Determination of dissolved organic carbon in seawater using high temperature catalytic oxidation techniques

The high temperature catalytic oxidation (HTCO)-discrete injection method for liquid samples is currently the preferred analytical technique for the determination of dissolved organic carbon (DOC) in natural water samples. This approach yields equivalent or greater amounts of DOC than wet chemical oxidation methods, is suitable for routine analyses and is stable for shipboard determinations. However, a limited understanding of evaluation criteria for instrument performance presents a number of analytical challenges. This article discusses current practical problems encountered in the (i) collection and handling, (ii) preservation, (iii)decarbonation and (iv) analysis of seawater samples and reviews recent improvements in HTCO systems. Particular reference is made to the issue of certified reference materials and the oxidation efficiency of the technique. (C) 2000 Elsevier Science B.V. All rights reserved.