Determination of tannic acid by adsorptive anodic stripping voltammetry at porous pseudo-carbon paste electrode

A novel and sensitive electrochemical sensor based on porous pseudo-carbon paste electrode (PPCPE) for tannic acid detection is described. PPCPE is fabricated by mixing calcium carbonate microspheres as the template, graphite powders as the filler, and pyrrole as the precursor of polymer which actually acted as the paste. After the polymerization of pyrrole catalyzed by Fe3+, the template calcium carbonate microspheres are removed with 0.1 M hydrochloric acid to form PPCPE. The diameters of these pores are in the range from 2 to 5 gm by SEM observations and the specific surface area of PPCPE is 59.26 m(2)/g by the Brunauer-Emmet-Teller (BET) method. A linear relationship between the anodic stripping peak current and the concentration of tannic acid from 0.02 to 1 mu M and a limit of detection as low as 0.01 mu M are obtained using PPCPE. (C) 2008 Elsevier B.V. All rights reserved.