大气中卤代烃的在线观测方法研究

High sensitive analytical method is needful in the observation field of volatile halogenated organic compounds (VHOCs), as the component of VHOCs is mplicated and the concentration of it is very low. Time resolutions of traditional analytical methods, GC-ECD and GC-MS, are low, which result in the nature of active VHOCs species is easy to change. Fragmentationless ionization of organic compounds, high sensitivity and high time resolutions are the merits of vacuum ultraviolet photoionization mass spectrometry (PI-MS), avoiding the abovementioned disadvantages. The PI-MS has the potential to apply to the VHOCs detection. This project is going to investigate the quantitative analysis to atmospheric VHOCs, using a PI-MS which was constructed by the applicant in the period of studing for a doctorate. By reconstructing the photoionization source of the instrument, the fingerprints of typical atmospheric VHOCs would be acquired. By means of improving the sampling system, optimizing process parameters, as well as intercomparing instruments, the online analytical and calibration methods for VHOCs in the background atmosphere in China would be set up. Practical observation is conducted in the Shangdianzi station, one of the atmospheric background stations run by China Meteorological Administration, with the purpose of validating the feasibility of the PI-MS. And try to interpret the observations , analysis of influencing factors and compare the data obtained by abroad stations. The observation results will be interpreted and the impact factors trying to analysis. For one thing, a technique for real-time monitoring VHOCs will be established by these research results. For another, the data would be helpful to the studies on the species, concentrations and variations of VHOCs.

大气中的挥发性卤代烃（VHOCs）成分复杂、浓度极低，对分析方法的检测灵敏度要求极高。普遍使用的GC-ECD和GC-MS法分析时间较长，且样品在分析过程中易变性。真空紫外光电离质谱（PI-MS）技术具有母离子峰产率高、灵敏度高、时间分辨率高的优点，可克服以上两种方法的缺点，具有在VHOCs探测领域应用的潜力。本项目拟使用申请人攻读博士期间研制的一台高灵敏PI-MS仪对VHOCs进行定量分析研究。通过改造仪器的电离源，获得典型VHOCs的特征谱图；通过改进仪器进样系统、优化系统参数、进行仪器比对，建立适用于本底VHOCs浓度的在线分析、标校方法；在上甸子国家级大气成分本底站进行实际观测，验证方法的可行性，并对观测结果进行解读，尝试进行影响因素的分析以及与国外本底站同期观测结果的对比研究。这些研究结果在为实时监测VHOCs提供必要技术的同时，会为VHOCs的种类、浓度、变化情况等方面的深入研究提供帮助。

本课题按申请书所列计划进行了开展，完成了申请书中所列的三个目标。首先是获取了6种目标卤代烃真空紫外光“软电离”的特征谱图；其次基于此，搭建了满足本底大气中卤代烃浓度观测要求的在线分析系统，分析结果与平行的气相色谱观测系统的数据进行了比对，结果良好；对所获取的上甸子站PCE、TCE观测数据进行了初步分析，探讨了其源的影响范围。在获取的成果方面，包括：授权实用新型专利2项、进入实审阶段发明专利1项；发表SCI论文2篇，正撰写欲投稿的1篇，同时资助了1篇；做了两次学术报告，为三名研究生的培养做了贡献。