Non-ammonium reduced nitrogen species in atmospheric aerosol particles

Abstract

The traditional belief that ambient aerosol particles contain nitrogen predominantly in the form of inorganic ionic species such as NH 4 + and NO 3 − was challenged about 10 years ago by results from x-ray photoelectron spectroscopic analysis (ESCA) of California aerosol particles. A significant fraction (∼ 50%) of the reduced nitrogen was observed to have an oxidation state more reduced than ammonium, characteristic of organic nitrogen species. We have used a recently developed thermal evolved gas analysis method (NO x) in conjunction with ESCA to confirm the existence of these species in aerosol particles collected in both the United States and Europe. The agreement of EGA and ESCA analyses indicates that these species are found not only on the surface but also throughout the particles.