激光诱导等离子体光谱直接探测气溶胶中的锶元素  

Direct monitoring of strontium in aerosols by laser-induced plasma spectroscopy

作　　者：何洪钰 高智星[1] 何运 张晓华[1] 郭冰[1] HE Hongyu;GAO Zhixing;HE Yun;ZHANG Xiaohua;GUO Bing(China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《光学精密工程》2023年第19期2827-2835,共9页Optics and Precision Engineering

基　　金：稳定支持项目(No.BJ19002211,No.WDJC-2019-02)。

摘　　要：气溶胶中锶元素的监测对于大气污染防治和工业设施排放监控具有重要意义。激光诱导等离子体光谱技术具有无需采样预处理、可原位快速检测等优势,在环境介质成分直接在线监测方面具有极大的应用潜力。介绍了基于实验室搭建的LIPS装置开展的气溶胶中锶元素的直接探测工作。利用整体平均法对气溶胶等离子体进行光谱分析,结果显示实验装置对锶元素的检测限为809μg/m3。对于低密度气溶胶光谱,条件分析法可以将平均光谱的信噪比提升8倍。基于实验结果讨论了含锶气溶胶统计学特性和数据分析方法的影响。气溶胶中颗粒物的密度对等离子体温度的影响极小,光谱强度变化直接反应了激光激发气溶胶颗粒物的数量。通过对条件分析法使用范围的讨论,提出在测量周期内利用累计光谱取代平均光谱,可将系统的灵敏度提升近3个数量级。实验装置的检测限达到1.3μg/m^(3),初步满足工业排放监测的需求。The direct monitoring of strontium in aerosols is crucial for air pollution prevention and the monitoring of emissions from industrial facilities.Laser-induced plasma spectroscopy(LIPS)offers a promising method for the direct and online monitoring of environmental mediums.Specifically,LIPS requires no sample preparation,allows rapid analysis,and facilitates online detection.This study introduces the direct detection of strontium in aerosols using an LIPS setup.The experimental findings confirm that,through ensemble averaging,the limit of detection(LOD)for strontium aerosols is 809μg/m^(3).Conditional analysis enhances the signal-to-noise ratio of the average spectrum eight-fold for low-density aerosols.Furthermore,this study delves into the effects of aerosol statistical characteristics and spectral analysis methods on spectral line intensity.Given that the aerosol particle density has minimal impact on plasma temperature and the spectral intensity is influenced by particle density,the scope of conditional analysis is further explored.Hence,it is proposed that the sensitivity of LIPS can be enhanced nearly three-fold by substituting the average spectrum with the cumulative spectrum over a given measurement period.With this adjustment,the LOD of the setup can approach 1.3μg/m^(3),fulfilling the requirements of industrial emission monitoring.

关 键 词：激光诱导等离子体光谱 气溶胶 锶 条件分析 

分 类 号：O53[理学—等离子体物理] TN249[理学—物理]