Reactive Oxygen Species in Biomass Burning Particles: Dependence on Chemical Composition and Photochemical Aging

化学系的环境化学科学项目支持Manabu Shiraiwa教授和Sergey Nizkorodv教授研究生物质燃烧气溶胶。生物质燃烧是全球气候变化时代大气颗粒物的重要来源，因为野火的频率和强度一直在增加。生物质燃烧有机气溶胶(BBOA)颗粒含有多种氧化还原活性化合物，可引发活性氧物种(ROS)的形成，ROS在大气中有机物的化学转化中起核心作用。为了更好地评估BBOA对空气质量和气候的影响，需要从分子水平和机理上了解BBOA颗粒的ROS多相化学和光化学。研究生和本科生将参与这项研究。少数民族初中生将举办生物质燃烧气溶胶研讨会和动手实验，以激发他们对环境化学科学的兴趣。该项目旨在阐明BBOA颗粒中氧化还原活性成分形成ROS的化学机理和动力学。电子顺磁共振波谱将用于定量BBOA替代物混合物和生物质样品热解和阴燃燃烧产生的BBOA中ROS的形成。BBOA颗粒的化学成分将使用与高分辨率质谱仪耦合的超高性能液相色谱仪进行表征。将评估光化学老化对ROS形成的影响，以促进对BBOA老化过程的机械理解。该奖项反映了NSF的法定使命，并已通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The Environmental Chemical Sciences Program in the Division of Chemistry supports Professors Manabu Shiraiwa and Sergey Nizkorodov for studies of biomass burning aerosols. Biomass burning is an important source of atmospheric particulate matter in the era of global climate change, as the frequency and intensity of wildfires have been increasing. Biomass burning organic aerosol (BBOA) particles contain various redox-active compounds, which can trigger the formation of reactive oxygen species (ROS) that play a central role in chemical transformation of organic compounds in the atmosphere. For better assessment of BBOA influence on air quality and climate, a molecular-level and mechanistic understanding of ROS multiphase chemistry and photochemistry by BBOA particles is needed. Graduate and undergraduate students will be involved in this research. Minority junior high school students will be hosted with a seminar on biomass burning aerosols and hands-on experiments to stimulate their interests on environmental chemical sciences.The project aims at elucidating chemical mechanism and kinetics of ROS formation from redox-active components in BBOA particles. Electron paramagnetic resonance spectroscopy will be applied to quantify the formation of ROS in BBOA surrogate mixtures and BBOA generated by pyrolysis and smoldering combustion of biomass samples. Chemical composition of BBOA particles will be characterized using an ultra-high-performance liquid chromatograph coupled to a high-resolution mass spectrometer. Impacts of photochemical aging on formation of ROS will be assessed to advance mechanistic understanding of BBOA aging processes.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.