[Determination of fluorides and fluorophosphates in drugs, toothpastes and mineral waters by gas liquid chromatography].

Fluorides and monofluorophosphates present in drugs, toothpastes and mineral waters are converted into an organic compound by trimethylchlorosilane at acidic pH. The trimethylfluorosilane formed is determined with isopentane as internal standard by gas liquid chromatography with flame ionization detection. Some drugs containing fluoride at therapeutic or physiologic concentrations also some toothpastes and mineral waters were analyzed easily by this method. No interferences due to excipients or to other active substances present in drugs or toothpastes were observed with this method. Because of its sensitivity (0.01 ppm), its accuracy (CV: 0.7 à 2%) and its simplicity, the chromatographic method proposed is suitable for the routine controls of fluorides in drugs, toothpastes and mineral waters.