Simultaneous determination of calcium and magnesium in water samples and beverages and the different types of water hardness by complexometric titration with potentiometric indication
This Bulletin describes a potentiometric titration method for the simultaneous complexometric determination of the calcium and magnesium ions in a sample using Na2EDTA as titrant. The ion-selective calcium electrode is used as indicator electrode. To achieve a better differentiation between the Ca and Mg potential jumps an auxiliary complexing agent is added that additionally masks Fe3+ and Al3+ . Fixing the pH value at pH = 8.5 prevents interferences that might be caused by the precipitation of CaCO3.
The method described is suitable for the automatic determination of the different types of water hardness (carbonate, calcium, magnesium, total and permanent hardness). The determination of calcium and magnesium in beverages (fruit and vegetable juices, wine) is also dealt with.
German:  AB_125_2_d.pdf (152 KB)
English:  AB_125_2_e.pdf (155 KB)
French:  AB_125_2_f.pdf (147 KB)
Industry
Food and Beverages > Softdrinks and juices
Food and Beverages > Drinking water and tap water (1-50)
Water > Drinking water and tap water (1-50)
Methods
Titration > Potentiometric titration > Other potentiometric titrations
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