X-ray Spectrometry of Individual Nitrate-Containing Particles in the Urban Atmosphere

[摘要] To study the nature and formation process of atmospheric nitrate particles, aerosol particles collected in summer at Nagoya were investigated with an analytical electron microscope. The individual nitrate-containing particles were identified with a vapor deposited nitron thin film method. Then, the elemental and chemical compositions of individual nitrate-containing particles were determined with an electron probe X-ray microanalysis (EPMA) and other reagent thin film methods. The results indicated that while N03-rarely existed in the fine particles, it existed in the coarse particles at all of the sampling times. Nitrate did not exist as a pure nitrate salt, but was internally mixed with sulfate in the fine particles. In the coarse particles, it was found that, in addition to sea-salt particles, soil particles (or flyash) were also important carriers of nitrate in the urban atmosphere. It is indicated that the neutralized sulfate particles can serve as an active center for the nitrate formation in the fine particle under humid conditions.

[学科分类] 大气科学