Study on Electrochemical Behavior of Emodin by Cyclic Voltammetry

Electrochemical behavior of emodin was studied by cyclic voltammetry,and direct determination of emodin in rhuharb by linear scanning polarography was proposed without pre-separation.In a B-R buffer solution of pH 5.72,a sensitive polarographic peak of emodin was observed at the potential of -0.434 V (vs.Ag/AgCl).Linear relationship between values of peak current and concentration of emodin was obtained in the range of 1×10-6-1.5×10-5mol·L-1.It was shown that,at a low scanning rate,the reduction process of emodin is an quasi-reversible electrode process,controlled mainly by adsorption.