大黄酚在玻碳电极上的直接电化学行为及其测定

目的: 研究大黄酚玻碳电极上的电化学行为;建立测定大黄酚含量的电化学分析新方法。 方法: 采用循环伏安法研究大黄酚在玻碳电极上的电化学行为及其电极反应机理,以差示脉冲伏安法建立了检测大黄酚含量的电化学分析新方法。 结果: 在pH 4.0醋酸盐缓冲液中,-0.8~+0.2 V点位区间内,大黄酚在玻碳电极表面发生的电极反应是受吸附控制的准可逆双电子转移过程,电子转移系数α=0.604;以差示脉冲伏安法(DPV)测得其氧化峰电流I_pa与浓度在1.0×10^-7 ~ 9.0×10^-6 mol·L^-1范围内呈良好的线性关系,检出限为5.0×10^-8 mol·L^-1。重现性试验的RSD为2.9%,加样回收率为98%~104%。 结论: 本法操作简单、快速准确,并用于实际样品中药大黄中大黄酚的含量检测,结果令人满意。

Objective: To study the voltammetric behavior and establish a novel method for the determination of the concentration of chrysophanol. Methods: The electrochemical behavior of chrysophanol was studied by voltammetry on a glassy carbon electrode.The results shows that a pair of well-defined redox peak of chrysophanol was observed and the electrode process is adsorption-controlled. Results: The relationship between oxidation peak current and the concentration of chrysophanol is linear in the range of 1.0 ×10^-7 -9.0×10^-6 mol·L^-1 by differential pulse voltammetric method.The detection limit had been estimated as 5.0×10^-8 mol·L^-1. Conclusion: The method has been successfully used to detect chrysophanol in Rhubarb.