Electrochemical Determination Of Pb Research Articles

Greener synthesis of novel nanocomposite material for efficient and selective trace detection of Pb<sup>2+</sup>: Insights of stability and real implications of fabricated electrode

This work reports the use of highly efficient nanocomposite material fabricated glassy carbon electrode (Ag(NPs)/ChS/GC) in the trace detection of Pb<sup>2+</sup> using differential pulse voltammetry (DPV). A facile method yielded the silane-grafted chitosan (ChS) using 3-trimethoxyoctylsilane, and the bioderived Ag(NPs) was <i>in situ</i> decorated on the ChS composite to obtain Ag(NPs)/ChS. X-ray Diffraction (XRD) results showed the presence of Ag(NPs) within the composite material. Spherical-shaped and uniform distribution of Ag(NPs) were observed in SEM and TEM images of the nanocomposite solid. The cyclic voltammetric studies revealed a significant increase in redox peak currents (i.e., 0.1283 mA), which was obtained using the Ag(NP)/ChS/GC compared to the bare glassy carbon electrode. Further, the electrochemical determination of Pb<sup>2+</sup> showed good linearity in anodic peak current and Pb<sup>2+</sup> concentrations (5.0-80.0 <i>μ</i>g/L), and the limit of detection was 1.97 <i>μ</i>g/L. With 10-fold increase in several cationic and anionic interfering ions, oxalic acid and glycine only show interference in determination of Pb<sup>2+</sup>. The reproducibility study showed a %RSD of 2.43%, and the electrode could be efficiently used for prolonged and repetitive detection having reasonably low %RSD of 2.55%. The real water analysis showed almost 100% recovery of Pb<sup>2+</sup> in two different real water samples.

A new modified carbon paste electrode using N1-hydroxy-N1,N2-diphenylbenzamidine for the square wave anodic stripping voltammetric determination of Pb(II) in environmental samples

This study presents a new method for simple, selective and sensitive electrochemical determination of lead(II) using N1-hydroxy-N1,N2-diphenylbenzamidine (HDPBA) modified carbon paste electrode. HDPBA was easily prepared in the laboratory from common chemicals. Morphological characterizations and spectroscopic analyses of the developed electrode were conducted using various analytical techniques such as electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), Fourier transform infrared (FTIR), and ultraviolet-visible (UV–Vis) spectroscopic techniques. The electrochemical determination of Pb(II) was performed using square wave anodic stripping voltammetry (SWASV) and cyclic voltammetry (CV). The effects of several experimental parameters such as modifier composition in the carbon paste, composition and pH of supporting electrolyte solutions, accumulation time, accumulation potential, and other instrumental parameters were studied for the analytical application. Pb(II) was accumulated for 270 s on the surface of the modified electrode using 0.1 M sodium acetate (NaAc) pH 5 at −0.90 V vs Ag/AgCl, followed by electrochemical stripping with SWASV in the same solution after a resting time of 10 s. The linear range was found to be 0.0001–2.5000 μM Pb(II) with a limit of detection of 0.0094 nM which are better than most of the reported method based on 2–4 different modifiers in a single electrode. The proposed method was found to be highly sensitive and selective. In addition, the developed electrode showed good reproducibility (with RSDs of 4.3%), long-term stability, and fast response. The proposed method has been successfully applied to the determination of trace levels of Pb(II) in various environmental samples such as wastewater, vegetable, fish, and cigarette samples.

Electrochemical Determination of Pb(II) Using Carbon Paste Electrodes Modified with Ion Imprinted Polymers (IIPs)

An easy, low-cost, and highly selective carbon paste electrode based on an ion-imprinted polymer (IIP) to determine Pb(II) in real samples was developed. The recognition cavities based on a cross-linked polymer selective to Pb(II) were created using vinyl pyridine. The modified CPE was constructed by a composite mixture with the synthesized IIP. A notable difference was observed in the electrochemical response of the electrodes modified with the IIP and a non-imprinted polymer, demonstrating the unique properties of the IIP recognition sites. The parameters related to the current intensity were optimized; the selectivity was also studied considering potential interference ions. The proposed modified electrode demonstrated to be as (or more) selective to Pb(II) compared to others previously reported in the literature. A linear concentration range from 3.3 mg/L to 33 mg/L with a limit detection of 1 mg/L was obtained. The Pb(II) preconcentrated on the electrode surface was successfully quantified in real potable water samples without previous treatment.

Single-Use Fluidic Electrochemical Paper-Based Analytical Devices Fabricated by Pen Plotting and Screen-Printing for On-Site Rapid Voltammetric Monitoring of Pb(II) and Cd(II).

This work reports the fabrication of integrated electrochemical fluidic paper-based analytical devices (ePADs) using a marker pen drawing and screen-printing. Electrodes were deposited on paper using screen-printing with conductive carbon ink. Then, the desired fluidic patterns were formed on the paper substrate by drawing with a commercial hydrophobic marker pen using an inexpensive computer-controlled x-y plotter. The working electrode was characterized by cyclic voltammetry and scanning electron microscopy. The analytical utility of the electrochemical PADs is demonstrated through electrochemical determination of Pb(II) and Cd(II) by anodic stripping voltammetry. For this purpose, the sample was mixed with a buffer solution and a Bi(III) solution, applied to the test zone of the PAD, the metals were preconcentrated as a bismuth alloy on the electrode surface and oxidized by applying an anodic potential scan. The proposed manufacturing approach enables the large-scale fabrication of fit-for-purpose disposable PADs at low cost which can be used for rapid on-site environmental monitoring.

