大气颗粒物中水溶性有机物的研究进展

WSOC（水溶性有机物）广泛存在于云、雨水和大气颗粒物中，其可作为CCN（cloud condensation nuclei，云凝结核）影响大气热动力平衡、气候变化甚至危害人体健康.分析归纳了近年来国内外有关WSOC的研究，阐述了WSOC的来源、化学组成、理化性质、污染特征等，并总结了WSOC的单分子鉴定方法.结果表明:传统的分析检测方法，如GC-MS（gas chromatography-mass spectrometry，气相色谱质谱联用）、HPLC（high performance liquid chromatography，高效液相色谱）等，可以分析出部分低分子羧酸类和醇类，但不能检测出高分子、极性高的组分.新兴的分析检测方法，如HNMR（hydrogen nuclear magnetic resonance，氢核磁共振），可以检测出WSOC中的官能团；IC（ion chromatography，离子色谱）可以较好、方便地检测出低碳有机酸类；HR-ToF-AMS（high resolution-time of flight-aerosol mass spectrometry，高分辨时间飞行气溶胶质谱）的分辨率较高，但由于其质谱谱图复杂，因此较难完整解析WSOC的结构信息；而FT-ICR-MS（Fourier transform ion cyclotron resonance，傅里叶变换离子回旋共振质谱法）可以与软电离结合，在尽可能获得更多分子离子峰的基础上，较多地解析出组分和结构信息；EEMs（excitation-emission-matrix spectra，三维荧光光谱）根据荧光分布和强度，可检测不同种类和来源的WSOC.据此，建议今后从以下几方面开展研究:①结合多种检测技术全面解析WSOC的组成和结构信息.②WSOC大气化学过程及形成机制的研究有待进一步深入.③WSOC的环境与健康效应.④不同种类、复杂的水溶性有机混合物的吸湿增长机制. 

The Advances of Water-Soluble Organic Compounds in Atmospheric Particles

Water-soluble organic compounds (WSOC) widely exist in clouds, rain droplets and atmospheric particulate matter. WSOC has attracted wide attention because WSOC can affect the atmospheric thermodynamic equilibrium and participate in the formation of cloud condensation nuclei (CNN), which will lead to the climate change and certain harm to human health. This paper summarizes the current work of WSOC, mainly focusing on the method of WSOC characterization, also introducing the chemical composition, physical and chemical properties and concentration variation of WSOC. Traditional analytical methods include GCMS and HPLC. These methods can analyze low molecular compounds including carboxylic acids and alcohols, but cannot effectively detect high molecular and polar components. In recent years, some emerging methods have been used for the characterization of WSOC:HNMR can identify the functional groups of WSOC. It is much more convenient and effective to use IC to analyze the low-carbon organic acids of WSOC. HR-ToF-AMS and FT-ICR-MS have high resolution ratio, but it is difficult to analyze the complete structure information of WSOC due to the complicated mass spectra. EEMs can be used to detect WSOC of different types and sources according to the fluorescence intensity and distribution. This paper compared the advantages and disadvantages of the above methods, summarizes the research progress, also proposes the study trend of WSOC:(1) Combine various characterization methods to acquire more complete information of WSOC''s chemical composition and molecular structures. (2) The mechanism of atmospheric chemical reactions and the processes of WSOC''s formation need to be further studied. (3) The study of environmental and health effects of WSOC should be refined in terms of the specific reactions of the formation of the harmful compounds. (4) Further study of the mechanism of hygroscopic growth of different complex water soluble organic mixtures is needed.