet extraction, chromatography column pre-treatment and GC-MS technique methods. It indicates by experimental data that the carbon number ranging from nC11 to nC32increases progressively with the carbon number,the larger range of relative content is between nC16 to nC29 ,n-alkanes peaks sequence is equal space,the chromatogram charts in autumn and summer are comparatively stable,the UCM bulge is comparatively small that is not obvious in winter and obvious in spring, 234 Cmax〈27,1〈CPI〈3,the average values of （nC21 ＋nC22）/（nC28 ＋nC29）are all less than 1 in addition to winter,these show that n-alkanes of PM10 in the northwest of Beijing City from 2004 to 2005 were mainly from modern biology such as higher plants and incomplete combustion of fossil fuels （oil,coal）.