Voltammetric Determination of Kojic Acid with the Multi-wall Carbon Nanotubes Modified Glassy Carbon Electrode

Electrochemical behavior of kojic acid at the multi-wall carbon nanotubes (MWCNT′s) modified glassy carbon electrode (GCE) was studied voltammetrically.As compared with the bare GCE,a remarkable increase of anodic peak current of kojic acid was obtained at the modified electrode.Linear relationship was found between values of peak current (Ip) and concentration of kojic acid in the range of 1.0×10-5-1.0×10-3mol·L-1 as determined by the differential pulse voltammetry (DPV).Detection limit (3S/N) of the method was found to be 5.0×10-6mol·L-1.Test for stability of the MWCNT′s modified GCE was made by successive determination of kojic acid in a soy sample and consistent results were obtained,while the results obtained by using bare GCE were decreased apparently.The proposed method was used for determination of kojic acid in some complex samples,e.g.,soy and millet wine,giving values of RSD′s (n=5) less than 5%,and of average recovery 99.5%.