Cutter, G. A.. Old Dominion University, 757-683-5303
Dryden, C. A.. Old Dominion University, 757-683-5303
DISSOLVED ORGANIC SULFUR IN THE CHESAPEAKE BAY AND WESTERN NORTH ATLANTIC OCEAN
Dissolved organic sulfur (DOS) is a poorly quantified component of the oceanic sulfur cycle, but broad classes of compounds in DOS probably include organic sulfides (e.g., sulfur amino acids in soluble peptides, dimethylsulfonium propionate, methane thiol, co-enzyme A, thiamine), sulfate esters (R-O-SO4), and sulfur compounds with intermediate oxidation states (e.g., dimethyl sulfoxide). Knowing the total amount of dissolved organic sulfur is then useful for studies of these specific compounds, but it also has implications for studies of trace metal complexation (-RSH is a strong ligand) and the production of the radiatively important gas, carbonyl sulfide, that is created by the photolysis of DOS. We have recently developed a method for the determination of DOS that includes sulfate removal and then reductive pyrolysis/gas chromatography. We have begun applying it to samples from the Chesapeake Bay, coastal shelf waters of the western North Atlantic Ocean, the Gulf Stream, and the Sargasso Sea. Surface concentrations in the open ocean range from 80-120 nmol S/L and decrease with depth.. We will speculate on the identity of compounds that comprise DOS using comparisons with DOC and DON concentrations, as well as data from selective column extractions (e.g., C-18, XAD-7).
Day: Friday, Feb. 5
Time: 09:30 - 09:45am
Location: Sweeney Center