Use of Selective Ion Electrodes to Determine Air Pollutant Species (Ambient and Source Level)

Selective ion electrodes measure the activity of an ionic species in solution by developing an absolute potential which is related to the ionic activity; it may be determined experimentally by measuring the difference in potential of an electrode pair consisting of the selective ion electrode and a suitable reference electrode (such as a calomel or silver-silver chloride reference electrode) with a high input impedance voltmeter. The potential response of a selective ion electrode to an ionic species A is defined by the Nernst equation