Protonated nitrosamide and its potential role in the release of HONO from snow and ice in the dark

A joint Fourier transform reflection absorption infrared spectroscopy/thermal programmed desorption (RAIRS/TPD) study has provided good evidence for the existence of protonated nitrosamide (NH₃NO ⁺) on surfaces at cold temperatures. This species has long been proposed to exist in studies of the DeNO_x process and the decomposition of ammonium nitrite. In the context of the current experiments, performed at low-temperatures in the absence and presence of water-ice, the results provided a firm mechanistic basis for understanding the release of HONO from snowpack in a "dark" mechanism and also under alkaline surface conditions.