波长色散-X射线荧光光谱法测定PM2.5中23种元素

摘要

研究以单元素标准膜为基础,结合NIST SRM 2783颗粒物滤膜标准样品,建立了波长色散-X射线荧光光谱法测定PM2.5中23种无机元素的测定方法,优化了测试条件,测量一个样品耗时约15 min,计算了各元素的方法检出限.对NIST SRM 2783滤膜标准品在一周内重复测定10次来计算方法的准确度与精密度,测定结果显示大多数元素的测量值在给出的参考值范围内,且测量标准偏差一般在10％以内.对比了石英与聚四氟乙烯材质(Teflon)滤膜的空白值,石英滤膜中Si、Fe、Na、Mg、Al、K、Ca等元素的背景值较高,Teflon滤膜的背景值较低,推荐选用Teflon滤膜作为PM2.5组分分析采样滤膜.分别用波长色散-X射线荧光光谱法及酸消解-ICP-MS法测定了样品膜中的元素组分,得到的测定结果基本一致.%A method for the determination of 23 inorganic elements in atmospheric fine particulate matter using WD-XRF has been established based on the single element standard filters of Micromatter and the NIST SRM 2783 particulate matter standard filter.The test conditions were optimized,the testing time for one sample was about 15 minutes,and then the method detection limit of each elements was calculated.In order to calculate the precision and accuracy of the method,the SRM NIST 2783 standard filter were measured for 10 times in one week,the results of most elements were within the range of the given reference value and the standard deviations were generally within 10％.The blank values of quartz and PTFE filers produced by Whatman company were compared.The background values of Si,Na,Fe,A1,Mg,Ca,K and other elements in quartz filter were higher,and the background values of Teflon filter were lower,so Teflon filter was recommended as the PM2.5 component analysis sampling filter.We also analyzed the PM2.5 filters by wavelength dispersive X-ray fluorescence spectroscopy and ICP-MS,the results of the two methods were basically the same.