RESUMEN
Objective To investigate spatial distribution and temporal trend of main water-soluble inorganic ions in PM2.5 of Wuhan. Methods PM2.5 samples were simultaneously collected at 5 sites in Wuhan from January 2017 to December 2017 (7 consecutive days per month). The main water-soluble ions in PM2.5 were determined by weighing method and ion chromatography. The seasonal variations and spatial distribution differences were analyzed. Results The results showed that the mass concentration of PM2.5 in Wuhan changed in different seasons. It was highest in winter, followed by spring and autumn, and lowest in summer. There were obvious seasonal changes in the mass concentrations and proportions of distinct ions. The concentrations of the four detected water-soluble inorganic ions were highest in winter. SO42- had highest concentration and proportion, followed by NO3- and NH4+, and Cl- was the lowest. In terms of spatial distribution, the total ion concentration and proportion was the largest in Wuchang and the lowest in Dongxihu. Conclusion The seasonal variation of main water-soluble inorganic ions in PM2.5 was obvious, and the spatial distribution was also different in Wuhan.