| Online data acquisitions of 5 representative atmosphere monitoring sites in Guilin were carried out for analyzing chemical composition and its distribution of PM2.5by single particle aerosol mass spectrometry. The results showed that more than 80% of the PM2.5 were in small size range from 0.2 μm to 1.0 μm, and less than 20% were in large size range from 1.0 μm to 2.5 μm. Chemical ion composition of PM2.5 contained Na+, K+, NH+4, C2H+3/Al+, Fe+, HSO-4, NO-3 , NO-2, CNO-, CN-, SO-3, O- and carbon ions. PM2.5 could be classified into 9 sorts: elemental carbon, organic carbon, elemental organic mixed carbon, manganese rich, iron rich, potassium rich particulates, mineral substance, levoglucosan and other metals, according to ion composition characteristics. Elemental carbon accounted for more than 50% of the total particulates in each monitoring site. Elemental carbon tended to mix with sulfate, ammonium salt and nitrate inside, in which elemental carbon and sulfate mixing were the most, up to 90%. |
