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    石墨烯-纳米银修饰电极的制备及用于芦丁的测定

    Preparation of Graphene-Nano Silver Composite Modified Electrode and Its Application for Determination of Rutin

    • 摘要: 采用水热法制备石墨烯-纳米银(GR-AgNPs)复合材料,然后用扫描电镜、红外吸收光谱法、电化学阻抗谱法对其进行了表征。将复合材料滴涂在玻碳电极上,用循环伏安法、差分脉冲伏安法研究了芦丁在修饰电极上的电化学行为。结果表明:在pH 3.4的磷酸氢二钠-柠檬酸缓冲溶液中,该修饰电极对芦丁有明显的电催化作用,据此提出了用差分脉冲伏安法测定芦丁含量的方法。芦丁浓度在1.0×10-7~2.5×10-5mol·L-1内与其氧化峰电流呈线性关系,方法检出限(3S/N)为1.0×10-8mol·L-1。方法用于市售芦丁药片和苦荞中芦丁含量的测定,加标回收率分别为98.9%~101%和99.4%~103%;测定值的相对标准偏差(n=5)为0.41%~3.6%。

       

      Abstract: Graphene-nanosilver composites (GR-AgNPs) were prepared by hydrothermal reaction, and then characterized by scanning electron microscopy, infrared absorption spectroscopy and electrochemical impedance spectroscopy. The composites were dropped on the surface of glassy carbon electrode (GCE), and then electrochemical behavior of rutin on the modified electrode was studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). As shown by the experimental results, the modified electrode had obvious electrical catalysis on rutin in pH 3.4 of Na2HPO4-citric acid buffer solution. Based on these findings, a selective method for determination of rutin by DPV was proposed. Linear relationship between values of oxidation peak current and concentration of rutin was kept in the range of 1.0×10-7-2.5×10-5mol·L-1 with detection limit (3S/N) of 1.0×10-8mol·L-1. The proposed method was used in the analysis of samples of commercially available rutin tablets and Fagopyrum tataricum, and values of recovery found were in the ranges of 98.9%-101% and 99.4%-103% respectively. Values of RSDs (n=5) found were in the range of 0.41%-3.6%.

       

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