SIMULTANEOUS DETERMINATION OF DISSOLVED ORGANIC-CARBON AND TOTAL DISSOLVED NITROGEN IN SEAWATER BY HIGH-TEMPERATURE CATALYTIC-OXIDATION - CONDITIONS FOR PRECISE SHIPBOARD MEASUREMENTS

Appropriate conditions have been achieved for the accurate, rapid, and highly precise shipboard simultaneous determination of dissolved orga nic carbon and total dissolved nitrogen in seawater by high temperatur e catalytic oxidation. A nitrogen-specific Antek 705D chemiluminescenc e detector and a CO2-specific LiCor Li6252 IRGA have been coupled in-s eries with a Shimadzu TOC-5000 organic carbon analyser. Precision of b oth simultaneous measurements is less than or equal to 1.5%, i.e. +/- 1 mu mol C l(-1) and +/-0.3 mu mol N l(-1), respectively. Quality of a nalysis is not compromised by vibrations associated with ocean going r esearch vessels. (C) 1998 Elsevier Science B.V. All rights reserved.