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Analytical & Bioanalytical Electrochemistry - Volume:10 Issue: 12, Dec 2018

Analytical & Bioanalytical Electrochemistry
Volume:10 Issue: 12, Dec 2018

  • تاریخ انتشار: 1397/09/10
  • تعداد عناوین: 10
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  • Masoumeh Tohidinia, Najmeh Sabbaghi, Shervin Shaybani, Meissam Noroozifar* Pages 1525-1537
    For the first time a cheap and simple modified carbon ceramic micro-electrode (MCCME) with nanosized LaFe0.2Ni0.8O3 perovskite has been developed for simultaneous determination of dopamine (DA), acetaminophen (AC) and xanthine (XN). The electrochemical response characteristics of the MCCME toward DA, AC and XN were investigated by cyclic voltammetry, differential pulse voltammetry and chronoamperometry. Under the optimum conditions, linear calibration plot was obtained over the range 6.66-131, 9.99-131 and 3.99-115 μM with detection limits 2.1, 3.2 and 1.3 μM for DA, AC and XN, Respectively. The value of diffusion coefficient was found to be 9×10-6, 6.3×10-5 and 4.8×10- 4 cm2s-1 for DA, AC and XN, respectively. The analytical performance of this sensor has been evaluated for simultaneous detection of these three analysts in human serum samples.
    Keywords: Simultaneous determination, Carbon ceramic micro-electrode, Nanosized LaFe0.2Ni0.8O3 perovskite
  • Muhammad Nurdin*, Nasriadi Dali, Irwan Irwan, Maulidiyah Maulidiyah, Zul Arham, Ruslan Ruslan, Baharuddin Hamzah, Sarjuna Sarjuna, Dwiprayogo Wibowo Pages 1538-1547
    Pb2+ ion was investigated by voltammetry selectivity using TiO2-Ionophores hexa(p-tert butyl)hexa(ethyl ester)calix[6]arene (BEK6) composite to increase the selectivity and sensitivity of carbon paste electrode (CPE). The BEK6 was synthesized by using hydrolysis method, meanwhile the TiO2-P25 and graphite powder were mixed as an electrode composite. The Scanning Electron Microscopy (SEM) shows that the CPE doped TiO2-BEK6 (CPE/TiO2-BEK6) have morphology likes a rough, non-porous, composed of fine particles, and homogeneously. The presence of Pb2+ ion in pH 5 citrate buffer electrolyte causes the peaks appearance on Epa and Epc were 0.17 V and 0.37 V with  the peak potential current generated of 15.15 μA and -12.0 μA, respectively. The 0.005 g BEK6 was increased significantly the peak current of the Pb2+ ion with the LOD value of 0.1756. In addition, the presence of TiO2-BEK6 composite shows the measurement current stability by %RSD of 0.83.
    Keywords: Pb2+, Ionophore, TiO2-BEK6, Cyclic voltammetry, Selectivity
  • Mehri, Saddat Ekrami, Kakhki, Sedigheh Abbasi*, Nahid Farzaneh Pages 1548-1561
    Here, graphene oxide is synthesized and functionalized with methyl viologen and chitosan to be used as a novel catalyst support for Pt nanoparticles. The particle size and distribution of Pt nanoparticles are characterized by transmission electron microscope images. Pt nanoparticles with the mean particle size of 3.62 nm are dispersed on the support very uniformly. The catalytic activity of the prepared catalyst is investigated for methanol oxidation by cyclic voltammetry technique. The prepared catalyst showed very good catalytic activity for methanol oxidation. The experimental and statistical analyses are used to investigate the effect of mutual interaction between temperature and methanol concentration on anodic current density of methanol oxidation. The statistical analysis results reveals that the influence of temperature and methanol concentration as main factors and their reciprocal interactions are significant at α=0.05. Meanwhile, the results confirm that the response increases with both main factors. The enhancement of the anodic current density of methanol oxidation with temperature and methanol concentration is equal to 530.22% and 184.89%, respectively. Therefore, the effect of temperature on the response is higher than that of methanol concentration.
