Particulate matter, the main pollutant in the atmospheric environment of the Santiago city in winter, was analyzed by means of the major water-soluble ionic species obtained under critical episodes of pollution in 2003. The particulate matter samples were collected using the Micro-Orifice uniform deposit impactors, with eight impactor stages connected in series, and the ionic species in particulate matter samples at each stage was analyzed by ion chromatography. While sulfate ion and nitrate ion showed bi-modal distributions, peaking in the fine and coarse mode, ammonium ion displayed a bi-modal size distribution, peaking in the fine and ultra fine mode. The equivalent concentration ratio of ammonium to sulfate was 2.03 ± 0.09, indicating the complete neutralization of sulfuric acid by ammonia. The excess ammonium ion was associated to nitrate ion. The study of the size distribution of water-soluble inorganic ions in particulate matter supports the notion that secondary aerosols play a significant role in the urban atmosphere.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.