scholarly journals Gold–Copper Film Electrode for Voltammetry Determination of Mercury in Water

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Nhi Phuong Thi Nguyen ◽  
Hue Thi Nguyen ◽  
Hop Van Nguyen ◽  
Long Thai Hoang

Gold-copper film electrode prepared in situ on carbon paste solid disk substrate (Au–CuF/CPE) was studied as a working electrode. The factors influencing mercury stripping peak currents, such as C Au III (0.20 mg/L), C Cu II (0.05 mg/L), type of acids and their concentration (HClO4, 0.005 M), deposition potential (-800 mV) for Au–CuF/CPE, deposition time (180 s), and interferents, were investigated and optimized. The method has a low limit of detection of 0.13 μg/L and is not affected significantly by the examined ions/substance. It was applied to detect the concentration of Hg in real water samples and is promising for practical usage.

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
T. Venu Gopal ◽  
Tukiakula Madhusudana Reddy ◽  
P. Shaikshavali ◽  
G. Venkataprasad ◽  
P. Gopal

Abstract A small scale of environmentally hazardous 4-aminophenol can show significant impact on human health. Hence, in the present work, we have designed L-Valine film (Vf) modified carbon paste electrode (Vf/CPE) for the determination of 4-aminophenol. Herein, a facile in-situ L-Valine film was developed by electrochemical polymerization method onto the surface of bare carbon paste electrode (BCPE) with the help of cyclic voltammetry (CV) technique. A two-folds of electrochemical peak current enhancement was achieved at Vf/CPE in comparison with BCPE towards the determination of 4-aminophenol in optimum pH 7.0 of phosphate buffer solution (PBS). This was achieved due to the large surface area and conductive nature of Vf/CPE, which was concluded through the techniques of cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The effect of pH of buffer and scan rate studies were successfully studied. Morphological changes of BCPE and Vf/CPE was studied with the help of scanning electron microscopy (SEM). The formation of Vf on CPE was also analyzed by Fourier transform infrared (FTIR) spectra. Under the optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) values of 4-aminophenol were estimated with the aid of chronoamperometry (CA) technique and was found to be 9.8 μM and 32 μM, respectively. Finally the proposed method was found to have satisfactory repeatability, reproducibility and stability results with low relative standard deviation (RSD) values.


2020 ◽  
Vol 307 ◽  
pp. 231-246
Author(s):  
Syaza Azhari ◽  
Roswanira Abdul Wahab ◽  
Rahmalan Ahamad

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Nguyen Thị Hue ◽  
Nguyen Van Hop ◽  
Hoang Thai Long ◽  
Nguyen Hai Phong ◽  
Tran Ha Uyen ◽  
...  

Development of adsorptive stripping voltammetry (AdSV) combined with in situ prepared bismuth film electrode (in situ BiFE) on glassy carbon disk surface using diethylenetriamine pentaacetic acid (DTPA) as a complexing agent and NO3− as a catalyst to determine the trace amount of chromium (VI) is demonstrated. According to this method, in the preconcentration step at Edep = −800 mV, the bismuth film is coated on the surface of glassy carbon electrodes simultaneously with the adsorption of complexes Cr(III)-DTPA. In addition to the influencing factors, the stripping voltammetry performance factors such as deposition potential, deposition time, equilibration time, cleaning potential, cleaning time, and technical parameters of differential pulse and square wave voltammetries have been investigated, and the influence of Cr(III), Co(II), Ni(II), Ca(II), Fe(III), SO42−, Cl−, and Triton X has also been investigated. This method gained good repeatability with RSD <4% (n = 9) for the differential pulse adsorptive stripping voltammetry (DP-AdSV) and RSD < 3% (n = 7) for the square wave adsorptive stripping voltammetry (SqW-AdSV), and low limit of detection: LOD = 12.10−9 M ≈ 0.6 ppb (at a deposition potential (Edep) of −800 mV and the deposition time (tdep) of 50 s) and LOD = 2.10−9 M ≈ 0.1 ppb (at Edep = −800 mV and tdep = 160 s) for the DP-AdSV and SqW-AdSV, respectively. This method has been successfully applied to analyze chromium in natural water.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Irdhawati Irdhawati ◽  
Ni Kadak Nevi Titasia ◽  
Emmy Sahara

In this study, the measurement of Cd(II) ion by anodic stripping voltammetry technique was conducted using bentonite modified carbon paste as working electrode (CPE-B). The performance of CPE-B was compared with carbon paste electrode without bentonite (CPE) and applied for determination of Cd(II) concentration in chicory. Optimized parameters were composition of bentonite in carbon paste electrode, deposition time, deposition potential, and scan rate. Validation of measurements was observed including determination of linear concentration range, detection and quantization limits, repeatability of measurement, and percentage of recovery. The optimum composition of bentonite in CPE-B was found at 50%. Furthermore, in the optimization of measurements condition was found the optimum deposition times were 90 and 60 s, deposition potentials were -0.63 and -0.53 V, and scan rates were 15 and 20 mV/s, for CPE and CPE-B. The linear range concentration for CPE observed at 25-2000 µg/L and CPE-B was 5-50 µg/L. Limit of detection and quantization using CPE-B were 0.337 µg/L and 0.349 µg/L, lower than CPE i.e., 0.470 µg/L and 0.471 µg/L, respectively. Repeatability measurement of Cd(II) had Horwitz Ratio value less than two, and percentage of recovery was 96.73 8.33%. The level of Cd(II) ion in chicory was found at 6.98 0.40 mg/kg.


2013 ◽  
Vol 10 (4) ◽  
pp. 498-504 ◽  
Author(s):  
Lorena Martiniano ◽  
Joseany Almeida ◽  
Glene Cavalcante ◽  
Edmar Marques ◽  
Teresa Fonseca ◽  
...  

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 537 ◽  
Author(s):  
Chrys. O. Chikere ◽  
Nadimul Haque Faisal ◽  
Paul Kong-Thoo-Lin ◽  
Carlos Fernandez

Amorphous zirconium oxide nanoparticles (ZrO2) have been used for the first time, to modify carbon paste electrode (CPE) and used as a sensor for the electrochemical determination of gallic acid (GA). The voltammetric results of the ZrO2 nanoparticles-modified CPE showed efficient electrochemical oxidation of gallic acid, with a significantly enhanced peak current from 261 µA ± 3 to about 451 µA ± 1. The modified surface of the electrode and the synthesised zirconia nanoparticles were characterised by scanning electrode microscopy (SEM), Energy-dispersive x-ray spectroscopy (EDXA), X-ray powdered diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). Meanwhile, the electrochemical behaviour of GA on the surface of the modified electrode was studied using differential pulse voltammetry (DPV), showing a sensitivity of the electrode for GA determination, within a concentration range of 1 × 10−6 mol L−1 to 1 × 10−3 mol L−1 with a correlation coefficient of R2 of 0.9945 and a limit of detection of 1.24 × 10−7 mol L−1 (S/N = 3). The proposed ZrO2 nanoparticles modified CPE was successfully used for the determination of GA in red and white wine, with concentrations of 0.103 mmol L−1 and 0.049 mmol L−1 respectively.


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