scholarly journals A Sensitive and Low-cost Analytical Method for the Electrochemical Determination of Quercetin, Based on 1-Ethylpyridinium Bromide/Carbon Paste Composite Electrode

2015 ◽  
Vol 7 (2) ◽  
pp. 27 ◽  
Author(s):  
Francis Tchieno ◽  
Ignas Tonle ◽  
Evangeline Njanja ◽  
Emmanuel Ngameni
Keyword(s):  
Carbon Paste Electrode ◽  
Analytical Method ◽  
Composite Electrode ◽  
Low Cost ◽  
Reduction Peak ◽  
Cyclic Voltammogram ◽  
Current Response ◽  
Carbon Paste ◽  
Paste Electrode

We report a simple, sensitive and low-cost electrochemical procedure for the quantification of quercetin (QCT), a flavonoid and an antioxidant, based on 1-ethylpyridinium bromide modified carbon paste electrode. A 1-ethylpyridinium bromide/carbon paste composite electrode was used. The cyclic voltammogram of QCT showed two oxidation peaks at +0.575 V (vs Ag/AgCl/3M KCl) and +0.865 V (vs Ag/AgCl/3M KCl), and a reduction peak at +0.371 V (vs Ag/AgCl/3M KCl) in HCl/KCl solution at pH 1. Differential pulse voltammetry (DPV) analysis in HCl/KCl at pH 1 showed three well-defined oxidation peaks while a single peak was recorded in phosphate buffer at pH 3. The peak currents of QCT significantly increased at the 1-ethylpyridinium bromide modified electrode in comparison with those recorded at the bare carbon paste electrode. This allowed the use of adsorptive stripping voltammetry to develop a simple and sensitive electroanalytical method for the determination of QCT. Key experimental parameters such as pH of the supporting electrolyte, the preconcentration time, the electrolysis potential, electrode composition, QCT concentration and interferents were investigated. The current response was found to be directly proportional to the concentration of QCT in the range from 2.48 x 10-7 M to 7.43 x 10-6 M, leading to a detection limit of 4.48 x 10-8 M. The developed analytical method was successfully applied to the determination of QCT in human urine samples.

scholarly journals Electroanalytical Performance of a Carbon Paste Electrode Modified by Coffee Husks for the Quantification of Acetaminophen in Quality Control of Commercialized Pharmaceutical Tablets

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Serge Foukmeniok Mbokou ◽  
Maxime Pontié ◽  
Jean-Philippe Bouchara ◽  
Francis Merlin Melataguia Tchieno ◽  
Evangeline Njanja ◽  
...  
Keyword(s):  
Carbon Paste Electrode ◽  
Low Cost ◽  
Pharmaceutical Formulations ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Current Response ◽  
Carbon Paste ◽  
Pharmaceutical Tablets ◽  
Paste Electrode

Electrochemical determination of acetaminophen (APAP) was successfully performed using a carbon paste electrode (CPE) modified with coffee husks (CH-CPE). Scanning electron microscopy (SEM) and SEM-energy dispersive X-ray spectroscopy (SEM-EDX) were, respectively, used for the morphological and elemental characterization of coffee husks prior to their utilization. The electrochemical oxidation of APAP was investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and square wave voltammetry (SWV). SWV technique appeared to be more sensitive since the oxidation current of APAP was twofold higher with the CH-CPE sensor than with the bare CPE, in relation to the increase in the organophilic character of the electrode surface. Furthermore, on CH-CPE, the current response of APAP varied linearly with its concentration in the range of 6.6 μM to 0.5 mM, leading to a detection limit of 0.66 μM (S/N=3). Finally, the proposed CH-CPE sensor was successfully used to determine the amount of APAP in commercialized tablets (Doliprane® 500 and Doliprane 1000), with a recovery rate ranging from 98% to 103%. This novel sensor opens the way for the development of low-cost and reliable devices for the electroanalysis of pharmaceutical formulations in developing countries.

scholarly journals Electrochemical Behaviour of Tinidazole at 1,4-Benzoquinone Modified Carbon Paste Electrode and Its Direct Determination in Pharmaceutical Tablets and Urine by Differential Pulse Voltammetry

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Yosef Nikodimos ◽  
Beyene Hagos
Keyword(s):  
Carbon Paste Electrode ◽  
Limit Of Detection ◽  
Direct Determination ◽  
Differential Pulse ◽  
Modified Carbon Paste Electrode ◽  
Reduction Peak ◽  
Current Response ◽  
Carbon Paste ◽  
Paste Electrode

A simple and highly sensitive electrochemical method based on a 1,4-benzoquinone modified carbon paste electrode (1,4-BQMCPE) was described for the determination of tinidazole (TDZ). In Britton Robinson buffer solution, TDZ yields well-defined irreversible reduction peak at −0.344 V on a 1,4-BQMCPE. Compared with that on a bare CPE, the reduction peak of TDZ increased significantly on the modified CPE and the effects of different parameters on the voltammetric responses were also investigated. Differential pulse voltammetric method was proposed and optimized for TDZ determination and its reductive peak current response at 1,4-BQMCPE was found to show linear dependence on the concentration of TDZ in the range of 1.0 × 10−6 to 5.0 × 10−4 M with a linear regression equation, correlation coefficient, limit of detection (LOD), and limit of quantification (LOQ) of IPC (μA) = 0.19958 + 0.02657C (μM), 0.99486, 1.10 × 10−7 M, and 3.77 × 10−7, respectively. Excellent recovery results for spiked TDZ in pharmaceutical tablet samples ranging within 97.44–97.51% and in urine ranging within 95.37–96.91% were observed. The selectivity of the method for TDZ was further studied in the presence of selected potential interferents and confirmed the potential applicability of the developed method for the determination of TDZ.

