Collaborative Research: Characterizing Isotopic Composition as a Tracer of Atmospheric Peroxyacetyl Nitrate (PAN) Sources and Chemistry

在化学系环境化学科学项目的支持下，纽约州立大学环境科学与林业学院（SUNY ESF）的Jiajue Chai，布朗大学的Meredith Hastings和科罗拉多州立大学的Emily Fischer以及学生，博士后和研究科学家将研究过氧乙酰硝酸盐（PAN），一种重要的二次空气污染物。氮氧化物（NOx）是决定臭氧和二次气溶胶等二次污染物形成的主要大气污染物，可对人类健康、生态系统和气候产生不利影响。在污染的空气中，PAN形成为NOx的最重要的临时储存库。PAN可以在冷空气团中短距离和长距离运输，并且当温度变暖时，它分解为例如改革NO2和酰基过氧自由基，从而影响全球范围内的NOx预算。该项目旨在开发一种新的方法来识别来自各种来源和化学途径的过氧乙酰硝酸盐（PAN），并提高对大气中PAN预算及其对空气质量和气候影响的理解。该项目还将支持研究生和本科生研究人员，并帮助建立他们在分析和环境化学领域工作所需的核心技能。该项目的成果将被纳入三所大学的多个环境科学课程，以及当地社区的K-8教育。将使用升级的PAN生成系统和气相色谱技术，并采用新的方法在实验室浓缩PAN，以测量PAN的同位素组成，特别关注氧和氮同位素。大气中活性氮物种的同位素分析已被证明为源解析和化学途径提供了新的见解。此外，PAN对PI开发的用于同位素分析的现有NOx和NO2收集技术的干扰也将进行研究，以更好地量化大气中的这些示踪剂。该项目有可能为更好地量化大气中的活性氮收支以及为未来在环境中的应用建立改进的现场准备技术做出重大贡献。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

With support from the Environmental Chemical Sciences Program in the Division of Chemistry, Jiajue Chai at the State University of New York - College of Environmental Science and Forestry (SUNY ESF), Meredith Hastings at Brown University, and Emily Fischer at Colorado State University along with students, postdocs and research scientists will investigate peroxyacetyl nitrate (PAN), an important secondary air pollutant. Nitrogen oxides (NOx) are key atmospheric pollutants that determine formation of secondary pollutants such as ozone and secondary aerosols, which can have an adverse impact on human health, ecosystems and climate. In polluted air, PANs form as the most important temporary reservoirs for NOx. PAN can be transported short and long distances in cold air masses, and when the temperature warms, it decomposes to reform NO2 and an acylperoxy radical, for example, thus influencing NOx budgets on a global scale. This project aims to develop a new method to fingerprint peroxyacetyl nitrate (PAN) from various sources and chemistry pathways and to improve the understanding of PAN budget in the atmosphere and its influence on air quality and climate. This project will also support graduate and undergraduate student researchers and help to build their core skills necessary for work in the fields of analytical and environmental chemistry. Results from this project will be incorporated into several environmental science courses across the three universities, as well as K-8 education in local communities.An upgraded PAN generation system and gas chromatography technique will be used with a new method for concentrating PAN in the laboratory for the purpose of measuring the isotopic composition of PAN with a particular focus on oxygen and nitrogen isotopes. The isotopic analysis of reactive nitrogen species in the atmosphere has proven to give new insights into source apportionment and chemical pathways. Additionally, interference of PAN with current NOx and NO2 collection techniques for isotopic analysis developed by the PIs will also be investigated to better quantify these tracers in the atmosphere. This project has the potential to make a significant contribution toward better quantification of the reactive nitrogen budget in the atmosphere and toward the establishment of improved field-ready techniques for future application in the environment.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.