TITLE:
Adsorptive Stripping Voltammetric Determination of Mangiferin Using an Activated Chitosan Modified Carbon Paste Electrode
AUTHORS:
Francis Merlin Melataguia Tchieno, Evangeline Njanja, Léon Azefack Tapondjou, Ignas Kenfack Tonle
KEYWORDS:
Mangiferin (Mangifera indica L.), Xanthones, Carbon Paste Electrode, Chitosan, Stripping Voltammetry
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.5 No.7,
May
27,
2014
ABSTRACT: A medium molecular weight powdered chitosan modified carbon paste electrode was used to investigate the electrochemical behaviour by cyclic voltammetry of the pharmacologically-active ingredient mangiferin (MG). An irreversible system was observed, with a peak at ﹢0.55 V (vs Ag/AgCl). The peak current increases about fourfold, at the modified electrode in comparison with that recorded at the chitosan free carbon paste electrode. This allowed the use of adsorptive stripping voltammetry to develop a simple and sensitive electroanalytical method for the determination of MG. The influence of key parameters was investigated, including the electrolysis potential, the preconcentration time, the pH of supporting electrolyte and MG concentration. Upon optimisation of these parameters, the electrode response was found to be directly proportional to the concentration of MG in the range from 2.06 × 10﹣6 M to 6.74 × 10﹣5 M, leading to a detection limit of 1.84 μM for 240 s preconcentration at ﹣0.1 V. A mechanism was also proposed for the electrochemical oxidation of MG.