Novel sensor for simultaneous determination of K + and Na + using Prussian blue pencil graphite electrode

Abstract

A novel approach for simultaneous determination of K + and Na + based on Na +-inhibited and direct K + intercalation processes at Prussian blue is proposed. The competing processes of Na +-inhibited and direct K + intercalation were established for the first time using a Prussian blue pencil graphite electrode (PB-PGE) and manipulation of the cyclic voltammetry (CV) scan rate. The pair of cathodic peak potentials result of Na +-inhibited and direct K + intercalations was used as analytical signals for K + and Na + determination via a simultaneous standard addition method. Simultaneous determination of K + and Na + was demonstrated in a laboratory prepared sample with satisfactory results, suggesting the proposed approach is amenable for further development as a Prussian blue-based electrochemical method for simultaneous K + and Na + determination. © 2012 Elsevier B.V.