Two new air-gap sensors with different indicator electrodes for the determination of nitrogen oxides and nitrites are described. The linear range of the electrode functions E=f(-lg[NO 2 ]) and E=f(-lg[N a NO 2 ]) for the sensor on the base of a combined glass pH electrode was 5x10 - 8 -1x10 - 3 M, and on the base of combined NO 3 - -ion-selective electrode it was 5x10 - 6 -1x10 - 3 M. The calibration curve slopes were 58.5mV in both cases. The designed sensors were used for nitrite determination in some environmental samples.