Investigation of PAH Photodegradation in Solutions

溶液中 PAH 光降解的研究

• 批准号: 7623546
• 负责人: KRISHNA L FOSTER
• 金额: $ 10.84万
• 依托单位: CALIFORNIA STATE UNIVERSITY LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7623546
• 关键词: Alcohols; Aldehydes; Aromatic Compounds; Aromatic Polycyclic Hydrocarbons; Asthma; Benzene; Benzo(a)pyrene; Biodegradation; Biological; Biomass; Bioremediations; Breathing; Carcinogens; Catalysis; Cations; Charge; Chemicals; Chronic; Chrysenes; Complex; Development; Electrons; Environment; Excision; Exposure to; Fossil Fuels; Glycols; Human; Human Activities; Investigation; Isomerism; Ketones; Kinetics; Life; Link; Mass Spectrum Analysis; Measures; Mediating; Methods; Modeling; Mutagens; Parents; Particulate Matter; Pathway interactions; Phase; Procedures; Process; Public Health; Pyrenes; Quinones; Relative (related person); Research; Role; Scientist; Site; Solutions; Structure; Surface; System; Techniques; Toxic effect; Water; Work; analytical tool; aqueous; autooxidation; charge transfer complex; cost effective; design; electron donor; flexibility; fluoranthene; minimally invasive; particle; photolysis; physical property; pollutant; quantum; remediation; respiratory; success; sunlight-induced; tool

DESCRIPTION (provided by applicant): Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic and mutanogenic pollutants ubiquitous in the natural world. Human activities, including the combustion of fossil fuels, contribute to the total abundance of these compounds in the environment. Semi-volatile PAHs adsorbed to fine particulate matter enter the body via inhalation. It is a matter of public health to understand the fate of PAHs after they are released into the environment. Sunlight-induced photooxidation is an important method of PAH removal from the environment. The proposed research is designed to measure photochemical rate constants and product quantum yields necessary to predict the rates of PAH decay in condensed phase systems including atmospheric particles, water, and other environmental surfaces. Unlike previous studies, the results of this study can be used to identify and quantify PAH photooxidation products in local environments. This is important information because PAH photooxidation products are not only more reactive than PAHs and another group of suspected carcinogens, but they are also more soluble in aqueous systems and consequently can be transported over longer distances. The hypothesis of the proposed work is that PAHs that degrade predominately via the radical-cation mediated mechanism will have degradation rates that are dependent on the electron-donor capacity of the media in which they reside, and there will be a diversity of under-characterized and previously unidentified photoproducts created in these processes. To explore this hypothesis, three specific objectives for the proposed research have been formulated: (1) Characterize photoproducts of PAH photodegradation using structurally sensitive HPLC/MS/MS techniques; (2) Measure formation rates and quantum yields of the observed photoproducts in solutions with varied polarity to elucidate the role of electron donors on the rates of PAH photodegradation in the environment; (3) Manipulate mechanism-specific intermediates during photolysis to elucidate the dominant mechanism for PAH photodegradation in matrices with a range of electron-scavenging potentials. The proposed work will use recently developed LC/MS/MS techniques to measure the product quantum yields of PAH photooxidation in solutions with exceptional sensitivity and selectivity relative to other analytical techniques. The success of this project will help to elucidate the role of the environment on the damaging effects of particle inhalation. The study will also provide kinetic parameters necessary to model the photodegradation of environmental PAHs, inspiring ideas for removal from contaminated sites.

描述（由申请人提供）：多环芳烃（PAHS）在自然世界中无处不在的致癌和杂种污染物。人类活动，包括化石燃料的燃烧，有助于这些化合物在环境中的总丰度。半挥发性PAHs吸附到细颗粒物中，通过吸入进入体内。公共卫生要了解PAH被释放到环境后的命运是一个问题。阳光引起的光氧化是从环境中去除PAH的重要方法。拟议的研究旨在测量光化速率常数和产品量子量产率，以预测凝结相系统中PAH衰变的速率，包括大气颗粒，水和其他环境表面。与以前的研究不同，本研究的结果可用于识别和量化当地环境中的PAH光氧化产物。这是重要的信息，因为PAH光氧化产物不仅比PAH和另一组可疑的致癌物更具反应性，而且它们也更易溶，因此可以在更长的距离内运输。 提出的工作的假设是，主要通过自由基天线介导的机制降解的PAH将具有降解速率，取决于它们所居住的培养基的电子支持能力，并且将在这些过程中产生的未经识别和先前未识别的光产物的多样性。为了探讨这一假设，已经提出了针对拟议研究的三个特定目标：（1）使用结构敏感的HPLC/MS/MS技术来表征PAH光降解的光产物； （2）测量具有不同极性的溶液中观察到的光产物的形成速率和量子产率，以阐明电子供体对环境中PAH光降解速率的作用； （3）在光解过程中操纵机理特异性中间体，以阐明具有一系列电子扫描电位的矩阵中PAH光降解的主要机制。 拟议的工作将使用最近开发的LC/MS/MS技术来测量具有与其他分析技术相对于其他分析技术具有出色敏感性和选择性的溶液中PAH光氧化的产物量子产率。该项目的成功将有助于阐明环境对粒子吸入的破坏作用的作用。该研究还将提供对环境PAH的光降解的必要动力学参数，从而鼓舞了从受污染的地点删除的想法。