An analytical system and sampling procedures have been developed for the determination of pore water DOC, using a modification of the high temperature, platinum catalyzed oxidation method of Sugimura and Suzuki (1988). This approach employs chromatographic CO2 separation, and allows quantification by flame ionization detection or alteratively, isolation of the DOC derived CO2 for isotopic analysis. These methods measure pore water profiles and benthic chamber DOC fluxes in continental margin sediments from the Western North Atlantic Ocean and are providing a set of &13C (DOC) determinations on pore water samples from the same cores. Two benthic carbon cycle studies will be carried out, one at the Bermuda time-series site (with Dr. Fred Sayles) and the other on the Peru continental margin (with Dr. Richard Jahnke). By carrying out the DOC investigation within the context of broader pore water/benthic flux studies of organic mater decomposition, the role of DOC in the carbon cycle and carbon isotope budgets at the sea floor will be quantified.
