The total content of the dissociated ions in water can be determined by measuring the anion-cation balance (according to W-000.19.999 Calculating the Content of Sodium (and Potassium) Ions in Water Based on the Ion Balance), which also serves to test the reliability of the other analysis methods, since errors in tallying the sum of the individual analyses for the total ion content can add up.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
Sodium ions (and potassium ions) are present in almost all natural waters. Their concentrations can range from a few mg/l up to several g/l. The concentration of potassium ions is usually low.
If a water sample is run through a strongly acidic cation exchanger, all of the cations are replaced with hydrogen ions, thus producing the corresponding free acids in equivalent quantities (total mineral acid value). Since the carbonates and bicarbonates are transformed into carbon dioxide and therefore escape determination, their content must be determined through titration with acid to a pH of 4.3 (m value).