Ecological Systems and Devices Annotation << Back DETERMINATION OF AMMONIA IN ATMOSPHERIC AIR BY SPECTRO-PHOTOMETRIC METHOD N.N. Roeva, S.S. Voronich, D.A. Zaytsev, B.A. Zachernyuk, E.N. Solovyova, I.A. Zaytseva For many years, ammonia has been studied primarily as a source of bound nitrogen absorbed by plants and soil. However, it was also found that it is the most common alkaline gas in the surface atmosphere, capable of neutralizing acids with the formation of a secondary aerosol with an aerodynamic particle diameter of less than 2,5 microns, which can be transported over long distances, affecting the climate. In view of this, ammonia poses a great environmental danger to the biosphere, since its content in the atmospheric air of urbanized centers is quite high. The article describes a method for determining ammonia in atmospheric air samples taken in the Moscow region, based on its capture by an acid solution and its photometric determination by indophenol formed as a result of the interaction of ammonium with hypochlorite and phenol in the presence of sodium nitroprusside. Keywords: Atmospheric air; ammonia; spectrophotometry; sampling; pollution; gaseous substances; absorption solution; single concentration. DOI: 10.25791/esip.12.2021.1273 Pp. 19-24.