CAS: Environmental Degradation Pathways for Some Emerging Contaminants

通过这一奖项，美国国家科学基金会化学分部的环境化学科学项目支持Barbara Finlayson-Pitts教授和她的团队研究新兴污染物(EC)的环境命运，EC是一种通常不受监测但可能在环境中广泛分布的化学物质。它们可能会对人类健康和生态系统产生不利影响。这类化合物包括一些药物、杀虫剂和弹药。一旦进入环境，这些化合物就会发生反应，使它们的毒性降低，或者在某些情况下，毒性更强。因此，了解它们一旦被释放后的命运对于了解其健康和环境风险以及指导危害较小的替代品的未来发展非常重要。芬雷森-皮茨小组的这项研究旨在了解某些类别的EC暴露在阳光下或大气中发现的氧化剂时发生的基本过程。这提供了关于它们在空气中反应的速度和形成的产品的性质的信息，可以用来指导毒理学研究。该项目为一名博士后和几名本科生提供了研究机会。PI还通过她领导的AirUCI研究所参与各种外联和培训活动。为了实现这些目标，人们采用多种实验方法相结合的方法来研究含有胺、硝基和某些情况下的烯基的化合物。对红外透射型晶体上的EC薄膜进行照射，实时跟踪EC的损耗和产物的形成。或者，在暴露于气相臭氧期间对薄膜进行监测。未反应的EC及其反应产物的混合物被提取到溶液中，并通过各种分离和质谱分析技术进行分析。应用动力学模型来确定气固反应中发生的反应和扩散的贡献。EC的模型化合物也暴露在气相中的臭氧中，臭氧是一种强氧化剂。这为控制氧化的因素提供了洞察力，并找到了气体和凝聚相中类似反应之间的差异。这些数据提供了对一些降解途径的基本了解，当这些化合物释放到环境中时，这些途径可能是重要的。该奖项反映了NSF的法定使命，并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。

With this award, the Environmental Chemical Sciences Program of the NSF Division of Chemistry supports research by Professor Barbara Finlayson-Pitts and her group to address the environmental fate of emerging contaminants (EC), which are chemicals that are not commonly monitored but may become widely distributed in the environment. They can have adverse effects on human health and ecological systems. This class of compounds includes some pharmaceuticals, pesticides and munitions. Once in the environment, these compounds can undergo reactions that either make them less, or in some cases, more toxic. Thus, understanding their fates once released is important for understanding the health and environmental risks as well as for guiding the future development of less harmful substitutes. The research in the Finlayson-Pitts group is directed at understanding the fundamental processes that occur when certain classes of EC are exposed to sunlight or oxidants found in the atmosphere. This provides information on how fast they will react in air and the nature of the products formed that can be used to guide toxicology studies. The project provides research opportunities for a postdoctoral student as well as several undergraduate students. The PI also engages in a variety of outreach and training activities through the AirUCI Institute which she leads. To accomplish these goals, a combination of experimental approaches is used to study compounds that contain amine, nitro and in some cases, alkene groups. Thin films of the EC on infrared transmitting crystals are irradiated, and the loss of the EC and formation of products are followed in real time. Alternatively, the thin films are monitored during exposure to gas phase ozone. The mixtures of unreacted EC and its reaction products are extracted into solution and analyzed by a variety of separation and mass spectrometry techniques. Kinetics modeling is applied to determine the contributions of reaction and diffusion that occur in the gas-solid reactions. Model compounds for the EC are also exposed to ozone, a strong oxidant, in the gas phase. This provide insights into the factors that control the oxidation and to find differences between similar reactions in the gas versus the condensed phase. These data provide a fundamental understanding of some of the degradation pathways that are likely to be important when these compounds are released into the environment.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.