Evaluation of a New Solid-State Reference Electrode Junction Material for Ion-Selective Electrodes

The performance and properties of a new low-resistance material, Refex, suitable for use in reference electrode junctions is described. The material is a solid polyvinyl acetate that contains a very large loading of KCl (1: 1 w/w KCl/PVA). Despite relatively large active surface areas in the designs studied (stand-alone reference and combination pH), leakage rates of KC! are remarkably low. pH measurements in ultrapure water and comparative measurements in common buffer solutions against standard reference electrodes confirm the stability of the potential developed across the junction to be very stable. Impedance studies verify the importance of the KC! doping for realization of the low resistance and attractive electrochemical properties of the material.