有机胺在大气中普遍存在，是二次有机气溶胶的重要前体物；在浓度极低的情况下，对新粒子形成的影响也可能超过氨；即使湿度比较低的情况下，也可发生吸湿增长。有机胺对大气复合污染生成的影响亟待开展深入研究。由于有机胺种类多，分析难度大，目前对有机胺形成及演化机制等方面的认识还很欠缺，国内的研究更是刚刚起步。本项目拟以有机胺为重点研究对象，利用在线和离线方法，通过烟雾箱模拟和现场观测，深入研究珠三角大气气相和颗粒相有机胺的分布特征，探讨气象条件、大气氧化性、颗粒酸度和混合状态等对颗粒相有机胺的组成和挥发性的影响机制；通过地用逆流虚拟撞击器与单颗粒质谱仪联用技术，分析极高湿度条件下，活性雾滴和雾间隙颗粒中有机胺的组成和颗粒类型特征，研究在高湿度下影响有机胺形成的主要因素。在此基础上，揭示高温、高湿和高氧化条件下，影响有机胺形成和演化的一些关键化学过程。研究结果将为进一步深入研究大气复合污染的生成机制奠定基础，并为珠三角未来大气PM2.5的精准控制提供科学依据。

Among the atmospherically-relevant organic compounds, amines are important nitrogen-containing organic compounds. Amines are ubiquitous in the atmosphere. They can react with atmospheric oxidants contributing to secondary organic aerosol (SOA) formation. Amines, which show much lower concentration than ammonia, contribute more to the new particle formation than ammonia. Meanwhile, amines may also occur hygroscopic growth at medium relative humidity. Thus, amines could significantly affect the formation of complex air pollution. Yet little is known about their formation mechanism, aging processes during the atmospheric transport because of their complex composition and analytical difficulty. In this project, the gaseous- and particulate-phase characterization, atmospheric oxidation reactions and volatility of amines in the Pearl River Delta region will be studied using on-line and off-line instruments by chamber experiment and field observation. The influence of meteorological conditions, atmospheric oxidation capacity, particle acidity and mixing state on the formation of particulate-phase amines and their volatility will be discussed. Then we will apply single particle aerosol mass spectrometer coupled with a ground counterflow virtual impactor (CVI) to directly measure the chemistry of individual amine-containing fog residues (obtained after evaporation of the water), and to explore the possibility and mechanism of amines during fog formation. These results will provide scientific base for the formation of complex air pollution, formulation of regional PM2.5 pollution control strategy.