| Biomass burning is an important source of carbonaceous aerosols in atmosphere. Levoglucosan（Lev）, mannosan（Man） and galactosan（Gal）, which are not only abundant but also chemically stable during photooxidation in the air, are considered to be the significant tracers of biomass burning emissions. And they had been widely used as marker compounds in the assessment of biomass burning contribution to atmospheric aerosols.At present, studies on the organic tracers of biomass burning in China are still limited. The published results are mainly on the concentration or contribution of tracers within one city or region. The studies on the composition characteristics of the organic tracers are maily on burning experiments（indoor or outdoor）, but less on atmospheric environment.In order to understand the composition characteristics of the organic tracers of biomass burning, this study is mainly on the analysis of PM2.5 of urban area（four seasons） and forest areas（18o N to 42o N） in Eastern China, with GC-MS and the multivariate statistical analysis method.The main conclusions of this study are listed as below:（1） In urban area, the concentrations between the organic tracers of biomass burning and OC had ignificant correlation（RLev（C）=0.720, RMan（C）=0.658, RGal（C）=0.688）. And the correlation between OC and PM2.5 exist significant correlation（R（C）=0.550）. These showed that the organic carbon（OC） had a great contribution to the atmospheric fine particulate matters and biomass combustion was one of the main contributions of the OC of PM2.5 in the atmospheric environment.（2） In the samples of forest area atmospheric, the average concentrations of levoglucosan（Lev） in CB station, CM station, DH station, HN station were 50.51 ng/m3, 80.72 ng/m3, 24.91 ng/m3 and 103.90 ng/m3, respectively. The level of concentrations of PM2.5 were 39.75μg/m3, 133.81 μg/m3, 39.28 μg/m3 and 44.69 μg/m3; and of OC were 3.38 μg/m3, 5.63 μg/m3, 2.35 μg/m3 and 2.97 μg/m3. The highest concentration of Lev was appeared in HN station; the highest concentration of OC and PM2.5 were appeared in CM station, showing that the contribution of biomass burning to the PM2.5 was relatively small in theses more human activity areas, but the pullotion of PM are more serious in the atmospheric environment.（3） In the urban area（Jinhua）, the pollution of biomass burning were heavy in autumn and winter in the air. The levels of average concentrations of the organic traces were the lowest in summer. The levels of Lev concentrations reached the highest in autumn; and Man and Gal concentrations reached the highest in winter. This might be due to the significant negative correlation between Man or Gal and atmospheric temperature（R:-0.465 to-0.619）; but the relationship between Lev and atmospheric temperature was weak（R:-0.294 to-0.392）. In autumn, the average concentration of Lev was 213.90 ng/m3, 247.58 ng/m3 and 271.28 ng/m3 in urban living areas, suburban living areas and suburban areas, respectively. It was showing that the existence of straw burning in urban areas and the surrounding areas.（4） The Lev/Man ratio of atmospheric fine particles in Jinhua was significantly higher in autumn, which were 4.91±0.85 in spring, 5.25±0.89 in summer, 13.36±2.09 in autumn and 3.10±0.42 in winter. This might be due to the structural differences caused by a large number of straw burning in autumn（Lev/Mancrop > Lev/Mansoftwood or hardwood）. The ratio of Lev/Man（4.0±0.7） of CB station in the atmospheric fine particles was the lowes in forest areas. And the HN station’s（6.8±0.5） was higher than it. The obvious regional difference showed the vegetation types in different regions（Lev/Mansoftwood<Lev/Man hardwood）.（5） The principal component analysis（PCA） and hierarchical cluster analysis（HCA） were both used in samples of urban area（Jinhua） and forest areas, showing that the results could be clearly distinguished in different seasons or different regions. In urban area, the ratios of the organic tracers of biomass burning in the atmospheric environmental samples of autumn were significantly different from other seasons. In the forest areas of different latitude, the ratios of these organic tracers could be initially distinguished between different regions. |
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