Abstract: In order to compare the water-soluble chemical species in ambient aerosol particles between haze days and normal days, TSP and PM2.5 samples were collected from Sep. 2005 to Sep. 2006. The result showed that the concentration of total water soluble ions in TSP and PM2.5 during haze days were 135.0 and 72.4 µg∙m-3, respectively. 11 water-soluble ions (Na+, NH4+, K+, Mg2+, Ca2+, F-, Cl-, Br-, NO2-, NO3- and SO42-) were measured. The results showed that NH4+, SO42- and NO3- were major species both in haze and normal days, while the percentage of concentration of these three major ions in TSP and PM2.5 during haze days was higher than that in normal days. Measurements of pH values for aerosol particles dilute showed haze day samples was more acid than those in normal days. Calculated the oxidation ratio of sulfur (SOR) and nitrogen (NOR) in two kind of weather conditions, it revealed that ratio of transformation of SO2 and NOx in haze days were more higher than those in normal days, especially for SO2.

Key words: water-soluble ions, haze, SOR, NOR