8.2.3 All Solid State Reference Electrodes
- 14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
- 8.2 Electrochemical Sensors II
- A. Michalska, A. Kisiel, K. Maksymiuk - Faculty of Chemistry, Warsaw University (Poland)
- 683 - 686
The important part of electrochemical measuring set up is a reference electrode, which is responsible for assuring constant potential during measurement. In conventional arrangement of reference electrode a liquid phase of concentrated electrolyte plays important role. The requirements for small, disposable electrochemical systems set the necessity of elimination of the liquid phase from its counter parts, including the reference electrode. This task is especially challenging if the potentiometric applications are envisaged, when high stability of reference element potentials in time is necessary. The composition of the reference membrane need to be tailored to show (ideally) no preference to any ion present in solution and to be relatively resistive to its composition changes. The approach we have adapted is based on incorporation of both cation- and ion-exchanger in the membrane phase, to assure balanced exchange of ions present in solution. The stability of potential is assured by the presence of silver/ silver chloride system accompanied by the solid potassium chloride, both dispersed in the polymeric membrane phase. The composition used was optimized with respect of membrane material applied resulting in highly stable potentials in time, independently of composition of the sample.