Sea-trials of three different methods for measuring non-volatile dissolved organic carbon in seawater during the JGOFS North Atlantic pilot study

• Published in: Marine Chemistry
• Main Authors: Baar, H.J.W. de, Brussaard, C., Hegeman, J., Schijf, J., Stoll, M.H.C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1993
• Subjects: Pacific; North Atlantic
• Online Access: https://hdl.handle.net/11370/94ec99d2-076e-433b-94bc-5770973895ba; https://research.rug.nl/en/publications/94ec99d2-076e-433b-94bc-5770973895ba; https://doi.org/10.1016/0304-4203(93)90112-2; https://pure.rug.nl/ws/files/14673137/1993MarChemdeBaar.pdf

In 1989 the shipboard comparison of three different methods for measuring concentrations of dissolved organic carbon (DOC) resulted in reasonable agreement, with differences likely as a result of a combination of calibration offsets and general instability of the instruments at sea. Typical concentrations were about 80-140 µmol in the upper 1000 m of the water column, with a tendency towards higher values (100-150 µmol) in the surface waters. These elevated surface water levels are below the 200-300 µmol values recently reported for the Atlantic and the Pacific Oceans. In 1990 the small dataset obtained with a further modified High Temperature Combustion instrument showed similar trends. Within the analytical error there is no significant offset between two HTCO methods and one wet oxidation technique.