茶叶中儿茶酚的电化学检测方法研究

ELECTROCHEMICAL DETECTION METHOD OF CATECHOL IN TEA LEAVES

利用多孔碳修饰金刚石电极,采用循环伏安法对茶叶中儿茶酚进行了定量分析。通过对电解质溶液种类、电解质溶液pH以及多孔碳修饰量的优化发现,当以0.1 mol/L pH为7.5的PBS为电解质溶液、多孔碳修饰量为4μL时,其灵敏度较高,催化活性最好。在最佳试验条件下,儿茶酚浓度(c)在10~70μmol/L范围内与峰电流呈良好的线性关系,线性方程为:Y=0.027 52c-0.115 5,R^2=0.998 3,相关性较好,利用绘制的标准曲线对茶叶中的儿茶酚进行检测分析,测得茶叶中儿茶酚含量为17.39 mg/g。采用制备好的多孔碳修饰的金刚石电极对1.0×10^(-4) mol/L儿茶酚进行连续循环伏安扫描10次,其RSD为1.83%,重复性较好,精密度较高。

In this paper, the porous carbon diamond composite electrode was prepared and the catechol（ CC ） in tea was quantitatively analyzed by cyclic voltammetry. The type of electrolyte solutions, pH, and the modification amount of the porous carbon were optimized, and the results showed that the porous carbon diamond composite electrode had the highest sensitivity and the best catalytic activity when the modification amount of porous carbon was 4 μL in the presence of 0.1 mol/L PBS （pH 7.5）as electrolyte solution. Under the optimal conditions, the CC concentration had good linear relationship within 10 to 70 p, mol/L, with linear regression regression equation of Y=0.027 52c-0.115 5, R=0.998 3. The content of catechol in tea leaves was determined as 17.39 mg/g by using the standard curve. The porous carbon diamond composite electrode was used to conduct cyclic voltammetry continue scanning ten times in phosphate buffer solution including 1.0xl0-4 mol/L catechol, and results showed that the method（RSD 1.83%）had high repeatability and high precision.