Integrated pervaporation/detection for the determination of fluoride in pharmaceuticals

A selective dynamic method for the determination of fluoride in pharmaceuti cals based on the integration of pervaporation and potentiometric detection in a laboratory-made module is proposed. The analyte was continuously conv erted into volatile trimetylfluorosilane by reaction with hexamethyldisilaz ane. injected into a donor stream and accepted in a basic buffer solution a fter pervaporation. The method thus developed has a determination range bet ween 1.5 and 200 mg 1(-1), precision (expressed as R.S.D.) of 3.4%, and has been applied to the determination of fluoride in different pharmaceutical products, with yields ranging between 90.6 and 100.3%. (C) 2000 Elsevier Sc ience B.V. All rights reserved.