Amperometric determination of ascorbic acid at a ferricyanide-doped Tosflexmodified electrode

Tosflex, a perfluoro-anionic exchange membrane, is not studied as much as Nafion for electroanalytical applications. In this study, electrocatalytic oxidation of ascorbic acid (AA) was demonstrated using a ferricyanide-doped Tosflex-modified electrode in pH 5 phosphate buffer solution. The modified electrode showed good stability over the studied pH range of 2–12. The electrocatalytic oxidation of AA on the modified electrode follows the surface-saturation kinetics in terms of Michaelis-Menten (MM) mechanism. The analytical estimations were performed amperometrically under hydrodynamic conditions at an applied potential of 300 mV versus Ag/AgCl. A linear response was observed in the range of 0–50 mu M with a regression coefficient of 0.998.