Author/Authors :
Heidari Parisa نويسنده Phase Equilibria Research Laboratory, Department of Chemistry, Faculty of Science, University of Zanjan, 45371-38791, Zanjan, Iran , Zamani Abbasali نويسنده Environmental Science Research Laboratory, Department of Environmental Science, Faculty of Science, University of Zanjan, 45371-38791, Zanjan, Iran , Koorepazan Moftakhar Mahdieh نويسنده Phase Equilibria Research Laboratory, Department of Chemistry, Faculty of Science, University of Zanjan, 45371-38791, Zanjan, Iran , Yaftian Mohammad Reza . نويسنده Phase Equilibria Research Laboratory, Department of Chemistry, Faculty of Science, University of Zanjan, 45371-38791, Zanjan, Iran
Abstract :
Benzo15-crown-5 (B15C5) has been examined as an ion sensing material for
fabricating a PVC membrane lead ion-selective potentiometric sensor. The best performance
of the electrode was observed with a membrane composition formed by 29% PVC, 60%
dibutylphthalate (DBP) as plasticizing solvent mediator, 2% sodium tetraphenylborate
(NaTPB) as ion excluder and 9% of B15C5 as ionophore. The electrode presents a nearly
Nernstian response (a slope of 29.7±0.5 mV/decade) over a concentration range 1×10-5-1×10-
3 M of lead ions, with a limit of detection 8.4×10-6 M. Its potential response was independent
on pH variation in the range 2.8-4.5. The dynamic response time of the electrode to achieve a
steady potential was found to be about 25 seconds. The selectivity of the prepared electrode
relative to some mono-, di-, tri- and tetra-valent metal ions was examined. This electrode can
be used for 2 months without considerable divergences in the potential response. It was
successfully used as an indicator electrode for the complex formation titration of lead inwater
sampless by EDTA
