石墨烯-Nafion修饰电极同时测定邻苯二酚、对苯二酚

通过恒电位法将氧化石墨烯还原为石墨烯,制备了石墨烯-Nafion修饰玻碳电极.用循环伏安法研究了邻苯二酚和对苯二酚两种异构体在该电极上的电化学行为.结果表明,该修饰电极对苯二酚的这两种异构体的氧化表现出了优异的识别能力和电催化性能.对苯二酚和邻苯二酚的氧化峰电位差值为102 mV,这表明两种异构体可以在石墨烯-Nafion修饰电极上完全分开.基于对苯二酚和邻苯二酚在石墨烯-Nafion修饰电极上的伏安行为,建立了苯二酚两种异构体同时测定的方法.在最佳实验条件下,邻苯二酚的浓度在6.0×10-5~1.0×10-3mol/L范围内与氧化峰电流呈线性关系,检出限为1.0×10-5mol/L.对苯二酚的浓度在8.0×10-6~1.0×10-3mol/L范围内与氧化峰电流呈线性关系,检出限为2.0×10-6mol/L.该电极可用于模拟样品中两种异构体的同时测定,结果令人滿意.

Simultaneous Determination of Catechol and Hydroquinone by Graphene-Nafion Modified Electrode

A graphene-Nafion modified glassy carbon electrode （graphene-Nafion/GCE） was prepared by potentiostatic reduced graphene oxide on electrode surface. The electrochemical behavior of catechol and hydroquinone at the graphene-Nafion/GCE was investigated by cyclic voltammetry. The experimental results showed that the graphene-Nafion/GCE exhibited strong recognition and electrocatalytical ability toward two dihydroxyhenzene isomers. The oxidation peak potential difference between hydroquinone and catechol was 102 mV,which indicated that the two isomers could be identified entirely at the graphene-Nafion/GCE. Based on their voltammetric behavior, a method was proposed for the simultaneous determination of two dihydroxybenzenes at the graphene-Nafion/GC electrode. Under the optimum conditions,the oxidation peak current was linearly proportional to the concentration of catechol in the range of 6.0 ×10-5~1.0 ×10-3 mol/L,and its detection limit was 1.0 ×10-5 mol/L. The calibration curves showed good linear relationship for hydroquinone in the range of 8.0 ×10 -6~1.0 ×10 -3 mol/L,and its detection limit was 2.0×10-6 mol/L. The proposed method was successfully applied in simultaneous determination of two dihydroxyhenzene isomers in simulated samples.