Dosage amperometrique rapide et directe de calcium et de magnesium dans l'eau,les ciments et le sol

An amperometric method for thé successive titration of calcium and magnesium with EGTA and EDTA respectively is proposed. The method is direct and rapid. Calcium and magnesium can be determined in waters (41.5 mg/l and 4.6 mg/l with a precision of ±1.15% and ±6.70%), in cements (66.7% CaO and 1.70% MgO with a precision of ±2% and ±8%), and in soils (16.5% CaCO₃ and 1.8% MgCO₃ with a precision of ±2.6% and ±5.5%). The results obtained are compared with those obtained by gravimetric or titrimctric methods.