scholarly journals Electrochemical behavior and differential pulse voltammetric determination of ceftazidime, cefuroxime-axetil and ceftriaxone

2013 ◽  
Vol 11 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Mara Aleksic ◽  
Nikola Lijeskic ◽  
Jelena Pantic ◽  
Vera Kapetanovic
Keyword(s):  
Reduction Process ◽  
Differential Pulse ◽  
Cefuroxime Axetil ◽  
Pharmaceutical Dosage Forms ◽  
Diffusion Controlled ◽  
Voltammetric Behavior ◽  
Pulse Voltammetry ◽  
Ph Range ◽  
Linear Concentration

The voltammetric behavior of three cephalosporins: ceftazidime, cefuroxime-axetil and ceftriaxone has been examined in pH range 2.0-8.0 by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), using a hanging mercury drop electrode (HMDE). The effect of pH of the electrolyte solution and scan rate on the peak currents and peak potentials was examined. The nature of the electrode reduction process in acid solution was found to be diffusion controlled for ceftazidime and cefuroxime-axetil, but strongly influenced by adsorption in the case of ceftriaxone reduction. The adsorption and reorientation of the ceftriaxone molecule at the electrode surface caused instability of the voltammetric signal and disabled its determination in the acid medium. Ceftriaxone adsorption decreased with the increase of pH, and at pH>7 the reduction process became diffusion controlled. Based on this study, DPV method was developed, validated and suggested for determination of ceftazidime at pH 2.0, cefuroxime-axetil at pH 3.5 and for ceftriaxone at pH 8.0. Linear concentration ranges, limits of detection (LOD) and quantification (LOQ) were determined. The method was applied for determination of cephalosporins in pharmaceutical dosage forms: Ceftazidime powder, Ceroxim tablets and Longaceph powder for injection solution.

scholarly journals Voltammetric Determination of Benazepril and Ramipril in Dosage Forms and Biological Fluids through Nitrosation

2001 ◽  
Vol 84 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Fathalla Belal ◽  
Ibrahim A Al-Zaagi ◽  
Mohamed A Abounassif
Keyword(s):  
Biological Fluids ◽  
Differential Pulse ◽  
Dosage Forms ◽  
Cathodic Current ◽  
Diffusion Controlled ◽  
Highly Sensitive ◽  
Voltammetric Behavior ◽  
Ph Range ◽  
Spiked Human Urine

Abstract A simple and highly sensitive voltammetric method was developed for the determination of benazepril (I) and ramipril (II). The compounds were treated with nitrous acid, and the cathodic current produced by the resulting nitroso derivatives was measured. The voltammetric behavior was studied by adopting direct current (DCt), differential pulse (DPP), and alternating current (ACt) polarography. Both compounds produced well-defined, diffusion-controlled cathodic waves over the whole pH range in Britton-Robinson buffers (BRb). At pH 3 and 5, the values of diffusion-current constants (Id), were 5.90 ± 0.40 and 6.66 ± 0.61 for I and II, respectively. The current–concentration plots for I were rectilinear over the range of 1.5–40 and 0.1–30 μg/mL in the DCt and DPP modes, respectively; for II, the range was 2–30 and 0.1–20 μg/mL in the DCt and DPP modes, respectively. The minimum detectabilities (S/N = 2) were 0.015 μg/mL (about 3.25 × 10−8M) and 0.012 μg/mL (about 2.88 × 10−8M) for I and II, respectively, adopting the DPP mode. Results obtained for the proposed method when applied to the determination of both compounds in dosage forms were in good agreement with those obtained using reference methods. Hydrochlorthiazide, which is frequently co-formulated with these drugs, did not interfere with the assay. The method was also applied to the determination of benazepril in spiked human urine and plasma. The percentage recoveries adopting the DPP mode were 96.2 ± 1.21 and 95.7 ± 1.61, respectively.

scholarly journals Simultaneous electrochemical determination of acetaminophen and metoclopramide at electrochemically pre-treated disposable graphite pencil electrode

2016 ◽  
Vol 6 (3) ◽  
pp. 265 ◽  
Author(s):  
Shreekant M Patil ◽  
Vijay P Pattar ◽  
Sharanappa T Nandibewoor
Keyword(s):  
Simultaneous Determination ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Experimental Conditions ◽  
Positive Direction ◽  
Oxidation Potentials ◽  
Voltammetric Behavior ◽  
Pulse Voltammetry ◽  
Apparent Shift

