ICP-MS与XRF测定PM_(2.5)中重金属含量的对比分析

Comparative Study of ICP-MS and XRF for Determination of Heavy Metals Content in PM_(2.5)

目前,大气颗粒物中重金属含量分析方法很多,现有环境空气质量标准并未对重金属分析方法进行统一规定,在实际监测过程中各地选择的分析方法都不尽相同。因此,确定合适的分析方法,满足快速准确测定PM_(2.5)中金属元素含量的需求显得极为重要。文章采用ICP-MS与XRF分别测定PM_(2.5)滤膜样品中Al、As等15种金属的含量,并对2组实验结果进行对比及相关性分析。结果显示,2种方法测定元素Al、Mn、Fe、Cu、Zn、As、Se、Pb的相关性系数R在0.818 5~0.953 6之间,趋势线斜率在0.787 9~1.252之间,可比性较好,测定上述元素时2种分析方法均可选用;Ti、V、Cr、Co、Ni、Cd、Ba相关性系数R和趋势线斜率较低,2种方法分析数据差异较大,测定时应选用灵敏度更高的分析方法如ICP-MS。在测定大气颗粒物中重金属元素时,应根据样品实际情况选择合适的分析方法。

At present,there are a number of methods for analysis of heavy metal content in atmospheric particulate matter;however,the lack of nationally regulated standard methods causes discrepancies of analytic results due to the methods used being not same in different places.Therefore,it is essential to select an appropriate analytical method to meet the requirement of rapid and accurate determination of metal elements in PM_（2.5）.In this paper,a laboratory experiment was conducted respectively using ICP-MS and XRF to measure the content of 15 kinds of metals contained in samples of PM_（2.5）that had been separated by filter membranes,and analytic results of the two groups were compared and analyzed.The results showed that when measuring Al,Mn,Fe,Cu,Zn,As,Se and Pb the correlation coefficient R between the two analytical methods ranged0.818 5~0.953 6,and the slope of trend line being 0.787 9~1.252,which indicated the two methods were good in comparability;while measuring Ti,V,Cr,Co,Ni,Cd and Ba the matching degree in terms of R and slope of trend line were not so good,and ICP-MS with higher sensitivity was better.In conclusion,selecting an appropriate analytic method for heavy metals in PM_（2.5）should take into consideration the actual condition of the samples.