1985 Volume 34 Issue 1 Pages 1-5
It was found with a glassy carbon electrode that, by preelectrolyzing the adenine and guanine solution containing copper(II) ion at +0.05V (vs. SCE), the anodic peak currents of these bases were remarkably enhanced. The same phenomenon was also found in the presence of either the adenine or the guanine containing copper (II) ion. The anodic peak potentials of adenine and guanine were ca. +1.15 V and +0.82 V (vs. SCE), respectively. Using the differential pulse staircase voltammetry (DSV), this phenomenon was applied to the electrochemical determination of the bases. The solution of the bases containing 1×10-3 mol dm-3 copper(II) acetate and 0.4 mol dm-3 acetate buffer (pH 4.0) was electrolyzed at +0.05 V (vs. SCE) for 3 min with stirring, and then the anodic DSV peaks of the bases were recorded without stirring. The relationships between the peak currents and the concentrations of the bases were linear in the concentration range from 5×10-7 to 8×10-6 mol dm-3. The slopes of the calibration curves for adenine and guanine were 1.3 and 3.1 (10-6 A/10-6 mol dm-3), respectively. The preelectrolysis time of 5 min made it possible to detect 2×10-7 mol dm-3 bases. It was considered that the effect of the copper(II) ion, by which the anodic peak currents of the bases were increased, was due to the adsorption of copper (ionic or metallic) compound of the bases on the electrode.
