Development of on-line analytical method for scrapped materials by using laser-induced plasma atomic emission spectrometry under evacuated atmosphere

提出了利用激光烧蚀和/或激光诱导等离子体对废弃材料进行快速定量分析的技术。为此，我们在原子发射光谱中开发了两种激发源：一种是降低氩气压力下的激光诱导等离子体源，另一种是与氦辉光放电等离子体相关的激光烧蚀源。前者可用于报废材料的在线分析，后者可用于报废材料中微量元素的精确测定。激光诱导等离子体源的发射信号因其背景强度很小而易于检测；因此，它适合作为在线分析的激励源。确定了最佳工作条件，使发射信号的信本比达到最大。高频Nd:YAG激光烧蚀源可用于氦辉光放电等离子体的样品导入，由于辉光放电等离子体和激光采样都非常稳定，可以作为可靠的激励源。

Analytical techniques for rapid quantification for scrapped materials have been proposed by use of laser ablation and/or laser-induced plasmas. For this purpose, we have developed two excitation sources in atomic emission spectrometry : one is a laser-induced plasma source under reduced argon pressures and the other is a laser-ablation source associated with a helium glow discharge plasma. The former could be employed for on-line analysis of scrapped materials, while the latter could be employed for the precise determination of minor elements in scrapped materials. The emission signals from the laser-induced plasma source are easily detected because the background intensity is very small ; it is therefore suitable for the excitation source for on-line analysis. The optimum operation conditions were determined so that the signal-to-background ratio of the emission signals could be maximized. The laser-ablation source with a high-frequency Nd:YAG laser can be employed for the sample introduction to the helium glow discharge plasma, which works as a reliable excitation source because the glow discharge plasma as well as the laser sampling are very stable.