A Novel Carbon Paste Electrode Modified with N1-Hydroxy-N1,N2-Diphenylbenzamidine for the Electrochemical Determination of Cadmium(II) in Environmental Samples

Abstract

The present study introduces a novel electrode for rapid, highly sensitive, and selective electrochemical sensor for cadmium(II) using 5% N1-hydroxy-N1,N2-diphenylbenzamidine (HDPBA) modified carbon paste electrode (CPE) (HDPBA‒CPE). Surface characterizations and structural analysis of the proposed HDPBA‒CPE were performed using several analytical techniques. The voltammetric measurements of Cd(II) were conducted by cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV). Several experimental conditions such as composition and pH of buffer solutions, HDPBA composition, accumulation potential and time, and other voltammetric conditions were optimized. Cd(II) was preconcentrated on the modified electrode surface for 270 s using Britton Robinson (B-R) buffer (0.1 M, pH 4) at −1.0 V versus Ag/AgCl, followed by electrochemical oxidation of the accumulated Cd(II) in the positive scan of SWASV after a quiet time of 10 s. Under optimized parameters, the proposed method showed a linear range of 0.3–100 nM Cd(II) with a detection limit of 0.032 nM. The fabricated HDPBA-modified carbon paste electrode exhibited excellent sensitivity, selectivity, stability, and reproducibility (with RSD of 3.8%). The developed HDPBA‒CPE was used for the quantification of Cd(II) in tobacco and environmental water samples, and it was found to be applicable for the determination of different types of real samples.

Development of a new electrochemical method for the determination of copper(ii) at trace levels in environmental and food samples

“…3a). 27,28,34 Aer modi-cation of the unmodied CPE with HDPBA (HDPBA/CPE), the pores distribution becomes uneven. Moreover the numbers and sizes of the pores increased due to the incorporation of HDPBA into the surface of the carbon paste (Fig.…”

“…22 Modied carbon paste electrodes (MCPEs) are versatile electrodes for the determination of heavy metal ions that have been extensively developed in recent times because of their regenerating ability, large surface area for modication, simple preparation, high sensitivity and selectivity of electrochemical techniques. [22][23][24][25][26][27][28][29] Among various types of modiers, organic ligands have been used for the modication of carbon paste electrodes in the electrochemical determination of metal ions due to their chelating capability with metal ions since they have electron donor atoms such as O, N, S, and P on their chemical structures which can form stable complexes with metals ions. N 1 -hydroxy-N 1 ,N 2 -diphenylbenzamidine (HDPBA) (Fig.…”

“…33 HDPBA modied carbon paste electrode has been successfully employed for the electrochemical determination of Hg(II), Cd(II) and Pb(II). 27,28,34 However, to the best of our knowledge, carbon paste electrode modied with HDPBA with and without the incorporation of MWCNTs has not been used for the voltammetric determination of copper(II). Therefore, the development of carbon nanotubes/ligands modied CPE is very important for the electrochemical determination of heavy metals with magnicent sensing performance.…”

“…22 Modified carbon paste electrodes (MCPEs) are versatile electrodes for the determination of heavy metal ions that have been extensively developed in recent times because of their regenerating ability, large surface area for modification, simple preparation, high sensitivity and selectivity of electrochemical techniques. 22–29…”

Simultaneous electrochemical determination of cadmium(II), lead(II), and mercury(II) ions in water and food samples using N1‐hydroxy‐N1,N2‐diphenylbenzamidine and multi‐walled carbon nanotubes modified carbon paste electrode

“…Previously, HDPBA was used for solvent extraction and spectrophotometric determination of several metal ions, such as cobalt(II) and iron(III) [26,27], molybdenum(V) [28], vanadium(V) [29], and manganese(VII) [30]. It was also successfully applied as a modifier in carbon paste electrodes for the voltammetric determination of individual metal ions, including Hg(II) [31], Cd(II) [32], Cu(II) [33], and Pb(II) [34]. However, HDPBA has not been applied for the simultaneous voltammetric determination of Cd-(II), Pb(II), and Hg(II).…”