将激光诱导击穿光谱技术应用到土壤检测中,分析了土壤样品形态对激光诱导等离子体特性的影响.采用波长1 064 nm的Nd-YAG脉冲激光器作为激发光源,在实验室大气环境下对粉状和片状2种形态土壤样本诱导产生激光等离子体,测量并分析了样品形态和粒径大小对元素特征谱线强度、等离子体温度和电子密度的影响.实验研究表明,相同实验条件下,粉状土样的激光等离子体温度和电子密度均高于片状土样,但片状土样的元素特征谱线强度更大,且受土壤粒径大小的影响较小,适用于土壤重金属元素的LIBS分析检测.
Laser-induced breakdown spectroscopy was used to analyze soil samples, and the influence of sample morphology on characteristics of laser-induced soil plasma was analyzed. The influence of sample morphology and particle size on characteristics of spectral line intensity, plasma temperature and electron density was measured and analyzed, using 1 064 nm Nd-YAG lasers as the excitation source to induce soil samples of powder and flake two forms plasma in the natural environment of the laboratory. The analysis results showed that the laser-induced plasma temperature and electron density of pulverized soil were high- er than those of flake soil under the same experimental conditions, but the characteristics spectral line in- tensity of flake soil was bigger, and the influence by soil particle size was smaller. The flake sample was suitable for soil heavy metals detection by LIBS.