Ion-Selective Electrodes in Environmental Analysis
Environment: Water and Waste
Published Online: 15 SEP 2006
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Forster, R. J. and Keyes, T. E. 2006. Ion-Selective Electrodes in Environmental Analysis. Encyclopedia of Analytical Chemistry. .
- Published Online: 15 SEP 2006
An ion-selective electrode (ISE) is an electroanalytical sensor that produces a potential whose magnitude is dictated by the activity of a small number of ions. The signal is generated by selective partitioning of a charged analyte across the sample–electrode interface. These sensors allow a wide range of environmental pollutants to be detected and quantified rapidly, sensitively and selectively.1 The ideal ISE can be inserted into the sample and will display the result of the chemical analysis within a few seconds with high precision and selectivity. Often no sampling, dilution or reagent addition is required, and changes in the analyte concentration or activity can be displayed in real time. Beyond the classical glass pH electrode invented in the early 1900s, the field now includes electrodes with several selective membranes for both sensing analytes and eliminating interferences, as well as ion-selective field-effect transistors (ISFETs). These new sensing approaches have greatly extended the range of environmentally relevant molecules that can be measured, and sensors exist for environmental pollutants as diverse as atmospheric carbon dioxide and radionucleotides in highly acidic solutions.