化学电离技术在大气气溶胶质谱分析中的应用与展望

化学电离技术在大气气溶胶质谱分析中的应用已较为广泛.本文对化学电离质谱的结构与工作原理进行了简介,重点归纳总结了近年来化学电离质谱技术对大气自由基和痕量气体的测量、在有机气溶胶的外场观测和实验室研究中的应用与进展情况,探讨了目前研究中尚待解决的难点问题,并对化学电离质谱未来的研究工作及发展趋势进行了展望.

Review on chemical ionization technique application in mass spectrometric analysis of atmospheric aerosols

Background, aim, and scope Atmospheric aerosols have great impacts on regional air quality, global climate, and human health. Characterization of aerosols is essential to accurately evaluate their impacts. Prior studies on atmospheric aerosols with the application of chemical ionization mass spectrometry (CIMS) are reviewed herein. Materials and methods This study introduces the fundamental principles of CIMS and their advantages. The recent developments in the characterization of atmospheric free radicals, trace gases, and organic aerosols are overviewed. Results Compared to other methods, chemical ionization is a soft ionization technique with the advantages of high selectivity and sensitivity, low detection limit, and less molecular fragmentation. It also can be applied under atmospheric pressure and is easy to qualitatively and quantitatively characterize the analyte molecules. Discussion High selectivity measurement of CIMS can be achieved by using different reagent ions to induce the ionization of analytes. It can be used for accurately analyzing trace gases and free radicals in the atmosphere, and also for determining volatile organic compounds, secondary organic aerosol, and aerosols with unknown complex components. Conclusions CIMS can obtain more compositional and molecular information compared to traditional techniques. It provides advanced knowledge on the chemical properties of atmospheric aerosols, in particular for secondary organic aerosols and their precursors. Recommendations and perspectives Challenges such as the ion generator source and the measurement accuracy of CIMS should be further improved and optimized. Characterizing the chemical properties of secondary organic aerosols associated to their formation and evolution processes would be an important topic for future studies using CIMS.