Lead(II) Determination in Aqueous and Firearm Discharge Residue Samples Using A Bistriazole-Modified Electrochemical Sensor

Abstract

The detection of heavy metals is necessary due to their toxic characteristics and bioaccumulation potential, which can be harmful to living organisms. Chemically modified electrodes have been widely used as an alternative in the detection of heavy metal ions, aiming for improved selectivity resulting from specific interactions with these analytes. Therefore, ligands derived from bistriazolic compounds emerge as new materials capable of interacting with metallic ions, potentially enhancing the detectability of the electrode. In this context, this work aims to obtain an electrochemical sensor based on a modifier derived from bistriazoles for the determination of lead(II) ions in different samples. The 1,3-bis(4-ethyl-1H−1,2,3-triazol-1-yl)propan-2-one (BT) was characterized using spectroscopic, spectrometric, and electrochemical techniques. Additionally, a method for the determination of lead(II) ions was developed using differential pulse voltammetry (DPV), where the bis-triazole modified electrode demonstrated remarkable detectability for Pb²⁺. Optimizations of the scan medium and DPV technique parameters showed a significant increase in the analytical signal current for Pb²⁺. An analytical curve was obtained, and the developed method achieved a limit of detection of 0.10 nmol L⁻¹. The method was applied to quantify the analyte in tap water, river water, and firearm discharge residue samples with recovery values ranging from 87.8% to 118%, highlighting the reliability and precision of the developed method.