LANTHANUM FLUORIDE ELECTRODE RESPONSE IN AQUEOUS CHLORIDE MEDIA

With the recent introduction of solid-state electrodes, very sensitive analytical tools have become available for several anions. The best characterized of these is the lanthanum fluoride electrode doped with Eu2+ (1, 2, 3). Of particular interest to the analytical and physical chemists are the interferences which must be taken into account. The sensitivity of the fluoride electrode is at least 1000-fold for fluoride over chloride (1, 3). Because equilibrium studies in aqueous solutions are commonly conducted in the presence of a relatively high concentration of inert electrolyte to control the ionic strength of the medium, the magnitude of the interferences become limiting factors. As a result of our interest in the use of chloride media at this laboratory we have examined in detail the chloride interference at 25 ° C. © 1968, American Chemical Society. All rights reserved.