Study on the electrochemical behaviour of the anticancer herbal drug emodin

The electrochemical behaviour of the anticancer herbal drug emodin was investigated by cyclic voltammetry (CV) at glassy carbon electrode. In 0.05 M NH3-NH4Cl (50% ethanol, pH 7.2) buffer solution, a pair of quasi-reversible redox peaks at potentials of Ep1Ep1 = −0.688 V and Ep2Ep2 = −0.628 V and one irreversible anodic peak, which was a typical anodic peak of emodin, at Ep3Ep3 = −0.235 V appeared at a scan rate of 100 mV/s. The irreversible anodic peak currents are linearly related to the emodin concentrations in a range from 8.9 × 10−8 M to 7.8 × 10−6 M with a pre-concentration time of 80 s under −0.620 V. Using the established method without pretreatment and pre-separation, emodin in herbal drug was determined with satisfactory results. Moreover, the electrode process dynamics parameters were also investigated by electrochemical techniques.