Determination of Water Soluble Organic Acids in PM2.5 of Atmosphere in Beijing City
北京市大气气溶胶PM2.5中水溶性有机酸的测定

Ten water soluble organic acids in PM2.5 of atmosphere in Beijing were determined by capillary electrophoresis, including low molecular weight dicarboxylic acids, aldehyde acids, ketoacids and methanesulfonic acid. The quantified detection limits ranged from 110 to 280 microg/L (extract). The precise of peak area was between 1.7% and 6.0%, and the correlation coefficients of standard curve were 0.995-0.999. The average total concentrations of the ten organic acids in summer, fall and winter were 721 ng/m3, 362 ng/m3 and 325 ng/m3, respectively, which were comparable with some foreign big cities. Oxalic acid was the most abundant species. By exploring seasonal variations of the acids, their source characteristics were simply discussed.