Highly selective iodide electrode based on the copper(II)-N,N′-bis(salicylidene)-1,2-bis(p-aminophenoxy)ethane tetradentate complex

In this paper, a new PVC-based liquid-membrane anion-selective electrode based on a copper(II) of N,N'bis(salicylidene)-1,2-bis(p-aminophenoxy)ethane tetradentate complex (Cu(II)BBAP) is described, which displays a preferential potentiometric response to iodide ion at pH 2.0 and an anti-Hofmeister selectivity sequence: I- > SCN- > ClO4- > NO2- > H2PO4- > NO3- > SO42- > Br- > Cl-. The electrode exhibits a near-Nernstian potential linear range of 8.2 x 10(-7) - 1.0 x 10(-1) M with a detection limit of 5.3 x 10(-7) M and a slope of -58.8 mV per decade. The A.C. impedance technique and the UV/Vis spectroscopy technique were used to analyze the response mechanism. The electrode could be applied to determine iodide in medicine analysis, and the obtained results were fairly satisfactory.