聚苏木精/氧化石墨烯修饰玻碳电极测定水样中痕量铅和镉

Determination of Lead and Cadmium by Differential Pulse Stripping Voltammetry Based on Graphene Oxid

摘要: 将玻碳电极用氧化石墨烯修饰后电聚合上苏木精聚合膜,利用该修饰电极差分脉冲溶出伏安法同时测定铅和镉.对支持电解质及其缓冲溶液、富集电位及富集时间测定条件进行了优化.在0.1 mol/L pH 3.5的NaAc-HAc缓冲液中,以此修饰电极为工作电极,在-1.1 V处搅拌富集220 s,用差分脉冲伏安法分别测定-0.58 V和-0.8V处的氧化峰电流.结果表明,该电极显著提高了铅和镉的电化学响应信号.在优化条件下,峰电流与铅和镉的浓度在0.011μmol/L范围内呈良好的线性关系,相关系数为0.9910.995.检出限分别为8 nmol/L（Pb2+）和1 nmol/L（Cd2+）（S/N=3）.将该法用于实际水样中痕量铅和镉的测定,回收率为92.2%105.8%

Abstract: Hematoxylin was electrodeposited on graphene oxide immobilized on the surface of a glassy carbon electrode（GCE）.The results show that hematoxylin-graphene oxide significantly improved the electrochemical response towards Pb2+ and Cd2+ in comparison with bare GCE.The peak currents varied linearly with the concentration of Pb2+ and Cd2+ over the range of 0.011 μmol/L with the detection limit of 8 and 1 nmol/L,respectively,after 220 s accumulation at-1.1 V in 0.1 mol/L NaAc-HAc（pH 3.5） b...