Instrument: CO2 Coulometer
A CO2 coulometer semi-automatically controls the sample handling and extraction of CO2 from seawater samples. Samples are acidified and the CO2 gas is bubbled into a titration cell where CO2 is converted to hydroxyethylcarbonic acid which is then automatically titrated with a coulometrically-generated base to a colorimetric endpoint.
PIC was determined from the other set of filter halves by coulometric analysis of acidified samples using a Model CM5014 UIC Coulometric Analyzer with Carbonate Acidification Module, as described in Honjo et al. (1995).