SUSPENSION EFFECT IN POTENTIOMETRY

Abstract

ABSTRACT ABSTRACT According to the capacitor model, the potential development of membrane electrodes is the result of adsorption of ions or charged particles on the electrode surface forming a double layer and capacitor. Our results differ from those previously reported in that the adsorption of charged particles at the pH glass electrode interface is the main cause of the suspension effect rather than the reference electrode effect. Charged particles, if adsorbed on the SCE tip opening, may cause minor suspension effects on the reference electrode potential. Our results have demonstrated how previous investigators misused the H+-form exchange resins in the suspension effect study, ignoring the exchange reaction between the H+ ion and K+ ion. The pH glass electrode, antimony electrode and lead electrode and ion exchange resin, activated carbon, graphite and silica gel were used in the study.