气雾化辅助激光诱导击穿光谱检测水中的痕量金属元素∗

摘要

In order to improve the limit of detection and linearity without losing the advantage of on-line and in-situ mea-surement, laser-induced breakdown spectroscopy assisted by nebulizer is investigated. The influences of the main exper-imental parameters, namely the defocusing amount, the distance between the nebulizer and the central of laser beam, the ablation energy and the delay are studied to maximize the signal-to-noise ratio. Using laser-induced breakdown spectroscopy assisted by nebulizer, we demonstrate that the detection limits are 1.2, 3.2, 19.1, 3.4, 2.8, and 15.9 ppm for Ca, Cr, K, Mg, Na, Pb respectively, and the linearities are all above 0.99. The results show that laser-induced breakdown spectroscopy assisted by nebulizer is an effective method to detect the tracing metal element in liquid on-line and in-situ.%为了改善其检测极限和定量分析的线性拟合系数,同时满足实时在线监测的需求,采用气雾化辅助激光诱导击穿光谱技术,对水溶液中钙(Ca),铬(Cr),钾(K),镁(Mg),钠(Na),铅(Pb)六种元素进行了定性和定量检测.通过对离焦量、横向距离、激光能量以及延时4个主要参数的优化,获得上述六种元素的检测极限分别为1.2,3.2,19.1,3.4,2.8和15.9 ppm,其线性拟合系数均达到0.99以上.实验结果表明,气雾化辅助激光诱导击穿光谱技术是一种快速在线检测液体中痕量金属元素的有效方法.