摘要
用循环伏安法、单扫描示波极谱法研究了甘草酸（ｇｌｙｃｙｒｒｈｉｚｉｃ，ＧＡ）在汞电极上的电化学行为及反应机理．证明甘草酸在ｐＨ＝４～１２的缓冲溶液（Ｈ３ＢＯ３＋Ｈ３ＰＯ４＋乙酸＋ＮａＯＨ）中有吸附峰，且示波极谱导数峰值与甘草酸浓度在８．３×１０－５～１．２×１０－６ｍｏｌ／Ｌ范围内成正比，使用悬汞电极（ＨＭＤＥ）线性扫描伏安法可使检测下限达２．４×１０－６ｍｏｌ／Ｌ．根据实验结果首次提出了甘草酸在汞电极上的反应机理．该机理同时被紫外光谱证明。
The electrochemical response characteristics of glycyrrhizic acid (GA) on the mercury electrode are described. In Britton Robinson buffer, the cyclic voltammograms exhibit two reduction peaks at a potential range of -0.80～-1.60 V.The peak potentials and currents change significantly when solution pH changes. By means of ultraviolet abosrption method, it is proved that the reduction position of GA molecular is ketenes radical. The peak potentials move positively with increasing pH demonstrate that the primary electrode reaction is accompanied by a coupled chemical reaction.The electrode reaction process is a typical example of ECE mechanism. Some effects of various parameters on adsorptive stripping voltammetry were also estimated. The proposed method has been applied to analysis practice examples.
出处
《电化学》
CAS
CSCD
1997年第1期50-54,共5页
Journal of Electrochemistry
