scholarly journals A cyclic voltammetric study of the influence of supporting electrolytes on the redox behaviour of Cu(II) in aqueous medium

1970 ◽  
Vol 24 (2) ◽  
pp. 158-164 ◽  
Author(s):  
Aftab Ali Shaikh ◽  
M Badrunnessa ◽  
Jannatul Firdaws ◽  
Md Shahidur Rahman ◽  
Nishat Ahmed Pasha ◽  
...  
Keyword(s):  
Aqueous Medium ◽  
Electrochemical Reaction ◽  
Supporting Electrolyte ◽  
Electrode Reaction ◽  
Chemical Society ◽  
Reduction Peak ◽  
Hydrogen Bridge ◽  
Peak Current ◽  
Bridge Bond ◽  
Electrochemical Redox

The electrochemical redox behavior of Cu(II) has been investigated at glassy carbon electrode (GCE) in Britton-Robinson (BR) buffer as well as in a mixture of BR buffer and potassium chloride media. It is apparent that BR buffer can act as a supporting electrolyte and modify the electrochemical behavior of Cu(II) ion in aqueous medium. In BR buffer medium, Cu(II) undergoes one two-electrons redox process, while in a mixture of BR buffer and KCl media it follows two one-electron electrochemical reaction routes. Because of the formation of hydrogen bridge bond between the supporting electrolyte and GCE surface, the Cu(II) ion follows Cu(II)/Cu(0) electrochemical reaction path, while in presence of KCl such a hydrogen bridge bond is not formed and it undergoes successive Cu(II)/Cu(I) and Cu(I)/Cu(0) electrode reaction processes. Moreover, the linear variation of peak current with the square root of scan rate indicates that the electrochemical redox processes are diffusion controlled. Keywords: Supporting electrolytes; Britton-Robinson buffer; Cu-reduction; Peak current DOI: http://dx.doi.org/10.3329/jbcs.v24i2.9704 Journal of Bangladesh Chemical Society, Vol. 24(2), 158-164, 2011

scholarly journals Modified Screen-Printed Electrode for Determination of Imidacloprid in Water Samples: A Preliminary Study

2019 ◽  
Vol 1 (2) ◽  
pp. 41-50
Author(s):  
Azrilawani Ahmad ◽  
Nur Anis Zafirah Zainordin ◽  
Nur Amira Jaafar
Keyword(s):  
Water Samples ◽  
Limit Of Detection ◽  
Supporting Electrolyte ◽  
Reduction Peak ◽  
Self Assembled Monolayer ◽  
Limit Of Quantification ◽  
Peak Current ◽  
Preliminary Study ◽  
Screen Printed

A preliminary assessment of a simple and rapid electrochemical method was carried out to analyse imidacloprid (IMI) in water samples using cyclic voltammetry (CV) based on modified screen-printed gold electrode (SPGE). Self-assembled monolayer (SAM) was optimized using 11-mercaptoundecanoic acid (11-MUA) with several parameters such as scan rates, type of supporting electrolyte, and pH of the supporting electrolyte. The modified SPGE showed high suppressed current against the potential due to the formation of a monolayer on the electrode surface. Surface morphology of the electrode was analysed using Scanning Electron Microscopy (SEM) confirming that 11-MUA was present on the modified SPGE. The water samples were collected from GM Peladang, Kuala Terengganu and two locations at Universiti Malaysia Terengganu. Method detection limit was expressed as limit of detection (LOD) and limit of quantification (LOQ) for modified SPGE which were calculated at 3.784 and 12.613 mg/L in water samples, respectively. This study showed that the reduction peak current observed on the modified electrode was lower compared with oxidation peak current. Hence, gold is unsuitable for IMI detection.

Effect of Sulfosalicylic Acid on Kinetics of Ce3+/Ce4+ Electrode Reaction

2011 ◽  
Vol 279 ◽  
pp. 451-455 ◽  
Author(s):  
Zhi Peng Xie ◽  
Feng Jiao Xiong ◽  
De Bi Zhou
Keyword(s):  
Electrochemical Behaviour ◽  
Supporting Electrolyte ◽  
Electrode Reaction ◽  
Peak Potential ◽  
Rotating Disc ◽  
Sulfosalicylic Acid ◽  
Peak Current ◽  
Stationary Electrode ◽  
Standard Rate ◽  
Kinetics Of

The effect of sulfosalicylic acid (SSA) on the electrochemical behaviour of Ce3+/Ce4+ redox couple was studied using voltammetry at stationary electrode and rotating disc electrode (RDE). When the SSA was added to the Ce3+/Ce4+ electrolyte there was change to the peak current and peak potential, i.e. the increase of peak current and the decrease of peak potential difference. The diffusion coefficient of Ce3+ is 6.5 × 10-6 cm2 s-1 and the standard rate constant of the Ce3+/Ce4+ redox reaction is 3.2 × 10-4 cm s-1 in the presence of SSA, which are all larger than that in the absence of SSA (3.6 × 10-6 cm2 s-1, 2.0 × 10-4 cm s-1). Therefore, the SSA as the additive in the supporting electrolyte for a cerium redox flow battery (RFB) application will result in a high voltage efficiency and will satisfy an important requirement for a RFB electrolyte.

