Selective detection of ammonia and its derivatives using MOX-sensor and microreactor

We report a device for selective detection of ammonia. The device consists of a MOX sensor and a converter transforming ammonia into nitrogen dioxide. When the converter is switched off, the sensor mainly detects ammonia (donor signal), and when the converter turned on, the sensor detects nitrogen dioxide (acceptor signal). The analytical signal is a normalized difference between the sensor signals when the converter is working and when it is turned off. The main advantage of this method is high selectivity of ammonia detection. Another advantage is the solution of the problem of sensor drift.