Determination of Cadmium Ions Using Schiff-Base Modified Carbon Paste Electrode: A Box-Behnken Design Approach

Abstract

Being one of the hazardous contaminants in the environment, continuous exposure to cadmium ions (Cd (II)) has been shown to severely affect the well being of both humans and animals. Therefore, development of a highly sensitive method to detect trace amounts of such substance in the environment acquires scientific pertinence. In this present work, carbon paste electrode modified with bis (benzylidene) ethelynediamine (BBE-CPE) was used for the determination of Cd (II) using square wave anodic stripping voltammetric (SWASV) technique. A response surface methodological approach employing the Box-Behnken design (BBD) based on four relevant variables; pH, deposition time, percentage ligand and deposition potential was used for optimizing the experimental conditions for detecting such ions. Under optimized conditions (supporting electrolyte: pH 4.5, deposition time: 350 s, ligand graphite composition: 6%, deposition potential: ‒1.1 V), a linear response over a wide range of Cd (II) concentrations (1–500 μg L−1) with low detection limit (0.4 μg L-1) and quantification limit (1.4 μg L-1) were observed with deposition time being the most impacting factor. Pertinently, the BBE-CPE developed here exhibited exceptional recovery of Cd (II) concentrations in the sea and tap water samples, comparable with that observed under simulated conditions, suggesting its applicability for a variety of real samples.