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Analytical & Bioanalytical Electrochemistry - Volume:8 Issue: 7, Nov 2016

Analytical & Bioanalytical Electrochemistry
Volume:8 Issue: 7, Nov 2016

  • تاریخ انتشار: 1395/09/10
  • تعداد عناوین: 10
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  • Ehsan Pourtaheri *, Mohammad Ali Taher, Hadi Beitollahi, Mehdi Ranjbar Pages 803-813
    An ionic liquid (n-hexyl-3-methylimidazolium hexafluoro phosphate)– ZnIn2S4 nanoparticles modified carbon paste electrode (ZISILCPE) was used as a fast and sensitive tool for the investigation of the electrochemical oxidation of penicillamine using voltammetry. The modified electrode offers a considerable improvement in voltammetric sensitivity toward penicillamine, compared to the bare electrode. Using differential pulse voltammetry (DPV), the electrocatalytic oxidation peak current of penicillamine shows a linear calibration curve in the range of 5.0×10-7 to 8.0×10−5 M penicillamine. The limit of detection was equal to 3.0×10-7 M. The electrode was also employed to determination of penicillamine in real samples.
    Keywords: Penicillamine, ZnIn2S4 nanoparticles, Ionic liquids, Carbon paste electrode
  • Amit B. Teradale, Shekappa D. Lamani *, Swastika N. Das* Pages 814-829
    A stable sensor for the determination of allopurinol (AP) was upgrade by effect of surfactant cetyltrimethyl ammonium bromide (CTAB) with running phosphate buffer solution (pH=3.0) at a carbon paste electrode (CPE). A sensitive electrochemical method was improved distinctly in the presence of low concentration of CTAB, the oxidation peak current signifying that CTAB exhibits noticeable enhancement effect to the determination of AP as well as under optimal conditions the linear sweep voltammetry response to AP has a linear concentration over the range from 0.6 µM to 60.0 µM, with limit of detection and quantification 97.2 nM and 0.324 µM respectively. This constructed voltammetry sensor was successfully applied to determination of AP in the human serum sample, urine sample and tablet. Finally this was shown to be sensitive and efficient.
    Keywords: Allopurinol, Surfactant effect, Electrochemical detection, Drug monitoring, Carbon paste electrode
  • Khaoula Alaoui, Younes El Kacimi *, Mouhsine Galai, Khadija Dahmani, Rachid Touir, Ahmed El Harfi, Mohamed Ebn Touhami Pages 830-847
    In this paper, the inhibition ability of Poly(1-phenylethene) against the carbon steel corrosion in 1.0 M HCl solution was studied at different temperatures range from 298 to 328 K using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). It was found that the studied compound exhibited a very good performance as inhibitor for carbon steel corrosion in 1.0 M HCl medium. The obtained thermodynamic adsorption parameters (∆G*ads, ∆H*ads, ∆S*ads) indicated that this polymer retarded both cathodic and anodic processes through physical adsorption and blocking the active corrosion sites. It is found also that this compound obeyed the Langmuir’s adsorption isotherm.
    Keywords: Corrosion, inhibition, Poly(1, phenylethene), Carbon steel, Hydrochloric acid, Adsorption isotherm, Thermodynamic parameters
  • Anuj Kumar *, Vinod Kumar Vashistha, Prashant Tevatia, Randhir Singh Pages 848-861
    In present studies, [MnIILCl2] and [CoIILCl2] pentaazamacrocyclic complexes (where L=Dichloro-2,3-dimethyl[b]-pyridyl-3,6,9,12,15-pentaazacyclopentadeca-2,12-diene) have been synthesized by template method and characterized by microanalysis, UV-Vis, IR and mass spectral studies. On the basis of electronic spectral studies, the saddle-shape octahedral geometry has been assigned to these pentaazamacrocyclic complexes. Electrochemical studies of HOMO-LUMO energy levels of these pentaazamacrocyclic complexes have been carried out by using cyclic voltammetry. The onset oxidation and reduction potentials of [MnIILCl2] and [CoIILCl2] macrocyclic complexes were determined under the similar experimental conditions to calculate the ionization potential (Ip) and electron affinity (Ea) for these macrocyclic complexes. The molecular modeling parameters were also calculated from the calculation of HOMO-LUMO energy levels. The obtained values of these parameters are indicating that [MnIILCl2] macrocyclic complex is more stable than [CoIILCl2] complex. The biological activity of these macrocyclic complexes were also taken into account against E. coli, B. cereus, P. aeruginosa, S. aureus and C. albicans microbial pathogen and compared with the standard drug Gentamycin.
    Keywords: Spectroscopy, Cyclic voltammetry, Redox modeling, Antimicrobial
  • Arash Fattah, Alhosseini*, Omid Imantalab Pages 862-874
    This work aims at studying the influence of grain refinement on the electrochemical behavior of pure copper by employing Mott–Schottky analysis in conjunction with point defect model (PDM). Microstructural evaluations revealed that the mean grain size decreased from about 26 μm for the annealed sample to about 190±20 nm after four passes of accumulative roll bonding (ARB). Compared to the annealed sample, the electrochemical impedance spectroscopy (EIS) revealed that the polarization resistance increased from about 49.63 kΩ.cm2 to 94.97 kΩ.cm2 for Ultra-fine grained (UFG) pure copper after four passes of ARB. Also, the semiconductor properties of the samples were investigated by employing Mott–Schottky analysis in conjunction with PDM. All electrochemical tests showed that the electrochemical behavior of pure copper is improved under influence of ARB process, mainly due to the formation of thicker and less defective oxide film.
