مرکز منطقه ای اطلاع رساني علوم و فناوري - Potentiometric determination of Cu²⁺ ions in environmental samples using a newly developed Cu²⁺-selective electrode based on schiff base

Abstract :

In this study, we investigated the possibility of preparing ion-selective electrodes for cationic species by using a newly synthesized Schiff base. PVC-membrane compositions in different ratios were prepared by using schiff base complex, polyvinylchloride, o-nitrophenyl octylether and potassiumtetrakis parachlorotetraphenylborate. The prepared membrane compositions were coated on the surfaces of solid state contact electrodes and ion selective electrodes were fabricated. Potentiometric measurements showed that; prepared electrodes exhibited selective behavior towards Cu2⁺ ions. The most suitable membrane composition of electrode was determined as 3.9% ionophore, 32.0% polyvinylchloride, 64.0% o-nitrophenyl octylether (plasticizer) and 0.1% potassiumtetrakis parachlorotetraphenylborate. The prepared Cu2⁺-selective electrode showed potentiometric working range to Cu²⁺ between the concentration of 1.0×10-5 and 1.0×10-1 M with a slope of 29.8±0.7 mV per decade (R2= 0.9966) in the presence of the common cationic species. It was observed that the electrode reached the equilibrium potential within 5 seconds and had a limit of 4.1×10-6 M. It was tested that the developed electrode exhibited potentiometric behavior at pH = 3.0-8.0 without being affected by the pH change of the test solutions. In addition, the potentiometric Cu²⁺-selective electrode had 12-week lifetime. The electrode was successfully used in the potentiometric titration of Cu²⁺ ions with EDTA and the potentiometric determination Cu²⁺ ions in water samples with different matrix structures such as tap water, river water and dam water.