IJERT-Experimental Setup of Square-Wave Anodic Stripping Voltammetry Measurement of Lead and Cadmium using Antimony Impregnated Activated Carbon Electrode (original) (raw)
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Heavy metals in human body cause chronic diseases when in excess like Parkinson’s disease and cancer. Techniques are developed to detect small concentrations of heavy metals in water; one of them is stripping voltammetry. It involves current detection against the applied voltage. The resulting voltammograms are used to quantify the heavy metals present in the water body. The current work is about manufacturing of working electrode by impregnation method to increase the detection efficiency and other characteristics. Vacuum impregnation of antimony over activated carbon was done. Four samples having 2%, 3%, 4% and 5% antimony by weight were prepared. Working electrode was prepared by holding samples over a copper structure with the help of a paraffin binder. “Square-wave Anodic Stripping Voltammetry” tests were performed in electrochemical cell with an AUTOLAB potentiostat. The correct experimental setup was first devised using several experimental arrangements of the apparatus. The optimization of the working parameters was also performed. This setup obtained remarkable voltammogram peaks of both cadmium and lead equal to 29.2 and 49.4 µA respectively as compared to previous values of 6 and 3 µA respectively. These values are in 100 µg/L of both cadmium and lead.
Detection of Lead and Cadmium Ions by Voltammetry using Antimony Impregnated Activated Carbon
This work deals with antimony-impregnated activated carbon electrode for the detection of heavy metal ions. Activated carbon is employed to enhance the surface area of the working electrode. Square-wave Anodic Stripping Voltammetry is performed to analyze the electrolytic solution. The peak currents for cadmium and lead are 29.2 and 49.4μA respectively, in 100 μg/L of cadmium and lead solution, which are considerably higher when equated with the previous reported values. Results also indicate that antimony-impregnated activated carbon is better when compared with the ratio of antimony amount to minimum detection limit.
Anodic stripping voltammetry of lead and cadmium using a mercury film electrode and thiocyanate
Analytica Chimica Acta, 1999
It is well known that lead and cadmium can be determined with good sensitivity using anodic stripping voltammetry (ASV) and a mercury ®lm electrode. However, the mercury ®lm formation is poorly reproducible and cannot fully be removed electrochemically. We have evaluated procedures to improve the reproducibility and sensitivity of the ASV method and found that in the presence of thiocyanate the ®lm can be plated reproducibly and removed fully after each scan. Furthermore we optimised the analytical parameters pH, electrolyte composition, and deposition time and potential. Optimal analytical conditions were found to be a thiocyanate concentration of 5 mM, and a pH of 5.6. Optimisation of the deposition potential unexpectedly showed that the sensitivity was greatly improved by using a very negative potential of À1.5 V, causing a 10-fold increase in the sensitivity of cadmium, and a 3-fold increase for lead. In these conditions the limit of detection (3') was 5 pM cadmium and 8 pM lead (standard deviations of 1.7% and 2%) using a deposition time of 5 min. The method was successfully applied to the determination of cadmium and lead in lake waters and certi®ed seawater after UV digestion.
Voltammetric Determination of Cadmium, Copper and Lead Using Glassy carbon Electrode
IOSR Journal of Applied Chemistry, 2014
Cyclic voltammetry and linear sweep voltammetry were used to determine cadmium, copper and lead metal ions using glassy carbon electrode. From cyclic measurements, cadmium, copper and lead showed a well single anodic peak at-547, +191.5 and-520 mV respectively. Several parameters affecting the stripping current response were investigated and optimized. Under optimal conditions, the glassy carbon electrode showed a good linear response to Pb 2+ , Cd 2+ and Cu 2+ in the concentration range from 8x10-6 M to 1x10-4 M. The detection limits were 2x10-7 M for Pb 2+ , 9x10-7 M for Cd 2+ and 1x10-7 M for Cu 2+ calculated for a single-tonoise ratio of 3 (S/N = 3). The proposed method was successfully applied for determining Pb 2+ , Cd 2+ and Cu 2+ contents in well water samples.
Journal of Chemistry, 2013
Seaweed is well known about for potential in chelating heavy metals. In this study, carbon paste electrodes were fabricated with siphonous seaweedAcetabularia acetabulumas the modifiers to sense lead (II) and copper (II) by square-wave anodic stripping voltammetry. Various scan rates and deposition potentials were measured to obtain the optimal peak current for Pb(II) and Cu(II). Optimum conditions ofAcetabularia-CPE for sensing Pb(II) were at the scan rate of 75 mV/s and deposition potential of −800 mV, while for Cu(II) sensing were at 100 mV/s and −300 mV, respectively. The electrodes were characterized by the duration of accumulation time, preconcentration over a range of standards, supporting electrolyte, and standard solutions of various pH values. Interference studies were carried out. Both Zn(II) and Cu(II) were found to interfere with Pb(II) sensing, whereas only Zn(II) causes interference with Cu(II) sensing. The electrode was found to have good regeneration ability via ele...
A sensitive voltammetric method has been developed for the determination of cadmium(II) utilizing a carbon paste electrode modi®ed with N-p-chlorophenylcinnamohydroxamic acid. The analyte was accumulated at the modi®ed electrode surface (via complexation) under open circuit and precisely controlled convective condition. It was then quanti®ed electrochemically by differential pulse anodic stripping voltammetry in a different nondeaerated electrolyte solution following medium exchange. Detailed experiments were conducted to establish the optimal carbon paste composition, pH and concentration of accumulation and stripping solutions, preconcentration time, bulk cadmium(II) concentration, and instrumental parameters. Two good linearities were obtained between the voltammetric current and cadmium concentration employing different preconcentration times. One was acquired in the concentration range 2.00610 77 ±3.20610 76 M Cd(II) (r 0.999) and the other from 4.00610 78 to 1.60610 77 M Cd(II) (r 0.999) with 1 min and 2 min preconcentration time, respectively. The detection limit was found to be 9.80610 79 M (1.1 ppb) Cd(II) with 2 min preconcentration time. For a series of six determinations of Cd(II) at 1610 76 M and 8610 78 M levels relative standard deviations of 2.6% and 5.5%, respectively, were achieved. Electrochemical cleaning was used to regenerate the surface rapidly and reproducibly; and this allows the use of a single modi®ed electrode surface in multiple analytical determinations over several weeks. Many common metal ions had little or no effect on the determination of cadmium(II). The method was veri®ed by the determination of trace cadmium(II) in municipal and mineral waters.
Heavy metals in human body cause chronic diseases when in excess like Parkinson’s disease and cancer. Techniques are developed to detect small concentrations of heavy metals in water; one of them is stripping voltammetry. It involves current detection against the applied voltage. The resulting voltammograms are used to quantify the heavy metals present in the water body. This research is about manufacturing of working electrode by impregnation method to increase the detection efficiency and other characteristics. Vacuum impregnation of antimony over activated carbon was done. Four samples having 2%, 3%, 4% and 5% antimony by weight were prepared. Working electrode was prepared by holding samples over a copper structure with the help of a paraffin binder. “Square-wave Anodic Stripping Voltammetry” tests were performed in electrochemical cell with an AUTOLAB potentiostat. Electrode characteristics like repeatability, reproducibility, optimal deposition time and minimum concentration detection were investigated. Results show that antimony-impregnated activated carbon is potentially the best electrode available. Peak currents obtained for cadmium and lead were 29.2 and 49.4 μA respectively as compared to previous values of 6 and 3 μA respectively in 100 μg/L of both cadmium and lead. The reproducibility, repeatability and minimum concentration values show that the prepared electrode is suitable for the practical applications.