been prepared. This electrode with a 10% Cu2S and 90% Ag2Se composition exhibited an
analytically useful potential change from 10− 6 to 10− 1M hydroxide ion, pH 8–13. The slope
of linear portion is about 58mV per decade change in hydroxide concentration. There was
no interference of K+, Na+, Ca2+, Zn2+ and Mg2+ cations and Cl−, NO3− and SO42−
anions. The response time was 30s and the lifetime was about 2 years.