Voltammetric Determination of Zn²⁺ in Antiseptic Dusting Powder and Multivitamins Using a Carbon Paste Electrode Modified with Bi Anchored on Amberlite^® IR120

This work presents a voltammetric method for Zn²⁺ determination in antiseptic dusting powder and multivitamin commercial samples, combining an alkaline extraction using NaOH aqueous solution with a carbon paste electrode chemically modified with Bi anchored on Amberlite^® IR120 ion exchange resin (CPEAmb/Bi). The best conditions for electrode preparation were: 10% (m/m) of Amberlite^® IR 120; 30 s Bi³⁺ accumulation time (open circuit) in 0.5 mmol L^-1 Bi³⁺ solution prepared in 0.1 mol L^-1 acetate buffer (pH = 5.5). The analytical curve for Zn²⁺ using the CPEAmb/Bi presented linear range from 0.05 to 8.2 µmol L^-1 and the limit of detection was 10 nmol L^-1. The voltammetric method was simple, fast, efficient and low-cost for the Zn²⁺ determination in antiseptic dusting powder and multivitamin samples.

Keywords:
anodic stripping voltammetry; chemically modified electrode; electrodeposition; Zn²⁺