New Possibilities of Potentiometric Stripping Analysis Based on Ion-Pair Formation and Accumulation of Analyte at Carbon Paste Electrodes. Preliminary Note

Abstract

A novel technique of potentiometric stripping analysis is based on extractive accumulation of anionic species of lipophilic character in polar pasting liquids of carbon paste electrodes. Determinations of both gold(III) which is accumulated as tetrachloroaurate(III) and iodide (accumulated at positive potentials as a halide complex of iodine) at a carbon paste electrode containing tricresyl phosphate are given as examples. Both the anions form ion-pairs with protonated tricresyl phosphate and accumulate at the working electrode on extraction principles; the accumulation step is followed by their reduction using constant current. Similar procedures based on ion-pair formation followed by extractive accumulation could be elaborated for many other ionic species. Thus, this may represent a new approach utilizable in potentiometric stripping analysis.