北京大气气溶胶表面无机组分的静态飞行时间二次离子质谱研究

采用特定的样品处理方式，利用静态飞行时间二次离子质谱(Static-TOF-SIMS)技术，对使用通用型大气污染物采样仪VAPS(URG-3000K)采集于非导电性的滤膜(聚碳酸酯滤膜)上的大气气溶胶细粒子(PM_2.5)与粗粒子(PM_2.5～10)的表面无机组分进行了探索性的比较分析.结果表明:大气气溶胶细粒子与粗粒子的表面无机组分组成特征具有明显的差异；气溶胶细粒子表面存在着大气中二次形成的亲水性化合物，会对其表面的疏水性/亲水性特征产生影响，从而影响其大气化学行为；气溶胶粗粒子表面存在氟化物，对生态环境和人体健康具有潜在的危害性，应该重视对气溶胶中氟污染的研究与控制；静态飞行时间二次离子质谱可以成为研究大气气溶胶表面化学组成特征的有利分析手段. 

Analysis of Inorganic Species on the Surface of Atmospheric Aerosols Collected in Beijing Using Time-of-flight Static Secondary Ion Mass Spectrometry

This paper presents a specific pretreatment and time-of-flight static secondary ion mass spectrometry (Static-TOF-SIMS) analysis of the surface inorganic composition of fine (PM2.5) and course (PM2.5-10) aerosol particles, which were collected on an insulating polycarbonate filter (nuclepore) using a versatile air pollutants sampler (URG-3000K). Results showed that there are obvious differences between the surface inorganic composition characteristics of fine aerosol particles and those of course aerosol particles. Atmospheric secondary hydrophilic inorganic compounds exist on the surface of fine aerosol particles. The presenceof such hydrophilic compounds on the surface of fine aerosol particles will have influence on the hydrophilicity/hydrophobicity of the surface of fine aerosolparticles, and thus may be an important factor determining the atmospheric chemical behavior of fine aerosol particles. Fluorides exist on the surface of coarse aerosol particles, which have potential harmfulness on the ecological environment and human health; as a result, more importance should be attached to the study on fluoride aerosol and the control of fluoride aerosol pollution. In addition, Static-TOF-SIMS technique has been proven to be a useful technique for the study on the surface chemical composition of atmospheric aerosols.