Gas-Sensing Electrodes in Ionometric Analysis of Natural and Man-Made Objects. Determination of Ammonium Ion in Water
Principle of operation of gas-sensing cells containing ion-selective electrodes for determination of gases or corresponding ions in solutions is described. Prospects of using cells in ionometric analysis of various objects are demonstrated. Analytical characteristics of gas-sensing cells, different types of gas-permeable membranes, compositions of internal electrolyte are discussed. An original gas sensing cell with ammonium-selective electrode for ammonium-ion determination in water is developed. The developed cell containing air space as a gas-permeable membrane is durable and rather simple in design. Conditions of ammonia static gas extraction and ionometric determination are specified. Statistical data processing proved high selectivity, correctness and repeatability of the developed procedure of ammonium-ion determination in mineralized water of complex composition.