Cyclic Voltammetry of Iodine at the Organic Liquid/Aqueous Solution Interface

2007 ◽  
Vol 72 (7) ◽  
pp. 917-926 ◽  
Author(s):  
Shaoai Xie ◽  
Jinping Jia ◽  
Hong-Jin Chen
Keyword(s):  
Metal Ion ◽  
Composite Electrode ◽  
Polar Solvent ◽  
Electrochemical Reaction ◽  
Organic Liquid ◽  
Supporting Electrolyte ◽  
Cyclic Voltammetric ◽  
Solution Interface ◽  
Donor Solvent ◽  
Solvent Complex

The electrochemical behavior of iodine extracted with an organic solvent at the liquid/liquid interface was studied using a new composite electrode. The effects of various solvents and supporting electrolyte on the electrochemical reaction of iodine were analyzed by cyclic voltammetric curves. The formation of a polar solvent complex of iodine and a strong donor solvent in organic solution was comfirmed by UV-VIS spectra. A possible mechanism was suggested based on experiments. This method makes it possible to measure heavy metal ion in solution indirectly.

scholarly journals Ultrasensitive Detection of Ferulic Acid Using Poly(diallyldimethylammonium chloride) Functionalized Graphene-Based Electrochemical Sensor

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Lin-jie Liu ◽  
Xia Gao ◽  
Pei Zhang ◽  
Shi-lan Feng ◽  
Fang-di Hu ◽  
...  
Keyword(s):  
Ferulic Acid ◽  
Supporting Electrolyte ◽  
Differential Pulse ◽  
Quantitative Detection ◽  
Angelica Sinensis ◽  
Functionalized Graphene ◽  
Long Term Stability ◽  
Diallyldimethylammonium Chloride ◽  
Potential Alternative ◽  
Electrochemical Redox

The electrochemical redox of ferulic acid (FA) was investigated systematically by cyclic voltammetry (CV) with a poly(diallyldimethylammonium chloride) functionalized graphene-modified glassy carbon electrode (PDDA-G/GCE) as a working electrode. A simple and sensitive differential pulse voltammetry (DPV) technique was proposed for the direct quantitative determination of FA inAngelica sinensisand spiked human urine samples for the first time. The dependence of the intensities of currents and potentials on nature of the supporting electrolyte, pH, scan rate, and concentration was investigated. Under optimal conditions, the proposed sensor exhibited excellent electrochemical sensitivity to FA, and the oxidation peak current was proportional to FA concentration in the range of8.95×10-8 M~5.29×10-5 M, with a relatively low detection limit of4.42×10-8 M. This fabricated sensor also displayed acceptable reproducibility, long-term stability, and high selectivity with negligible interferences from common interfering species. Besides, it was applied to detect FA inAngelica sinensisand biological samples with satisfactory results, making it a potential alternative tool for the quantitative detection of FA in pharmaceutical analysis.

Application of Nano Drug Carrier in the Detection of Human Hemoglobin Content

2020 ◽  
Vol 12 (2) ◽  
pp. 125-131
Author(s):  
Jixing Yang
Keyword(s):  
Modified Electrode ◽  
Silver Particle ◽  
Drug Carrier ◽  
Silver Electrode ◽  
Reduction Peak ◽  
Human Hemoglobin ◽  
Silver Particles ◽  
Hemoglobin Content ◽  
Peak Current ◽  
Nano Silver

This paper studies the application of nano drug carrier in the detection of human hemoglobin content. Taking nano modified electrode as nano drug carrier, the application of nano silver particle modified silver electrode and nano poly thionine modified electrode in the detection of human hemoglobin content is studied. Atomic force microscope, UV-Vis and FT-IR are used to characterize the nano poly(thionine), and the electrochemical properties of nano poly(thionine) modified electrode. The silver electrode decorated with nano silver particles is made. The electrochemical behavior of hemoglobin on the modified electrode is studied. The experimental results show that a pair of redox peaks appear in the silver electrode modified by nano silver particles. With the increase of Hb concentration, the redox peak current in the cyclic voltammogram of the silver electrode modified by nano silver particles increases correspondingly, and the hemoglobin has a good current response on the silver electrode modified by nano silver particles, which is a kind of adsorption current. The electrochemical activity of nano poly thionine shows a decreasing tendency with pH value. After adding hemoglobin, there is a significant reduction peak near –0.4 V. With the increase of hemoglobin concentration, the reduction peak current increases accordingly. The nano poly thionine modified electrode has a catalytic effect on the reduction of hemoglobin. The results show that the two nano drug carriers, nano poly thionine modified electrode and nano silver particle modified silver electrode, can effectively analyze and determine human hemoglobin.

