Electrochemical Determination of Vitamin B12 (Cyanocobalamin) using Mercury Nanodroplets Supported at Montmorillonite on a Carbon Paste Electrode (CPE)

Abstract

A simple and effective electrochemical sensor for cobalt using mercury nanodroplets supported on montmorillonite (MMT) was developed. Physical analyses allowed the identification of crystalline structure, morphology, and presence of mercury structures in MMT-Hg2+ with nanometric dimensions between 3 and 11 nm. Electrochemical responses obtained by differential pulse anodic stripping voltammetry (DPASV) using carbon paste electrode modified with montmorillonite decorated with mercury nanodroplets (CPEM-MT-Hg) toward cobalt (II) provide a limit of detection (LOD) of 3.4 × 10−6 mol L−1, limit of quantification (LOQ) of 1.1 × 10−5 mol L−1, and a linear dynamic range (LDR) from 3.5 × 10−5 to 2.9 × 10−4 mol L−1. The developed method was applied to the determination of cobalt ions in a commercial vitamin B12 sample.