应用激光诱导击穿光谱分析技术(laser-induced break-down spectroscopy,LIBS)开展了土壤中重金属铬元素含量探测研究。实验中激光波长为1064 nm,脉冲宽度为8 ns,重复频率10 Hz,选取 Cr 427.4 nm作为光谱分析谱线。实验结果表明,在光谱采集相对于激光脉冲延迟时间为4.78μs,土壤样品表面位于聚焦透镜焦后1 mm 的实验条件下,Cr 元素浓度测量的相对标准偏差(RSD)为12.1%,检测限为2.01 ppm,元素实验测量与标准值的相对偏差为5.15%。可以看出 LIBS 技术具有低检测限、测量精度高等优点,这对土壤中重金属污染和监测环境质量的精确、快速检测等问题具有重要意义。%The elemental concentration of Cr contained in soil is measured with laser induced breakdown spectroscopy (LIBS). As the LIBS laser power,the laser wavelength is of 1 064 nm with pulse width of 8 ns and laser repetition frequency of 10 Hz in this experiment and Cr 427.4 nm is selected as the analytical line of LIBS.The experimental results show that the relative stand-ard deviation (RSD)of the detected content of Cr is 12.1% at the delay time of 4.78 μs and the soil sample surface 1 mm behind lens focal point.The limit of detection (LOD)of LIBS is 2.01 ppm.The measured relative deviation between the measured value and the nature value is 5.1 5%.Because the LIBS has advantages such as lower LOD and higher detection precision,LIBS has a guiding significance to detect heavy metal in soil and to monitor environmental quality precisely and rapidly.
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