Department of Chemistry & Biochemistry and The Large Lakes Observatory
University of Minnesota – Duluth
Monday, Feb. 18
1:30 p.m., Room SL102
Organic matter in Lake Superior
Natural aquatic organic matter (NOM) plays significant roles in regional and global carbon, nitrogen and phosphorus cycles. Because NOM interacts with with trace metals and organic pollutants (e.g., via chelation and absorption), it impacts toxicology as well. It is believed that these roles can be better predicted if we know the chemical structures of NOM constituents and how they vary in different aquatic environments. The major component of NOM in many aquatic systems, including Lake Superior, is dissolved organic matter (DOM). I will discuss ways in which DOM can be characterized. In particular, I will focus upon the application of solid phase extraction and electrospray ionization Fourier transform ion cyclotron resonance mass spectroscopy (FT-MS) to characterize samples from the Lake Superior watershed. Lake Superior’s extractable DOM contains a large number of lignin-like and reduced hydrocarbon formulae and relatively few protein, lipid, and carbohydrate-like signatures.