葛根素及其与金属离子的极谱行为研究

采用单扫描极谱法(LSP)研究了葛根素的极谱行为,在建立一种简单、快捷和灵敏的葛根素单扫描极谱分析方法的同时,考察了金属离子对于葛根素极谱波的影响及其相关性质.实验研究表明:在pH=12.40的乙二胺(1 mol/L)底液中,以滴汞电极(DME)为工作电极,Pt电极为对电极,饱和甘汞电极(vs·SCE)为参比电极的三电极系统,在-0.30 V～-0.80 V之间用LSP法扫描,发现葛根素在峰电位(Ep)为-0.58 V(V,SCE)处有一个灵敏的二阶导数的极谱峰,其浓度在0.M5～5.53mg/L时峰高(Ip)与浓度成很好的线性关系.标准曲线的相关系数为0.994 9,最小检测限为0.065mg/L.在最佳实验条件下,在葛根素溶液中加入金属离子Cu2 、Al3 、Pd2 、Fe3 进行LSP扫描,发现不同金属离子可使葛根素极谱峰的峰电位产生不同程度的负移和峰高增大现象,说明金属离子和葛根素有一定的络合反应发生,因此依据实验结果,计算得出金属离子Cu2 、Fe3 和葛根素络合反应的K稳.从样品分析的结果得出,利用葛根素在Ep为-0.58 V(vs·SCE)时的二阶导数极谱波对葛根素进行极谱分析的方法是可行的.

Single-sweep Polarographic Study on Puerarin

A simple, rapid and sensitive single-sweep polarographic method is set up for the polarographic study on puerarin, and the influence of metal ions on the polarographic wave is investigated. In the experiments, a solution of ethylenediamine with a pH value of 12. 40 and a Three-Electrode System, which consists of DEM (working electrode), Pt electrode (reduced electrode) and VS (SCE reference electrode), are used. LSP method is adopted to sweep from -0. 30 V to -0. 80 V, and a sensitive first derivative single sweep polarography peak of puerarin is found at -0. 58 V (VS, SCE). A linear relationship with the peak is obtained over the concentration range of 0. 145-5. 53 mg/L: The linear dependent coefficient is 0. 994 9, and the minimum detection limit is 0. 065 mg/L. In the best conditions, Cu2+ , Al3+ , Pd2+ and Fe3+ are added, and the peak of puerarin is found higher. The K of complex can be obtained by taking the Cu2+ for example. Based on the experiment results, we find that using this method to analyze the specimen is simple, rapid and sensitive.