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Analytical & Bioanalytical Electrochemistry - Volume:4 Issue: 3, Jun 2012

Analytical & Bioanalytical Electrochemistry
Volume:4 Issue: 3, Jun 2012

  • تاریخ انتشار: 1391/07/26
  • تعداد عناوین: 8
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  • Ali K. Attia*, Manal A. El, Shal Pages 213-224
    A highly sensitive electroanalytical method for the determination of moxifloxacin hydrochloride using differential pulse voltammetry was described. The electrochemical behavior of the used drug was investigated in Britton-Robinson buffer in the pH range of 2.0 to 11.0 at chloranil modified carbon paste electrode. The anodic peak currents increased linearly with the concentration in the range of 4.0×10-7 to 3.6×10-6 mol L-1. The limits of detection and quantification were 6.74×10-8 mol L-1 and 2.25×10-7 mol L-1, respectively. The relative standard deviation was found in the following range: 0.569-0.974%. The percentage recovery was found in the following range: 99.28-100.60%. The method was successfully applied to the determination of moxifloxacin hydrochloride in tablets without previous separation.
    Keywords: Moxifloxacin Hydrochloride, Chloranil, Oxidation, Differential Pulse Voltammetry, Tablets
  • Jamballi G. Manjunatha, Bahaddurghatta E. Kumara Swamy*, Mellekatte T. Shreenivas, Ganjeenahalli P. Mamatha Pages 225-237
    A carbon paste electrode (CPE) modified with poly (nicotinic acid) was used for the sensitive and selective voltammetric determination of dopamine (DA). The electrochemical response characteristics of the modified electrode toward DA, ascorbic acid (AA) were investigated by cyclic voltammetry (CV). The results show an efficient catalytic activity of the electrode for the electro-oxidation of DA, which leads to an improvement to the reversibility of the electrode response. The effect of pH and potential sweep rate on the mechanism of the electrode process was investigated. The modified electrode exhibits an efficient electron mediating behavior along with well-separated oxidation peaks for AA and DA. Under the optimum pH of 7.0 in 0.2 M phosphate buffer solution (PBS), the CV anodic peak current showed a linear relation vs. DA correlation coefficients. High sensitivity and selectivity, high reproducibility, along with ease of preparation and regeneration of the electrode surface by simple polishing make this method suitable for the determination of DA and AA in pharmaceutical and clinical preparations.
    Keywords: Carbon Paste Electrode, Nicotinic Acid, Electropolymerisation, Dopamine, Ascorbic Acid, Cyclic Voltammetry
  • Dalibor Stankovic*, Goran Roglic, Milica Jovic, Ivan Andjelkovic, Jelena Mutic, Dragan Manojlovic Pages 238-245
    The potentiometrical analysis of Cu2+ using Nafion- modified electrode with Cu complex with DPABA (Methyl 3,5-bis{bis-[(pyridin-2-yl)methyl]amino}methyl)benzoate) incorporated, is described. Parameters and conditions such as the volume of 2% Nafion, pH, and the concentration of Cu complex with DPABA and pH of medium were optimized. Interference of Fe3+, Co2+ and Zn2+ with Cu2+ were examined. Calibration curve was linear in the range of 1×10-7-5×10-5 mol/L. The detection limit was 7×10-8 mol/L. A response time of the proposed electrode was 3 s.
    Keywords: Modified Electrode, Potentiometry, Copper Determination, Cyclic Voltammetry
  • Leila Hajiaghababaei*, Sara Kazemi, Alireza Badiei, Pezhman Zarabadi, Poor, Mohammad Reza Ganjali, Ghodsi Mohammadi Ziarani Pages 246-261
    A PVC membrane electrode to determination of lead ions based on hydroxymethyl -modified SBA-15 nanoporous silica as a carrier was prepared. The electrode exhibits a Nernstian response for Pb2+ over a concentration range (1.010-1 to 1.010-4 mol L 1) with a slope of 28.9±0.2 mV per decade. The limit of detection of the sensor is 5.510-5 mol L-1. The sensor has a relatively fast response time (10s) and a useful working pH range of 3.5– 8.0. Interference of some divalent cations was also evaluated. It was used as an indicator electrode in potentiometric titration of Pb2+ with EDTA and in direct determination of lead ion in wastewater and pepper samples. The results indicate that this electrode is sensitive for determination of Pb2+.
