Effect of buffer capacity on electrochemical behavior of dopamine and ascorbic acid

Jianguo Wang, Lingling Wang, Yuling Wang, Weiwei Yang, Lili Jiang, Erkang Wang*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)

Abstract

It is well known that the electrochemical oxidation of dopamine and ascorbic acid includes the proton and electron transfers at a glassy carbon electrode and their redox potentials are dependent on the pH of solution. When the concentration of the buffer is not enough to neutralize the protons produced by electrochemical oxidation of dopamine and ascorbic acid, two peaks of them can be observed in cyclic voltammograms. The height of the new peak is in proportion to the concentration of proton acceptor including HPO4 2 -, 2,4,6-trimethylpyridine, tris (hydroxymethyl) aminomethane. Moreover, the potential of it is dependent on the type and the concentration of buffer at the same pH of bulk solution. However, this phenomenon cannot be attributed to the interaction between proton acceptor and dopamine or ascorbic acid. So, we think the phenomenon is caused by the acute change of pH at the surface of working electrode. Similar results were also observed in the rotating disk voltammograms. It can be concluded that the electrochemical behavior of some compounds is dependent on the concentration of buffer when this concentration is not enough to neutralize the protons produced in electrochemical oxidation. Therefore, we have to attach importance to the buffer capacity in electrochemical measure of some concentrated compounds like ascorbic acid and dopamine.

Original languageEnglish
Pages (from-to)107-111
Number of pages5
JournalJournal of Electroanalytical Chemistry
Volume601
Issue number1-2
DOIs
Publication statusPublished - 15 Mar 2007
Externally publishedYes

Keywords

  • Ascorbic acid
  • Buffer capacity
  • Dopamine
  • Electrochemistry
  • Glassy carbon electrode

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