Simultaneous determination of vitamins B2, B6 and C using silver-doped poly(L-arginine)-modified glassy carbon electrode

Abstract

The silver doped poly(L-arginine)-modified glassy carbon electrode was prepared by electropolymerization. Cyclic voltammetry and electrochemical impedance spectroscopy were used to study the electrochemical properties of the modified electrode. The modified electrode exhibits good electrocatalytic activity for the oxidation of vitamin B₂ (VB₂), vitamin C (VC) and vitamin B₆ (VB₆). Under optimal conditions, VB₂, VC and VB₆ are oxidized at–0.298, 0.317 and 1.058 V, respectively, at the modified electrode using linear sweep voltammetry method. The linear ranges for VB₂, VC and VB₆ are 1.0 × 10^–7–2.3 × 10^–5, 5.0 × 10^–6–4.0 × 10^–3 and 1.0 × 10^–5–3.0 × 10^–3 M, respectively, and the detection limits are 8 × 10^–8, 3 × 10^–6 and 5 × 10^–6 M. The modified electrode has been successfully applied to simultaneous determination VB₂, VC and VB₆ in multivitamin tablets with satisfactory results.