A chalcogenide glass membrane based on germanium-antimony-selenium and
doped with 20.8% copper was used in the preparation of a copper ion-s
elective electrode (ISE). It shows an almost Nernstian response of 31
mV. It is specific in the presence of Na+, K+, Ca2+, Co2+, and Ni2+ Wi
th selectivity coefficients of 10(-2) for Na+ and K+, and 10(-3) for t
he other ions. For both UO22+ and Zn+, the selectivity coefficient is
0.1, whereas for Al3+ and Fe3+ it is 0.06 and 0.5, respectively. Iron(
II) interferes very strongly. The electrode response is independent of
pH in the range 1-3. The copper ISE was used as an indicator electrod
e for the potentiometric titration of copper ions in solution (10(-4)-
0.1 mol l(-1)) using standard ethylenediaminetetraacetic acid, a sharp
potential change occurs at the end-point.