Coupling mass spectrometry with optical spectroscopy and chemical tests to evaluate and monitor dissolved organic matter in natural waters

Academic Research Topics in Environmental Measurement and Monitoring
Oral Presentation

Prepared by M. Bianca1, M. Gonsior2, R. Del Vecchio3, C. Cartisano1, N. Blough1
1 - Department Chemistry and Biochemistry, University of Maryland College Park, Department Chemistry and Biochemistry, University of Maryland Building 091, College, Maryland, 20742, United States
2 - University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, 146 Williams St, Solomons, Maryland, 20688, United States
3 - Earth System Science Interdisciplinary Center, Department Chemistry and Biochemistry, University of Maryland Building 091, College, Maryland, 20742, United States


Contact Information: mbianca@umd.edu; 610-406-2551


ABSTRACT

Dissolved organic matter (DOM) comprises a complex, heterogeneous mixture of thousands of species, is found in almost all aquatic environments and is one of Earth’s largest carbon reservoirs. Thus, DOM plays an important role in aquatic environments and may help understanding the mechanisms of the global carbon cycle. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR MS) is a powerful tool that can be used to acquire detailed molecular information for DOM. Optical measurements can help to determine the molecular fingerprint of DOM that is optically active, i.e. the chromophoric DOM (CDOM), which has the ability to absorb light and therefore, alter the aquatic light field and potentially have a considerable impact on biogeochemical processes within the aquatic environment. To gain further insights and monitor DOM/CDOM structure/source(s), ESI-FT-ICR MS was coupled with chemical tests (sodium borodeuteride reductions) and with optical spectroscopy on reference materials and extracts from open oceans. With this approach, this study aims to gather information on the chemical structure of the optically active DOM to help understanding differences/similarities between terrestrial and marine CDOM/DOM molecular composition and its role in the aquatic environment.