Collaborative Research: Photolysis of environmentally-relevant organometallic compounds in aqueous matrices

有了这个奖项，化学系的环境化学科学项目资助了巴尔的摩县马里兰州大学（UMBC）的Lee Blaney教授和巴尔的摩马里兰州大学（UMB）的凯瑟琳Squibb教授，以研究环境中有机金属物质的化学性质。该项目旨在了解有机金属化合物由于直接和间接的太阳光分解而引起的环境变化。有机砷、有机铂、有机硒和有机锡化合物在本研究中被包括，因为它们广泛存在于环境系统中。两名博士水平的研究生和一些本科生助理参与了相关的研究。项目团队与UMBC Meyerhoff学者计划（MSP）和技术女性中心（CWIT）合作，从对环境化学感兴趣的代表性不足的群体中招募学生。此外，PI与MSP，CWIT和UMBC本科教育办公室合作，让来自代表性不足的群体的学生参加研讨会，研讨会和演示，旨在促进环境化学科学的本科研究和教育。该研究的某些方面正在纳入环境化学（UMBC）和高级毒理学（UMB）的研究生课程。正在开发先进的分析方法，使用固相萃取液相色谱串联质谱（SPE-LC-MS/MS）用于有机金属，以提高转化产物的鉴定和定量。的摩尔消光系数和光转化动力学的8种有机金属物质正在确定跨pH值和波长梯度的直接和间接的光解机制。此外，正在确定这些化学品从有机形式到贱金属物质的转化途径。由于有机金属化合物及其贱金属的毒性不同，采用有针对性的生物测定方法来证明光解降解的毒性变化。 具体而言，研究目标包括：（i）发展固相萃取液相色谱电喷雾串联质谱（二）通过城市地表水中的直接和间接光解测量有关有机金属化合物的转化动力学;（iii）确定通过目标有机金属化合物的直接和间接光解形成的转化产物，以及（iv）使用靶向生物测定方法表征含有有机金属化合物和光转化产物的溶液的残留生物化学活性。这种研究方法有望提高对有机金属化学品在环境系统中的光化学命运的理解。

With this award, the Environmental Chemical Sciences Program in the Division of Chemistry is funding Professor Lee Blaney of the University of Maryland, Baltimore County (UMBC) and Professor Katherine Squibb of the University of Maryland, Baltimore (UMB) to investigate the chemistry of organometallic substances in the environment. This project seeks to understand the environmental transformations of organometallic compounds due to direct and indirect solar photolysis. Organoarsenic, -platinum, -selenium, and -tin compounds are included in this research because they are widespread in environmental systems. Two PhD-level graduate students and a number of undergraduate assistants are involved with the associated research. The project team works with the UMBC Meyerhoff Scholars Program (MSP) and Center for Women in Technology (CWIT) to recruit students from underrepresented groups who are interested in environmental chemistry. In addition, the PIs partner with MSP, CWIT, and the UMBC Office of Undergraduate Education to engage students from underrepresented groups in workshops, seminars, and demonstrations, with a goal to promote undergraduate research and education in the environmental chemical sciences. Select aspects of the research are being incorporated into graduate level courses in Environmental Chemistry (UMBC) and Advanced Toxicology (UMB).Advanced analytical methods are being developed using solid-phase extraction liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) for organometallics to enhance identification and quantitation of transformation products. The molar extinction coefficients and photo-transformation kinetics of eight organometallic substances are being determined across pH and wavelength gradients for direct and indirect photolysis mechanisms. Furthermore, the transformation pathways for these chemicals from the organic form to the base metal species are being identified. As the toxicity of organometallics and their base metals differ, a targeted bioassay approach is employed to demonstrate changes in toxicity with photolytic degradation. More specifically, the research aims include: (i)developing solid-phase extraction liquid chromatography electrospray ionization tandem mass spectrometry (SPE-LC-ESI-MS/MS) analytical methods for these organometallic species; (ii) measuring the transformation kinetics of the organometallic compounds of concern by direct and indirect photolysis in urban surface water; (iii)identifying transformation products formed through direct and indirect photolysis of targeted organometallic compounds and (iv) characterizing the residual biochemical activity of solutions containing organometallic compounds and phototransformation products using a targeted bioassay approach. This research approach is expected to improve understanding of the photochemical fate of organometallic chemicals in environmental systems.