Iodide-Selective PVC Membrane Electrodes Based on Five Transitional Metal Chelates ofbis-furfural-semi-o-tolidine

Abstract

Some new PVC membrane electrodes based on Co(II), Mn(II), Ni(II), Cu(II), and Zn(II)chelates of bis-furfural-semi-o-tolidine as carriers are described. The electrodes exhibited different selectivity behaviour compared with the electrode using a classical anion exchanger such as tetraalkyl ammonium. The results showed that the Cobalt(II) chelate-based electrodes had a Nernstian response to iodide ion ranging from 1.0 × 10⁻¹ to 1.0 × 10⁻⁶ mol.L⁻¹ in a phosphate buffer solution of pH 2.0 with a detection limit of 6.4 × 10⁻⁷ mol.L⁻¹ and a slope of 57.8 mV/dec at 25deg;C. The response mechanism was also investigated by use of both a.c. impedance and SPQC techniques. The Co(II) chelate-based electrodes were used to determine the iodide content of a drug with satisfactory results.