Electrochemical Behaviors of Vitamin B₂ at Poly-Alizarin Red S Modified Carbon Paste Electrode and Its Application

Alizarin red S (ARS) was polymerized on the surface of carbon paste electrode (CPE) by CV, to prepare poly-ARS film modified CPE (ARS/CPE). Electrochemical behavior of vitamin B₂ at this modified electrode was studied by CV and DPV. It was found that in a buffer medium of 0.1 mol·L^-1 HOAc-NaAc solution of pH 4.6, significant electrocatalytic action toward the redox reaction of vitamin B₂ was observed at the modified electrode, and values of diffusion coefficient (D) of 3.26×10^-5cm²·s^-1 and electron transfer coefficient (α) of 0.817 4 were found. Linear relationship between values of oxidation peak current and concentration of vitamin B₂ was kept in the range of 1.0×10^-6-8.0×10^-4mol·L^-1, with detection limits (3S/N) of 2.5×10^-8mol·L^-1. The proposed method was applied to the analysis of vitamin B₂ tablets, giving values of RSD's (n=5) in the range of 1.8%-2.7%. Recovery was tested by standard addition method, values of recovery found were ranged between 99.5% and 102%.