Comparative Electrochemical Study of Some Phenothiazines with Carbon Paste, Solid Carbon Paste and Glass-Like Carbon Electrodes

2000 ◽  
Vol 65 (6) ◽  
pp. 1014-1028 ◽  
Author(s):  
Robert V. Sandulescu ◽  
Simona M. Mirel ◽  
Radu N. Oprean ◽  
Simion Lotrean
Keyword(s):  
Modified Electrodes ◽  
Linear Sweep Voltammetry ◽  
Pharmaceutical Formulations ◽  
Oxidation Potential ◽  
Electrochemical Study ◽  
Carbon Electrodes ◽  
Potential Range ◽  
Solid Carbon ◽  
Carbon Paste ◽  
Linear Sweep

In order to obtain modified electrodes with phenothiazines and to develop electrochemical methods for their determination in pharmaceutical formulations, promazine maleate, promethazine maleate and levomepromazine, were studied by linear sweep voltammetry using different types of working electrodes: carbon paste, solid carbon paste and glass-like carbon electrodes. A comparative electrochemical study of the above mentioned pheno- thiazines was performed in aqueous-alcoholic solutions, investigating the influence of pH, ionic strength and concentration on the current-potential curves. Linear sweep voltammetry in potential range from -0.1 to +1.3 V revealed that the oxidation potential and the current, strongly depend on the type of electrode and pH, the best results being obtained in acid buffer (pH 1.0). The current intensity depending linearly on the concentration in the range of 2.5·10-5-5·10-4 M promazine maleate, 2.5·10-5-2.5·10-4 M promethazine maleate and 6.2·10-5-1.2·10-3 M levomepromazine permits the development of electroanalytical methods to determine these phenothiazines in pharmaceuticals. The electrochemical determination yielded results comparable with spectrophotometric methods. Linear sweep voltammetry of carbon paste electrodes modified by incorporation of phenothiazines opens the possibility to use them as mediators in the design of some enzyme selective electrodes.

A new Methimazole sensor based on nanocomposite of CdS NPs–RGO/IL–carbon paste electrode using differential FFT continuous linear sweep voltammetry

Talanta ◽  
2014 ◽  
Vol 127 ◽  
pp. 94-99 ◽  
Author(s):  
Parviz Norouzi ◽  
Vinod Kumar Gupta ◽  
Bagher Larijani ◽  
Mohammad Reza Ganjali ◽  
Farnoush Faridbod
Keyword(s):  
Carbon Paste Electrode ◽  
Linear Sweep Voltammetry ◽  
Continuous Linear ◽  
Carbon Paste ◽  
Linear Sweep ◽  
Paste Electrode

scholarly journals Current calculation of irreversible electrode reaction mechanismsin linear sweep voltammetry

2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Ján Mocák ◽  
Estera Rábarová
Keyword(s):  
Chemical Reaction ◽  
Infinite Series ◽  
Digital Simulation ◽  
Linear Sweep Voltammetry ◽  
Electrode Reaction ◽  
Potential Range ◽  
Linear Sweep ◽  
Potential Region ◽  
Current Function ◽  
Simulation Techniques

Application of exponential infinite series gives highly accurate analytical solution contributing to the theory of linear sweep voltammetry for single scan experiments. We have calculated theoretical dimensionless current function (usually denoted as π1/2χ(bt)) at relevant potentials for irreversible charge transfer without a coupled chemical reaction. For this purpose several transformation techniques were used, which convert the derived infinite series into summable sequences. Since infinite series of further electrochemical mechanisms with irreversible electrode reaction have similar features (particularly those comprising preceding and catalytic chemical reaction), the same approach can be successfully applied also for further electrochemical mechanisms. The respective infinite series are divergent in the most important potential region at and after voltammetric peak therefore their transformation by Epsilon and Levin transform techniques was used. Necessary arbitrary precision arithmetic (APA) was implemented by UBASIC. The results were compared to the customary solution of Nicholson and Shain, who computed the current-potential curves by means of numerical solution of the integral equations but with a much lower precision. Our results were obtained in a broad potential range including the potential regions where the series are divergent. Obtained current functions are precise to 12 valid decimal numbers, which is utilizable for evaluation of the results achieved by various faster but less precise digital simulation techniques.

THE ELECTROCHEMICAL STUDY OF SELF-ASSEMBLED 1,3-PROPANEDITHIOL ON GOLD

2007 ◽  
Vol 14 (01) ◽  
pp. 111-115
Author(s):  
YUQING MIAO ◽  
JIANRONG CHEN ◽  
XIAOHUA WU ◽  
KEMING FANG
Keyword(s):  
Gold Electrode ◽  
Modified Electrodes ◽  
Gold Surface ◽  
Electrochemical Study ◽  
Potential Range ◽  
Electrochemical Behaviors ◽  
Bare Gold Electrode ◽  
Self Assembled ◽  
Bare Gold

The electrochemical behaviors of bare/dithiol-modified gold electrode were studied in the PBS solution with/without dithiols. A pair of current peaks between -1.4 and -0.5 V is related to dithiol adsorption or re-adsorption. An oxidative peak at 0.37 V accompanied by a slight peak at 0.03 V is observed between -0.5 and 0.7 V for the bare gold electrode in the thiol solution, which is due to the formation of bilayer. When the potential is scanned to a very positive value at 1.2 V, a new oxidative peak at 1.07 V appears for the bare gold electrode in the dithiol solution or the PBS solution. The assembled dithiols are desorbed, and gold surface is exposed. The study indicates that the 1,3-propanedithiol modified electrodes should be used during the potential range of -0.8 to 0.8 V to keep the assembled layer stable.

