Collaborative Research: Reactivity Associated with Ambient Particles: Hydrogen Peroxide, Quinones, Transition Metals and Hydroxyl Radical

这项研究将采取一种全面的方法，通过监测和模拟过氧化氢和羟基自由基的生成以及过渡金属、溶解铁和有机化合物的氧化状态，以及环境气溶胶样品和实验室生成的测试气溶胶中的潜在有机电子给体，来了解颗粒物自由基的形成及其相关的活性氧物种(ROS)。在加利福尼亚州圣华金河谷和洛杉矶盆地的现场测量将提供样本，用于持续测量过氧化氢和羟基自由基的产生及其与感兴趣变量的关系，现场收集的样本将使不同类型的颗粒得以检查。一系列环境室内实验将从生物和人为碳氢化合物用纯臭氧和高、低氮氧化物光化学氧化产生二次有机气溶胶，有或没有由金属盐或柴油烟尘组成的种子气溶胶，以及可能的其他材料，如地壳粉尘。此外，还将探索混合化学以探索金属、苯二酚和其他有机物之间的相互作用，并将在简化的系统中研究光对ROS化学的影响。将开发和改进一个化学动力学模型，以指导准确评估ROS化学的努力。该项目将加强本科生、研究生和博士后学者的教学和培训，并将在加州大学洛杉矶分校和加州州立大学弗雷斯诺分校之间建立新的伙伴关系。这一伙伴关系将使参与的学生受益，并将带来协同效益，这将转化为更好的课堂材料和外联活动。该项目将加强代表不足的群体对科学的参与，其结果可能有助于解决与人类健康和气候有关的关键科学问题。

This study will take a comprehensive approach to understanding particulate radical formation and its related reactive oxygen species (ROS), by monitoring and modeling hydrogen peroxide and hydroxyl radical generation as well as transition metals, the oxidation state of dissolved iron and organics, including quinones, organic hydroperoxides and potential organic electron donors, in ambient aerosol samples and laboratory generated test aerosols. Field measurements at sites in the San Joaquin Valley and the Los Angeles Basin, California will provide samples for ongoing measurements of hydrogen peroxide and hydroxyl radical production and their relationships to variables of interest, and samples collected at the field sites will enable different particle types to be examined. A series of environmental chamber experiments will generate secondary organic aerosol (SOA) from oxidation of biogenic and anthropogenic hydrocarbons with pure ozone and high and low nitrogen oxide photochemistry, with and without seed aerosols composed of metal salts or diesel soot, and possibly other materials such as crustal dusts. Bulk mixture chemistry will also be explored to probe the interplay between metals, quinones and other organics, and effects of light on ROS chemistry will be examined in simplified systems. A chemical kinetics model will be developed and refined to guide the efforts to accurately assess ROS chemistry.The project will enhance teaching and training of undergraduate and graduate students and postdoctoral scholars, and will establish a new partnership between the University of California, Los Angeles, and California State University, Fresno. The partnership will benefit the students involved, and will lead to synergistic benefits that will translate into enhanced classroom materials and outreach activities. The project will enhance participation in science by underrepresented groups, and the results will potentially contribute to key scientific questions related to human health and climate.