Calcium in Tablets
The amount of calcium in tablets is quantified first by preparing test sample liquid.
Crush the sample tablet, and add pure water with 10% hydrochloric acid. Warm the liquid in bath at 80°C, and cool. Then, filter, and add water to make test sample liquid. Further, add water with 10% potassium hydroxide and potassium cyanide for titration with 0.05 mol/L EDTA. The endpoint is determined by the colour change of indicator on titration curve.
Calcium is calculated from titration volume of EDTA.