Adsorptive Cathodic Stripping Voltammetric Studies of Emodin

A differential pulse cathodic stripping voltammetric (DP-CSV) method for determination of emodin in Britton- Robinson buffer (pH2) at a hanging mercury drop electrode (HMIDE) is described. The method is based on measuring the reductive peak height at —0.25V vs. Ag/AgCl reference electrode. The linear relationship between the peak current and emodin concentration allowed the voltarnmetric determination of emodin over a wide concentration range 1.0 X 10-2 —2.5 X10-6 M, with a relative standard deviation of 3.3% (10 determinations at 1 X 10-2 M). Adsorption of emodin at HMDE enabled a detection limit of 2X10-1°M after 3 min accumulation at 0.0V. The applicability of the suggested method was found to be suitable for the determination of emodin in roots, stems and leaves of Rumex cyprius plant.