Atmospheric Particulate Organic Nitrates by Photoelectron Resonance Capture Ionization-Mass Spectrometry

该项目开发了一种使用光电共振电子捕获电离质谱仪(PERCI-MS)的分析系统，这是一种基于软电离的技术，可以最大限度地减少分析物离子的碎裂。该系统的设计将能够测量大气颗粒物中的硝化有机物，包括硝基多环芳烃(NPAHs)，有助于测量与周围颗粒物结合的有机物对健康和环境的影响。为了研究自由基引发的NPAH形成的粒子相机理，我们将测量一些硝化有机化合物的共振电子俘获曲线。与北卡罗来纳大学合作，将使用室外反应室分析二次气溶胶形成过程中形成的有机硝酸盐。PERCI-MS系统还将用于在选定的现场部署期间对环境中的NPAH进行测量。该项目的更广泛影响包括与对空气质量和人体健康至关重要的大气过程直接相关，开发这种软电离技术作为大气痕量化合物分析工具的价值，以及在一个重要的科学研究领域支持本科生和研究生的教育和专业发展。地球科学局大气科学大气化学方案司和数学和物理科学局化学分析和表面化学群司共同支持这一奖项。

This project develops an analytical system using photoelectric resonance electron capture ionization mass spectrometry (PERCI-MS), a technique based on soft-ionization which minimizes the fragmentation of the analyte ions. The system design will enable the measurement of nitrated organics including nitro-polycyclic aromatic hydrocarbons (NPAHs) in atmospheric particulates, useful in gauging the health effects and environmental impact of organics bound to ambient particulate matter. Resonance electron capture profiles will be measured for a number of nitrated organic compounds in order to study radical-initiated particle-phase mechanisms of NPAH formation. In collaboration with the University of North Carolina, an outdoor reaction chamber will be used to analyze organic nitrates formed during secondary aerosol formation. The PERCI-MS system will also be used to make measurements of ambient NPAHs during selected field deployments. The broader impacts of this project include direct relevance to atmospheric processes important to air quality and human health, the value of developing this soft-ionization technique as an analytical tool for atmospheric trace compounds, and support of education and professional development of undergraduate and graduate students in an important area of scientific research. The Division of Atmospheric Sciences Atmospheric Chemistry Program in the Geosciences Directorate and the Division of Chemistry Analytical and Surface Chemistry Cluster in the Mathematical and Physical Sciences Directorate support this award jointly.