Characterization Of Proteinaceous Matter In Fine Particulate Matter

Proteinaceous matter is an important fraction of atmospheric aerosols,which can potentially cause significant health effects due to their allergenicity and play an important role in atmospheric chemistry and physics.Here,fine particulate matter(PM2.5)samples were collected in Guangzhou(Tianhu)and Beijing(Institute of Atmospheric Physics),respectively.Proteins and amino acids(free and combined)as well as some other chemical components were analyzed for the PM2.5 samples.The aims of this study were to investigate the characteristics of aerosol proteinaceous matter including mass concentrations and compositions,and their sources and atmospheric processes in different regions.Both proteins and amino acids(free and combined)were detected in the PM2.5 samples collected at Tianhu,Guangzhou(March 2012-February 2013)and Institute of Atmospheric Physics,Beijing(15 October-13 November 2014).The major results are shown as follows:(1)Both proteins and free amino acids exhibited distinct seasonal variations with higher concentrations in autumn and winter than those in spring and summer at Tianhu,Guangzhou.(2)Correlation analysis and positive matrix factorization(PMF)analysis suggest that aerosol proteinaceous matter at Tianhu was mainly derived from intensive agricultural activities,biomass burning and fugitive dust/soil resuspension.(3)Our observation confirmed that free amino acids could be degraded from proteins under the influence of O3 and the stoichiometric coefficients of the reactions(α)were estimated for total free amino acids and glycine.(4)The concentrations and compositions of proteins and amino acids before APEC(without emission controls)and during APEC(with the emission controls)varied largely,pointing to the influence of different emission control measures.(5)Cluster analysis and potential source contribution function(PSCF)analysis suggest that the aerosol proteinaceous matter in urban Beijing was mainly contributed by local sources,while the influence of long-range transport was minor.(6)Except the contributions of biogenic activities,biomass burning and fugitive dust/soil resuspension to the aerosol proteinaceous matter in Beijing,the contributions of industries and vehicle emissions were also suggested by the correlation analysis.