Accurate determination of total alkalinity in estuarine waters for acidification studies

One of the effects of the atmospheric CO2 increase is ocean acidification. Over the past 20 years, accurate
measurements of the seawater carbonate system have become a high priority because this is the main
system controlling seawater acidity. However, this phenomenon has not been widely studied in estuaries,
even if they are among the most productive natural habitats in the world, lodging some of the highest
biotic diversity and production. Due to that lack of information, this work aims to develop and discuss
new strategies for the determination of total alkalinity (TA), one of the most measured parameters in the
study of acidification, in estuarine waters in the wide range of salinities that can be found in these
systems. For that purpose, a new set of stability constants for the carbonate system was established and
compared with those most widely used up to date. For the determination of TA, different approaches
were studied for the data treatment of the potentiometric titration data.