EAGER: Advancing the Analysis of Secondary Organic Aerosols Through Innovations in Soft Ionization Aerosol Mass Spectrometry

该项目涉及开发一个更全面的了解的形成，生长和老化的生物和人为的二次有机气溶胶（BSOA和ASOA，分别）。大气气溶胶通过影响全球和区域辐射能量平衡、能见度、水文循环、温室气体和活性气体的调节以及人类健康，在大气中发挥着核心作用。SOA是亚微米大气气溶胶的主要贡献者，因此，提高对其在大气中的生命周期的理解是非常重要的。迄今为止，大多数基于腔室的SOA研究主要侧重于了解单萜对BSOA形成和生长的影响，而专注于ASOA的研究通常只采用苯衍生物，重点是甲苯，三甲苯和二甲苯。有必要了解的作用，不常研究的挥发性和半挥发性有机化合物（VOC和SVOC，分别）在SOA的形成和大气处理。这个探索性项目的目标是扩大这些边界，包括化合物的基本特征（如胺），虽然潜在的重要SOA的形成和转化，已收到很少的关注，到目前为止，在很大程度上是由于缺乏合适的分析方法。该方法将是开发和利用增强的气溶胶质谱系统（即，近红外激光解吸/电离AMS，NIR-LDI-AMS）能够同时测量SOA的酸性和碱性有机组分，同时消除与更剧烈电离AMS方法相关的离子的广泛碎裂和重排。新的双模式仪器将使用对称反射飞行时间质谱仪来测量来自同一气溶胶样品的正离子和负离子。重点将放在有机氮化合物（ON，如胺和尿素）对SOA的形成，生长和老化的影响。这些研究将包括直接从ON VOCs中解决SOA的形成和增长;以及ON对SOA的反应性吸收以及初级有机气溶胶（POA）的影响。本科生和研究生将在实验室实施和执行实验以及通过演示和准备手稿传播结果方面发挥关键作用。学生将接受多个领域的培训，包括质谱，气体/气溶胶生成和控制以及大气化学。该项目还将加强首席研究员小组与哈佛大学和阿默斯特学院各小组之间已开始的合作。从研究中获得的结果将在国家和国际会议上传播，以及在不太正式的会议上传播，如关于气溶胶和大气化学的新英格兰夏季会议日，来自东北部机构的学生和博士后学者在会上展示结果并交流想法。

This project involves developing a more comprehensive understanding of the formation, growth, and aging of biogenic and anthropogenic secondary organic aerosols (BSOA and ASOA, respectively). Atmospheric aerosols play a central role in the atmosphere by influencing global and regional radiative energy balance, visibility, the hydrological cycle, regulation of greenhouse and reactive gases, and human health. SOA is the predominant contributor to submicron atmospheric aerosols, therefore developing an improved understanding of its life cycle in the atmosphere is of great importance. Most chamber-based SOA studies to date have placed emphasis largely on understanding the impact of monoterpenes on the formation and growth of BSOA whilst studies that focus on ASOA typically only employ benzene derivatives with emphasis on toluene, trimethylbenzene, and xylene. There is a need to understand the role of less commonly studied volatile and semivolatile organic compounds (VOC and SVOC, respectively) in SOA formation and atmospheric processing. The goal of this exploratory project is to expand these boundaries to include compounds of basic character (such as amines) which, although potentially important in SOA formation and transformation, have received little attention to date, in large part due to the paucity of suitable analytical methods. The approach will be to develop and utilize an enhanced aerosol mass spectrometry system (i.e., near-infrared laser desorption/ionization AMS, NIR-LDI-AMS) capable of simultaneous measurement of the acidic and basic organic components of SOA, while abnegating extensive fragmentation and rearrangement of ions associated with more vigorous ionization AMS methods. The new, dual-mode instrument will use symmetric reflectron time-of-flight mass spectrometers to measure positive and negative ions from the same aerosol sample. Focus will be placed on the influence of organic nitrogen compounds (ON, such as amines and urea) on the formation, growth and aging of SOA. The studies will include addressing the formation and growth of SOA directly from ON VOCs; and the effects of reactive uptake of ON on SOA, as well as primary organic aerosols (POA). Undergraduate and graduate students will play key roles in implementing and executing experiments in the laboratory as well as disseminating results through presentations and preparation of manuscripts. Students will be trained in several areas, including mass spectrometry, gas/aerosol generation and control, and atmospheric chemistry. The project will also enhance collaborations that have been initiated between the Principal Investigator's group and groups at Harvard University and Amherst College. Results garnered from the studies will be disseminated at national and international conferences, as well as at less formal meetings such as the New England Summer Conference Day on aerosols and atmospheric chemistry, where students and post-doctoral scholars from institutions in the Northeast present results and exchange ideas.