饮料中大黄酸在多壁碳纳米管修饰玻碳电极上的电化学行为及测定

Studies on electrochemical behaviors and analysis of rhein in drink at MWNTs modified glassy carbon electrode

目的：研究饮料中大黄酸在多壁碳纳米管（MWNTs）化学修饰玻碳电极（GCE）上的电化学行为。方法：建立了一种灵敏、直接检测大黄酸的电化学分析方法。结果：在pH4．7的NaAc-HAc缓冲溶液中于0.10V富集120S后，大黄酸在多壁碳纳米管修饰玻碳电极（MWNTs—GCE）上表现出灵敏的电化学响应，且氧化峰电位出现在-0．34V（VSSCE）。优化了底液的pH、修饰剂的用量、扫描速度、富集时间等测定参数。结论：多壁碳纳米管能催化大黄酸在修饰玻碳电极上的氧化还原。大黄酸的氧化峰电流与其浓度在0．20μg／ml到2．8μg／ml之间有良好的线性关系，回归方程y=40．39X-0，91，r=0．9996。回收率在102．1％～95.2％之间，RSD为1.5％～4．0％，方法的检测限为0．1μg／ml。

Objective：The electrochemical behaviors of rhein at the multi - wall carbon nanotubes （MWNTs） modified glassy carbon electrode （GCE） have been studied. Methods：The MWNTs modified GCE could be applied to detect rhein directly with high sensitivity. Results：When the rhein was deposited at 0. 1 V for 120 s in a NaA HAC buffer solution （ pH 4. 7）, the MWNTs modified GCE showed sensitive response toward rhein. Compared with the bare GCE, the redox peak currents of rhein significantly increased at the MWNTs - modified GCE under the optimal conditions. Conclusion ： The MWNTs show excellent electrocatalytic activity toward rhein. A linear range of 0. 2μg/ml - 2. 8μg/ml （ r = 0. 9954） with a detection limit of 0. 1μg/ml are observed at the applied oxidation peak potential of -0.34 V.