The Synthesis of a New Thiophene-Derivative Schiff's Base and Its Use in Preparation of Copper-Ion Selective Electrodes

Abstract

A highly selective and sensitive PVC-membrane electrode for Cu(II) ion was developed by using a new thiophene-derivative Schiff's base. The electrode exhibits a Nernstian slope of 29.3±0.7 mV per decade at 25 °C over a very wide concentration range (1.0×10−1–6.0×10−8 M) with a detection limit of 2.0×10−8 M (1.28 ng/mL). The ion selectivity of this electrode for Cu2+ was greater than 3.0×103 times over various metal ions. It was successfully applied to the determination of trace amounts of copper in Iranian black tea, and as indicator electrode, in potentiometric titration of copper ion.