Determination of Ammonia in Waste Waters by a Differential pH Method Using Flow Injection Potentiometry and a Nonactin-Based Sensor

Abstract

A method is described for the determination of total ammoniacal nitrogen in waters using an ammonium ion-selective sensor based on nonactin. The flow injection method relies on the measurement of the potential of the sensor at two pH values, 6.0 and 9.4, and the use of a mathematical expression to calculate the total ammoniacal nitrogen concentration. The method also compensates for the interference from moderate concentrations of other cations such as potassium and sodium.