Analysis of fluoride in toothpastes on the Belgian market.

We developed a method for the quantitative determination of sodium fluoride (NaF), sodium monofluorophosphate (SMFP) and amine fluoride (AmF) in toothpastes on the Belgian market. Samples were suspended in water and the determination was made using anion chromatography with conductivity detection after chemical suppression. The described ion chromatographic method is an easy and reliable isocratic high-performance liquid chromatography method for the determination of total soluble fluoride content in toothpastes. The analytical repeatability and reproducibility, the matrix effects and the method's decision limit of three different toothpastes containing NaF, SMFP and AmF at a concentration close to the permitted one of 0.15 g % total F are determined. All the samples analysed are in conformity with the Cosmetics Directive 76/768/EC; none exceeds the limit of 0.15 g %.