TA - ANALYSER FOR TOTAL ALKALINITY IN SEAWATER

The CONTROS HydroFIA® TA is a flow through system for the determination of the total alkalinity in seawater. It can be used for continuous monitoring during surface water applications as well as for discrete sample measurements. The autonomous TA analyser can be easily integrated into existing automated measuring systems on voluntary observing ships (VOS) such as FerryBoxes.

Total alkalinity is an important sum parameter for many scientific fields of application including ocean acidification and carbonate chemistry research, monitoring of biogeochemical processes, aqua culture / fish farming as well as pore water analysis.

OPERATING PRINCIPLE

A defined amount of seawater is acidified by injection of a fixed amount of hydrochloric acid (HCl).
After acidification the generated CO₂ in the sample is removed by means of a membrane based degassing unit resulting in a so-called open-cell titration. The subsequent pH determination is carried out by means of an indicator dye (Bromocresol green) and VIS absorption spectrometry.
Together with salinity and temperature, the resulting pH is directly used for the calculation of total alkalinity.

HydroFIA® TA

Product sheet
Application note

FEATURES

  • Measurement cycles of less than 10 min
  • Robust pH determination using absorption spectrometry
  • Single-point titration
  • Low sample consumption (<50 ml)
  • Low reagent consumption (100 μL)
  • User-friendly “Plug and Play” reagent cartridges
  • Minimized biofouling effects due to acidification of the sample
  • Autonomous long-term installations

OPTIONS

  • Integration into automated measuring systems on VOS
  • Cross-flow filters for high turbidity / sediment loaded waters

  REFERENCES

VARIABILITY OF USA EAST COAST SURFACE TOTAL ALKALINITY DISTRIBUTIONS REVEALED BY AUTOMATED INSTRUMENT MEASUREMENTS
Automated total alkalinity (TA) analyses greatly expanded spatiotemporal coverage. Field and lab assessment of the autonomous analyzer providing information about regional distributions of TA relative to salinity and changes between seasons and years.

MARINE CHEMISTRY, https://doi.org/10.1016/j.marchem.2021.103960

FIRST LONG-TERM HIGH-RESOLUTION TOTAL ALKALINITY DATASET GENERATED IN THE GERMAN WADDEN SEA USING CONTROS HYDROFIA TA
The Wadden Sea bioreactor has been found to produce significant amounts of total alkalinity during the spring and summer months. Continuous measurements of TA and related parameters on a ferry revealed strong differences in the nearshore and adjacent coastal regions resulting in a TA flux potentially affecting the ocean carbon budget.

LIMNOLOGY AND OCEANOGRAPHY, DOI 10.1002/LNO.11103

TRACKING OCEAN ALKALINITY USING NEW CARBON MEASUREMENT TECHNOLOGIES
Exciting NOAA funded project expanding the quantity and quality of ocean acidification monitoring across Northeastern U.S. coastal waters specific to meeting industry needs.

PROJECT TAACT

CHARACTERIZATION OF A NOVEL AUTONOMOUS ANALYZER FOR TOTAL ALKALINITY
Field and lab assessment of the autonomous analyzer providing a deep insight into the performance characteristics of the HydroFIA TA instrument.

L&O METHODS, DOI 10.1002/LOM3.10329