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Analytical & Bioanalytical Electrochemistry - Volume:8 Issue: 8, Dec 2016

Analytical & Bioanalytical Electrochemistry
Volume:8 Issue: 8, Dec 2016

  • تاریخ انتشار: 1395/09/25
  • تعداد عناوین: 10
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  • Magadi Puttaswamy Deepak*, Magadi Puttaswamy Rajeeva, Ganjeenahalli Puttagiddappa Mamatha Pages 931-947
    The electrochemical method using Ni0.02Sn0.98O2 nanoparticles modified carbon paste electrode (NSNMCPE) for the determination of dopamine (DA) and uric acid (UA). The Ni0.02Sn0.98O2 nanoparticles were synthesized by gel combustion method. These synthesized Ni0.02Sn0.98O2 nanoparticles were characterized by XRD and SEM. Then the carbon paste electrode is modified with the synthesized Ni0.02Sn0.98O2 nanoparticles by grinding method. The surface morphology of NSNMCPE was confirmed by SEM. The NSNMCPE was successfully used to study the electrochemical investigation of DA and UA in 0.1 M phosphate buffer solution (PBS) of pH 7.0 and pH 6.0 by cyclic voltammetric technique (CV). The low detection limit (LOD) of DA and UA were found to be 0.831×10-5 M and 1.11×10-5 M and the low quantification limit (LOQ) of DA and UA were 2.77×10-6 M and 0.371×10-6 M respectively. The NSNMCPE was used for the simultaneous determination of DA and UA, the separation of the overlapping voltammograms of dopamine and uric acid at modified electrode in a mixture is successfully carried by using cyclic voltammetric technique. The proposed method was successfully applied for the determination of DA and UA due to its good sensitivity, lower detection limit and ease of preparation of the NSNMCPE allows the development of a highly sensitive voltammetric sensor for the determination of DA and UA.
    Keywords: Dopamine (DA) Uric acid (UA), Ni0.02Sn0.98O2 nanoparticles, Carbon paste electrode, Cyclic Voltammetry
  • Yasser Shahbazi, Farhad Ahmadi *, Farnoosh Fakhari Pages 948-961
    The concentrations of Pb, Cd, Cu, Zn and Se metal ions in milk and dairy products (pasteurized milk, doogh, cheese and yoghurt) were determined with differential pulse anodic and cathodic stripping voltammetry technique at HMDE electrode. For more accurate and selective metal ions determination the samples were digested by dryness-HNO3ὤ軣 H2O2 heat digestion method. The concentration linear ranges of Pb, Cd, Zn, Cu and Se in fermented milk sample were in the range of 0.5-200, 0.3-220, 0.1-500, 0.1-450, and 0.4-120 ppb, respectively. The recovery for metal ions in all samples was in the range of 89 to 99%. The intermetallic effect of metal ions was omitted by change of pH. This study shows that nearly in all cases the concentration of the measured amounts are lower than the international permissible limits and there is no health threatening concern due to the consumption of milk and dairy products in Iran.
    Keywords: Stripping voltammetry, Milk, Dairy products, Heavy metals, Health risk assessment
  • Abdelillah Benabida, Mouhsine Galai *, Mohamed Cherkaoui, Omar Dagdag Pages 962-976
    The application of Nigella sativa oil extract (NS) as a corrosion inhibitor for mild steel (MS) protection was investigated in neutral solution of 3% NaCl solution has been investigated byusingweight loss method, potentiodynamic polarizationand electrochemical impedance spectroscopy (EIS). Polarization curves indicate that NS is a cathodic inhibitor. The inhibition efficiency of NS reached 94% at 250 ppm. However, the adsorption of thisinhibitor at the metallic surface is a physisorption type and follows the Langmuir isotherm adsorption. Thus the thermodynamic and kinetic parameters were calculated and discussed.
    Keywords: Nigella sativa oil extract, Mild steel, Corrosion inhibition, EIS, Polarization
  • Sayed Zia Mohammadi *, Hadi Beitollahi, Hakimeh Afzali Pages 977-987
    A new isoproterenol electrochemical nano sensor was fabricated using a acarbon paste electrode modified with ionic liquid (n-hexyl-3-methylimidazolium hexafluoro phosphate) and magnetic core-shell nanoparticles (MCSILCPE). The electrochemical study of the modified electrode, as well as its efficiency for oxidation of isoproterenol, is described. Differential pulse voltammetry (DPV) exhibits a linear dynamic range from 1.0×10-6 to 7.0×10−4 M isoproterenol. The limit of detection was equal to 6.3×10-7 M. The electrode was also employed to determination of isoproterenol in real samples.
    Keywords: Isoproterenol, Magnetic core, shell nanoparticles, Ionic liquids, Drug analysis
  • Electrocatalytic Oxidation and Detection of Hydrazine at Glassy Carbon Modified Electrode with Prussian Blue-Complex by Sol-Gel Method
    Sohrab Ershad*, Zahra Danandeh Pages 988-999
    A carbon ceramic electrode was prepared with MWCNTs and Prussian blue (PB) complex and applied to the electrocatalytic oxidation of hydrazine. The resulting PB-modified GCE greatly reduced the over potential by about 177 mV with obviously increase the current response compared with the unmodified GCE. Cyclic voltammetry was employed to characterize the electrochemical behavior of the chemically modified electrode. The electrocatalytic efficiency of the modified electrode towards hydrazine oxidation depends on solution pH, and optimum pH value for oxidation of hydrazine is 7.0. The overall number of electrons involved in the catalytic oxidation of hydrazine and the number of electrons involved in the rate-determining steps are 4 and 1, respectively. And diffusion coefficient of hydrazine was estimated using chronoamperometry.
