Electrochemical behaviour and micromolar determination of the antineoplastic agent azaribine and its mixtures with cytidine

1997 ◽  
Vol 440 (1-2) ◽  
pp. 95-102
Author(s):  
D Marín
Keyword(s):  
Electrochemical Behaviour ◽  
Antineoplastic Agent

scholarly journals Electrochemical Behaviour of a Gold Film- Glassy Carbon Electrode for Determination of Chromium (VI)

2021 ◽  
Author(s):  
Nevila Broli ◽  
Loreta Vallja ◽  
Majlinda Vasjari
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Electrochemical Behaviour ◽  
Supporting Electrolyte ◽  
Anodic Stripping Voltammetry ◽  
Carbon Electrode ◽  
Modulation Amplitude ◽  
Chromium Vi ◽  
Relative Standard

A gold nanostructured film modified glassy carbon electrode (Aufilm/GCE) was developed for the determination of chromium (VI) in water sample. GCE was immersed into HAuCl4 solution (10-3M) and electrodeposition of thin gold layer was conducted at –0.4 V (vs Ag/AgCl) for 10 min. The strong affinity between Au and Cr species resulted with increasing of Cr (VI) signal, compared with the bare glassy carbon electrode. The electrodepositing time, type of supporting electrolyte, pH, the scan rate, modulation amplitude, and modulation time were optimized using differential pulse anodic stripping voltammetry (DP-ASV). The calibration graph using accumulation time of 120 s was linear from 10 to 120 µgL-1 with a sensitivity 1.3 x 10-2 µA/µgL-1. Under optimum experimental conditions, a good correlation coefficient R2=0.9971, and a low detection limit 5.5 µg/L Cr (VI) was obtained. The signal was reproducible with a relative standard deviation ±4.5 %. The developed Aufilm/GCE sensor was applied for the Cr (VI) determination of in sewage water samples.

Etude polarographique de l'antimoine(III) et (V) dans le fluorure d'hydrogène anhydre et dans ses mélanges avec l'eau

1978 ◽  
Vol 56 (5) ◽  
pp. 703-708 ◽  
Author(s):  
Jacques Devynck ◽  
Bernard Tremillon ◽  
Hugues Menard ◽  
Germain Comarmond
Keyword(s):  
Electrochemical Reaction ◽  
Electrochemical Behaviour ◽  
Mercury Electrode ◽  
Analytical Applications ◽  
Dropping Mercury Electrode

The electrochemical behaviour of Sb(III) and Sb(V) in water–HF mixtures (2.5 to 50% HF) and in anhydrous HF is described. A Teflon capillary dropping mercury electrode is proposed for polarographie investigations in these fluorinated media. It is shown, by classical or puise polarography, that Sb(III) can be reduced to Sb(0), as in acidic non-fluorinated media. The electrochemical reaction becomes reversible by addition of Cl−, Br− or I−. Sb(V) is not electroactive in the various HF-media, except when it is introduced as the SbCl5. In this case, the two polarographie waves of Sb(V) disappear with time because of SbF6− formation. Analytical applications to the determination of Sb(III) in water–HF and in anhydrous HF are discussed.

scholarly journals Interaction between Amorphous Zirconia Nanoparticles and Graphite: Electrochemical Applications for Gallic Acid Sensing Using Carbon Paste Electrodes in Wine

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 537 ◽  
Author(s):  
Chrys. O. Chikere ◽  
Nadimul Haque Faisal ◽  
Paul Kong-Thoo-Lin ◽  
Carlos Fernandez
Keyword(s):  
Gallic Acid ◽  
Limit Of Detection ◽  
Electrochemical Behaviour ◽  
Differential Pulse ◽  
White Wine ◽  
Zro2 Nanoparticles ◽  
Carbon Paste ◽  
X Ray ◽  
Zirconia Nanoparticles

