激光诱导击穿等离子体发射光谱技术测定土壤中铅的研究

Determination of lead in soil by laser-induced breakdown spectroscopy

由于在土壤中包含较多的元素,这些元素谱线不同,造成谱线有吸附性和自蚀现象,导致检测结果准确性较差,为此利用激光诱导击穿等离子体发射光谱(LIBS)测定土壤中铅的含量。分析LIBS技术检测原理并设置实验装置,采集与预处理待检测土壤,计算样品等离子体的温度与密度值后,获取土壤样品的组分和含量信息,最后采用最小二乘法实现土壤重金属含铅量的检测。实验结果表明,所提方法土壤重金属含铅量检测值与实际情况相差较小,提高了检测准确性和实时性,可以满足检测方法的设计需求。

Because there are many elements in the soil,the spectral lines of these elements are different,resulting in adsorption and self erosion of the spectral lines,resulting in poor accuracy of the detection results.Therefore,the content of lead in the soil is determined by laser-induced breakdown plasma emission spectroscopy(LIBS).Firstly,the detection principle of LIBS technology is proposed and the experimental device is set up,then the soil to be detected is collected and pretreated,and finally the lead content of heavy metals in the soil is detected.In the detection,the polarization characteristics are analyzed and the plasma temperature and density are calculated.On this basis,the composition and content information of soil samples are obtained,Finally,the least square method is used to detect the lead content of soil heavy metals.The experimental results show that the proposed method has little difference between the detection value of soil heavy metal lead content and the actual situation,improves the detection accuracy and real-time,and can meet the design requirements of the detection method.