    Keywords: Carbon Ceramic Electrode, MWCNTs, Prussian blue (PB) Complex, Electrocatalytic Oxidation, Hydrazine
  • Somayeh Tajik*, Mohammad Ali Taher Pages 1000-1011
    A novel carbon paste electrode modified with ZnS/ZnAl2S4 nanocomposite and an ionic liquid (ZZ/IL/CPE) was fabricated and used for the electrochemical study of Dpenicillamiene (D-PA). This modified electrode offers a considerable improvement in voltammetric sensitivity toward D-PA, compared to the bare electrode. Square wave voltammetry (SWV) exhibits a linear dynamic range from 5.0×10−7 to 3.0×10−4 M and a detection limit of 1.0×10−7 M for D-PA. Finally, the proposed method was successfully applied to the determination of D-PA in real samples.
    Keywords: D, Penicillamine, Carbon paste electrode, ZnS, ZnAl2S4 nanocomposite, Chemically modified electrodes
  • Chandrabhan Verma, M. A. Quraishi*, Rishi Korde Pages 1012-1032
    Present study describes the effect of electron donating hydroxyl (-OH) group (s) on adsorption behavior of three 5-(phenylthio)-3H-pyrrole-4-carbonitriles (PPCs) on mild steel corrosion in 1 M H2SO4 using gravimetric, Tafel polarization and impedance spectroscopy (EIS), quantum chemical calculations and molecular dynamics simulations methods. The inhibitors showed the maximum efficiency of 91.32%, 92.97% and 94.62% for PPC-I, PPC-II and PPC-III, respectively at 1.29×10-4 mol/L concentration and behaved as mixed type inhibitors. Adsorption of studied inhibitors on mild steel surface followed the Langmuir adsorption isotherm. The quantum chemical calculation parameters such as EHOMO, ELUMO, ΔE, global harness, softness, electronegativity and fraction of electron transfer (DN) were calculated using DFT method to correlate the electronic properties with the adsorption behavior of studied molecules. The adsorption behavior of the inhibitor molecules was further supported by their adsorption energies using molecular dynamics simulations method.
    Keywords: Adsorption, EIS, Tafel, Quantum chemical calculations, molecular dynamics simulations
  • Hesam Asari Bami, Mohammad A. Khalilzadeh, Hassan Karimi Maleh* Pages 1033-1043
    A square wave voltammetric sensor based on carbon paste electrode modified with CdO nanoparticles (CdO/NPs) and 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid (CdO/NPs/BIHF/CPE) was fabricated for tert-butylhydroxyanisole (BHI) analysis. CdO/NPs were characterized with TEM and XRD methods. The CdO/NPs/BIHF/CPE showed good electrocatalytic activity to the electro-oxidation of BHI. The peak currents of square wave voltammograms (SWV) of BHI increased linearly with its concentration in the ranges of 0.08–550 μM. The detection limit for BHI was 0.04 μM. The CdO/NPs/BIHF/CPE was successfully applied for the determination of BHI in food samples.
    Keywords: 1, Butyl, 3, methylimidazolium hexafluorophosphate, CdO nanoparticles, Voltammetry, Butylhydroxyanisole
  • Volodymyr V. Tkach, Yana G. Ivanushko, Lyudmyla V. Romaniv, Svitlana M. Lukanovas., Iacute, Lvio C. De Oliveira, Reza Ojani, P. I. Yagodynets Pages 1044-1054
    detection, based on its azo-coupling with conducting polymer-based diazonium salts has been evaluated theoretically. The mathematical model, describing the case, was developed and analyzed by means of linear stability theory and bifurcation analysis. It was shown, that the reaction may be realized with electroanalytical efficiency, when the pH is neutral or mildly acidic. Also it was shown, that the oscillatory behavior in this case is more probable, than for general case, due to DEL influences of diazocoupling.
    Keywords: Saccharine, Electrochemical detection, Azo coupling conducting polymers, Stable steady, state
  • Farnoush Faridbod*, Meraj Shoghi Kalkhoran, Morteza Pirali Hamedani Pages 1055-1066
    Two novel potentiometric Morphine sensors were designed, optimized and used for the determination of this alkaloid drug. The electrodes were based on the symmetric and asymmetric designs for the application of PVC membrane sensors. Both the symmetric membrane and the asymmetric wire coated electrodes were worked based on morphinetetraphenyl borate ion-pair complexes which act as the sensing material and they responded based on ion exchange mechanism. The optimal response behavior was at 5% wt. of the ionpair, 30% wt. of PVC and 65% wt. of DBP for the symmetric devices and at 25% wt. of PVC, 5% wt. of the ion-pair morphine-tetraphenyl borate, 2% wt. of ionic additive and 68% DBP. The PVC membrane sensor was found to have a Nernstian behavior in the concentration range of 5.0×10-5-1.0×10-2 mol L-1, while the wire coated electrodes showed linear behaviors from 1.0×10-7 to 1.0×10-4 mol L-1. Both devices proved to satisfactorily applicable in the analysis of Morphine hydrochloride in pharmaceutical formulation under laboratory conditions.
    Keywords: Morphine hydrochloride, Potentiometry, Ion, selective electrode, Wire coated, PVC membrane, Sensor