Preliminary study of DOC in the Tamar Estuary, UK, using UV-persulphate and HTCO techniques

• Published in: Marine chemistry 1993, Vol.41 (1), p.223-228
• Main Authors: Miller, A.E.J., Mantoura, R.F.C., Suzuki, Y., Preston, M.R.
• Format: Article
• Language: English
• Subjects: Brackish; Earth sciences; Earth, ocean, space; Exact sciences and technology; External geophysics; Geochemistry; Mineralogy; Physical and chemical properties of sea water; Physics of the oceans; Silicates; Water geochemistry
• ISSN: 0304-4203; 1872-7581
• DOI: 10.1016/0304-4203(93)90123-6

A comparative study of techniques for the determination of dissolved organic carbon was conducted on estuarine waters. High-temperature catalytic oxidation was performed using the home-built system of Sugimura and Suzuki (Mar. Chem., 24: 105–131 (1988)) and a commercially available Shimadzu TOC-500, and wet-chemical oxidation was carried out with a UV-persulphate system. Interpretation of relative oxidation efficiencies is discussed in light of the procedures adopted for instrument calibration and determination of appropriate blank values. Data from UV-persulphate are generally lower than from both HTCO techniques. Large differences are observed in low-salinity waters, where colloidal concentrations are highest. Contrasting behaviour between HTCO systems is possibly due to compositional differences in dissolved organic matter with varying susceptibility to each oxidation technique. UV-persulphate derived data appear to demonstrate conservative behaviour whereas both sets of HTCO values are non-conservative; this finding confirms previous reports from the Severn and Delaware Estuaries, respectively.