Voltammetric Study of N-Benzoylthiourea and Its N',N'-Disubstituted Derivatives as Possible Electrode Modifiers

1999 ◽  
Vol 64 (12) ◽  
pp. 1937-1952 ◽  
Author(s):  
Karl-Heinz Lubert ◽  
Lothar Beyer ◽  
Markus Guttmann
Keyword(s):  
Surface States ◽  
Carbon Surface ◽  
Carbon Electrodes ◽  
Potential Range ◽  
Carbon Paste ◽  
Oxidation Current ◽  
Irreversible Reduction ◽  
Voltammetric Behavior ◽  
Positive Scan ◽  
Morpholine Derivatives

The voltammetric behavior of N-benzoylthiourea (BTU) and some of its N',N'-disubstituted derivatives is studied using glassy carbon and carbon paste electrodes in ethanolic solution. Irreversible reduction of the compounds takes place in a potential range between -0.5 and -1.1 V, where carbon surface groups are reduced as well. The products formed by reductive cleavage of the C-N bond of the amide group are oxidized in the subsequent positive scan at +0.5 V. Irreversible oxidation of the thiocarbonyl group of BTU (or its derivatives) takes place at about +1.0 V followed further by an oxidation of its N',N'-dialkyl and morpholine derivatives at more positive potentials. Oxidation current at +0.8 V is only observed in the case of the N',N'-diphenyl derivative. The oxidation current at +1.0 V depends linearly on the concentration of BTU (or its derivatives) and is suitable for their electroanalytical determination with carbon electrodes. The experimental results are compared with electrochemical behavior of related compounds. Furthermore, the influence of carbon surface states is discussed. It was concluded that N',N'-disubstituted derivatives of the BTU can be employed as modifying agents for carbon electrodes applicable in the potential range from +0.7 to -0.5 V.

scholarly journals Glassy Carbon Electrode Modified by Molybdenum to Detection Hydrochlorothiazide

2020 ◽  
Author(s):  
Ahmad Khalaf Alkhawaldeh ◽  
Rawia Alkhawaldeh
Keyword(s):  
Glassy Carbon ◽  
Correlation Coefficients ◽  
Modified Electrodes ◽  
Pharmaceutical Formulations ◽  
Carbon Electrodes ◽  
Low Molecular Weight ◽  
Molybdenum Oxides ◽  
Statistical Parameters ◽  
Glassy Carbon Electrodes

Molybdenum oxides is well-known electro-catalysts in fuel cells systems, they are usually used as anodic materials for the oxidation of low molecular weight alcohols. The utilization of Mo as catalysts in the pharmaceutical analysis is not common yet. In this study, bare glassy carbon electrodes were modified by the oxides by means of electrochemical deposition and the modified electrodes were used as catalysts for the electrochemical oxidation of hydrochlorothiazide (HCT). Well-resolved anodic peaks were reported for the analyzed pharmaceuticals when the Mo/GCE was utilized for the analysis of HCT. Analytical performance of the modified electrodes was evaluated based on the following statistical parameters; linearity ranges, correlation coefficients, limits of detection and quantitation, and recovery values. The prepared electrodes were used for the determination of the active ingredients in their pharmaceutical formulations and the reported activity was correlated to influence of the utilized pH on both structures of the used electrodes and the detected analytes.

Determination of Levodopa in Pharmaceuticals Using a Disposable Electrochemically Activated Carbon-Paste Electrode by Linear Sweep Voltammetry

2018 ◽  
Vol 51 (10) ◽  
pp. 1520-1528 ◽  
Author(s):  
Alexander Chebotarev ◽  
Konstantin Pliuta ◽  
Anastasiya Koicheva ◽  
Kateryna Bevziuk ◽  
Denys Snigur
Keyword(s):  
Activated Carbon ◽  
Carbon Paste Electrode ◽  
Linear Sweep Voltammetry ◽  
Carbon Paste ◽  
Linear Sweep ◽  
Paste Electrode

Linear sweep voltammetry with carbon paste electrodes in the rat striatum

Neuroscience ◽  
1982 ◽  
Vol 7 (8) ◽  
pp. 1945-1954 ◽  
Author(s):  
R.D. O'Neill ◽  
R.A. Grünewald ◽  
M. Fillenz ◽  
W.J. Albery
Keyword(s):  
Linear Sweep Voltammetry ◽  
Rat Striatum ◽  
Carbon Paste ◽  
Linear Sweep ◽  
Carbon Paste Electrodes
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