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

AbstractIn 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‐carboxylic acid (L2) and ethyl 2‐amino‐4,5,6,7‐tetrahydrobenzo[d]thiazole‐6‐carboxylate (L3) ionophores. It was determined that the potentiometric performance characteristics 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 (KTpClPB). The newly developed sensor had a low detection limit of 6.74 × 10−7 mol L−1 over a wide concentration range of 1.0 × 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.