    Keywords: Lead, Hydroxymethyl, Modified Nanoporous Silica, PVC Membrane Electrode
  • Samsulida Abd Rahman, Jaafar Abdullah*, Hamidah Sidek, Nur Ellina Azmi Pages 262-276
    A mediated amperometric biosensor based on bi-layer glutamate dehydrogenase (GLDH)/diaphorase immobilized on screen printed carbon paste electrode (SPCE) for the determination of ammonium has been described. In this work the electrochemical oxidation of NADH was used as indicator reaction for the quantification of ammonium concentration. The use of ferrocene carboxaldehyde as an electron transfer mediator lowered the oxidation potential of NADH to +0.4 V vs. Ag/AgCl. Parameter optimization improves the analytical performance of the biosensor within the linearity range of 2.5 μM to 500 μM with the detection limit of 2.5 μM. The reproducibility of the fabricated biosensor was also evaluated and it was found to be good with a relative standard deviation (RSD) of 4.17% (n=5). A good agreement with the Indothymol method was obtained for the measurement of ammonium in water samples.
    Keywords: Ammonium Biosensor, Glutamate Dehydrogenase, Diaphorase, Ferrocene Carboxaldehyde, Chitosan
  • Reza Ansari*, Fatemeh Emsakpour Pages 277-295
    Potentiometric sensor based on commercial pencil graphite electrodes coated with polyaniline (PAni) composite with Eosin Y (EY) termed as PGE/PAni-EY have been developed for potentiometric determination of silver ion. The electrode exhibited linear response with Nernstian slope of 57.6±0.8 mV per decade within the range of 1.0×10-6 to 1.0×10-1 M with limit of detection 6.5×10-7 M silver ion. Fast and stable response time of the electrode (15 s) was obtained over the concentration range of 1.0×10-1 M to 1.0×10-4 M. This electrode was also used as indicator electrode in potentiometric titration of halide ions successfully. This study shows that the introduced electrode (PGE/PAni-EY) is highly selective toward silver ion and can be used to determine silver ions in solutions with high accuracy and precision.
    Keywords: Silver electrode, Potentiometry, Polyaniline, Eosin Y, Nanocomposite
  • Arpit Singh, Sanjay Singh*, Gyanendra Singh Pages 296-314
    The three chelates 1,5-bis(o-aminobenzoate)-3-thiapentane (L1), 1,5-bi (omethoxybenzoate)- 3-thiapentane (L2), 1,5-bis(o-chlorobenzoate)-3-thiapentane (L3) have been synthesized and explored as a neutral ionophores for preparing poly(vinyl chloride) based membrane sensors selective to Er3+. The addition of sodiumtetraphenylborate and various plasticizers, viz., o-NPOE, TBP, DBBP, TEP and DOS has been found to substantially improve the performance of the sensor. The best performance was obtained with the sensor no.6 having membrane of ionophore (L2) with composition PVC: o-NPOE: ionophore (L2): NaTPB (%w/w) of 35:56:2:7. This sensor exhibits Nernstian response with slope 22.1±0.3 mV decade-1 of activity in concentration range 3.0×10-9 to 1.0×10-2 M Er3+, performs satisfactorily over wide pH range (1.5-6.7), with a fast response time (8 s). The sensor was also found to work satisfactorily in partially non-aqueous media up to 20% content of methanol, ethanol or acetone and could be used for a period of 5 months without any change in response characteristics. The Er3+ selective sensor was used as an indicator electrode for the titration of 25 ml 1×10-3 M EDTA solution and for the determination of Er3+ ion in different synthetic samples. The proposed electrode no. 6 was also used for the determination of fluoride ion in two mouth wash sample.
    Keywords: Sensor, Potentiometry, Ionophore, Erbium, Selectivity
  • Farnoush Faridbod* Pages 315-326
    Clomipramine hydrochloride, active component of an antidepressant drug, was determined in the pharmaceutical formulation by two kinds of potentiometric sensor; a PVC membrane sensor and a carbon paste electrode modified by MWCNTs and ionic liquid. Both sensors were corporated with clomipramine-tetraphenylborate ion-pair complex and they respond based on ion exchange mechanism. The best PVC membrane sensor response was obtained by the membrane composition of 7% ion-pair, 30% PVC and 63% DBP, and in case of modified carbon paste electrode, the best response was obtained by a paste composed of 25% ion-pair, 5% MWCNTs, 25% ionic liquid and 45% graphite powder. The PVC membrane sensor showed a Nernstian response in the range of 1.0×10-4-1.0×10-2 mol L-1 and modified carbon paste electrode 1.0×10-5-1.0×10-2 mol L-1. The both sensors work well in laboratory conditions in analysis of clomipramine hydrochloride in the tablet.
    Keywords: Clomipramine hydrochloride, Potentiometry, Ion, selective Electrode, PVC Membrane, Sensor, MWCNTs, Carbon Paste