    Keywords: Mutual interaction, Anodic current density, Methanol oxidation, Design ofexperiments
  • Ramesh Bhat *, A. Chitharanjan Hegde, Sudesh Bekal Pages 1562-1573
    Optimization of acidic chloride bath containing triethanolamine and citric acid for deposition of a smooth and uniform Zn-Ni alloy coating over mild steel is discussed in the present work. Bath constituents and operating parameters were optimized by standard Hull cell method. Triethanolamine and citric acid were used as additives altered the phase content in the coatings, most likely as a result of their adsorption at the surface of the cathode. The effect of citric acid was more pronounced than that of triethanolamine. The composition of coatings was determined by using colorimetric method. The bath followed anomalous codeposition with preferential deposition of Zn over nobler metal Ni. The experimental results reveal that a bright Zn-Ni alloy coating having ~4.92 wt.%Ni was showing peak performance of the coating against corrosion. Deposition was carried out under different condition of current densities and molar ratio of [Ni+2]/[Zn+2]. No transition current densities at which codeposition behaviour changed from anomalous to normal type was observed. The cathode current efficiency was higher than 80%. As the current density was increased or the bath temperature was decreased, the concentration of the nobler metal in the coating was increased. The thickness and hardness of all coatings increased as the applied current density was increased. The throwing power and reflectance of the coating was increased with current density to a peak value, and then decreased. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods were used to assess the corrosion resistance of Zn-Ni alloy coatings at different current densities. Surface morphology of the coatings was examined using Scanning Electron Microscopy (SEM). A new and cheap Chloride bath, for bright Zn–Ni alloy coating on mild steel has been proposed, and results are discussed.
    Keywords: Electrodeposition, Corrosion resistance, Anomalous coating, Triethanolamine, Cathode current efficiency
  • Azam Khodabandeloie*, Arash Fattah, alhosseini Pages 1574-1586
    In this study, the 5052 aluminum alloy was coated by plasma electrolytic oxidation (PEO) process in the 12 g.l-1 sodium silicate (Na2SiO3. 5H2O), 2 g.l-1 potassium hydroxide (KOH) using 2 g.l-1 potassium fluoride (KF) electrolytes and also not using it. The formed films in the solutions were compared in the case of KF absence or presence in the electrolyte. The coating surface morphology was inspected using the scanning electron microscopy (SEM). Both coating composition and corrosion behavior were studied by means of X-ray diffraction (XRD) and electrochemical methods. Finally, the experimental results illustrated that having added 2 g.l-1 KF to the electrolyte, the corrosion resistance of the coating was enhanced in addition to improving the film growth rate, despite the fact that there was no significant influence, applying varied voltages.
    Keywords: PEO, 5052 aluminum alloy, Potassium fluoride, Polarization, Corrosion, Electrochemical impedance spectroscopy
  • Amin Salhi, Imad Hamdani, Abdelhamid Bouyanzer, Nabila Chahboun, Hassan Amhamdi, Ismail Warad, Belkheir Hammouti, Fouad Bentiss, Abdelkader Zarrouk * Pages 1587-1610
    The present work is devoted to study the Thymus Algeriensis (TA) extracts as antioxidants and green corrosion inhibitors of mild steel (MS) in 1 M HCl medium at 303 K. The extract from aerial parts of Thymus Algeriensis were obtained by distillation and analyzed. Antioxidant activity of methanolic extract of TA was examined by using both DPPH radical scavenging and β-carotene-linoleic acid bleaching and likened with ascorbic acid and BHA (butylated hydroxyanisole) used as reference compounds. Corrosion inhibition of of mild steel (MS) in HCl by ethyl acetate (EATA) and methanol (EMTA) extracts of TA was studied using weight loss and electrochemical techniques. TA extract was found to be a better inhibitor. Indeed, the inhibition efficiency increased with increase EATA and EMTA concentration but decreased with rise in temperature. The variation of inhibitory efficacy with temperature point towards physical adsorption which is supported by the kinetic and thermodynamic parameters derived from the experimental data. Polarization studies show that the EATA and EMTA act as mixed typed inhibitor. Inhibitive effect was afforded by adsorption of the EATA and EMTA components which was found to accord with Langmuir adsorption isotherm.