Polarographic Study of the Electrode Reaction of Zn(II) in Formamide and Dimethylformamide

1975 ◽  
Vol 30 (5-6) ◽  
pp. 350-354 ◽  
Author(s):  
Sudhindra Swarup Sharma ◽  
Mukhtar Singh
Keyword(s):  
Kinetic Parameters ◽  
Organic Solvents ◽  
Metal Ion ◽  
Supporting Electrolyte ◽  
Electrode Reaction ◽  
Polarographic Study ◽  
Aqueous Mixtures ◽  
Diffusion Controlled ◽  
And Diffusion

The reduction of Zn(II) at the d.m.e. has been studied in aqueous mixtures of formamide and dimethylformamide. The general polarographic characteristics have been determined, using 0.1 M NaNO3 as the supporting electrolyte. The reduction of Zn(II) in these organic solvents is irreversible and diffusion controlled. The kinetic parameters, αna and kf,h have been calculated separately by KOTECKY and DELAHAY treatments. The change of polarographic characteristics and kinetic parameters is explained in terms of solvation of the metal ion in these solvents. The electrocapillary curves in the presence of these solvents have also been studied.

scholarly journals Electrochemical Determination of Metronidazole in Tablet Samples Using Carbon Paste Electrode

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yosef Nikodimos ◽  
Meareg Amare
Keyword(s):  
Correlation Coefficient ◽  
Carbon Paste Electrode ◽  
Reduction Peak ◽  
Carbon Paste ◽  
Peak Potential ◽  
Peak Current ◽  
Potential Shift ◽  
Scan Rate ◽  
Paste Electrode

Cyclic voltammetric investigation of metronidazole at carbon paste electrode revealed an irreversible reduction peak centered at about −0.4 V. Observed peak potential shift with pH in the range 2.0 to 8.5 indicated the involvement of protons during the reduction of metronidazole, whereas the peak potential shift with scan rate in the range 10–250 mV/s confirmed the irreversibility of the reduction reaction. A better correlation coefficient for the dependence of peak current on the scan rate than on the square root of scan rate indicated an adsorption controlled kinetics. Under the optimized method and solution parameters, an excellent linearity between the reductive peak current and the concentration of metronidazole was observed in the concentration range 1.0 × 10−6to 5.0 × 10−4 M with a correlation coefficient, method detection limit (based ons=3σ), and limit of quantification of 0.999, 2.97 × 10−7 M and 9.91 × 10−7 M, respectively. Good recovery results for spiked metronidazole in tablet samples and selective determination of metronidazole in tablet formulations in the presence of selected potential interferents such as rabeprazole, omeprazole, and tinidazole confirmed the potential applicability of the developed method for the determination of metronidazole in real samples like pharmaceutical tablets.

Rapid Differential Pulse Polarographic Determination of Tiaprofenic Acid

1984 ◽  
Vol 67 (4) ◽  
pp. 684-687
Author(s):  
Mohamed E Mohamed ◽  
Abdel-Aziz M Wahbi ◽  
EL Rasheed A Gad-Kariem ◽  
Mahmoud M A Hassan
Keyword(s):  
Supporting Electrolyte ◽  
Tiaprofenic Acid ◽  
Reference Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Experimental Conditions ◽  
Tablet Form ◽  
Peak Current ◽  
Pulse Polarography

Abstract Tiaprofenic acid (Surgam®) has been determined directly by using differential pulse polarography (DPP) and pH 5.5 acetate buffer as a supporting electrolyte. The differential pulse polarogram was obtained under constant amplitude pulses of 50 mV superimposed on a linearly increasing dc ramp. Peak current was measured at the peak potential of — 0.990 V vs Ag/AgCl reference electrode. Under the experimental conditions used, a linear relationship between peak current and concentration was established over the range 0.5-5.0 ng/mL. Mean percentage recoveries for tiaprofenic acid in authentic and tablet forms were 100.27 ± 2.25 and 99.45 ± 1.44, respectively. The results obtained by the DPP method were compared with those of the spectrophotometric method used by the manufacturer for the analysis of tiaprofenic acid and its tablet form.

scholarly journals Effects of the variation of metal substitution and electrolyte on the electrochemical reaction of metal hexacyanoferrates

RSC Advances ◽  
2018 ◽  
Vol 8 (65) ◽  
pp. 37356-37364 ◽  
Author(s):  
Miyuki Asai ◽  
Akira Takahashi ◽  
Kazuki Tajima ◽  
Hisashi Tanaka ◽  
Manabu Ishizaki ◽  
...  
Keyword(s):  
Redox Potential ◽  
Prussian Blue ◽  
Electrochemical Reaction ◽  
Supporting Electrolyte ◽  
Hydration Energy ◽  
Metal Substitution ◽  
Prussian Blue Analogs

The redox potential of metal hexacyanoferrates (MHCFs), also called Prussian blue analogs, is qualitatively understood with the hydration energy of the cations in the supporting electrolyte.

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