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既定的激励竞争性研究计划(EPSCoR)共同资助。阿拉斯加大学安克雷奇分校的汤姆科和雷德曼博士将调查在阿拉斯加水道中发现的三种污染物的环境破坏率，这些污染物是由阳光引起的。这一过程的机制对于寒冷的高纬度地区来说可能是独一无二的，在那里，每天的日照发生极端的季节性变化。将对影响这一过程的几个因素进行调查，包括天然有机物的作用、活性氧物种和温度依赖性。将确定每种污染物降解时形成的分解产物。这项研究有望为预测水质评估的发展提供信息，这可能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学仪器方法的机会，并将目标纳入阿拉斯加原住民学生和妇女，以努力扩大对此类物理科学研究的参与。这项研究将调查亚北极新出现的污染物被降解的水光化学途径，以及高纬度环境因素将在多大程度上影响持久性。与温带环境条件相比，亚北极环境条件具有独特的污染物衰减时间表，以及直接和间接过程的独特相对贡献。这项研究具体评估了三个优先化合物：12α-羟基鱼藤酮、6-PPD苯二酚和氟里酮。6-对苯二酚是广泛使用的轮胎添加剂和抗氧剂N-(1，3-dimethylbutyl)-N′-phenyl-p-phenylenediamine，的氧化产物。最近在阿拉斯加水道中持续检测到其中的每一种，但没有关于自然水域中的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、单线态氧和三线态激发态的单独贡献。每个过程的温度依赖性将在4摄氏度、12摄氏度和20摄氏度进行比较，这些温度跨越典型的地表水温度范围。每个过程产生的感光产品将使用高分辨率质谱学结合非目标分析方法进行分析。这些信息预计将提供对这些光化学过程的环境驱动因素的更好的基本了解。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 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.