Multiphase Chemistry of Organic Nitrates from Monoterpene Oxidation and Their Role in Aerosol Growth

在这个由化学部环境化学科学项目资助的项目中，普渡大学的乔纳森·h·斯莱德博士正在研究影响有机硝酸盐生命周期的过程，这些有机硝酸盐是由树木排放的有机化合物在大气中产生的。有机硝酸盐是氮氧化物的重要储存库和储库，氮氧化物是对流层臭氧的前体。有机硝酸盐还影响颗粒物质的形成和命运，从而影响人类健康、云的形成和地球表面温度。为了更好地理解有机硝酸盐在空气质量和气候中的作用，人们正在对含有活性功能并在颗粒阶段保持活性的有机硝酸盐的吸收、多相处理和命运进行新的测量。这项工作包括实验室和实地工作，大大扩展了有机硝酸盐对大气颗粒物、空气质量和气候演变影响的日益增长的知识基础。本项目重点研究森林环境中烯烃有机硝酸盐的多相化学及其对有机气溶胶形成和命运的影响。采用化学电离质谱（CIMS）结合反应室和气溶胶流动反应器，研究了合成的多烯烃单萜氧化过程中有机硝酸盐的产率，以及合成的多功能单萜有机硝酸盐的气溶胶吸收动力学与相对湿度和颗粒酸度的关系。此外，还评估了这些有机硝酸盐的水解速率和随后的水相化学转化，包括齐聚化和磺化。在两次夏季实地研究期间，正在调查森林环境中气相和气溶胶相的硝酸萜烯的生产和化学性质。这项研究广泛地促进了对影响空气质量和气候的因素的基本理解，包括：空气污染物和气候因子、臭氧和颗粒物。这项工作广泛地影响着本科生和研究生研究人员的教育。这项研究被用于制定一项年度推广计划，旨在为当地高中学生提供进行与大气科学、天气和空气质量有关的研究的经验。

In this project funded by the Environmental Chemical Sciences program of the Chemistry Division, Dr. Jonathan H. Slade of Purdue University is investigating the processes that affect the lifecycle of organic nitrates that are produced in the atmosphere from organic compounds that are emitted by trees. Organic nitrates serve as an important reservoir and sink for nitrogen oxides, the precursor to tropospheric ozone. Organic nitrates also impact the formation and fate of particulate matter, which affects human health, cloud formation and Earth's surface temperature. To better understand the role organic nitrates play in air quality and climate, new measurements are being made regarding the uptake, multiphase processing, and fate of organic nitrates that contain reactive functionalities and remain reactive in the particle phase. This effort consists of both laboratory and field work which significantly extends a growing knowledge base of the impact organic nitrates have on the evolution of atmospheric particulate matter, air quality, and climate.This project focuses on the multiphase chemistry of olefinic organic nitrates and their impact on the formation and fate of organic aerosol in forested environments. The organic nitrate yields from the oxidation of multi-olefinic monoterpenes, and the aerosol uptake kinetics of synthetic multifunctional monoterpene organic nitrates are examined as a function of relative humidity and particle acidity using chemical ionization mass spectrometry (CIMS) coupled with a reaction chamber and aerosol flow reactor. In addition, the hydrolysis rates and subsequent aqueous-phase chemical transformations including oligomerization and sulfonation of these organic nitrates are being evaluated. The production and chemistry of gas- and aerosol-phase terpene nitrates in a forested environment are being investigated during two summer field studies. The research contributes broadly to a fundamental understanding of the factors affecting air quality and climate, with respect to: air pollutants and climate forcers, ozone and particulate matter. This work broadly impacts the education of undergraduate and graduate researchers. The research is used to develop an annual outreach program aimed at providing local area high school students the experience of conducting research related to atmospheric science, weather, and air quality.