NSF Award
1508170
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).<br/><br/>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.
