复杂颗粒状物质中微量元素的LIBS稳定性研究

Stability of Laser-Induced Breakdown Spectroscopy from Microelements in Complex Granular Matters

以具有复杂颗粒特征的商业食盐为模型样品,通过实验研究了激光诱导击穿光谱(LIBS)技术检测复杂颗粒状物质中微量元素光谱的稳定性。通过测量和分析食盐中Ca(800×10^(-6))、Sr(35.1×10^(-6))、Mg(6.4×10^(-6))、Fe(1.7×10^(-6))微量元素在250~465nm波段的发射谱线强度、相对标准偏差和信噪比随距焦量、激光脉冲累加次数和光谱采集延迟时间的变化规律,确定了采集微量元素对应分析谱线的最优实验条件。基于优化的实验条件,采集食盐颗粒中4种微量元素的LIBS稳定性分别优于10%、14%、13%和28%。这表明LIBS技术具备检测食盐颗粒中质量分数为10^(-6)量级元素的能力,为LIBS技术在线定量分析复杂颗粒形态物质中微量元素的工业应用提供了实验依据。

Taking the commercial salt as a model sample of granular matters with complex size and component distribution,we study the stability of laser-induced breakdown spectroscopy（LIBS）from microelements in complex granular matters.We measure the intensities of emission spectral lines,relative standard deviation and signal to noise ratio from four typical microelements（Ca with mass fraction of 800×10^-6,Sr with mass fraction of 35.1×10^-6,Mg with mass fraction of 6.4×10^-6,and Fe with mass fraction of 1.7×10^-6）in the salt sample in the band from 250 nn to 465 nm to determine the most optimal experimental conditions for synchronously detecting the four microelements.Based on these optimal conditions,we quantitatively obtained that the LIBS stability of the four microelements is above 10%,14%,13% and 28%,respectively.This indicates that LIBS technology has the ability to detect microelement with mass fraction of 10^-6 in salt,providing experimental references for the detection of microelements in complex granular matters using LIBS in on-line industrial processes.