Analysis of lead and copper in soil samples by laser-induced breakdown spectroscopy under external magnetic field

The purpose of the present study was to improve the detection limits of copper and lead in the soil samples by coupling Laser-Induced Plasma Spectrometry (LIPS) with an external magnetic field. The laser-induced plasma was generated using an Nd:YAG laser (532 nm) and the emission spectra were registered using a set of four spectrometers covering the wavelength region from 250 to 870 nm. The application of external magnetic field (0.7 T) perpendicular to the propagation of the plasma plume increases the plasma temperature, electron density, and plasma emission intensity. This enhancement in the plasma parameters is attributed to the plasma confinement. The detection limit of Pb and Cu has been improved from 12 ppm to 4.1 ppm and from 3.9 ppm to 1.4 ppm by applying magnetic field. The plasma temperature and electron number density decays slowly along the plasma expansion axis in the presence of external magnetic field.