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

该奖项由化学部的环境化学科学计划和刺激竞争性研究的既定计划（EPSCoR）共同资助。阿拉斯加大学安克雷奇分校的Tomco和Redman博士将调查阿拉斯加水道中三种污染物的环境分解率，这些污染物是由阳光引起的。这一过程的机制可能是寒冷的高纬度地区所独有的，在这些地区，每日阳光照射发生极端的季节性变化。影响这一过程的几个因素将被调查，包括天然有机物，活性氧物种和温度依赖性的作用。将识别每种污染物降解时形成的分解产物。预计这项研究将为预测水质评估的发展提供信息，这些评估可用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，提供学习质谱分析中先进仪器方法的机会，和目标包括阿拉斯加原住民学生和妇女，努力扩大参与这样的物理科学研究。这项研究将调查水生光化学途径，其中新兴的污染物在亚-北极的气候退化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轴，以及直接和间接过程的独特相对贡献。本研究专门评估了三种优先化合物：12α-羟基鱼藤酮、6-PPD醌和氟啶酮。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醌式氧化产物，是一种广泛应用的轮胎添加剂和抗氧剂。最近在阿拉斯加水道中持续检测到这些物质，但没有关于自然沃茨中光化学途径和光转化产物的信息。这项研究将确定溶解的有机物，羟基自由基，单线态氧和三重激发态的个人贡献。每个过程的温度依赖性将在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。将使用高分辨率质谱法结合非目标分析方法对每个过程产生的光产物进行分析。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。

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.