Potentiometric determination of iron in polluted water samples using new modified Fe(III)-screen printed ion selective electrode

This article is focused on the determination of Fe(III) ion as an important factor in water pollution. A potentiometric method based on screen-printed ion-selective electrode was described for the determination of Fe(III) ion in different polluted water samples. It is based on incorporation of the Fe-phosphotungstate ion-associate in a screen-printed electrode (SPE) composition and tricresylphosphate (TCP) as plasticizer. The influences of the paste composition, different conditioning parameters and foreign ions on the electrode performance were investigated. The reversibility and also response time of the electrode have been studied. The electrode showed Nernstian response of 19.20 ± 0.73 mV decade−1 in the concentration range of 1 × 10−7–2.5 × 10−2 mol L−1. The electrode was found to be usable within the pH range of 3–7.5 and exhibited a fast response time (about 7 s), low detection limit (1.57 × 10−7 mol L−1), long lifetime (>6 months) and good stability. The isothermal temperature coefficient (dE0/dt) of the electrode was calculated. The electrode was successfully applied for the determination of Fe(III) ion in pure solutions and polluted water samples (formation, tab and sea water samples) using potentiometric determination technique. The results obtained applying this potentiometric electrode is comparable with those obtained using inductive coupled plasma technique.