Atmospheric Fates of Neonicotinoid Insecticides

该奖项由化学部的环境化学科学（ECS）计划资助。 加州大学欧文分校（UCI）的Barbara Finlayson-Pitts教授和她的团队研究了类烟碱杀虫剂的环境命运。最近，在授粉中发挥重要作用的蜜蜂在世界范围内显著减少。新烟碱类杀虫剂与这种下降有关，沿着其他因素，如寄生虫和病原体，栖息地的丧失和传粉者的多样性。新烟碱类农药对哺乳动物的毒性较低。 然而，在大气中，它们可能会发生转化，形成比母体化合物更具毒性的新产物。 该项目的目标是阐明类尼古丁的大气反应，它们在环境中转化为其他分子的速率，以及所得分子的性质。 这项研究的结果将有助于从分子水平上了解类烟碱农药在环境中的大气寿命和归宿。 收集的数据使科学家能够建立这些化合物的风险评估。培训目前的技术研究表面上的非均相化学提供给一组不同的学生和博士后研究员。 本研究的目的是提供一个分子水平上的理解的光化学表面结合类烟碱杀虫剂（NN）和它们的反应与痕量大气气态氧化剂。自大约25年前首次引入以来，NN的使用越来越多，主要是作为种子包衣和土壤处理。 它们进入大气层后的反应尚不清楚。 该项目研究了七种常用的类烟碱的光化学和大气反应，这些类烟碱是硝基胍（吡虫啉、噻虫嗪、噻虫胺和呋虫胺）、氰脒（噻虫啉和啶虫脒）或硝基亚甲基（烯啶虫胺）。 测量了在与大气相关的波长处吸收光的化合物的光解的量子产率。此外，气相和固态产物都是使用各种技术测定的。这些技术包括衰减全反射和透射傅里叶变换红外光谱法和几种质谱技术。的身份和产品的产量和臭氧，羟基自由基和硝酸根的氧化动力学进行了测量。Finlayson-Pitts教授是AirUCI的联合主任，AirUCI是UCI的一个教师合作小组，赞助了一些教育计划，包括学生研究务虚会，有效沟通培训和职业选择的讨论。 合作和接待国际游客为团体成员提供了广泛的经验和交流机会。

This award is funded by the Environmental Chemical Sciences (ECS) Program in the Division of Chemistry. Professor Barbara Finlayson-Pitts and her group at the University of California-Irvine (UCI) study the environmental fate of neonicotinoid pesticides. There has been a significant, recent, worldwide decline in bees, which play a major role in pollination. Neonicotinoid pesticides have been implicated in this decline, along with other factors such as parasites and pathogens, loss of habitat and diversity of pollinators. Neonicotinoid pesticides have low toxicity to mammals. However, in the atmosphere they may undergo transformations to form new products that are more toxic than the parent compounds. The goals of this project are to elucidate the atmospheric reactions of neonicotinoids, the rate at which they are changed into other molecules in the environment, and the nature of the resultant molecules. The results of this research will contribute to a molecular level understanding of the atmospheric lifetimes and fates of neonicotinoid pesticides in the environment. The data collected enable scientists to establish the risk assessments for these compounds. Training in current techniques for studying heterogenous chemistry on surfaces is provided to a diverse group of students and postdoctoral fellows. The goal of this research is to provide a molecular level understanding of the photochemistry of surface-bound neonicotinoid insecticides (NNs) and their reactions with trace atmospheric gaseous oxidants. NNs have found increasing use since their first introduction about 25 years ago, largely as seed coatings and soil treatments. Their reactions once in the atmosphere are not well known. This project studies the photochemistry and atmospheric reactions of seven commonly used neonicotinoids which are nitroguanidines (imidacloprid, thiamethoxam, clothianidin and dinotefuran), cyanamidines (thiacloprid and acetamiprid) or nitromethylenes (nitenpyram). The quantum yields for photolysis of the compounds that absorb light at wavelengths relevant to the atmosphere are measured. Also, both the gas phase and solid state products are determined using a variety of techniques. These techniques include attenuated total reflectance and transmission Fourier transform infrared spectrometry and several mass spectrometry techniques. The identity and yields of the products and the kinetics of oxidation by ozone, the hydroxyl radical and the nitrate radical are measured. This is used for a quantitative assessment of the atmospheric lifetimes and fates of neonicotinoids in air.Professor Finlayson-Pitts' is the Co-Director of AirUCI, a collaborative group of faculty at UCI that sponsors a number of educational initiatives, including student research retreats, training in effective communication and discussions of career options. Collaborations and hosting international visitors provides breadth of experience and networking opportunities to group members.