Application of cation-exchange resin loaded with oxyzirconium-tetrakis(sulfophenyl)porphine to the determination of fluoride ion

To extend analytical application of ion-exchange resins, a ternary salt-like resin, a cation-exchange resin (Amberlite CG-50) on which oxyzirconium ion and tetrakis(sulfophenyl)porphine (TPPS) were loaded, was prepared. The ternary resin (R-Zr�TPPS) reacts with fluoride ion to liberate TPPS. Since the amount of released TPPS corresponds to that of fluoride ion, fluoride ion can be determined spectrophotometrically. It was found that the result was the most satisfactory, when the ternary resin was prepared by loading 53.4 mg of zirconium oxynitrate and 25 mg of TPPS on 1 g of CG-50 and then washing the resin with diluted nitric acid (1 M and 0.1 M). The calibration curve obtained was linear in the range of 1 to 5 ppm fluoride ion. The relative standard deviation (w = 10) was satisfactory (2.2%). R-Zr'TPPS was expected to be useful as a new conceptional reagent.