<p class="PaperAbstract"><span lang="EN-US">A sensitive and economic voltammetric method was developed for the simultaneous determination of acetaminophen (AMP) and metoclopramide (MCP) using pre-treated graphite pencil electrode (PTGPE). Compared to a graphite pencil electrode, the pre-treated electrode showed an apparent shift of the oxidation potentials in the positive direction and a notable enhancement in the current responses for both AMP and MCP. Cyclic voltammetry (CV) was used to study the voltammetric behavior of the drugs, while differential pulse voltammetry (DPV) was used to determine AMP and MCP simulta­neously. The dependence of the current on scan rate, pH and concentration was investi­gated to boost the experimental conditions for simultaneous determination. The calibra­tion curves were obtained over the range of 0.1</span><span lang="EN-US">×</span><span lang="EN-US">10<sup>-7</sup> to 1.1</span><span lang="EN-US">×</span><span lang="EN-US">10<sup>-7</sup> M, the concentration of each of both the drugs was varied by keeping the other constant, and achieved lower detection limit of 3.25 nM for AMP and 1.16 nM for MCP. The developed method was found to be selective and rapid for the simultaneous determination of AMP and MCP. The proposed method was applied simultaneously in real samples and pharmaceutical samples, with satisfactory results.</span></p>

scholarly journals Simultaneous electrochemical determination of acetaminophen and metoclopramide at electrochemically pre-treated disposable graphite pencil electrode

2016 ◽  
Vol 6 (3) ◽  
pp. 265
Author(s):  
Shreekant M Patil ◽  
Vijay P Pattar ◽  
Sharanappa T Nandibewoor
Keyword(s):  
Simultaneous Determination ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Experimental Conditions ◽  
Positive Direction ◽  
Oxidation Potentials ◽  
Voltammetric Behavior ◽  
Pulse Voltammetry ◽  
Apparent Shift

<p class="PaperAbstract"><span lang="EN-US">A sensitive and economic voltammetric method was developed for the simultaneous determination of acetaminophen (AMP) and metoclopramide (MCP) using pre-treated graphite pencil electrode (PTGPE). Compared to a graphite pencil electrode, the pre-treated electrode showed an apparent shift of the oxidation potentials in the positive direction and a notable enhancement in the current responses for both AMP and MCP. Cyclic voltammetry (CV) was used to study the voltammetric behavior of the drugs, while differential pulse voltammetry (DPV) was used to determine AMP and MCP simulta­neously. The dependence of the current on scan rate, pH and concentration was investi­gated to boost the experimental conditions for simultaneous determination. The calibra­tion curves were obtained over the range of 0.1</span><span lang="EN-US">×</span><span lang="EN-US">10<sup>-7</sup> to 1.1</span><span lang="EN-US">×</span><span lang="EN-US">10<sup>-7</sup> M, the concentration of each of both the drugs was varied by keeping the other constant, and achieved lower detection limit of 3.25 nM for AMP and 1.16 nM for MCP. The developed method was found to be selective, and rapid for the simultaneous determination of AMP and MCP. The proposed method was applied simultaneously in real samples and pharmaceutical samples, with satisfactory results.</span></p>

scholarly journals Utility of Activated Glassy Carbon and Pencil Graphite Electrodes for Voltammetric Determination of Nalbuphine Hydrochloride in Pharmaceutical and Biological Fluids

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Hoda M. Elqudaby ◽  
Hassan A. M. Hendawy ◽  
Eglal R. Souaya ◽  
Gehad G. Mohamed ◽  
Ghada M. G. Eldin
Keyword(s):  
Glassy Carbon ◽  
Biological Fluids ◽  
Differential Pulse ◽  
Pencil Graphite Electrode ◽  
Buffer Solution ◽  
Graphite Electrodes ◽  
Diffusion Controlled ◽  
Pulse Voltammetry ◽  
Voltammetric Peak

This work compares voltammetric response of nalbuphine hydrochloride (NP·HCl) at both activated glassy carbon and pencil graphite electrodes. The electrochemical oxidation of the drug was studied using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and square wave voltammetry (SWV) techniques. For analytical purpose a well-resolved irreversible diffusion controlled voltammetric peak was established in Britton-Robinson (B-R) buffer solution of pH 6.00 using pencil graphite electrode (PGE). Using activated glassy carbon electrode (GCE) a well-resolved irreversible diffusion controlled voltammetric peak was obtained at pH 7.00 using the same buffer solution. According to the linear relationship between the peak current and NP·HCl concentration, DPV and SWV methods were developed for their quantitative determination in pharmaceutical and human biological fluids. The linear response was obtained in the range from1.6×10-5to1.5×10-4 mol L−1using PGE and from12.5×10-6to13.75×10-5 mol L−1using a GC electrode, respectively. Precision and accuracy of the developed method were checked by recovery studies.

scholarly journals Differential Pulse Voltammetric Determination of Fulvestrant in Pharmaceutical Dosage Forms and Serum Samples

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Dilek Kul ◽  
Burcu Doğan-Topal ◽  
Sibel A. Özkan ◽  
Bengi Uslu
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Oxidation Mechanism ◽  
Differential Pulse ◽  
Carbon Electrode ◽  
Serum Samples ◽  
Standard Samples ◽  
Pharmaceutical Dosage Forms ◽  
Diffusion Controlled

The electrooxidation behavior and determination of fulvestrant at a glassy carbon electrode were investigated. The voltammetric study of the model compounds allowed elucidating the possible oxidation mechanism of fulvestrant. The dependence of the peak current and peak potentials on pH, concentration, nature of the buffer, and scan rate was determined. The oxidation of fulvestrant showed a single and irreversible peak at glassy carbon electrode, and the process was found diffusion controlled. Linear responses were obtained for the concentrations between4×10−6M and6×10−5M in standard samples and between2×10−5M and1×10−4M in serum samples. The repeatability of the method was found 0.93 RSD%. The repeatability, reproducibility, precision, and accuracy of proposed method were investigated.

