Nafion/石墨烯/苯并-18-冠醚-6修饰玻碳电极方波阳极溶出伏安法测定蒲公英中的痕量铅

Square Wave Anodic Stripping Voltammetric Determination of Trace of Lead in Dandelion Using Nafion/Graphene/Benzo-18-Crown-6 Decorated Glassy Carbon Electrode

将全氟代磺酸脂、石墨烯(graphene)和苯并-18-冠醚-6(B18C6)修饰在玻碳电极(GCE)表面制备出Nafion/石墨烯/苯并-18-冠醚-6复合膜修饰玻碳电极(NA/GN/B18C6/GCE),通过方波阳极溶出伏安法选择性测定蒲公英中草药中痕量Pb^(2+)。在0.1 M pH为4.5的醋酸-醋酸钠缓冲液中对溶液pH值、沉积电位和沉积时间等实验参数进行了优化。NA/GN/B18C6/GCE电极呈现出明晰、可重复和尖锐的溶出峰,在5~60μg/L浓度范围内峰值电流随金属浓度增加呈线性响应,在S/N=3倍条件下Pb^(2+)的检测限为0.04μg/L。将NA/GN/B18C6/GCE电极成功应用于实际蒲公英样品中Pb^(2+)的测定,结果与电感耦合等离子体质谱法(ICP-MS)测定的结果相吻合,表明该电极在电化学分析应用中可有效替代传统铋膜电极。

A glassy carbon electrode(GCE)was modified with Nafion(NA),graphene(GN)and benzo-18-crown-6 to give an electrode(NA/GN/B18C6/GCE)for the selective determination of trace of Pb^(2+) in Chinese medicinal herb dandelion via square wave anodic stripping voltammetry(SWASV).Operational parameters such as solution pH value,deposition potential and deposition time were optimized with respect to the determination of Pb^(2+) in 0.1 M HAc-NaAc buffer solution(pH 4.5).The NA/GN/B18C6/GCE electrode gave well-defined,reproducible and sharp stripping peaks,and the peak current response increased linearly with the metal concentration in a range of 5~60μg/L,with a detection limit of 0.04μg/L under S/N=3 condition.The NA/GN/B18C6/GCE electrode was successfully applied to analysis onPb^(2+) in real dandelion sample and the result was well consistent with determination by inductively coupled plasma mass spectrometer(ICP-MS)technique,suggesting that the electrode can be considered as an effective alternative to the conventional bismuth film electrode for practical use in electrochemical analysis studies.