    Keywords: Pure copper, Point defect model, EIS, Mott–Schottky
  • Volodymyr V. Tkach*, Yana G. Ivanushko, Olena I. Aksimentyevas., Iacute, Lvio C. De Oliveira, Genilson R. Da Silva, Reza Ojani, Petro I. Yagodynets Pages 875-884
    The possibility of use of conducting polymer (CP), saturated by radical growth centers, as an electrode modifier for carbendazim electrochemical detection has been evaluated by mechanistic way. A mechanism of its electrochemical transformation has been suggested and two mathematical models for oxidation and reduction stages were developed and analyzed by means of linear stability theory and bifurcation analysis. It was proved that, despite of the mechanism´s hybrid character, the conducting polymer, saturated with radical sites, may be an excellent electrode modifier for carbendazim electrochemical detection. The possibility of the oscillatory behavior in this system has also been verified, and it may be possible on both radical formation and recombination stages, being caused by surface and electrochemical factors.
    Keywords: Intoxication prevention, Food security, Carbendazim, Electrochemical sensors, Conducting polymers, Stable steady, state
  • Deswati *, Hilfi Pardi, Hamzar Suyani, Rahmiana Zein, Admin Alif, Tri Widya Edelw Pages 885-898
    An adsorptive cathodic stripping voltammetric method is presented for the simultaneous determination of Pb(II), Cd(II) and Zn(II) in tap water with alizarin as a complexing agent. The method is based on adsorptive accumulation of the complexes of Pb(II), Cd(II) and Zn(II) ions with alizarin onto hanging mercury drop electrode (HMDE), followed by the reduction of the adsorbed species by adsorptive cathodic stripping voltammetry (AdCSV). The optimized experimental conditions include: supporting electrolyte (acetate buffer), pH (5), alizarin concentration (0.5 mM), accumulation time (60 s), accumulation potential (-0.2 V). This method has been applied to determine Pb(II), Cd(II) and Zn(II) in tap water. The concentration of metal ion in tap water was obtained Pb(II) 0.045, Cd(II) 20 and Zn(II) 129 μg/L. the detection limit was Pb(II) 0.008, Cd (II) 0.005 and Zn(II) 0.001 μg/L, relative standard deviation was obtained Pb(II) 1.2, Cd(II) 0.4 and Zn(II) 1.12% (n=10), recovery was obtained Pb(II) 99.45, Cd(II) 98.66 and Zn(II) 99.72%. The accuracy of the obtained voltammetric analytical results was validated by comparing with that obtained by the atomic absorption spectrometric method, Concentration of the metal ion in tap water was obtained with AAS technique Cd(II) 16 μg/L, Zn(II) 115 μg/L and Pb(II) not detected .
    Keywords: Adsorptive cathodic stripping voltammetry, Pb(II), Cd(II), Zn(II), Alizarin
  • Somayeh Tajik *, Mohammad Ali Taher, Shohreh Jahani, Maryam Shanehsaz Pages 899-909
    A novel CdTe quantum dots is synthesized and used for modification of carbon paste electrode (QDMCPE). This modified electrode was used to study the electrooxidation of ascorbic acid using cyclic voltammetry (CV), square wave voltammetry (SWV) and chronoamperometry (CHA) as diagnostic techniques. SWV peak currents of ascorbic acid increased linearly with its concentrations in the range of 5.0×10-7-8.0×10-4 M with a detection limit of 3.0×10−7 M. The main objectives of QDMCPE for determination of ascorbic acid are: wide linear dynamic range, short time of the procedure and no use of electron transfer mediator.Finally this new sensor was used for determination of ascorbic acid in some real samples.
    Keywords: Ascorbic acid, Carbon paste electrode, CdTe quantum dots, Chemically modified electrodes
  • Carol Cuadrado, Laura Ibarra, John Hurtado*, Olimpo Garc, Iacutea., Beltr, Aacuten., Edgar Nagles Pages 910-921
    [Co(bdmpzm)2(NCS)2] (bdmpzm=bis(3,5-dimethylpyrazol-1-yl)methane) was dispersed in graphene oxide (GOx). Composite GOx-[Co(bdmpzm)2(NCS)2] was deposited on a glassy carbon electrode (GCE) and reduced at -1.0 by 60 s. The modified electrode rGOx-[Co(bdmpzm)2(NCS)2]/GCE allowed the oxidation for dopamine (DA) at 0.41 V Our results showed reversible and sensitive process, (∆V 0.09 V) compared with the electrode without modified in buffer phosphate solution pH 3.0. The detection limit (3σ/b) for dopamine was 0.11 µmol L-1 and the RSD was 3.0%. The presence of uric acid and ascorbic acid did not interfere with the signal for dopamine.
    Keywords: Dopamine, Uric acid, Human urine, Cobalt(II) complex, Adsorptive voltammetry, Graphene oxide
  • Mahbobe S. Rahmanpour, Mohammad A. Khalilzadeh* Pages 922-930
    A fast response voltammetric sensor based on ZnO nanoparticles (ZnO/NPs) carbon paste electrode (ZnO/NPs/CPE) is suggested for the determination of tertbutylhydroquinone in the aqueous buffer solution. ZnO nanoparticles synthesized by direct chemical precipitation method and characterized with X-ray diffraction (XRD) method. In the second step, application of the ZnO/NPs for the preparation of modified carbon paste electrode was investigated. At the optimum condition (pH 7.0), the oxidation signals of tertbutylhydroquinone increased linearly with its concentration in the ranges of 1.0–750 μM. The detection limit for tert-butylhydroquinone was 0.7 μM. The ZnO/NPs/CPE was used for the determination of tert-butylhydroquinone in food samples such as sesame and soybean oil.
    Keywords: Tert, butylhydroquinone, ZnO nanoparticles, Food sample analysis, Modified electrode