镉离子选择电极电位滴定测定钙镁

POTENTIOMETRIC TITRTION OF CALCIUM AND MAGNESIUM USING CADMIUM ION SELECTIVE ELECTRODE AS INDICATING ELECTRODE

建立了以镉离子选择电极作指示电极EDTA、EGTA电位滴定测定钙、镁的方法,详细考察了电位滴定的适宜条件,干扰离子的影响及消除办法。在四硼酸钠-氢氧化钠(pH10)缓冲介质中,EGTA滴定钙,EDTA滴定钙镁含量。测定矿泉水及硅酸盐样品中钙镁含量,结果符合要求。

The method for the titration of mixtures containing calcium and magnesium with cadmium ion selective electrode as a indicating electrode, based on the difference in the formatiom constants of their complexs with EDTA and EGTA, was established. Calcium is titrated in the presence of magnesium with EGTA in buffer solution of Na2B4O7-NaOH(pH 10) ,and the total calcium and magnesium is determined in same buffer solution. The samples of natural spring water and silicates were analyzed by the proposed method with satisfactory results.