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Vol 54, No 10 (2018)

Article

The Quantitative Detection of Phenylephrine in Pharmaceutical Preparations and Spiked Human Urine by Voltammetry

Yagmur S., Ture M., Saglikoglu G., Sadikoglu M., Yilmaz S.

Abstract

A voltammetric method was used for the quantitative detection of phenylephrine in pharmaceutical preparations and spiked human urine. The electrochemical measurements were carried out in various buffer solutions in the pH range from 0.51 to 12.00 on ultra-trace graphite electrode (UTGE) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The dependence of pH on the oxidation peak current and peak potential was investigated. Britton–Robinson buffer (pH 8.02) was selected for analytical purposes. The peak was established to be diffusion controlled nature of electrode. A linear calibration curve for DPV analysis was constructed in the phenylephrine concentration range from 8 × 10–6 to 1 × 10–4 M. Limits of detection (LOD) and quantification (LOQ) were obtained as 2.07 × 10–7 M and 6.91 × 10–6 M respectively. The repeatability, accuracy and precision of the developed technique were checked in spiked urine and pharmaceutical preparations.

Russian Journal of Electrochemistry. 2018;54(10):741-746
pages 741-746 views

Application of 1,4-Diaminoanthraquinone as a New Sensing Material for Fabrication of a Iron(III)-Selective Modified Carbon Paste Electrode

Ghohari H., Zamani H.A., Joz-Yarmohammadi F., Ebrahimi M., Abedi M.R.

Abstract

In the present work, a novel sensitive electrochemical potentiometric sensor for sensing Fe3+ ions based on 1,4-diaminoanthraquinone (DAQ) as a hydrophobic selector element was prepared to implement as an ion selective carbon paste electrode in the aqueous solutions. The adequate amounts of ionophore (5%), paraffin oil (25%) as a binder, Nanosilica (NS: 0.5%) multi-wall carbon nanotubes (MWCNTs: 1%) as a modifier, and graphite powder (68.5%) as an inert matrix was occupied to form the paste. This new FeCP sensor demonstrated a Nernstian slope of 19.7 ± 0.7 mV per decade over widish linear range between 1.0 × 10–8 to 1.0 × 10–2 mol L–1 at working pH range of 1.9–5.0 in the optimized conditions. The average elapsed time to response of electrode was about ~6 s for concentrations from lower (1.0 × 10−8 mol L–1) to higher (1.0 × 10−2 mol L–1) of Fe3+ ion solution. The selectivity of electrode toward Fe3+ ions in comparison with other cations was studied by matched potential method. The making FeCP sensor has been put to use successfully as an indicator electrode in analytical applications such as the potentiometric titration and determination of iron(III) ion in blend of different ions.

Russian Journal of Electrochemistry. 2018;54(10):747-754
pages 747-754 views

Effect of N719 Dye Dipping Temperature on the Performance of Dye-Sensitized Solar Cell

Rahman M.Y., Roza L., Samsuri S.A., Umar A.A.

Abstract

Preparation parameter of dye plays important role in determining DSSC performance. This paper reports the influence of N719 dye dipping temperature on the optical properties and performance parameters of the DSSC utilizing TiO2 films prepared via microwave technique. The TiO2 coated N719 dye films were prepared at various temperatures, namely, 30, 50, 60, 70 and 80°C. It is found that the TiO2 film dipped into N719 dye solution at 50°C possesses the broadest optical absorption window and the highest dye loading. It is also found that the dye dipping temperature does not affect the leak current in the device. The short-circuit current density (JSC) and power conversion efficiency (η) are strongly influenced by the dipping temperature. The DSSC utilizing the sample prepared at 50°C demonstrated the highest JSC and η of 4.06 mA cm–2 and 1.36%, respectively due to highest dye loading and recombination resistance.

Russian Journal of Electrochemistry. 2018;54(10):755-759
pages 755-759 views

Electrochemical Behavior of an Anti-Viral Drug Valacyclovir at Carbon Paste Electrode and Its Analytical Application

Devarushi U.S., Shetti N.P., Bukkitgar S.D., Tuwar S.M.

Abstract

Valacyclovir (VCH) is an antiviral drug, used in the management of viral infections such as herpes simplex and varicella-zoster in humans. It is rapidly converted to acyclovir which has antiviral activity against herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) and Varicella-zoster virus (VZV) both in vitro and in vivo. Electrochemical behavior was studied using cyclic voltammetric method, and the analytical application was studied using differential pulse voltammetric technique. The process on the surface of electrode was found to be irreversible and diffusion controlled. The charge transfer coefficient, heterogeneous rate constant, the number of electron transferred and activation parameters were calculated. Possible free radical reaction mechanism taking place on the surface of electrode was proposed. Calibration plot constructed using differential pulse voltammetric technique and applied for quantitative analysis in pharmaceutical and human urine sample. Limit of detection (LOD) and limit of quantification (LOQ) were calculated and found to be 0.028 and 0.09 μM, respectively. The present work describes the electrochemical behavior of an antiviral drug, VCH and its determination in pharmaceutical samples. The method shows the development of a sensor for selective and sensitive determination of VCH.

Russian Journal of Electrochemistry. 2018;54(10):760-768
pages 760-768 views

Oxygen Electroreduction Catalysts Based on Polymer Complexes of Nickel with Schiff Bases

Novozhilova M.V., Danilova Y.S., Karushev M.P., Timonov A.M., Malev V.V., Levin O.V.

Abstract

In energy-storage systems such as fuel cells and metal-air batteries, the main current-forming process is the reaction of oxygen electroreduction (OER). A simple method is proposed for synthesizing OER catalysts based on polymer complexes of transition metals (nickel, palladium) with Schiff bases prepared by electrochemical polymerization of starting monomers. The OER catalysts are prepared by thermolysis of polymers in inert atmosphere. Their properties are characterized by the methods of cyclic voltammetry with the use of a rotating disk electrode. The surface state (the catalyst film density, the size and composition of particles) is controlled by scanning electron microscopy with X-ray microanalysis. The electrode demonstrates the high catalytic activity in the oxygen electroreduction reaction in alkaline solutions (higher than 750 mA/mg of the initial polymer mass).

Russian Journal of Electrochemistry. 2018;54(10):769-774
pages 769-774 views

Effect of Parameters of Pulsed Electric Field on Average Current Density through Nafion 438 Membrane in Electrodialysis Cell

Zyryanova S.V., Butyl’skii D.Y., Mareev S.A., Pis’menskaya N.D., Nikonenko V.V., Pourcelly G.

Abstract

Pulsed electric fields (PEF) have been used to advantage in electroplating for more than half a century. Recently, interest has increased in the application of these electric modes in the membrane processes. In this work, the effect of parameters (potential, frequency of current, and duty cycle) of pulsed current mode on the average current density in the electrodialysis cell is studied. For this purpose, the plots of current vs. time were measured in the mode of pulsed potential drop on a Nafion 438 (NafionTM N438) cation-exchange membrane. It is shown that the largest gain in the current density of 33% can be attained by varying parameters of PEF.

Russian Journal of Electrochemistry. 2018;54(10):775-781
pages 775-781 views