大气有机气溶胶（OA）组成复杂，且在大气传输中由于各种物理化学过程影响，其理化性质不断发生变化，因此对于OA的全面准确表征是评价其环境与健康影响的关键问题。本项目将原用于在线观测的Aerodyne 黑碳气溶胶质谱仪（SP-AMS）用于滤膜样品的离线质谱分析，整合了SP-AMS化学分辨率高检测质荷比范围大，及膜样品采集简便、覆盖区域广和时间跨度大的优点，大大开拓了AMS分析应用领域。项目针对我国多种典型大气环境下实际颗粒物以及多种一次源直接排放颗粒物样品，创建水溶及非水溶性OA组分连续萃取-质谱分析方法，尤其是对当前研究极少涉及的非水溶性组分开展AMS质谱表征，并利用所得OA化学信息改进和完善离线AMS质谱源解析技术，研究成果深化对OA完整化学组成、污染机制以及变化规律的认识，有助于我国大气复合污染的成因解析及应对。本项目研发的质谱分析技术对于其他环境样品有机物的分析也有一定参考价值。

Chemical composition of atmospheric organic aerosol (OA) is highly complex, and dynamically changing due to various physical and chemical processes, therefore a thorough and accurate characterization of OA is key to assess its environmental and health effects. This project aims to apply the Aerodyne Soot-particle aerosol mass spectrometer (SP-AMS) that is originally designed for “online” measurement to “offline” analyze the filter aerosol samples. Such technique combines the advantage of high chemical resolution and wide detection mass-to-charge range of the SP-AMS, and the advantage of easy-to-do collection, wide spatial and temporal coverage of filter sampling, therefore greatly expands the AMS application. By using ambient aerosol samples collected under different atmospheric environments in China, samples directly emitted from various primary sources, we establish a continuous extraction - mass spectrometric analysis method for both water-soluble and water-insoluble OA, in particular, this project conducts mass spectrometric analyses on the currently overlooked OA component, which is the water-insoluble OA species; furthermore, by using the AMS OA mass spectra, we modify and improve the offline AMS source apportionment technique. Findings from this project can improve our understanding on the OA composition, formation mechanism and changing pattern, which are helpful to tackle the air pollution complex in China. The mass spectrometry technique developed in this project is also valuable for the organic analyses in other environmental samples.