2006年3月22日至9月22日，使用Mini-vol便携式气溶胶采样仪，在西安市高新区进行大气气溶胶（PM2.5）观测研究，并用被动式采样器Ogawa采集NH3样品，使用离子色谱仪对样品进行分析，获得大气气溶胶中水溶性离子和NH3的浓度变化，结合大气SO2、NO2浓度数据，对西安市春、夏季气体及PM2.5中水溶性组分的特征和来源进行了研究。分析显示，西安市春、夏季PM2.5中水溶性离子主要由SO42-、NO3-和NH4+组成，分别占PM2.5质量浓度的21.68%、7.52%和5.62%；PM2.5整体偏酸性；NH3与水溶性NH4+， SO2与水溶性SO42-，NO2与水溶性NO3-的相关系数都不高，西安大气中硫酸盐，硝酸盐以及铵盐气溶胶的形成受到多种机制的共同作用。

The investigation of PM2.5 aerosols using a portable mini-volume sampler was conducted between May 22 and September 22, 2006, in high-tech zone, Xi’an. Meantime NH3 gases were also sampled using passive Ogawa sampler. Water soluble ions (WSI) and NH3 concentrations were analyzed using an ion chromatogram (IC) analyzer. Integrating these data with SO2 and NO2 concentrations, the characteristics and sources of WSI of PM2.5 in spring and summer in Xi’an were studied. The results indicated that WSI in spring and summer was mainly composed of SO42-, NO3- and NH4+, accounting for 21.68%, 7.52% and 5.62% in mass, respectively, and the PM2.5 in spring and summer in XI’an were generally acidic. SO2 concentrations were poorly correlated with SO42-, NO3- and NO2, indicating that sulfate, nitrite, and ammonium in Xi’an are of different origins.