超声提取离子色谱法测定大气PM2.5中9种阴、阳离子

Determination of 9 kinds of anion and cation in atmospheric PM2.5 by ultrasonic extraction / ion chromatography

目的建立大气PM2.5中9种阴、阳离子的超声洗脱离子色谱测定法。方法取1/8滤膜样品,经陶瓷剪刀剪碎后于超声提取40 min并离心过滤后进样,经离子色谱分离后,电导检测器检测,保留时间定性,峰面积定量。结果在本研究所使用的离子色谱条件下,9种阴、阳离子分别得到很好的分离,且峰形较好,能够满足实验的要求。各种离子在测定浓度范围内与峰面积具有良好的线性关系,相关系数（r）≥0.999 2,能够准确定量。在高、中、低3种加标浓度下,9种阴、阳离子的精密度为0.47%~7.26%,加标回收率为92.6%~114.0%。一次超声9种离子的提取效率为97.53%~99.95%。结论该方法简便快捷,测定大气PM2.5中9种阴、阳离子的测定下限明显低于实际样品中阴、阳离子的最低浓度,适合大气PM2.5中9种阴、阳离子的测定。

Objective To establish a method to determine 9 kinds of anion and cation in atmospheric PM2. 5 by ultrasonic extraction / ion chromatography. Methods One eighth of membrane filters was cut into pieces using the ceramic scissor,and then extracted by ultrasound for 40 min. The extracting solutions were centrifuged and filtered by 0. 45 μm filters and then the target ions were determined by ion chromatography / conductivity detector. All ions were qualitatively determined by the retention time and quantitatively determined by peak area. Results The separation of 9 ions was good under the experiment conditions used in this study. The good peak shape can meet the requirement of experiment. There was good linearity between concentrations and peak areas of ions,and correlation coefficients（ r） were not less than 0. 999 2,with accurate quantity. The precision ranges of determination of the 9 kinds of anion and cation were among 0. 47%- 7. 26%,and the recovery rates were among 92. 6%-114. 0% in measuring different level of samplers（ high,medium,low）. The extraction efficiency within an ultrasonic extraction / ion chromatography of 9 ions was among 97. 53%- 99. 95%. Conclusion This method is simple and suitable for the determination of 9 kinds of anion and cation in atmosphere PM2. 5,in which the minimum limit of determination was significantly lower than the lowest concentration of anions and cations in actual samples.