激光诱导击穿光谱技术测定土壤中元素Cr和Pb

为了提高激光诱导击穿光谱技术对物质成分的检测水平,在实验中加入了平面反射镜装置约束激光等离子体。用Nd:YAG纳秒脉冲激光激发产生土壤等离子体发射光谱,测量绘制了元素的定标曲线,定量分析了土壤样品中重金属元素Cr和Pb,并与不加入平面反射镜装置条件下的检测结果进行比较。计算表明,实验中加入平面反射镜装置以后,元素Cr和Pb的测量结果的相对标准偏差与无平面反射镜装置时的相比较,分别从5.22%和8.12%降低到了3.43%和3.94%;而元素分析检出限分别由4.13×10-3%和62.54×10-3%降低到2.61×10-3%和44.22×10-3%。可见,利用平面反射镜装置能够明显提高激光诱导击穿光谱技术的测量精度。

Determination of Cr and Pb in soil by laser-induced breakdown spectroscopy

In order to improve the detection level of laser-induced breakdown spectroscopy on material composition, laser plas- ma was constrained by the plane mirror device in the experiment. The elements calibration curve was measured and drawed ,and the content of element Cr and Pb in the soil samples was quantitatively analyzed by the method of excitating soil plasma emission spec- troum. The soil plasma was induced by Nd： YAG laser. The detection results were compared with that without the plane mirror de- vice. Calculation shows that, when the plane mirror device was added in the experiments, the relative standard deviation of the measurement results of element Cr and Pb from 5.22% and 8.12% decreased to 3.43% and 3.94% than that without mirror; while the detection limits from 4.13 ~ 10-3% and 62.54 ~ 103% decreased to 2.61 ~ 10-3% and 44.22 ~ 10-3%, respectively. It is thus that the plane mirror device can obviously improve the measurement accuracy of laser-induced breakdown spectroscopy.