离子色谱研究亚微米细颗粒物中水溶性离子含量水平和污染评价

Assessment of pollution and contents of water-soluble ions in airborne submicrometer particles using ion chromatography

建立一种采用离子色谱仪同时测定空气亚微米细颗粒物(PM_(1.0))中5种水溶性离子(F^-、Cl^-、NO_3^-、SO_4^(2-)、NH_4^+)的方法,分析了北京市东部某城区2017—2018采暖季PM_(1.0)中主要水溶性离子的含量和污染特征.采用石英纤维滤膜采集居住区环境空气样品,经超纯水超声浸提洗脱后,F^-、Cl^-、NO_3^-、SO_4^(2-)选用岛津IC-SA2柱,以碳酸钠/碳酸氢钠溶液作为淋洗液进行分离,NH_4^+选用岛津IC-C4柱,以草酸溶液作为淋洗液进行分离,经电导检测器测定.F^-、Cl^-、NO_3^-、SO_4^(2-)、NH_4^+在0.078—25μg·mL^(-1)线性范围内线性相关系数≥0.9990,方法精密度在0.016%—0.76%之间,对标准参考物质进行分析,测定结果符合参考值.

A method for simultaneous determination of five water-soluble ions (F^-,Cl^-,NO3^-,SO4^2-,NH4^+) in airborne submicrometer particles was established. And the method was used to analyze the contents of the water-soluble ions in airborne submicrometer particles collected in east urban Beijing during 2017-2018 heating season. The airborne submicrometer particle samples in residential areas in the east of urban Beijing were collected using quartz fiber filter membrane. After ultrasonic extraction with ultra-pure water, the contents of F^-,Cl^-,NO3^-,SO4^2- and NH4^+ were determined simultaneously by ion chromatography. Shimazin IC-SA2 column was chosen for separation of F^-,Cl^-,NO3^-,SO4^2- with sodium carbonate/sodium bicarbonate solution as leaching solutions, and Shimazin IC-C4 column was for NH4+ separation with oxalic acid solution as leaching solution. The conductivity detector was used. The linear correlation coefficients of F^-,Cl^-,NO3^-,SO4^2- and NH^+ were not less than 0.9990 within the linear range of 0.078-25 μg·mL^-1, and the RSD was in the range of 0.016%-0.76%.