CAS: Environmental Degradation Pathways for Some Emerging Contaminants

有了这个奖项，NSF化学部的环境化学科学计划支持Barbara Finlayson-Pitts教授和她的团队的研究，以解决新兴污染物（EC）的环境命运，这些污染物是不常监测但可能广泛分布在环境中的化学物质。它们可能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大。 因此，了解其释放后的命运对于了解健康和环境风险以及指导未来开发危害较小的替代品非常重要。 Finlayson-Pitts小组的研究旨在了解某些类别的EC暴露于阳光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以及所形成的产物的性质的信息，可用于指导毒理学研究。该项目为一名博士后学生和几名本科生提供了研究机会。PI还通过她领导的AirUCI研究所参与各种推广和培训活动。为了实现这些目标，实验方法的组合用于研究含有胺，硝基和在某些情况下，烯烃基团的化合物。辐射在红外透射晶体上的EC薄膜，并且真实的时间跟踪EC的损失和产物的形成。或者，在暴露于气相臭氧期间监测薄膜。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技术进行分析。动力学建模应用于确定发生在气-固反应中的反应和扩散的贡献。 EC的模型化合物也暴露于气相中的臭氧，一种强氧化剂。这提供了对控制氧化的因素的深入了解，并找到了气体与冷凝相中类似反应之间的差异。这些数据提供了对这些化合物释放到环境中时可能很重要的一些降解途径的基本理解。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值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.