Graphene Modified Molecular Imprinting Electrochemical Sensor for Determining the Content of Dopamine

2019 ◽  
Vol 15 (6) ◽  
pp. 628-634
Author(s):  
Rong Liu ◽  
Jie Li ◽  
Tongsheng Zhong ◽  
Liping Long
Keyword(s):  
Electrochemical Sensor ◽  
Molecular Imprinting ◽  
Neurological Disorders ◽  
Room Temperature ◽  
Low Cost ◽  
Differential Pulse ◽  
Current Response ◽  
Specific Selectivity ◽  
Pulse Voltammetry

Background: The unnatural levels of dopamine (DA) result in serious neurological disorders such as Parkinson’s disease. Electrochemical methods which have the obvious advantages of simple operation and low-cost instrumentation were widely used for determination of DA. In order to improve the measurement performance of the electrochemical sensor, molecular imprinting technique and graphene have always been employed to increase the selectivity and sensitivity. Methods: An electrochemical sensor which has specific selectivity to (DA) was proposed based on the combination of a molecular imprinting polymer (MIP) with a graphene (GR) modified gold electrode. The performance and effect of MIP film were investigated by differential pulse voltammetry (DPV) and cyclic voltammetry (CV) in the solution of 5.0 ×10-3 mol/L K3[Fe(CN)6] and K4[Fe(CN)6] with 0.2 mol/L KCl at room temperature. Results: This fabricated sensor has well repeatability and stability, and was used to determine the dopamine of urine. Under the optimized experiment conditions, the current response of the imprinted sensor was linear to the concentration of dopamine in the range of 1.0×10-7 ~ 1.0×10-5 mol/L, the linear equation was I (µA) = 7.9824+2.7210lgc (mol/L) with the detection limit of 3.3×10-8 mol/L. Conclusion: In this work, a highly efficient sensor for determination of DA was prepared with good sensitivity by GR and great selectivity of high special recognization ability by molecular imprinting membrane. This proposed sensor was used to determine the dopamine in human urine successfully.

Polarographic and voltammetric determination of 6-mercaptopurine and 6-thioguanine

1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Detection Limits ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Pulse Voltammetry

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.

The polarographic and voltammetric determination of 2,6-dicyano-4-nitro-2'-acetylamino-4'-diethylaminoazobenzene

1990 ◽  
Vol 55 (6) ◽  
pp. 1508-1517 ◽  
Author(s):  
Jiří Barek ◽  
Dagmar Civišová ◽  
Ashutosh Ghosh ◽  
Jiří Zima
Keyword(s):  
Azo Dye ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Determination Limit ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Optimal Conditions ◽  
Pulse Polarography ◽  
Pulse Voltammetry

The polarographic reduction of the title azo dye was studied and optimal conditions were found for its analytical utilization in the concentration range 1 . 10-6 - 1 . 10-7 mol l-1 using differential pulse polarography and 1 . 10-6 - 1 . 10-8 mol l-1 using fast scan differential pulse voltammetry or linear scan voltammetry at a hanging mercury drop electrode. When the latter technique is combined with adsorptive accumulation of the studied substance on the surface of the hanging mercury drop, the determination limit can be further decreased to 3 . 10-9 mol l-1.

The voltammetric determination of 4-nitrobiphenyl

1991 ◽  
Vol 56 (3) ◽  
pp. 595-601 ◽  
Author(s):  
Jiří Barek ◽  
Gulamustafa Malik ◽  
Jiří Zima
Keyword(s):  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Hanging Mercury Drop Electrode ◽  
Optimum Conditions ◽  
Mercury Drop Electrode ◽  
Working Electrode ◽  
Pulse Voltammetry ◽  
Unstirred Solution

Optimum conditions were found for the determination of 4-nitrobiphenyl by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-5 to 2 . 10-7 mol l-1. A further increase in sensitivity was attained by adsorptive accumulation of this substance on the surface of the working electrode, permitting determination in the concentration range (2 – 10) . 10-8 mol l-1 with one minute accumulation of the substance in unstirred solution or (2 – 10) . 10-9 mol l-1 with three-minute accumulation in stirred solution. Linear scan voltammetry can be used to determine 4-nitrobiphenyl in the concentration range (2 – 10) . 10-9 mol l-1 with five-minute accumulation in stirred solution, with the advantage of a smoother baseline and smaller interference from substances that yield only tensametric peaks.

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