Nafion修饰玻碳电极吸附伏安法直接测定邻氨基苯酚

在 p H=2 .0的 0 .1 mol/ L H3 PO4 缓冲溶液中 ,开路搅拌富集 2 min后 ,从 0 .0 0～ +1 .0 0 V阳极扫描 ,OAP在 Nafion修饰玻碳电极上出现一灵敏的氧化峰 ,峰电位位于 0 .44 V。该峰电流与 OAP在 1× 1 0 - 7～ 2 .5× 1 0 - 5mol/ L的浓度范围内有良好的线性关系 ,检出限为 1× 1 0 - 8mol/ L。对支持电解质的种类及 p H值、Nafion的用量、富集电位及时间、以及扫描速度等进行了优化 ,提出了一种直接测定邻氨基苯酚的电化学方法。将此方法用于水样中邻氨基苯酚的测定 ,取得了满意的结果

Adsorptive Voltammetric Determination of o-aminophenol Using Nafion-modified Glassy Carbon Electrode

In this paper, a Nafion-modified glassy carbon electrode(GCE) for the determination of o-aminophenol(OAP) is described. In pH 2.0 0.1 mol/L H 3PO 4 buffer, OAP has very sensitive oxidation peak at the Nafion-modified GCE at 0.44 V(vs. SCE). Compared with the bare GCE, the Nafion-modified GCE can significantly improve the oxidation peak current. The parameters for the determination of o-aminophenol, such as supporting electrolyte, pH values, accumulation potential, open-circuit preconcentration time, and scan rate, are optimized. In pH 2.0 0.1 mol/L H 3PO 4 buffer, OAP can attract protons and have excess positive charges. Nafion contains -SO 3 - group and can attract cations. Via ion-exchange interaction, OAP can adsorb on the Nafion-modified glassy carbon electrode. Therefore, Nafion can enhance the sensitivity of determination of OAP. Using the Nafion-modified GCE, OAP in water samples has been determined. The average recovery is 101.74%.