氟离子选择电极法测定白菜中氟化物

摘要

本法用硝酸－双氧水消解烘干后的白菜，以柠檬酸钠溶液作离子强度缓冲调节剂并采用氟离子选择电极在pH 5~6时直接测定游离态氟离子浓度.方法标准偏差≤0．16，变异系数＜5．44％，平均回收率为102．62％.%In this work,the cabbage was digested by nitric acid-hydrogen peroxide firstly. Then,sodium citrate solution was used as the buffer to regulate the ionic strength. Finally,free fluoride ion concentration was determined by fluorine ion selective electrode at pH5~6. Standard deviation was 0.16,coefficient of variation was 5.44%,and average recovery was 102.62%.