Sensitive and interference-free electrochemical determination of Pb(II) in wastewater using porous Ce-Zr oxide nanospheres

Herein, combined the synergetic effects and excellent adsorption of binary oxides, a novel sensor interface was designed by using porous Ce-Zr oxide nanospheres modified glassy carbon electrode (Ce-Zr oxide/GCE), which has successfully realized high sensitivity and anti-interference detection of Pb(II). The electrochemical determination of Pb(II) has been investigated by square wave anodic stripping voltammetry (SWASV) range from 0.02 to 0.5μM, and a high sensitivity per unit area of 1666.02μAμM−1cm−2 was obtained with a limit of detection of 0.006μM (3σ method). The enhancement of Pb(II) stripping signal is attributed to the excellent adsorption performance of porous Ce-Zr oxide nanospheres, which has been confirmed with X-ray photoelectron spectroscopy (XPS). Importantly, Ce-Zr oxide/GCE possesses highly anti-interference ability against the influence of Hg(II), Cd(II), Cu(II), and Zn(II) in the determination of Pb(II). Meanwhile, the remarkable stability and reproducibility were obtained. Finally, the accurate analysis of Pb(II) in wastewater collected from Wangtang sewage disposal plant was achieved. These results indicate that porous Ce-Zr oxide nanospheres are identified as promising modifier for the reliable and accurate determination of Pb(II).

SWASV performance toward heavy metal ions based on a high-activity and simple magnetic chitosan sensing nanomaterials

A high-activity, eco-friendly and inexpensive magnetic chitosan sensing nanomaterials were introduced for individual electrochemical detection toward Pb(II), Hg(II), Cu(II) and Cd(II) by square wave anodic stripping voltammetry (SWASV). The morphology and structure of Fe3O4-chitosan nanoparticles were characterized by TEM, XRD and FTIR respectively, and their electrochemical behavior based on the sensing materials modified glassy carbon electrode (GCE) was studied by cyclic voltammograms (CV) and electrochemical impedance spectra (EIS). Serving as a heavy metal ions sensor, the chitosan magnetic nanoparticles exhibited much more remarkable electrochemical response toward heavy metal ions. Especially, the introduction of chitosan significantly enhanced the SWASV performance toward Pb(II) with the high sensitivity of 50.6 μA/μM and LOD of 0.0422 μM, which was about 4.8 times than pure Fe3O4 nanoparticles. This result might be due to the strong charge-transfer interaction as well as the chelation and electrostatic interaction existence between Pb(II) and Fe3O4-chitosan unit, which will generate a high concentration region at electrode surface for efficient redox interaction between electrode and Pb(II). Furthermore, the Fe3O4-chitosan modified GCE offers good stability and potential practical applicability in the electrochemical determination of Pb(II). This work provides a potential simple and low cost material for electrochemical detection of toxic metal ions.

Continuous preparation of Fe3O4 nanoparticles through Impinging Stream-Rotating Packed Bed reactor and their electrochemistry detection toward heavy metal ions

We reported the continuous preparation and electrochemical behavior toward heavy metal ions of the Fe3O4 nanoparticles (Fe3O4 NPs). This Fe3O4 NPs were fabricated through a novel Impinging Stream-Rotating Packed Bed reactor with a high production rate of 2.23 kg/hour. The as-prepared Fe3O4 NPs were quasi-spherical with a mean diameter of about 10 nm and shown the characteristics of superparamagnetism with the saturated magnetization of 60.5 emu/g. The electrochemical characterization of the as-prepared Fe3O4 NPs toward heavy metal ions were evaluated using square wave anodic stripping voltammetry (SWASV) analysis. The results indicated that the modified electrode could be used to individual detection of Pb(II), Cu(II), Hg(II) and Cd(II). In particular, the modified electrode exhibited the selective detection toward Pb(II) with higher sensitivity of 14.9 μA/μM, while the response to Cu(II), Hg(II) and Cd(II) were negligible. Besides, the modified electrode shown good stability and potential practical applicability in the electrochemical determination of Pb(II). This above results offered a simple method for continuous preparation sensing materials in the application field of electrochemical detection of toxic metal ions through the technology of process intensification.

Electrochemical determination of Pb(II) at a gold electrode modified with a self-assembled monolayer of 2,5-dimercapto-1,3,4-thiadiazole

2,5-Dimercapto-1,3,4-thiadiazole (DMTD) self-assembled monolayer on gold electrode was prepared and investigated by electrochemical measurement. The DMTD/Au electrode exhibited a significantly increased sensitivity and selectivity for Pb(II) in acetate buffer (pH 5.5) at a potential of −1.0 V (vs Ag/AgCl) for 4 min by anodic stripping voltammetry. The influence of various experimental parameters on the voltammetric response was studied. Under the optimized working conditions, the dependence of the stripping peak current response on concentration of Pb(II) was linear in the range of 1–45 µmol L−1 with a correlation coefficient of 0.9988, and the detection limit was 0.10 µmol L−1. The relative standard deviation of the results was 3.4% for six successive determinations of a 20 µmol L−1 Pb(II) solution. A study of interfering substances was also performed. The method was applied to the determination of Pb(II) in water samples with satisfactory results.