Selectrode ®—The universal ion-selective solid-state electrode : Part II. Comparison of copper(II) electrodes in metal buffers and compleximetric titrations

Abstract

The concept of metal buffers and their use for calibration, testing and comparison of ion-selective electrodes is described. A series ofcopper(II) buffers has been prepared and used for intercomparison of a newly developed copper(II) Selectrode with corresponding Orion, Beckman and Radiometer solid-state membrane copper(II)-selective electrodes. Theoretical and experimental calibration curves are related to compleximetric titrations by means of Reilley diagrams which are then used for selecting the pH at which the largest potential break and optimum selectivity is obtained. EDTA titrations ofCu 2+, Zn 2+ and Ca 2+ as well as titrations of EDTA, NTA and Chel DP by copper(II) using the copper(II) Selectrode are described. Finally, standard potentials of various copper(II) Selectrodes are discussed in connection with Sato's theory of the half-cell potentials of the semiconductive binary compounds.