A GLASS-ELECTRODE WITH SOLID INTERNAL CONTACT BASED ON PRUSSIAN BLUE

A novel type of glass electrode has been constructed in which the usua l combination of internal buffer solution and reference electrode is s ubstituted by the solid mediator substance Na+-containing Prussian blu e (NaPB) (NaFeFeII)-Fe-III(CN)(6). This mixed-valent compound exhibits ionic conduction (by sodium ions) as well as electronic conduction an d thus causes the potential differences at the interphases glass/NaPB and NaPB/metal to be thermodynamically well defined. Hence, with this solid-state glass electrode exceedingly stable potentiometric signals are obtained. (C) 1998 Published by Elsevier Science Ltd. All rights r eserved.