1990 年 6 巻 3 号 p. 439-442
Cyclic and differential pulse (DP) voltammograms of dopamine (DA) in Ringer′s solution were measured at a graphite-reinforcement carbon (GRC) electrode. GRC is available as the lead of mechanical pencils. Cyclic voltammograms of DA exhibited two anodic peaks, at ca. -0.0V and ca. 0.4V vs. SCE, and a cathodic peak at 0.05V vs. SCE in the solution of pH 6.8. Ascorbic acid (AA) presented an irreversible anodic wave at 0.2V at pH 6.8. Voltammograms in the mixed solution of AA and DA were not a simple sum of each voltammogram, and hence were associated with chemical complications between AA and DA. DP voltammograms of the mixed solution had an anodic and a cathodic peak at ca. 0.05V, which were stable during 4 days′ soaking of the electrode in the solution. The anodic peak height was proportional to the concentration of DA in the range from 5.0×10-6 to 1.2×10-4mol dm-3. DA could be determined quantitatively from a calibration curve in the presence of AA from 5 to 20 times larger than DA concentrations.
