RUI: Determination of the Kinetic Expressions and Mechanisms of the Photochemical Degradation and Oxidation of Dicamba

化学系环境化学科学项目的这一奖项支持了古斯塔夫·阿道夫学院阿曼达·尼诺教授的工作。她正在研究除草剂麦草畏的化学反应。虽然麦草畏已经在市场上销售了三十多年，但现在它更经常地用于农业领域，因为新的转基因大豆植物可以耐受麦草畏。2017年的生长季节，这些大豆首次在美国使用-到夏末，有数千名农民在农田附近的土地上投诉。除草剂在空气中漂流，似乎对顺风田的作物造成了损害。在该项目中，对环境系统（例如，基于水或空气的系统）进行检查，以了解麦草畏如何通过与环境中其他化合物的反应以及通过与阳光的相互作用而发生变化。此外，该项目为本科生提供研究机会，为他们进入劳动力市场或研究生或专业学校做好准备。这些学生还将帮助为地区高中学生开发和建立一个“化学之夜”。 该团队还与法国的国际合作伙伴合作，从多个角度研究了氯化除草剂麦草畏的光化学和反应性以及添加剂对配制农产品的影响。这些包括表皮蜡和叶子表面上的非均相光化学，气相光化学，以及与主要气相氧化剂羟基自由基的非均相反应性。研究了麦草畏商业配方中表面活性剂和非活性成分对这些反应的影响。研究结果为深入了解麦草畏的光降解和氧化机理及光氧化产物提供了依据。该研究增强了目前对麦草畏环境化学的理解。这项工作也提供了新的方法来研究表面吸附的化学物质的光解和气相氧化剂的非均相反应。本科生参与这个跨学科项目的各个方面，并在广泛的领域获得经验。先前成功的化学推广与年轻学生是扩大后，与规划的区域，主要是农村，高中学生。这一奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

This award by the Environmental Chemical Sciences Program of the Chemistry Division supports work by Professor Amanda Nienow at Gustavus Adolphus College. She is examining chemical reactions of the herbicide dicamba. Although dicamba has been on the market for over thirty years, it is being used more often on agricultural fields now as new genetically-modified soybean plants can tolerate dicamba. The 2017 growing season saw the first use of these soybeans in the US - and by the end of the summer, there were thousands of complaints from farmers on land adjacent to fields. Herbicide drifting through the air appeared to be causing crop damage in down-wind fields. In this project, environmental systems (for example, water or air based systems) are examined to understand how dicamba changes through reactions with other compounds in the environment and through interactions with sunlight. In addition, this project provides research opportunities for undergraduate students, which prepares them to enter the workforce or graduate or professional schools. These students will also help develop and institute a "Chemistry Night" for regional high school students. The team also collaborates with international partners in France.The photochemistry and reactivity of the chlorinated herbicide dicamba and the impact of additives in formulated agricultural products is being examined from several angles. These include heterogeneous photochemistry on the surface of epicuticular waxes and leaves, gas-phase photochemistry, and heterogeneous reactivity with hydroxyl radical, the primary gas-phase oxidant. The influence of surfactants and inactive ingredients in the commercial formulation of dicamba on these reactions is examined. The results may provide insight into the photodegradation and oxidation mechanisms and (photo)products of dicamba. This research enhances the current understanding of the environmental chemistry of dicamba. This work also provides new methods to examine the photolysis of chemicals sorbed to surfaces and heterogeneous reactions with gas-phase oxidants. Undergraduates participate in all aspects of this interdisciplinary project and gain experience in a wide range of fields. Prior success with chemistry outreach with young students is expanded upon with programming for regional, mostly rural, high school students.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.