离子选择性电极法测定饮料中钙含量

Determination of Calcium Ion in Drinks by Ion Selective Electrode Method

提出了以钙离子选择性电极为指示电极,甘汞电极为参比电极,EGTA标准溶液为滴定剂的电位滴定法测定有色或混浊饮料中钙含量。滴定终点由电位突跃来判断。此法简便、灵敏、准确,相对标准偏差钙奶为0.11%,橙汁的为2.1%。加标回收率,钙奶的为99%～100%,橙汁的为102%～105%。可用于直接测定混浊或有色液体中钙含量。

This article told us a new potentiomtery that used the calcium ion selective electrode as the indicating electrode,saturated mercury chloride electrode as the reference electrode and EGTA standard solution as the titration reagent to assay the content of calcium ion in the muddy and color drinks.The end-point of titration could be deterrmined by the potential break.The method was simple,sensitive and accurate.The relative standard deviation of calcium milk was 0 11% and that of fruit juice was 2 1%.The recovery Percent of added standard sample of calcium milk was 99%～100%,and that of fruit juice was 102%～105%.It could also be used to directly determinate the content of calcium ion in the muddy and color liquid.