Development of a Fluoride-Selective Electrode based on Scandium(III) Octaethylporphyrin in a Plasticized Polymeric Membrane

A scandium(III) porphyrin-based fluoride-selective potentiometric sensor and its application in the analysis of hydrofluoric acid is described. Scandium(III) octaethylporphyrin, an ionophore recently developed for the optical fluoride sensor, was employed as a host molecule for the selective binding with fluoride in the plasticized PVC membrane. Nernstian response for F‒ between 10‒4.6 to 10‒1 M was observed at a glycine-phosphate buffer (pH 3.0). The selectivity pattern was observed as F‒, salicylate >> SCN‒ > Cl‒, Br‒, NO3‒, ClO4‒, which is consistent with the binding constant data measured in the plasticized PVC membrane based on a sandwich membrane method. This highly selective and reversible fluoride-sensitive electrode was employed for the analysis of hydrofluoric acid (HF). A disposable differential-type HF sensor was fabricated on the screen-printed electrode and demonstrated its ability to detect the neutral HF in the acidic solution. KCI Citation Count: 11