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

该奖项由化学系环境化学科学计划颁发，以支持古斯塔夫斯·阿道夫斯学院的阿曼达·尼诺教授的工作。她正在检查除草剂麦草畏的化学反应。尽管麦草畏已经上市30多年了，但由于新的转基因大豆植株可以耐受麦草畏，它现在正被更频繁地用于农业领域。2017年的种植季节见证了这些大豆在美国的首次使用-到夏末，农民在田地旁的土地上收到了数千起投诉。漂浮在空气中的除草剂似乎正在造成顺风向田野的作物损害。在这个项目中，研究了环境系统(例如，基于水或空气的系统)，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，为他们进入劳动力大军或研究生或专业学校做好准备。这些学生还将帮助发展和建立一个区域高中生的“化学之夜”。该小组还与法国的国际合作伙伴合作。正在从几个角度审查氯化除草剂麦草畏的光化学和反应性，以及配方农产品中添加剂的影响。这些包括表皮层蜡层和叶表面的异相光化学，气相光化学，以及与主要气相氧化剂-羟基自由基反应的异质性。考察了商业制剂麦草畏中表面活性剂和非活性成分对这些反应的影响。这一结果可能为深入了解麦草畏的光降解和氧化机理以及(照片)产物提供依据。本研究加深了目前对麦草畏环境化学的认识。这项工作还为研究吸附在表面的化学物质的光解以及与气相氧化剂的非均相反应提供了新的方法。本科生参与这个跨学科项目的所有方面，并在广泛的领域获得经验。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。

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.