EFFECT OF THE TEMPERATURE ON THE RESPONSE CHARACTERISTICS OF ISES CONSTITUTED BY SILVER(I) SULFIDE + COPPER(II) SULFIDE OR CADMIUM(II) SULFIDE MIXTURES APPLIED TO ELECTRICALLY CONDUCTIVE EPOXY SUPPORTS

The effect of the temperature on the response of copper(II) and cadmium(II) ion-selective electrodes with membranes made of Ag2S+MS (M = Cu or Cd) mixtures applied to supports made of conductive epoxies of three different types (silver-, copper- or graphite-loaded), or dispersed in non-conductive epoxy, or applied to a hydrophobized graphite body, as well as on commercial electrodes, has been studied. Isothermal measurements were made in the temperature range 10-60° C and included calibrations at different temperatures for evaluation of operational temperature ranges, slope and standard potential variations and isopotential points, and determination of hysteresis curves. The nature of the support material and of the internal support-sensor contact has a marked influence on the temperature properties of the electrodes. Electrodes with supports of graphite-loaded epoxy show better behaviour than electrodes with silver- or copper-loaded epoxy. The results show that, at least in principle, the support can be changed to displace the isopotential point concentration to a convenient position (within or near the concentration range where the electrode is used for measurements). © 1990.