Total alkalinity and dissolved inorganic carbon in seawater (VINDTA 3C)

The VINDTA 3C (Versatile INstrument for the Determination of Total inorganic carbon and titration Alkalinity) combines the proven VINDTA alkalinity titration concept with a simplified extraction unit for coulometric dissolved inorganic carbon (DIC) measurement.

The alkalinity part of the VINDTA 3C is nearly identical to the VINDTA 3S system; an additional part for the extraction of CO₂ from seawater for coulometric titration has been added to allow for determination of dissolved inorganic carbon from the same sample simultaneously (the DIC-only system is available as VINDTA 3D).

The sample transport is performed with peristaltic pumps and the acid addition is done using a membrane pump; therefore no pressurizing system is required (in contrast to the SOMMA system) and only one gas supply (nitrogen or dry and CO₂-free air) is necessary. As option, a Peltier cooler system for the condenser (this saves one circulation bath) is available.

features:

• determine alkalinity and dissolved inorganic from the same sample simultaneously
• easily transportable and sea-going
• only one gas (carrier gas) required
• precision typically ± 1 µmol/kg ( AT and/or DIC; open ocean water)
• simplified operation for DIC compared to the SOMMA
• user friendly software interface using LabVIEW^TM
• optional control PC (Shuttle-PC) tested with the hardware and with all software and drivers installed

LabVIEW™ is a trade mark of National Instruments Inc.

Additional hardware required or recommended:
UIC coulometer model 5011, 5012, 5014, 5015 (with 5011 emulator option), 5015O
METROHM Titrino (719SET or similar) with stirrer 728 and 5 mL burette unit
Metrohm reference electrode # 60729.100
Thermo Orion ROSS electrode #8101BN
circulation bath for temperature control (20 or 25ºC) of the system equilibration of sample bottles
second circulation bath for the condenser (around 2ºC; not required with Peltier option)
carrier gas supply (nitrogen or dry and CO₂-free air)