Measurement and analysis of arsenic in soil using laser-induced breakdown spectroscopy

This paper analyzed the characteristics of laser-induced breakdown spectroscopy (LIBS) of metal element arsenic in soil using the Nd:YAG (wavelength: 1064 nm) laser as the excitation source, where the spectral signals were detected by the high resolved, wide spectral ECHELLE spectrograph and intensity charged coupled device (ICCD). The time evolution of the characteristic spectral line of arsenic was obtained by changing the delay time of ICCD at the same concentration and the gate of ICCD with wavelength of 228.8 nm of arsenic as the characteristic spectral line, from which a best delay time of 1 s and a gate width of 2 s were found. By measuring the intensities of the characteristic spectral line with different arsenic concentrations, it was demonstrated that the intensities of the spectral line increased with the concentration of arsenic under the condition of low concentration. From the results, the LIBS calibration curve of arsenic was obtained, and the detection limit of arsenic in soil at 45 mg/kg was obtained.