XRF测定大气颗粒物中Pb元素的标样制备  

Standard sample preparation of Pb element determination in atmospheric particles by XRF

作　　者：陈诚[1] 李丹[1] 赖万昌[1] 王广西[1] 翟娟[1] 洪自强[1] 

机构地区：[1]成都理工大学核技术与自动化工程学院,成都610059

出　　处：《核技术》2015年第12期14-19,共6页Nuclear Techniques

基　　金：国家863计划项目(No.2012AA06180303);四川省教育厅自然科学项目(No.15ZB0075)资助~~

摘　　要：X射线荧光光谱分析(X-Ray Fluorescence,XRF)测定大气PM2.5中元素成分具有快速、无损的优点,但是其标样的选择和制备却是一个复杂的问题。本文对X射线荧光薄样制备技术进行了讨论,利用点滴法制备了Pb的薄标样,论述了亲水型聚四氟乙烯(Polytetrafluoroethylene,PTFE)滤膜作为载体材料的可行性,对比分析了玻璃和聚四氟乙烯材料作为制样垫板时对制样效果的影响,讨论了滴液量与制样重现性之间的关系,确定了制样的最佳滴液量为0.3 m L。采用上述薄样制备方法建立了大气颗粒物中Pb元素的分析工作曲线,其线性相关系数为0.996,准确度与精密度较好,对Pb的检出限为35 ng·cm-2。利用该工作曲线分析了成都市某大气采样点2015年4月份大气PM2.5中Pb的含量,分析结果表明,采样期间PM2.5中Pb的浓度为0-526 ng·m-3,夜间PM2.5中Pb的平均浓度稍高于日间。Background： X-ray fluorescence （XRF） determination of elements in atmospheric PM2.5 has the advantages of being fast and nondestructive, but it is a complicated problem for the selection and preparation of standard sample. Purpose： The aim is to introduce a standard sample preparation of Pb element determination in PM2.5 by XRF which is a simple, cheap, accurate and reproducible method for preparing the sample. Methods： The thin sample was prepared with the help of drip Pb standard method, and the feasibility of the hydrophilic polytetrafluoroethylene （PTFE） membrane as a carrier material was discussed. The metal ions with PTFE of strong hydrophobicity and low adsorption were chosen as sample preparation slab. After the discussion on the relationship between droplet volume and the reproducibility of sample preparation, the best droplet volume for sample preparation reached 0.3 mL. The standard sample of Pb element analysis of PM2.5 was prepared by using above methods. Results： The working curve of Pb was established with the linear correlation 0.996, which was of good accuracy and precision. The detection limit was 35 ng.cm 2. Conclusion： Using the working curve, Pb content in the atmosphere in April, 2015, in Chengdu city is analyzed. The results showed that the concentration range of Pb in PM2.5 was 0-526 ng·cm^-3, and the average concentration of Pb in the nighttime was higher than that in the daytime.

关 键 词：X荧光分析 标样 PM2.5 PB 

分 类 号：TL817[核科学技术—核技术及应用]