Study of automobile exhaust particles by spectromicroscopy

In this paper,automobile exhaust particles of Gol and Santana 3000 were studied by spectro microscopy. The STXM results show that the single particulate is sized at 500 nm, with the mass distribution reducing towards the center. The N 1s NEXAFS spectra of automobile exhaust particles have similar structure with those of nitrates, which can be deduced as the main chemical species of nitrogen in automobile exhaust particles. There are minor amounts of ammonium and organic nitrogen compounds in automobile exhaust particles. A single Gol automobile exhaust particle was stack scanned in the energy range of 396-416 eV. By principal component analysis and cluster analysis, it can be deduced that there are main three chemical species of nitrogen. The particle surface consists of mainly nitrates, the inside consists of mainly ammonium and organic nitrogen compounds, and the middle layer is an inter gradation consisting of mainly nitrates and organic nitrogen compounds. (authors)