SOME RECENT STUDIES ON THE USE OF ELECTROCHEMICAL SENSORS IN NONAQUEOUS SOLUTION CHEMISTRY

Four recent studies in the authors' laboratory on the use of electroch emical sensors in nonaqueous solutions are reported. (1) Si3N4- and Ta 2O5-type ISFETs proved to be useful in nonaqueous solutions as sensors for pH and for proton solvation, because of their more rapid response than a conventional glass electrode. They were used to study the acid -base equilibria in gamma-butyrolactone and to determine the proton tr ansfer activity coefficients between different solvents. (2) A univale nt cation-sensitive glass electrode was used to study the solvation of lithium ions in mixed solvents applicable to lithium batteries. (3) A membrane of polyacrylamide coupled to a cobalt phthalocyanine complex and coated onto a platinum electrode functioned as a sensor for fluor ide and cyanide ions in aprotic solvents. It was used to determine the solubility products of alkali and alkaline earth metal fluorides and cyanides in acetonitrile and propylene carbonate. (4) A new method is proposed for the estimation of the liquid junction potential between d ifferent solvents, and a comparative study has been made between the n ew method and some conventional methods.