Dataset: Carbonate chemistry

DIC samples were very gently filtered through a GFF syringe filter on the morning of the experimental day, then stored in air tight vials which were overflowed to minimize air exposure and allowed to come to room temperature until analysis on the same day using an Apollo SciTech DIC Analyzer AS-C3 which incorporates the LI-7000 CO2/H2O Analyzer, then corrected for density based on temperature and salinity.  Samples for pH were collected in a similar fashion to DIC, and also run on the same day after reaching 25 degrees in a temperature controlled water bath.  Samples were carefully transferred from the vials to a jacketed 5 cm cuvette.  pH was determined via spectrophotometric methods, with the addition of 20 uL of m-cresol blue to each sample after taking a baseline measurement.  The ratio of the two absorbance peaks was corrected based on samples in which two dye additions were made.  Other parameters were calculated with CO2sys.  Some samples for total alkalinity were also run for QC purposes.  These were preserved with HgCl2 and stored in 120 ml glass bottles with Teflon lined screw cap seals.  Alkalinity was measured by gran titration using a Titrando 888, and 0.1 N HCl titrant, in a temperature controlled titration vessel.