Electrochemical determination of ferulic acid in Chinese traditional medicine Xiao Yao Pills at electrode modified with carbon nanotube

The electrochemical behaviors of ferulic acid were investigated at the glassy carbon electrode modified with multi-walled carbon nanotube. In pH 5.5, 0.1 mol l(-1) HAc-NaAc buffer solution, ferulic acid exhibited a pair of stable and sensitive redox signals at the modified electrode. The reaction mechanism was explored. Through the cyclic voltammetry, trace amount of ferulic acid was detected quantitatively. In the range of 1 x 10(-5) to 5 x 10(-3) mol l(-1), the oxidation peak currents of ferulic acid have a linear relationship to the concentrations, the limit of detection was estimated to be 1 x 10(-7) mol l(-1) (S/N = 3). The influences of substrate, pH and interference of coexisting substances were investigated for response properties of the electrode. Actual Xiao Yao Pill samples were analyzed and satisfactory results were obtained, which meant that the method could be used to detect the trace amount of ferulic acid in medicament.