فهرست مطالب

Analytical & Bioanalytical Electrochemistry
Volume:2 Issue: 3, Sep 2010

  • تاریخ انتشار: 1390/05/20
  • تعداد عناوین: 5
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  • Sayed Mehdi Ghoreishi, Mohsen Behpour, Hamid Ahmadi Zahrani, Mahshid Golestaneh Pages 112-124
    Ketotifen (KET)–selective electrode of both conventional polymer membrane and coated graphite types, based on incorporation of ketotifen–tetraphenyl borate (KETTPB) ion-pair have been constructed. The influences of membrane composition, temperature, pH of the test solution, ionic strength and foreign ions on the electrode performance were investigated. The electrode showed a Nernstian concentration range 1.0×10-5 to 1.0×10-2 M and 5.0×10-6 to1.0×10-2 M with a slope of 57.5±1.07 and 59.0±0.9 mV per decade and lower limit of determination are 1.0×10-5 M and 5.0×10-6 M for conventional and coated graphite types, respectively. The electrodes display a good selectivity for ketotifen with respect to a number of common foreign inorganic and organic species. The response not affected by pH between 2.0 and 4.9. The electrode was successfully used for determination of ketotifen both in pure solution and in pharmaceutical preparation. The solubility product of the ion-pair and also the formation constant of the precipitation reaction leading to the ion-pair formation were determined conductometrically.
    Keywords: Selective, electrode, Ketotifen Hydrogen Fumarate, Coated Graphite, Amiten Syrup, Conductometry
  • Sulekh Chandra, Kusum Sharma, Adarsh Kumar Pages 125-138
    A polymeric membrane based lead selective electrode was developed by using zinc complex of salicylaldehyde semicarbazone. The best performance was recorded with amembrane composition of PVC: DBP: Ionophore: NaTPB as 33: 58: 4: 5 (w/w %). The Nernstian slope calculated from the calibration curve for Pb2+ sensor was 29.2 mV/ decade. The detection limit of the sensor was 3.10×10-9 M, in the linear concentration range of 1.0×10- 2-1.0×10-8 M. It was relatively fast response time (<10s for concentration ≥1.0×10-3 and <15s for concentration of ≥1.0×10-6 M) and can be used for 9 months without any considerable divergence in potentials. The proposed sensor exhibit relatively good selectivity and high sensitivity for lead(II) as other mono, di and trivalent cations and can be used in a pH range of 2.0-10.5. It was used successfully as an indicator electrode in potentiometer titrations and also determines the concentration of lead in water of Yamuna River at different sites of Delhi.
    Keywords: Pb(II) Electrode, PVC, Ionophore, Potentiometry, Water Sample
  • Pradeep Kumar Upadhyay, Afaq Ahmad Pages 139-154
    An emulsion method with ammonium persulfate as oxidant was used to synthesized a series of Poly (o/m-toluidine-co-o/m-nitroaniline) copolymers of different compositions. The two probe method was used to study the electrical conductivity measurements. The conductivity was found to be higher than that of its homopolymers. Among these copolymers, the conductivity of Poly (o/m-toluidine-co-o/m-nitroaniline) 1:1 was found to be maximum. Temperature dependence of electrical conductivity showed that charge transport was mainly through Variable range hopping model though a mixed conduction behavior was observed at higher temperature range. All the copolymers were completely soluble in DMSO. Electronic spectra showed blue shift in the π-π* and benzenoid→quenoid transitions revealing a decrease in the extent of conjugation in the copolymers. FT-IR and UV-Visible spectroscopy were used for the structural confirmation of these copolymers. Stability is explained in terms of ac electrical conductivity measurements.
    Keywords: Polyaniline, Electrical conductivity, Yield, Thermal Degradation, Stability etc
  • Mohammad Mazloum, Ardakani, Mohammad Ali Sheikh, Mohseni, Ali Benvidi Pages 155-164
    In this work we developed a new salicylate-selective membrane based on the trioctylmethyl ammonium chloride as the ion exchanger. The treatment of membrane investigated and compared in two different types. In one type membrane put on the PVC tube, electrode with internal solution (IS), and in another type membrane glued on a glassy carbon electrode, solid contact electrode (SC). Both sensors show a Nernstian response (56±1.0 and 57.7±1.0 mV decade-1, respectively) to salicylate ions over a very wide concentration ranges (3×10-6−1 M and 1×10-6−1 M, respectively). The detection limits of these sensors are 1×10-6 and 8×10-7 M, respectively. The electrodes possess satisfactory reproducibility, very short response time (~ 5 s) in the whole concentration ranges, and discriminating ability for salicylate ions with respect to the most common inorganic anions and special organic and biological anions. The selectivity coefficients, linear range and detection limit were better for membrane that glued on glassy carbon electrode. Two electrodes could be used in pH rang 5.0 to 12.0. The electrodes were successfully used for determination of salicylate in real samples.
    Keywords: Ion selective electrode, Solid contact electrode, Salicylate, Ion exchanger, Potentiometry
  • Hamed Gharibi, Amir Hossein Mahvi, Mohammad Chehrazi, Razih Sheikhi, Sara Sadat Hosseini Pages 165-177
    In this study, phosphorous removal from wastewater effluent performed using electro-coagulation by aluminum and iron plates. This work had 3step: assessment of electrocoagulation for phosphate removal with phosphate concentration based on wastewater effluent in standard conditions (6mg/l), and evaluation of pH (3, 5.5, 7, 8.5, 10), voltage (20 V, 30 V, 40 V), and contact time(10 min, 20 min, 40 min, 60 min) for elucidation of best condition in phosphate removal; evaluation of the process according to the best conditions obtained in step 1 in different concentrations of 4, 8, and 10 mg/l; test of optimum conditions obtained in first two steps on real wastewater. Result obtained from synthetic waste water showed that the most effective phosphate removal with AL/AL plates is >99% in pH 8.5 and 40 V and 40 min after starting process and for IR/IR plates is >99% in pH 5.5 and 40 V and 40 min after starting process. Result obtained from 2th step revealed that the removal efficiency was high whenever concentration of phosphate decreased and efficiency of removal with AL plates is higher than IR plates. In 3th step, efficiency of phosphorous removal using electro-coagulation assessed and efficiency of this step with aluminum plates on real wastewater under different conditions is >99%.
    Keywords: Phosphorous removal, Electro, coagulation, Wastewater effluent