Sensitive and simultaneous method for the determination of naphthol isomers by an amino-functionalized, SBA-15-modified carbon paste electrode

Abstract

The amino-functionalized, SBA-15-modified carbon paste electrode (NH₂-SBA15/CPE) was prepared and successfully developed for the sensitive and simultaneous electrochemical determination of naphthol isomers. The electrochemical behaviors of 1-naphthol (1-NAP) and 2-naphthol (2-NAP) on different electrodes were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in Britton–Robinson buffer solutions (pH 2.5). The results demonstrated that the NH₂-SBA15/CPE exhibited better electrocatalytic performance and higher sensitivity toward naphthol isomers than those at the SBA15/CPE and bare CPE, and it could well separate their oxidation peaks by CV and DPV. Under the optimized conditions, the oxidation peak currents showed good linearity in the ranges of 1.0 × 10⁻⁸–1.0 × 10⁻⁶ M for 1-NAP and 2-NAP, with a low detection limit of 1.0 × 10⁻⁹ M (S/N = 3). More importantly, the developed method was applied to the quantitative determination of 1-NAP and 2-NAP in wastewater samples from a chemical plant and displayed satisfactory sensitivity and selectivity.