Molecular characterization and reactivity of dissolved organic matter along a river to ocean transect by high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

GEOC 13

Patrick G Hatcher, phatcher@odu.edu1, Rachel L Sleighter, rsleight@odu.edu1, Zhanfei Liu, zxliu@odu.edu1, and Susan A Hatcher, shatcher@odu.edu2. (1) Department of Chemistry and Biochemistry, Old Dominion University, 4541 Hampton Blvd, Norfolk, VA 23529, (2) College of Sciences Major Instrumentation Cluster, Old Dominion University, Norfolk, VA 23529
Information on the chemical composition of dissolved organic matter (DOM) is crucial to understand its source and reactivity. We sampled water from a transect, beginning in the Dismal Swamp, continuing up to the Chesapeake Bay and out to its adjacent coastal areas. DOM characterization was achieved using HPLC and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Our results showed that there is a major shift from aromatic to aliphatic components in DOM from the Elizabeth River to the Chesapeake Bay mouth. Based on the ion fragment analysis, the aromatic components source from lignin in degraded woods, and the lignin-derived compounds are either decomposed or highly modified into aliphatic compounds by micro-organisms or photochemistry. This new elemental approach for the analysis of DOM has allowed for its extensive characterization and is the first time that molecular level information has been acquired for DOM along this type of transect.
 

The Biogeochemical Cycling of Natural Organic Matter in the Coastal Zone
8:30 AM-11:55 AM, Sunday, August 19, 2007 Boston Park Plaza -- Thoreau Rm, Oral

Sci-Mix
8:00 PM-10:00 PM, Monday, August 20, 2007 BCEC -- Exhibit Hall - B2, Sci-Mix

Division of Geochemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007