Electrochemical behavior of menadione on glassy carbon rotating disk electrode (RDE)

The 2-methyl-1,4-naphthoquinone electrochemical behavior on glassy carbon r otating disk electrode has been the focus of this study. Ln order to obtain the best results, the optimal conditions for this voltammetric study have been determined by performing a chemometric analysis of the data. The influ ence of five factors on the diffusion current has been studied, finding tha t the greatest effect is due to three of them. The optimum values for all o f these parameters were: pH 7, nu (potential sweep rate) = 87.1 mV/s, C-met (methanol concentration)= 4.14%(v/v), t(eq) (equilibrium time) = 2.5 min, and t(dea) (purge time) = 2 min. These data were used to determine the mass transfer parameters: diffusion coefficient (D = (1.4 +/- 0.3) x 10(-4) cm( 2)/s) and diffusion layer thickness (delta = (6.6 +/- 0.5) x 10(-3) cm), th e kinetic parameters: charge transfer constant (K-0 = 2.91 x 10(-6) cm/s) a nd charge transfer coefficient (alpha = 0.248), and the standard potential (E-0 = 0.083 +/- 0.011 V).