诱导击穿光谱技术（LIBS）具有实时快速、 多元素同时探测的优势, 并且无需样品预处理, 检测成本低, 是土壤重金属定量分析检测的一种重要分析手段。 将LIBS技术应用于冶炼厂区周围土壤中重金属的含量分布分析研究, 利用Cu, Pb和Cr三种元素的特征谱线强度分析了冶炼厂区周围土壤中Cu, Pb和Cr三种元素的含量分布。 实验结果表明冶炼厂区土壤LIBS光谱中Cu和Pb两种元素的特征谱线强度分布与实际含量分布呈较好的线性关系, 而Cr元素的特征谱线强度分布与实际含量分布相关性较差。 为了提高Cr元素含量分布分析的准确性, 利用CF-LIBS结合Saha方程应用于土壤Cr元素的含量分布分析中。 实验结果表明基于CF-LIBS计算的Cr和Si两种元素含量比值分布与土壤Cr元素的实际含量分布之间具有良好的一致性。 相比于其他的化学分析方法, LIBS技术结合CF-LIBS可以快速的对区域土壤重金属元素的含量分布进行检测, 因此将LIBS技术与CF-LIBS相结合用于土壤重金属的含量分布检测中, 为污染区域的重金属防治提供方向。

Laser-induced breakdown spectroscopy (LIBS) has become a powerful technology for quantitative analysis of the toxic heavy metals in soils due to its excellent attributes of rapid analysis speed, simultaneous multi-element assay, and low-cost detection with slight sample preparation. In this work, LIBS was applied to analyze the spatial concentration distribution of toxic heavy metals in soils around a smelter. The spectral lines of copper (Cu), lead (Pb) and chromium (Cr) were used to directly analyze the concentration distribution in soils around the smelter. The relevance between the spectral line intensities of Cr and the total concentrations detected by inductively coupled plasma optical emission spectrometry (ICP-OES) was poor. To improve the analysis accuracy, the calibration-free LIBS (CF-LIBS) method combined with Saha equation was used. Compared with the preliminary analysis result of spectral line intensities, the concentration ratios of Cr/Si obtained from CF-LIBS showed a good correlation with the total concentrations. Then, the map of the spatial relative concentration distribution of Cr superposed on the aerial view of the locations was established. Our results demonstrate that LIBS is an efficient rapid method for mapping the spatial contaminated distribution of heavy metal elements and giving us the clear direction to treat heavy metal pollution.