The use of thiazole derivative molecules as sensor materials: Potentiometric determination of Cu(II) ions

Abstract

In this study, poly(vinyl chloride) (PVC)-membrane potentiometric sensors for the determination of copper(II) ions were prepared using 2-acetamido-4- (2-hydroxyphenyl)thiazole (L1), 2-amino-4-(trifluoromethyl)thiazole-5 acid (L2) and ethyl 2-amino-4,5,6,7-tetrahydrobenzo[d]thiazole-6-carboxylate (L3) ionophores. It was determined that the potentiometric performance char- acteristics of the sensors prepared with L1 were superior to the others. Based on these properties, the optimum membrane composition was determined as 3.0% ionophore (L1), 64.0% bis(2-ethylhexyl)adipate (DEHA), 32.0% PVC and 1.0% potassium tetrakis (p-chlorophenyl) borate (KTpCIPB). The newly developed sen- sor had a low detection limit of 6.74 x 10⁻⁷ mol L⁻¹ over a wide concentration range of 1.0 x 10⁻¹-1.0×10⁻⁶ mol L⁻¹. Compared with different metal ions, the sensor showed good selectivity to copper(II) ions, had a repeatable, stable and fast response time. The copper(II)--selective sensor could work in a wide range without being affected by pH changes (5.0-9.0). It was used as indicator electrode for the potentiometric titration of copper(II) ions with ethylenediaminetetraacetic acid (EDTA), and successfully applied for the determination of copper(II) ions content in different water samples.