Amorphous zirconium oxide nanoparticles (ZrO2) have been used for the first time, to modify carbon paste electrode (CPE) and used as a sensor for the electrochemical determination of gallic acid (GA). The voltammetric results of the ZrO2 nanoparticles-modified CPE showed efficient electrochemical oxidation of gallic acid, with a significantly enhanced peak current from 261 µA ± 3 to about 451 µA ± 1. The modified surface of the electrode and the synthesised zirconia nanoparticles were characterised by scanning electrode microscopy (SEM), Energy-dispersive x-ray spectroscopy (EDXA), X-ray powdered diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). Meanwhile, the electrochemical behaviour of GA on the surface of the modified electrode was studied using differential pulse voltammetry (DPV), showing a sensitivity of the electrode for GA determination, within a concentration range of 1 × 10−6 mol L−1 to 1 × 10−3 mol L−1 with a correlation coefficient of R2 of 0.9945 and a limit of detection of 1.24 × 10−7 mol L−1 (S/N = 3). The proposed ZrO2 nanoparticles modified CPE was successfully used for the determination of GA in red and white wine, with concentrations of 0.103 mmol L−1 and 0.049 mmol L−1 respectively.

scholarly journals A Comparative Electrochemical Behaviour Study and Analytical Detection of the p-Nitrophenol Using Silver Solid Amalgam, Mercury, and Silver Electrodes

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Djenaine De Souza ◽  
Lucia H. Mascaro ◽  
Orlando Fatibello-Filho
Keyword(s):  
Electrochemical Behaviour ◽  
Analytical Determination ◽  
Silver Solid Amalgam Electrode ◽  
Silver Electrodes ◽  
Repeatability And Reproducibility ◽  
Mercury Electrodes ◽  
Behaviour Study ◽  
Interesting Alternative ◽  
Analytical Detection

This work reports a comparative electrochemical behaviour study and p-nitrophenol analytical detection using silver solid amalgam, hanging dropping mercury, and silver electrodes. For this, square wave voltammetry was employed, where the analytical responses and the redox mechanisms could be compared for reduction processes of 4-nitrophenol by analysis of the voltammetric responses. The analytical performance of the electrode was evaluated and detection and quantification limits, recovery percentages, repeatability, and reproducibility for the silver solid amalgam and hanging dropping mercury electrodes presented similar values; the results presented for the silver electrode indicated worse analytical parameters than the other electrodes. The results indicate that the silver solid amalgam electrode can be considered a suitable tool and an interesting alternative for the analytical determination of 4-nitrophenol, as well as for the determination of other biological and environmentally interesting compounds that present analytical responses on mercury surfaces.

scholarly journals Developing an electrochemical sensor based on a carbon paste electrode modified with ZnO nanoparticles synthesized by microwave for determination of chlorpheniramine maleate

2021 ◽  
Vol 4 (01) ◽  
pp. 16-25
Author(s):  
Hamideh Asadollahzadeh
Keyword(s):  
Carbon Paste Electrode ◽  
Zno Nanoparticles ◽  
Electrochemical Behaviour ◽  
Differential Pulse ◽  
Oxidation Potential ◽  
Carbon Paste ◽  
Chlorpheniramine Maleate ◽  
Peak Current ◽  
Paste Electrode

Zinc oxide (ZnO) nanoparticles with an average size of 60 nm have been successfully prepared by microwave irradiation. Carbon paste electrode (CPE) was modified with ZnO nanoparticles and used for the electrochemical oxidation of chlorpheniramine maleate (CPM). Cyclic voltammetry (CV) study of the modified electrode indicated that the oxidation potential shifted towards a lower potential by approximately 106 mV and the peak current was enhanced by 2 fold in comparison to the bare CPE (ZnO/CPE-CV). The electrochemical behaviour was further described by characterization studies of scan rate, pH and concentration of CPM. Under the optimal conditions, the peak current was proportional to CPM concentration in the range of 8.0 ×10-7 to 1.0 × 10-3 mol L-1 with a detection limit of 5.0 × 10-7 mol L-1 by differential pulse voltammetry (DPV). The peak current of CPM is linear in the concentration range of 0.8 - 1000 µM (R2=0.998). The ZnO/CPE has good reproducibility and high stability for the determination of CPM using this electrode. The proposed method was successfully applied to the determination of CPM in pharmaceutical samples. In addition, the important analytical parameters were compared with other methods which show that ZnO/CPE-CV procedure is comparable to recently reported methods.

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