Collaborative Research: Impact of Metals on Photochemical Aging of Water Soluble Organic Carbon in Atmospheric Particulate Matter: A Combined Lab and Field Study

本研究旨在加深对大气中细颗粒物中可溶铁与有机物相互作用的认识。这项研究涉及更大的问题，即大气铁如何影响大气颗粒物中有机物的加工和老化。这一结果将为大气化学家和环境卫生专业人员提供有用的信息。该项目将研究水溶性有机碳的铁辅助氧化途径的重要性。它包括三项任务：(1)现场采样，(2)颗粒物质的表征，(3)光化学实验室实验。将对现场样品进行分析，以评估大气中铁的来源，因为铁的来源可能决定其化学形态，从而决定其溶解度和对化学反应的有效性。现场样品的水萃取物将经过人工老化过程，并进行氧化态和总铁的化学形态分析，并对活性氧物种的产生进行量化。通过研究过渡金属的作用并考虑水化学，该项目将提供有机化合物在大气中如何“老化”的更完整的图景。这些结果将提供有关铁在处理大气颗粒物中有机化合物的过程中所起的作用以及这些混合颗粒物对人类健康的潜在影响的有用信息。

This study is focused on improving the understanding of the interactions between soluble iron (Fe) and organic material in fine particles in the atmosphere. This research is relevant to the larger question of how atmospheric iron affects the processing and aging of the organics in atmospheric particulate matter. The results will provide information useful to atmospheric chemists and to environmental health professionals.The project will examine the importance of the Fe-assisted oxidation route of water-soluble organic carbon. It consists of three tasks: (1) field sampling, (2) characterization of the particulate matter, and (3) photochemical laboratory experiments. The field samples will be analyzed to assess the sources of the atmospheric Fe, since the source of the Fe may determine its chemical speciation and, thus, its solubility and availability to chemical reactions. Aqueous extracts of the field samples will be subjected to an artificial aging process and undergo analysis for oxidation state and the chemical speciation of total iron, and the production of reactive oxygen species will be quantified. By investigating the role of transition metals and taking into account aqueous chemistry, this project will offer a more complete picture of how organic compounds are "aged" in the atmosphere. The results will provide useful information on the role iron plays in the processing of organic compounds in atmospheric particulate matter and the potential impacts of these mixed particles on human health.