基于激光诱导击穿光谱定量检测土壤中营养元素的研究

发布时间：2018-04-23 05:35

  本文选题：光谱学 + 激光诱导击穿光谱　； 参考：《中国激光》2017年11期

【摘要】：采用激光诱导击穿光谱(LIBS)对土壤中的营养元素进行了定量检测。采用输出波长为1064nm、脉宽为5.82ns的Nd…YAG脉冲激光器作为光源,将激光聚焦在土壤表面产生激光诱导等离子体,使用三光栅光谱仪和门宽控制的增强电荷耦合器件(ICCD)测量等离子体发射光谱。基于传统LIBS系统,新增了扩束镜系统和实时监测系统,研制了笼式结构LIBS系统,优化了笼式结构中扩束镜系统的激光聚焦位置,获得了最佳的激光聚焦位置0.2cm。测试了MgⅡ279.56nm、MgⅡ 280.26nm和MgⅠ 285.21nm谱线的信号强度。结果表明,笼式结构LIBS系统在信号稳定性上优于传统LIBS系统。定量分析了土壤中营养元素Cu、Mn、Mg、K的质量分数,它们的检出限分别为0.42×10~(-6)、13.2×10~(-6)、38.5×10~(-6)、62×10~(-6),优于传统LIBS系统得到的检出限。基于定标模型预测了土壤中Cu、Mn、Mg、K元素的质量分数,它们预测值的平均相对误差分别为9.2%、9.6%、8.5%、10.9%。
[Abstract]:The nutrient elements in soil were quantitatively determined by laser induced breakdown spectroscopy (LIBS). ND with output wavelength of 1064 nm and pulse width of 5.82ns... Laser induced plasma is produced by focusing the laser on the soil surface as a light source. The plasma emission spectra are measured by a three-grating spectrometer and an enhanced charge coupled device controlled by gate width. Based on the traditional LIBS system, the beam expanding mirror system and the real time monitoring system are added, and the cage structure LIBS system is developed. The laser focusing position of the beam expanding mirror system in the cage structure is optimized, and the optimal laser focusing position is obtained at 0.2 cm. The signal intensities of mg 鈪，

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