scholarly journals Online Coupling of Lab-on-Valve Format to Amperometry Based on Polyvinylpyrrolidone-Doped Carbon Paste Electrode and Its Application to the Analysis of Morin

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Yang Wang ◽  
Guojun Yao ◽  
Jie Tang ◽  
Chun Yang ◽  
Qin Xu ◽  
...  
Keyword(s):  
Carbon Paste Electrode ◽  
Supporting Electrolyte ◽  
Phosphate Buffer Solution ◽  
Current Response ◽  
Oxidation Peak ◽  
Carbon Paste ◽  
Buffer Solution ◽  
Electrochemical Behaviors ◽  
Paste Electrode

The potential capabilities and analytical performance of lab-on-valve (LOV) manifold as a front end to amperometry have been explored for the on-line determination of morin. Meanwhile, the electrochemical behaviors of morin were investigated based on polyvinylpyrrolidone- (PVP-) doped carbon paste electrode (CPE), which found that PVP can significantly improve its oxidation peak current. The excellent amperometric current response was achieved when the potential difference (ΔE) of 0.6 V was implemented in pH 6.5 phosphate buffer solution (PBS) that served as the supporting electrolyte. A well-defined oxidation peak has been obtained in studies using PVP as a modifier of CPE based on the oxidation of morin. The present work introduces the LOV technique as a useful tool for amperometric measurement, documents advantages of using programmable flow, and outlines means for miniaturization of assays on the basis of PVP modified CPE. The proposed method was applied successfully to the determination of morin in real samples, and the spiked recoveries were satisfactory.

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.

scholarly journals Electrochemical determination of atenolol and propranolol using a carbon paste sensor modified with natural ilmenite

2021 ◽  
Vol 19 (1) ◽  
pp. 875-883
Author(s):  
Nevila Broli ◽  
Majlinda Vasjari ◽  
Loreta Vallja ◽  
Sonila Duka ◽  
Alma Shehu ◽  
...  
Keyword(s):  
Carbon Paste Electrode ◽  
Beta Blockers ◽  
High Sensitivity ◽  
Modified Carbon Paste Electrode ◽  
Current Response ◽  
Carbon Paste ◽  
Linear Calibration ◽  
Pharmaceutical Tablets ◽  
Paste Electrode

Abstract In this study, a simple voltammetric method was reported for independent determination of propranolol (PROP) and atenolol (ATN) in pharmaceutical tablets using carbon paste electrode modified with natural Ilmenite (CPE-I). The analytical performance of the modified sensor was evaluated using the square wave voltammetry and cyclic voltammetry for determination of both β(beta) blockers in 0.1 mol L−1 of sulfuric acid solution (H2SO4). The signal obtained with modified carbon paste electrode in 0.1 mol L−1 of H2SO4 showed a good electrocatalytic activity toward the oxidations of PROP and ATN compared with the bare one. The enhanced oxidation peak current response can be attributed to the catalytic effect of the ilmenite nanomaterial incorporated into the carbon paste electrode. Under optimal condition, good linear calibration curves were obtained ranging from 0.20 to 8.9 mmol L−1 for PROP and 2.0 to 9.9 µmol L−1 for ATN, with detection limits of 80 and 0.31 µmol L−1, respectively. The CPE-I sensor had good repeatability and reproducibility (RSD ≤ 3.2%) and high sensitivity for the detection of both ATN and PROP. The proposed sensor was applied for detection of these drugs in pharmaceutical tablets. The obtained results indicate that the voltammetric CPE-I sensor could be an alternative method for the routine quality control of the β blockers in complex matrices.

scholarly journals Highly Sensitive Determination of Cadmium and Lead Using a Low-cost Electrochemical Flow-through Cell Based on a Carbon Paste Electrode

2012 ◽  
Vol 28 (2) ◽  
pp. 141 ◽  
Author(s):  
Wanida WONSAWAT ◽  
Wijitar DUNGCHAI ◽  
Shoji MOTOMIZU ◽  
Suchada CHUANUWATANAKUL ◽  
Orawon CHAILAPAKUL
Keyword(s):  
Carbon Paste Electrode ◽  
Low Cost ◽  
Carbon Paste ◽  
Highly Sensitive ◽  
Sensitive Determination ◽  
Flow Through ◽  
Cadmium And Lead ◽  
Paste Electrode

scholarly journals Electrochemical Determination of Dopamine and Uric Acid Using Poly(proline) Modified Carbon Paste Electrode: A Cyclic Voltammetric Study

2021 ◽  
Vol 15 (2) ◽  
pp. 153-160
Author(s):  
Edwin S. D’ Souza ◽  
◽  
Jamballi G. Manjunatha ◽  
Chenthattil Raril ◽  
◽  
...  
Keyword(s):  
Uric Acid ◽  
Modified Electrode ◽  
Carbon Paste Electrode ◽  
Oxidation Potential ◽  
Modified Carbon Paste Electrode ◽  
Current Response ◽  
Carbon Paste ◽  
Cyclic Voltammetric ◽  
Paste Electrode

A cyclic voltammetric technique was used for electropolymerisation of proline on the surface of carbon paste electrode and for individual and concurrent determination of dopamine (DA) and uric acid (UA). The surface morphology of the developed electrode was studied by using field emission scanning electron microscopy. The modified electrode showed a high current response towards DA as compared to the bare electrode. The developed modified electrode shows good catalytic activity with a different oxidation potential of DA and UA. The electrode process was found to be adsorption controlled. The developed method shows very good stability and reproducibility. Under the optimized conditions, the concentration range is (1‒2)∙10-4 M and the observed detection limit was 4.7∙10-6 M. The developed sensor was applied for the determination of DA in the real sample with a good recovery.

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