RUI: Photochemical Pathways and Photoproducts of Current and Emerging Sub-Arctic Aquatic Contaminants

该奖项由化学部门的环境化学科学项目和促进竞争研究的既定项目（EPSCoR）共同资助。Drs。阿拉斯加安克雷奇大学的Tomco和Redman将调查在阿拉斯加水道中发现的三种由阳光引起的污染物的环境分解率。这一过程的机制可能是寒冷的高纬度地区所特有的，在那里，每天的阳光照射会发生极端的季节性变化。影响这一过程的几个因素将被研究，包括天然有机物的作用，活性氧种类和温度依赖性。当每种污染物降解时形成的分解产物将被识别。这项研究有望为预测水质评估的发展提供信息，从而有助于确定这些系统中的衰减率。该项目将吸引本科生和研究生参与研究，提供学习先进的质谱仪器方法的机会，并目标包括阿拉斯加土著学生和妇女，以扩大对此类物理科学研究的参与。本研究将探讨亚北极地区新出现的污染物被降解的水生光化学途径，以及高纬度环境因素对持久性的影响程度。与温带条件相比，亚北极环境条件具有独特的污染物衰减时间线，以及直接和间接过程的独特相对贡献。本研究特别评估了三种优先化合物：12α-羟基鱼藤酮、6-PPD醌和氟酮。6-PPD醌是由N-（1,3-二甲基丁基）-N′-苯基-对苯二胺氧化而成的类醌类氧化产物，是一种广泛使用的轮胎添加剂和抗氧化剂。最近在阿拉斯加的水道中持续检测到这些物质，但没有关于天然水域中光化学途径和光转化产物的信息。这项研究将确定溶解有机物、羟基自由基、单线态氧和三重态激发态的个体贡献。每个过程的温度依赖关系将在4、12和20摄氏度进行比较，这跨越了地表水温度的典型范围。每个过程产生的光产物将使用高分辨率质谱结合非靶向分析方法进行分析。这些信息有望为这些光化学过程的环境驱动因素提供更好的基础理解。该奖项反映了美国国家科学基金会的法定使命，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。

This award is jointly funded by the Environmental Chemical Science Program in the Chemistry Division and the Established Program to Stimulate Competitive Research (EPSCoR). Drs. Tomco and Redman at the University of Alaska-Anchorage will investigate the environmental breakdown rates of three contaminants found in Alaskan waterways, as caused by sunlight. The mechanism of this process can be unique to cold, high-latitude regions, where extreme seasonal changes in daily sunlight exposure occur. Several factors that affect this process will be investigated, including the role of natural organic matter, reactive oxygen species, and temperature dependence. The breakdown products formed as each contaminant degrades will be identified. This study is expected inform the development of predictive water quality assessments that can be useful for identifying the attenuation rates in these systems. The project will engage undergraduate and graduate students in research, provide opportunities to learn advanced instrumental methods in mass spectrometry, and target inclusion of Alaska Native students and women to work toward broadening participation in such physical science studies.This study will investigate the aquatic photochemical pathways by which emerging contaminants in the sub-Arctic are degraded and the extent to which high latitude environmental factors will impact persistence. Subarctic environmental conditions have a unique timeline of contaminant attenuation compared to temperate conditions, and a unique relative contribution of direct and indirect processes. This study specifically assesses three priority compounds: 12α-hydroxy-rotenone, 6-PPD quinone, and fluridone. 6-PPD quinone is the quinonoid oxidation product from oxidation of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine, a widely used tire additive and anti-oxidant. Each of these have recently been detected persistently in Alaskan waterways, but no information exists regarding photochemical pathways and photo-transformation products in natural waters. This study will determine individual contributions of dissolved organic matter, hydroxyl radicals, singlet oxygen, and triplet excitation states. The temperature dependence of each process will be compared at 4, 12, and 20 degrees C, which spans the typical range of surface water temperatures. Photoproducts resulting from each process will be profiled using high resolution mass spectrometry combined with non-targeted analytical approaches. This information is expected to provide a better fundamental understanding of the environmental drivers for these photochemical processes.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.