采用索氏萃取法提取大气降尘中的有机物,用自制的硅胶层析柱进行了分离纯化,并以气相色谱/质谱法对提取物进行了分析.结果表明:从临沂师范学院前十学生公寓和临沂市汽车总站采集到的大气降尘样品中都含有较多的烷类、醛酮类、苯类和酯类有机化合物,并检测到一定量的卤代烃、酞酸酯类、多环芳烃类等有害于健康的物质.经初步推测,大气降尘中的有机化合物与机动车尾气排放有很大关系.文中对大气降尘中有机化合物的分析将为进一步研究大气降尘中有害物质的来源、迁移及其转化规律提供参考.

Samples of atmospheric dust fall were taken from some definite area in the city by dry method,and organic compounds in the sample were extracted with acetone in a Soxhlet′s extractor at 68 ℃ for 3 h.The extract was evaporated to 5 mL,then separated and purified on silica gel column.Organic compounds in the eluate from the column were analyzed by GC/MS.Analytical conditions of GC/MS were described in detail.Relatively high contents of alkanes,aldehydes,ketones,benzene homologues and esters especially some harmful compounds,i.e.halohydrocarbons,phthalates and polycyclic aromatic hydrocarbons,were found in the samples.It was deducted that the sources of these contaminants were the tail-gas discharged by the motor vehicles.The results of this work were helpful to the study on the source,migration and transformation of harmful organic substances in the atmospheric dust fall.