title: Potentiometric determination of silver(I) by selective membrane electrode based on derivative of porphyrin.
abstract: The performance of silver metal complexes with meso-tetraphenylporphyrin ([H2T(4-CH3)]PP) as ionophores for ion-selective electrodes was studied. The electrode exhibited linear response with Nernstian slope of 59.2 +/- 1.0 mV per decade within the concentration range of 1.0 x 10(-7)-1.0 x 10(-1) M silver ions. The limit of detection as determined from the intersection of the extrapolated linear segments of the calibration plot, was 1.0 x 10(-7) M. The response time of the electrode was < 10 s over the entire concentration range. The silver-selective electrode exhibited good selectivity for Ag(I) with respect to alkali, alkaline earth and heavy metal ions. The electrodes could be used at least three months without a considerable divergence in their potential. The electrodes are suitable for use in aqueous solutions in a wide pH range of 3.0-9.0. They were used as indicator electrodes in titration of Ag(I) with sodium iodide solution and were successfully applied to direct determination of silver in real samples.
authors.affiliation: Department of Chemistry, Yazd University, Yazd, 89195-741, Iran. mazloum@yazduni.ac.ir
authors.forename: Mohammad
authors.initials: M
authors.lastname: Mazloum Ardakani
authors.forename: Hossein
authors.initials: H
authors.lastname: Dehghani
authors.forename: Maryam
authors.initials: M
authors.lastname: Jalayer
authors.forename: Hamid R
authors.initials: HR
authors.lastname: Zare