Fluoride and chloride in sodium fluoride for pharmaceutical use

Sodium fluoride for pharmaceutical use needs to comply with USP requirements. The actual monograph (USP 42) uses three different methods for the identification, the assay, as well as the content of chloride as an impurity. Ion chromatography allows the measurement of these three parameters in two determinations on a single system. In the course of the USP monograph modernization, this ion chromatographic approach brings an increased ease of use for this type of analysis.