Woods Hole Oceanographic Institution

Elizabeth B Kujawinski Behn

»Using stable isotope probing to characterize differences between free-living and sediment-associated microorganisms in the subsurface.
»DOM in Lake Superior
»Deepwater Horizon hydrocarbons in the marine environment
»Microbes and marine DOM, Ann. Rev. Mar. Sci. 2011
»Greenland ice sheet outlet glacier: Insights from a new isotope-mixing model
»Groundwater DOM, GCA 2011
»Dispersants & DWH, ES&T 2011
»FT-MS variability in DOM, Org Geochem 2010
»Predatory Flavobacteria, FEMS Microb Ecol 2010
»Greenland Ice Sheet DOM, GCA 2010
»Protozoa and bacteria in aquifers, FEMS Microb Ecol, 2009
»Source markers in DOM, GCA 2009
»Automated data analysis, Anal. Chem. 2006
»Marine DOM and ESI FT-ICR MS; Marine Chem 2004
»DOM extraction by C18; Org. Geochem. 2003
»Black carbon by ESI FT-ICR MS; ES&T 2004
»ESI FT-ICR MS review; Env. Forensics 2002
»Marine protozoan surfactants; Marine Chem. 2002
»ESI MS and NOM; Org. Geochem. 2002
»ESI FT-ICR MS & humic acids; Anal. Chem. 2002
»Protozoan DOM & PCBs; ES&T 2001
»Protozoa & Fe, Th, C; Aquat. Microb. Ecol. 2001
»PCB uptake by protozoa; AEM 2000

E. B. Kujawinski, P. G. Hatcher and M. A. Freitas, High-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) of humic and fulvic acids: Improvements and comparisons, Analytical Chemistry 74:413-419, 2002

Full structural characterization of complex mixtures such as humic acid extracts has been elusive because of insufficient compound resolution with conventional techniques.  Using electrospray ionization (ESI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), we were able to resolve individual compounds within humic and fulvic acid mixtures (mass resolving power » 80,000 at 300 m/z).  We examined two samples in detail: 1) dissolved organic matter (primarily fulvic acids) from Suwannee River , GA , and 2) a humic acid extract from a degraded wood collected on Mt. Rainier , WA .  Sample conditions (such as solvent, pH, and concentration) and instrument parameters (such as source voltages, trapping potentials, excitation parameters, etc.) were optimized to yield the highest mass resolving power with the least mass discrimination in positive ion mode.  High resolving power was achieved with low ion densities combined with co-adding numerous scans.  The increased resolution allowed molecular-level comparisons of the two samples which in turn could be used to estimate the relative similarity of individual compound distribution as well as an indication of the dominant diagenetic processes in the two source environments.


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