scholarly journals A study of the electrochemical activity of some macrolide antibiotics on a gold electrode in a neutral electrolyte

2007 ◽  
Vol 72 (12) ◽  
pp. 1427-1436 ◽  
Author(s):  
Milka Avramov-Ivic ◽  
Slobodan Petrovic ◽  
D.Z. Mijin
Keyword(s):  
Gold Electrode ◽  
Structural Changes ◽  
Linear Sweep Voltammetry ◽  
Electrochemical Determination ◽  
Electrochemical Reactions ◽  
Cathodic Peak ◽  
Experimental Conditions ◽  
Neutral Electrolyte ◽  
Anodic Reactions

The aim of the present study is to present the different reactivity of azithromycin and clarithromycin (pure and commercial) at a gold electrode in neutral electrolyte using cyclic linear sweep voltammetry under the same experimental conditions. A gold electrode was successfully used for the electrochemical qualitative and quantitative determination of azithromycin dihydrate and azithromycin from capsules (Hemomycin?) and for the separation of azithromycin from one of the excipients, lactose monohydrate. The good catalytically activity of the gold electrode was employed only for the qualitative electrochemical determination of pure clarithromycin by appearance of one cathodic and four anodic reactions, which enabled structural changes in this molecule during electrochemical reactions to be studied. Commercial clarithromycin, Clathrocyn? was qualitative determined by one reproducible anodic reaction. The activity of one of the excipients, Avicel, observed as a cathodic peak at different potential from the cathodic peak obtained with pure clarithromicin was used for the determination of its presence in Clathrocyn? tablets. FTIR Analysis showed the apparent changes in structure of pure clarithromycin, as well as in the molecule of clarithromycin in Clathrocyn? tablets. HPLC Analysis showed a significant decrease in the concentration of azithromycin, Hemomycin? clarithromycin and Clathrocyn? after the electrochemical reactions.

scholarly journals A study of the electrochemical behavior of methomyl on a gold electrode in a neutral electrolyte

2009 ◽  
Vol 74 (5) ◽  
pp. 573-579 ◽  
Author(s):  
Andjelka Tomasevic ◽  
Milka Avramov-Ivic ◽  
Slobodan Petrovic ◽  
Mica Jovanovic ◽  
Dusan Mijin
Keyword(s):  
Gold Electrode ◽  
Hplc Analysis ◽  
Linear Sweep Voltammetry ◽  
Electrochemical Determination ◽  
The Other ◽  
Potential Range ◽  
Linear Sweep ◽  
Qualitative And Quantitative ◽  
Neutral Electrolyte

A gold electrode was used for the qualitative and quantitative electrochemical determination of analytical methomyl in a neutral electrolyte (0.050 M NaHCO3) using cyclic linear sweep voltammetry. In the potential range from -800 mV vs. SCE to 1000 mV vs. SCE the analytical methomyl was quantitatively determined in the concentration range 4.0-16 mg L-1. In the potential range from -1300 mV vs. SCE to 1300 mV vs. SCE, methomyl was qualitatively determined by two anodic and four cathodic reactions. Cycling the potential in this range for 150 min caused the degradation of the molecule, which was confirmed by HPLC analysis. On the other hand, technical methomyl exhibited an inhibition of the gold electrode surface due to the impurities.

Anodic Voltammetric Behavior of Lincomycin and its Electroanalytical Determination in Pharmaceutical Dosage form and Urine at Gold Electrode

2017 ◽  
Vol 231 (5) ◽  
Author(s):  
Jyothi C. Abbar ◽  
Manjunath D. Meti ◽  
Sharanappa T. Nandibewoor
Keyword(s):  
Gold Electrode ◽  
Dosage Form ◽  
Oxidation Process ◽  
Linear Sweep Voltammetry ◽  
Linear Sweep ◽  
Experimental Conditions ◽  
Pharmaceutical Dosage Form ◽  
Antibiotic Drug ◽  
Voltammetric Behavior

AbstractThe anodic voltammetric behavior of an antibiotic drug, lincomycin hydrochloride (LIN) at gold electrode (GE) has been investigated using cyclic and linear sweep voltammetry. The dependence of the current on pH, concentration and scan rate were investigated to optimize the experimental conditions for the determination of lincomycin. The anodic peak was characterized and the process was adsorption-controlled. The number of electrons transferred in the oxidation process was calculated. In the range of 8.0×10

The qualitative electrochemical determination of clarithromycin and spectroscopic detection of its structural changes at gold electrode

2007 ◽  
Vol 9 (7) ◽  
pp. 1643-1647 ◽  
Author(s):  
M.L. Avramov Ivić ◽  
S.D. Petrović ◽  
F. Vonmoos ◽  
D.Ž. Mijin ◽  
P.M. Živković ◽  
...  
Keyword(s):  
Gold Electrode ◽  
Structural Changes ◽  
Electrochemical Determination

Comparison of Gold and Platinum Electrode Responses in Activated Sludge

1993 ◽  
Vol 28 (11-12) ◽  
pp. 473-480
Author(s):  
A. Heduit ◽  
B. Martin ◽  
I. Duchamp ◽  
D. R. Thevenot
Keyword(s):  
Electron Transfer ◽  
Activated Sludge ◽  
Gold Electrode ◽  
Platinum Electrode ◽  
Electrochemical Determination ◽  
Exchange Current ◽  
Experimental Conditions ◽  
Equilibrium Exchange ◽  
Prolonged Contact ◽  
Current Densities

