大黄酸微分脉冲伏安法的研究和应用

Studies on Electrochemical Behaviour of Rhein

利用循环伏安法(CV)、线性扫描伏安法(LSV)、方波伏安法(SWV)和微分脉冲伏安法(DPV)等现代电化学技术,对大黄酸在玻碳电极(GCE)上的电化学氧化还原行为以及电极反应机理进行了研究,同时还建立一种灵敏的测定大黄酸的分析方法.实验结果表明,在 pH 4.6的B R缓冲液中,大黄酸在 0.492 V(vs.SCE)电位处产生灵敏的微分脉冲阴极还原峰, 该还原峰的峰电流值与大黄酸的浓度在 4.0×10-7 mol/L^1.0×10-5 mol/L范围内呈良好的线性关系,最低检测限(D = 3σ/K)为3.9×10-8 mol/L.该法已成功地用于大黄碳酸氢钠片剂和兔血清中大黄酸的测定,结果令人满意,其回收率介于90.0%~100.1% 之间.并进一步对大黄酸在玻碳电极(GCE)上的电化学反应机理进行了探讨.

In 0.04 mol/L Brittion-Robinson buffer solution(pH=4.60) , the electrochemical behavior of rhein at a glassy carbon electrode has been studied by cyclic voltammetry, linear sweep and pulse voltammetry. The experimental results indicated that the number of electron involved in this electrochemical reation was 2, and the electrode transfer coefficient was 1.06. Meanwhile, the electrochemical reaction mechanism of this system has also been discussed. The linear response range for Rhein was 4.0×10^(-7) mol/L～1.0×10^(-5) mol/L with a detection limit of 3.9×10^(-8) mol/L (D = 3σ/K). The method has been used for the determination of Rhein in Rhubarb and Sodium Bicarbonate Tablets and in serum of rabbit.