Evaluation of carbon paste electrode modified with heavy metals for the analysis of paracetamol by voltammetry and impedance spectroscopy

Abstract

The present document reports on the electrocatalytic activity of heavy metals (Copper(II), Nickel(II), Manganese(II) and Lead(II)) modified carbon paste electrodes (HM/CPE) for the paracetamol (Pr) oxidation where its results are compared with carbon paste electrode. The voltammetric behavior of Pr is explored where a sensitive anodic peak has appeared at about 0.27 V (vs. Ag/AgCl/3 M KCl) in 0.1 M Na2 SO4 (pH 12). This peak results from the irreversible oxidation of Pr at HM/CPE surface. The catalytic effect was evaluated using cyclic and square wave voltammetry. Electrochemical impedance spectroscopy also confirms our experimental results as the HM/CPE shows the least charge transfer resistance. Also, HM/ CPE can be utilized successfully to ameliorate the electroanalysis of Pr at very weak concentration with excellent sensitivity. The calibration curves were linear from 6.0 · 10-5 to 8.0 · 10-4 mol L-1. The detection limits were found approaching 10-9 mol L-1. Then, the proposed method was applied to detect Pr in river water samples with satisfactory results.