大黄酚的电化学行为及其应用研究

Studies on Electrochemical Behaviour of Chrysophanol and Its Application

大黄酚在０．１５ｍｏｌ／ＬＨＡｃ－ＮａＡｃ（ｐＨ４．９）底液中，出现一灵敏的示波极谱导数峰，峰电位为－０．４５Ｖ（ｖｓ．ＳＣＥ），峰电流与大黄酚浓度在２．０×１０－７～５．０×１０－６ｍｏｌ／Ｌ范围内成线性关系，检测限为２．０×１０－８ｍｏｌ／Ｌ。用于生药大黄中大黄酚的测定，回收率９２．４％～１０８．４％。用多种电化学手段研究体系的电化学行为，测得电极反应电子数ｎ＝２。体系具有吸附性，并符合Ｆｒｕｍｋｉｎ吸附等温式，吸附系数β＝７．９２×１０４，吸引因数α＝１．７０。

In 0.15mol/L HAc NaAc(pH=4.9) solution,a sensitive wave of chrysophanol is obtained by single sweep polarography.The peak potential is -0.45V( vs .SCE) .The linear relationship holds between the peak current and the chrysophanol concentration ranging from 2.0×10 -7 ～5 0×10 -6 mol/L with a detection limit of 2.0×10 -8 mol/L.The electrochemical behaviour of the system was studied by cyclic voltammetry,etc.Its adsorption obeys Frumkin adsorption isotherm.The adsorption coefficient β is 7.92×10 4 ,the attraction factor α is 1.70