Analytical Sciences

Abstract − Analytical Sciences, 20(10), 1427 (2004).

An Eu(III) Sensor Based on N,N-Diethyl-N-(4-hydroxy-6-methylpyridin-2-yl)guanidine
Mohammad REZA GANJALI,* Mehdi RAHIMI,** Bozorgmehr MADDAH,*** Abolghasem MOGHIMI,*** and Shahin BORHANY**
*Departments of Chemistry, Tehran University, Tehran, Iran
**Departments of Chemistry, Amirkabir University, Tehran, Iran
***Departments of Chemistry, Immam Hossein University, Tehran, Iran
A highly selective poly(vinyl chloride)-based membrane sensor produced by using N,N-diethyl-N-(4-hydroxy-6-methylpyridin-2-yl)guanidine (GD) as active material is described. The electrode displays Nernstian behavior over the concentration range 7.0 × 10-5 - 1.0 × 10-1 M. The detection limit of the electrode is 5.0 × 10-5 M. The best performance was obtained with the membrane containing 30% PVC, 55% benzyl acetate, 5% GD and 10% oleic acid. The response of the sensor is pH-independent in the range of 3.0 - 7.0. The sensor possesses satisfactory reproducibility, fast response time (< 20 s), and specially excellent discriminating ability for Eu(III) ion with respect to the alkali, alkaline earth, transition and heavy metal ions. The membrane sensor was used as an indicator electrode in potentiometric titration of Eu(III) ion with EDTA. It was also applied in determination of fluoride ions in mouth wash preparations.