Investigation of the Electrochemical Behavior of Ethyl Caffeate at Glassy Carbon Electrode

In this paper, cyclic voltammetry were utilized to study the electrochemical behavior of ethyl caffeate at glassy carbon electrode. It was shown that the shape of electrochemical redox peak and the corresponding peak current in acetic acid/sodium acetate buffer are well-defined and high, respectively. The electrochemical behavior of ethyl caffeate at glassy carbon electrode was found to have a good reversibility, and the electron transfer number n was calculated to be 2 and the diffusion coefficient D0 is 2.4×10-6 cm2 s-1. The redox peak potential of ethyl caffeate was linearly correlative with the pH value of acetic acid/sodium acetate buffer, indicating the numbers of electron transfer and proton were equal. From the experiment data, it was observed that the redox peak current is rectilinear to ethyl caffeate concentration in the range of 4.0×10-7 mol L-1 to 7.2×10-6 mol L-1 (r = 0.9994, n = 8). The detection limit was 1.0×10-7 mol L-1, and the relative standard deviation was 2.0% (n = 11) at the 2.0×10-6 mol L-1 level.