    Keywords: Extract of Thymus Algeriensis, Antioxidant activity, Corrosion inhibition, Acidic medium, Mild steel
  • Sedighe Jabarian, Ali Ghaffarinejad *, Hojjat Kazemi Pages 1610-1619
    In this study for the first time, the electrocatalytic performance of an electrochemically synthesized metal–organic framework (MOF) was compared with a solvothermally synthesized MOF. HKUST-1 MOF was synthesized by the electrochemical method at room temperature and very short time. Then, its performance as an electrocatalyst for oxygen reduction reaction (ORR) was studied in 0.5 M H2SO4, phosphate buffer 6 (PBS6) and 0.1 M NaOH solutions, among which the best result was obtained in PBS6. At the optimum condition the ORR was compared with a HKUST-1 synthesized by a common solvothermal method (at very longer time and higher temperature and pressure). ORR peak currents on glassy carbon electrode (GCE), solvothermally synthesized MOF (STMOFGCE), and electrochemically synthesized MOF (ECMOF-GCE) were 0.8, 8.1 and 29.6 mA. cm-2 respectively, and ORR peak potentials (Ep) were -0.83, -0.11 and -0.13 V, respectively. In comparing the ECMOF-GCE and STMOF-GCE, the Ep is almost the same, but the peak current density for the former is very greater and its ORR onset potential is considerably more positive than STMOF-GCE, which means the ORR is thermodynamically easier on ECMOF-GCE.
    Keywords: Metal–Organic Framework, Solvothermal method, Electrochemical synthesis, HKUST-1, Electrocatalyst, Oxygen reduction reaction
  • Mohammed Khair Hourani *, Mohammad Amayreh, Wafa Hourani Pages 1620-1628
    A novel, simple, convenient, inexpensive and green voltammetric sensing for iron in human blood serum was developed. The method is based on linear sweep voltammetry at an iodine-coated polycrystalline platinum electrode. A miniaturized home-made small scale 0.5-mL cell was used for the analysis. Oxidation of iron at the iodine-coated platinum electrode was manifested by a peak centered at 0.5 V. The established calibration curve for the relationship between iron (II) concentration and current extracted from the linear sweep voltammograms revealed an excellent linearity(R2=0.9923). The calculated lowest detection limit, LOD, is 0.26 ppm and the limit of quantification is 0.87 ppm. Recovery studies for a concentration of 1.0 ppm yielded a value of 1.02 ppm (102% percent recovery). No interference with other common essential elements in blood serum was observed which attests to the suitability and accuracy of the method. The developed method was applied to analysis of real blood samples. The results of analysis were compared with the results from conventional standard methods used in medical laboratories where an excellent agreement between the two analytical methods was observed.
    Keywords: Voltammetric sensors, Iodine-coated platinum electrode, Serium analysis, Irondetermination in blood
  • Mahshid Ershadi, Mehran Javanbakht*, S. Hamid Reza Beheshti, Behrooz Mosallanejad, Zahra Kiaei Pages 1629-1653
    A patent analysis method has been applied to study patenting activities on development of liquid electrolytes for lithium-ion batteries. The method is done via two steps:First, planning a searching strategy and second, an analysis of the information obtained from selected patents. The results showed that the patents on liquid electrolytes for Li-ion cells were published in a time interval of 1964 to 2017 with a significant growing publishing number between 2010 and 2013. The obtained patenting time trend illustrated that the technical knowledge of this technology has been became probably mature and it is predicted that patenting trend in this area will be continued with a slow rate in upcoming years. It was found that Japan, China, South Korea and USA are the most targeted countries for patent publication in this field which is an indicator of their potential market for this technology. Investigation of the competitors patent assignees showed that LG CHEM, Mitsubishi Chemicals, UBE Industries, Sony and Sanyo Electric are the pioneer players having more patented publications among others, respectively.
    Keywords: Electrolyte additive, Lithium hexafluorophosphate, Lithium-ion batteries, Patentanalysis, Patent landscape
  • Shirin Mahmoudi, Hamid Rashedi , Farnoush Faridbod * Pages 1654-1667
    A molecular imprinted polymer (MIP)-based biomimetic sensing device was constructed for the analysis of clarithromycin (CM). The novel MIP was prepared using a methacrylic acid (MAA) (functional monomer) and Ethylene glycol dimethylacrylate (EGDMA) (cross-linker) and the target species (i.e.CM) as the template molecule. The resulting MIP had considerable adsorption capacity and excellent selectivity toward CM compound. After some experiments, optimum 1:6 mole ratio of template to MAA was selected for the synthesis of CM MIP. The non-covalent CM-MIP was used for the construction of a potentiometric sensor for CM. The proposed had selective and sensitive response to CM concentration in aqueous media. The electrode response had a Nernstian response of 50.8±1.0 mV decade−1from 1.0×10-6 to 5.0×10-3 M and had a detection limit as low as 8.0×10-7 M. The response time of the electrode was about 15 s, and it had a long-term stability of over 45 days. The sensor also proved applicable to the analysis of CM concentration in tablets with good sensitivity and accuracy.
    Keywords: Clarithromycin, Sensor, Potentiometry, Molecularly imprinted polymer