Gold and platinum were compared to ascertain how they expressed a stabilized potential in activated sludge. The comparison was based on electrochemical determination of the electron transfer rate (i.e. equilibrium exchange current density) and recording of potentials against time. When both metals are treated in the same way, platinum gives equilibrium exchange current densities approx. 10 times higher than gold, both in aerated activated sludge and in treated water. For platinum, the equilibrium exchange current densities range from 0.1 to 0.25 µA/cm2 immediately after polishing and decrease during prolonged contact with activated sludge subjected to alternating aeration/anoxia sequences. The lower kinetics of electron transfer on gold go together with significant differences in response:- In an aerobic medium a gold electrode potential is lower than that of a platinum electrode. In a strongly anaerobic medium, the reverse is true. Consequently, the amplitude of the potential variation between aerobic and anaerobic media is smaller for gold than for platinum. Under our experimental conditions this amplitude was approx 350 mV for gold and 850 mV for platinum.- The slopes of the linear relationships between potential and pH or potential and the logarithm of the dissolved oxygen concentration are two or three times greater for platinum than for gold. Although the values obtained with platinum electrodes cannot represent a veritable equilibrium state, the platinum electrode zero-current potential would seem to be far more sensitive to variations in the medium than that of the gold electrode; it is, therefore, more suitable for use in activated sludge.

scholarly journals Electrochemical determination of sertraline in pharmaceutical formulation and serum using a gold electrode in a pH 8.4 bicarbonate solution

2021 ◽  
Vol 152 (2) ◽  
pp. 185-192
Author(s):  
Jelena Lović ◽  
Jelena Lađarević ◽  
Nemanja Trišović ◽  
Filip Andrić ◽  
Aleksandar Mladenović ◽  
...  
Keyword(s):  
Gold Electrode ◽  
Electrochemical Determination ◽  
Pharmaceutical Formulation

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 The qualitative determination of oseltamivir phosphate in Tamiflu® capsule by cyclic voltammetry

2011 ◽  
Vol 65 (1) ◽  
pp. 87-91 ◽  
Author(s):  
Milka Avramov-Ivic ◽  
Slobodan Petrovic ◽  
Dusan Mijin ◽  
Katica Drljevic-Djuric
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Method ◽  
Gold Electrode ◽  
Cyclic Voltammogram ◽  
Carbon Electrode ◽  
Experimental Conditions ◽  
Concentration Dependency ◽  
Oseltamivir Phosphate ◽  
Qualitative Determination

A gold electrode was applied in the voltammetric determination of oseltamivir phosphate standard in 0.05 M NaHCO3. Oseltamivir phosphate as a standard and as a component of Tamiflu? capsule exhibited the identical cyclic voltammogram. The peaks originated from excipients in capsule do not appear under the applied electrochemical conditions. The electrochemical method for the qualitative determination of oseltamivir phosphate in Tamiflu? capsule by cyclic voltammetry was developed. The presence of oseltamivir phosphate as standard and as a content of Tamiflu? capsule in electrolyte as well as their concentrations were simultaneously checked by HPLC. The lack of the current/concentration dependency was established. The not pretreated glassy carbon electrode cannot be used for the determination of oseltamivir phosphate under identical experimental conditions presented for gold electrode.

scholarly journals A Nafion Film Cover to Enhance the Analytical Performance of the CuO/Cu Electrochemical Sensor for Determination of Chemical Oxygen Demand

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 669 ◽  
Author(s):  
Tanya Carchi ◽  
Byron Lapo ◽  
José Alvarado ◽  
Patricio J. Espinoza-Montero ◽  
Jordi Llorca ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Oxygen Demand ◽  
Linear Sweep Voltammetry ◽  
Copper Surface ◽  
Electrochemical Determination ◽  
Electrochemical Characteristics ◽  
Wide Range ◽  
Nafion Film ◽  
Electrochemical Electrode

We modified and evaluated the performance of a CuO/Cu electrochemical electrode for chemical oxygen demand (COD) determination by covering it with a Nafion (Nf) film. The resulting modified CuONf/Cu electrode sensor was used for the electrochemical determination of COD in river, slaughterhouse and estuarine water samples in order to evaluate its performance for this particular task. It was compared with the CuO/Cu sensor with no Nafion. The main electrochemical characteristics of interest, resistance, sensitivity, accuracy and reproducibility, were assessed by means of Linear Sweep Voltammetry using glucose as a standard. Results of these essays indicate that the procedure used produced smooth and firmly attached Nf films covering the whole copper surface. This sensor was shown to be resistant to interferences and effective in electro-oxidation of a wide range of organic compounds and therefore very useful for COD determination. Using the newly developed CuONf/Cu electrode an analytical linear range of 50 to 1000 mg·L−1 COD, with a detection limit of 2.11 mg·L−1 (n = 6) COD was achieved. The comparison shows that the CuONf/Cu sensor is more appropriate for COD determination than its counterpart with no Nafion.

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