Research Of Rapid Measurement Of Heavy Metals Pband Mnin Soil Samples Using A Laser-induced Breakdownspectroscopy

Laser-Induced Breakdown Spectroscopy(LIBS) is widely used in the analysis of element contents in sample.The significant figures of the measurement of heavy metals in soil have been validated in environment monitoring and in agricultural developement. LIBS is a type of atomic emission spectroscopy which uses a highly energetic laser pulse as the excitation source. The laser is focused to form a plasma, which atomizes and excites samples. LIBS can analyse any matter regardless of its physical state. LIBS can detect all elements, limited only by the power of the laser as well as the sensitivity and wavelength range of the spectrograph and detector. If the constituents of a material to be analyzed are known, LIBS may be used to evaluate the relative abundance of each constituent element, or to monitor the presence of impurities. In practice, detection limits are a function of the plasma excitation temperature, the light collection window, and the line strength of the viewed transition.This paper introducesthe rapid measurement techniques of heavy metals Pband Mnin soil samples using a laser-induced breakdown spectroscopy. After the analysis of traditional heavy metal detection technologies was performed, the LIBS approach was chosen to detect the heavy metalsrapidly. Theory of laser-induced plasma were studied, and the laser-induced plasma spectroscopy and its features are also investigated, including the fundamentalprinciples of plasma emission spectrometry, LIBS experimental setup and performance parameters. The quantitative analysis methods including the external standard method, internal standard method, multi-element analysis of calibration methods, calibration-free method, and multivariate analysis methods(PCA, PLS, ANN.) are discussed in this paper in addition to the theory and performances.The experimental platform for the detection of heavy metallic elements in soil using laser-induced breakdown spectroscopy was built. The experimental parameters were analyzed and preliminary optimized. By detecting different concentrations of soil heavy metals Pb and Mn, LIBS spectrum of Pb and Mn were obtained. The LIBS emission lines for determination of Pb and Mn elements in soil samples are 405.78 nm and 257.61 nm. The calibration curve was established according to the experimental data. The content of Pb and Mn was analyzed. The experimental results show that the technique of laser-induced breakdown spectroscopy can be used quickly to detect Pb and Mn in soil, which is of great significance for the rapid analysis of heavy metals in the soil. A new way of rapid measurement techniques of heacy metals in soil was provided.