Electrochemical Behavior and Detection of Plant Hormone 6-Benzyl Adenine in Acetate Buffer at Mercury Electrode

Abstract

The electrochemical behavior of 6-benzyl adenine (6-BA) has been studied in 0.1 mol L^–1 HAc–NaAc solution (pH 3.8). Cyclic voltammetry, single-sweep polarography and direct current polarography were employed to clarify the mechanism of the electrode process; the kinetic parameters of the rate-determining step were determined. Reduction of 6-BA involves two pH-dependent processes, corresponding to the overall irreversible reduction of the 1,6 and 3,2 N=C bonds. Each reduction stage consists a preprotonation of the nitrogen atom at the electroactive site and a rapid two-electron transfer. In the presence of 6-BA, the reduction potentials of some ions were shifted. Under the given conditions, 6-BA displays one irreversible reduction peak controlled by adsorption. Two linear response were observed in the range 2.0 × 10^–8–8.0 × 10^–7 mol L^–1 and the range 1.0 × 10^–6–8.0 × 10^–6 mol L^–1, with correlation coefficients of 0.9995 and 0.9998, respectively. The detection limit is 7.1 × 10^–9 mol L^–1. The method had been applied to the determination of 6-BA in bean sprout samples with satisfactory results.