An accurate and precise reference method for determination of dissolved organic carbon (DOC) in seawater is a prerequisite to obtaining the accurate data necessary to understand the role of dissolved organic matter in the oceanic carbon cycle. This project has three basic objectives: (1) to develop a reliable DOC reference method based on the sealed tube combustion (STC) technique, (2) to use the STC reference method to evaluate the accuracy of direct-injection high temperature catalytic oxidation (HTCO) and chemical oxidation methods, and (3) to analyze ultrafiltered seawater by STC, HTCO, and chemical oxidation methods in order to assess the effect of DOC molecular weight on oxidation efficiency. Seawater samples will be collected at the U.S. JGOFS Bermuda Atlantic Times Series (BATS Station using an established sampling and processing protocol. The BATS Station provides an accessible open ocean site and the available time-series data will provide a context for interpreting the results. This study will be coordinated with a DOC instrument comparison being conducted by the U.S. JGOFS.
