大气可吸入颗粒物中含硫和含氧芳烃化合物的气相色谱-质谱分析

Determination of Sulfur and Oxygen Containing Polycyclic Aromatic Hydrocarbons in Inhalable Particulate by Gas Chromatography-Mass Spectrometry

采用超声萃取 ,硅胶柱层析分离 ,毛细管气相色谱 -质谱联用方法分析了大气可吸入颗粒物中芳烃化合物。根据其质量色谱图和特征碎片离子、标准谱库检索和保留指数作定性分析 ,鉴定出 1 8个含硫和含氧芳烃化合物 ,以 3～ 4环结构为主 ,主要为二苯并噻吩、苯并萘并噻吩和二苯并呋喃系列化合物。用内标法进行定量测定的结果表明 :在城乡结合部化合物的含量为 0 .2 3～ 5 .0 5 ng/ m3 ,在郊区含量为 0 .0 4～ 1 .2 7ng/ m3 ,前者的各个化合物含量分别是后者的 2 .8～ 1 0 .8倍 ,两个地区的母核芳烃含量都高于带取代基芳烃 ,反映了这些化合物主要来源于化石燃料 (主要是煤 )

Aromatic compounds in inhalable particulate were extracted under ultrasonic agitation and extracts were separated by chromatographic column packed with silica gel and alumina. The aromatic fraction was detected by gas chromatography-mass spectrometry coupled with capillary column. On the basis of mass chromatogram and characteristic fraction ions, NIST library searching and retention indices, qualitative analysis of eighteen sulfur and oxygen containing polycyclic aromatic hydrocarbons were performed. They are mainly composed of aromatic heterocycles with 3—4 rings, such as dibenzothiophenes, benzonaphthothiophenes and dibenzofurans. The quantitative analysis results with internal standard showed the concentration of these compounds in urban border site and suburban site was 0.23—5.05ng/m 3 and 0.04—1.27ng/m 3,respectively. The former concentration was 2.8—10.8 times higher than the latter. The concentration of parent aromatic heterocycles was much higher than that of alkyl substituted derivatives, which attributing to fossil fuel (mainly coal) combustion process.