scholarly journals Trace Voltammetric Determination of Lead at a Recycled Battery Carbon Rod Electrode

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 770 ◽  
Author(s):  
Kevin Honeychurch

Carbon rod electrodes (CREs) were obtained from recycled zinc–carbon batteries and were used without further modification for the measurement of trace concentrations of lead (Pb). The electrochemical behavior of Pb at these electrodes in a variety of supporting electrolytes was investigated by cyclic voltammetry. The anodic peaks obtained on the reverse scans were indicative of Pb being deposited as a thin layer on the electrode surface. The greatest signal–to–noise ratios were obtained in organic acids compared to mineral acids, and acetic acid was selected as the supporting electrolyte for further studies. Conditions were optimized, and it was possible to determine trace concentrations of Pb by differential pulse anodic stripping voltammetry. A supporting electrolyte of 4% v/v acetic acid, with a deposition potential of −1.5 V (vs. SCE) and a deposition time of 1100 s, was found to be optimum. A linear range of 2.8 µg/L to 110 µg/L was obtained, with an associated detection limit (3σ) of 2.8 µg/L. A mean recovery of 95.6% (CV=3.9%) was obtained for a tap water sample fortified with 21.3 µg/L.

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Andréa Claudia Oliveira Silva ◽  
Luis Carlos Ferreira de Oliveira ◽  
Angladis Vieira Delfino ◽  
Mario Roberto Meneghetti ◽  
Fabiane Caxico de Abreu

The use of nanomaterials, such as nanoparticles and nanotubes, for electrochemical detection of metal species has been investigated as a way of modifying electrodes by electrochemical stripping analysis. The present study develops a new methodology based on a comparative study of nanoparticles and nanotubes with differential pulse anodic stripping voltammetry (DPASV) and examines the simultaneous determination of copper and lead. The glassy carbon electrode modified by gold nanoparticles demonstrated increased sensitivity and decreased detection limits, among other improvements in analytical performance data. Under optimized conditions (deposition potential −0.8 V versus Ag/AgCl; deposition time, 300 s; resting time, 10 s; pulse amplitude, 50 mV; and voltage step height, 4 mV), the detection limits were 0.2279 and 0.3321 ppb, respectively, for determination of Pb2+ and Cu2+. The effects of cations and anions on the simultaneous determination of metal ions do not exhibit significant interference, thereby demonstrating the selectivity of the electrode for simultaneous determination of Pb2+ and Cu2+. The same method was also used to determine Cu2+ in water samples.


2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Piotr Markowski ◽  
Grzegorz Dzido ◽  
Irena Baranowska ◽  
Andrzej B. Jarzębski

AbstractA simple and selective differential pulse anodic stripping voltammetry (DPASV) method for the determination of Ag+ and Cu2+ ions in mixture samples obtained in the microwave assisted polyol process was developed and validated. Analytical methods for the preparation of the reaction mixture for voltammetric analysis (dilute samples in the supporting electrolyte) were worked out and optimized. All measurements were conducted in three-electrode cell system equipped with glassy carbon electrode (GCE) as a working electrode, silver/silver chloride (Ag|AgCl|KCl(sat.)) as a reference and platinum wire as a auxiliary electrode. The optimal conditions for quantitative determination were obtained in an mixture Britton–Robinson buffer at pH 4.1 / ethylene glycol (100/1; v/v). The calibration curves of analysed compounds are linear within the range of concentration: 0.032 − 0.420 μg mL-1 and 0.075 − 0.960 μg mL-1 for Ag+ and Cu2+, respectively. Good linear behaviour over the investigated concentration ranges were observed with the values of r2 higher than 0.996 for the silver and cooper ions. The accuracy of analytical determinations ranged from 0.4 to 3.6%. The levels of analysed ions in the reaction mixture can be successfully determined using this developed method with no matrix effect.


2019 ◽  
Vol 63 (1) ◽  
Author(s):  
Mehdi Jalali ◽  
Zeinab Deris Falahieh ◽  
Mohammad Alimoradi ◽  
Jalal Albadi ◽  
Ali Niazi

The electrochemical behavior of Bi+3 ions on the surface of a glassy carbon electrode, in acidic media and in the presence of tamoxifen, was investigated. Cyclic voltammetry, chronoamperometry, differential pulse voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy with energy-dispersive X-ray spectroscopy were used to find the probable mechanism contributing to the reduction of the peak height of bismuth oxidation with an increase in the concentration of tamoxifen. The obtained results show a slight interaction between the bismuth species and tamoxifen which co-deposit on the surface of glassy carbon electrode. Therefore, the reduction in the peak height of bismuth oxidation as a function of tamoxifen concentration was used to develop a new differential pulse anodic striping voltammetry method for determination of trace amount of tamoxifen. The effects of experimental parameters on the in situ DPASV of Bi+3 ions in the presence of tamoxifen shown the optimal conditions as: 2 mol L-1 H2SO4 (1% v v-1 MeOH), a deposition potential of -0.5 V, a deposition time of 60 s, and a glassy carbon electrode rotation rate of 300 rpm. The calibration curve was plotted in the range of 0.5 to 6 µg mL-1 and the limits of detection and quantitation were calculated to be 3.1 × 10-5 µg mL-1 and 1.0 × 10-4 µg mL-1, respectively. The mean, RSD, and relative bias for 0.5 µg mL-1 (n=5) were found to be 0.49 µg mL-1, 0.3%, and 2%, respectively. Finally, the proposed method was successfully used for the determination of tamoxifen in serum and pharmaceutical samples.


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