多壁碳纳米管化学修饰电极线性扫描伏安法测定药片中芦丁

LINEAR SCANNING VOLTAMMETRIC DETERMINATION OF RUTIN WITH MULTI-WALL CARBON NANOTUBE (MWNT) MODIFIED ELECTRODE

多壁碳纳米管化学修饰电极的制备及应用该电极线性扫描伏安法测定药片中芦丁。将化学修饰电极置于含一定量芦丁的磷酸盐缓冲溶液中开路富集进行线性伏安扫描,记录0.54V左右的氧化峰电流对芦丁进行定量测定。试验条件为多壁碳纳米管用量为16μg·cm^(-2),支持电解质为0.1mol.L^(-1)磷酸盐缓冲溶液(pH2.0),开路搅拌富集4min,电位扫描范围从0～1.0V,扫描速度为75mV·s^(-1)。在最佳条件下,芦丁的线性范围在1×10^(-7)～2×10^(-5)mol·L^(-1),相对平均偏差为3.56%,检出限为5×10^(-8)mol·L^(-1)。该方法应用于药片中芦丁的测定,结果良好。

Method of preparation of the MWNT-modified glassy carbon electrode was described. The modified electrode showed good electrochemical response to rutin and was used in the voltammetric determination of rutin in rutin drug tablets. Rutin in the sample solution was first preconcentrated for 4min under open circuit condition in a 0. lmol·L^(-1) phosphate buffer solution of pH 2. 0, and the linear sweeping voltammetric diagram was taken in the potential range of 0. 0～1.0V with a scanning rate of 75mV·s^(-1). The content of rutin was determined by recording the oxidative peak current (i_p) near 0. 54V (vs. SCE). Under the optimum condition, linear relationship between i_p and concentration of rutin in the range of 1×10^(-7)～2×10^(-5) mol·L^(-1) was obtained with a detection limit of 5×10^(-8) mol·L^(-1)(S/N=3). Repeatability of the electrode was tested and RSD was found to be 3.56% (n=10) at the concentration level of 2×10^(-6)mol·L^(-1) of rutin. The proposed method has been used in the analysis of rutin drug tablets, and recoveries in the range of 97.8%～104.2% were obtained.