碳糊电极阳极溶出法测定单宁酸的研究

Study on Anodic Stripping Voltammetric Determination of Tannin Acid with Carbon Paste Electrode

用碳糊电极阳极溶出法研究了单宁酸的测定方法。实验表明，在1．0mol／L HCl介质中，富集120s，单宁酸在0．65V（vs．SCE）处出现阳极溶出峰，在5．0×10^-7～6．0×10^-5mol／L范围内，其峰电流的大小与单宁酸的浓度呈线性关系，相关系数为0．9991，检出限为1．0×10^-7mol／L。该法灵敏度较高，操作简便，可用于啤酒中单宁酸的测定，平均回收率为99．8％。

A carbon paste electrode is applied to the determination of tannin by the anodic stripping voltammetry. In 1.0 mol/L HCl solution, the anodic stripping peak of tannin is observed at ＋0. 65 V （vs. SCE）. The linear relationship between the peak current （ip） and the concentration of tannin is obtained in the range of 5.0×10^-7～6.0×10^-5mol/L,with a correlation coefficient of 0. 9991. Detection limit of this method is 1.0 × 10^-7mol/L. This methods has been applied to the determination of Tannin in beer, the recoveries was 99. 8%. This method is proved to be of high sensitivity, convenient and rapid in operation.