[Laser induced breakdown spectroscopy for the determination of Cr and Sr in soil]

As a powerful and promising analytical technique, laser-induced breakdown spectroscopy (LIBS) has been undergoing a rapid development in the past years. LIBS technique allows for rapid, multi-elemental, in situ measurements, and has been proposed for real time soil analysis. Currently, a global effort is focused on how to further improve the analytical accuracy and repeatability of this promising technique. In the present paper, a method of laser induced breakdown spectroscopy (LIBS) for the determination of Cr and Sr in soil was established. The experimental instrument was mainly equipped with a pulsed 1 064 nm Nd : YAG laser and a portable spectrometer. The behavior of shot to shot variation in spectra line intensity emitted by the laser plasma was studied. Data acquisition and processing procedures were experimentally optimized. The precision of the method was, in terms of RSD, 9.02% for Cr 425.44 nm and 10.5% for Sr 460.73 nm respectively (n = 8). Detection limits were 25.3 mg x g(-1) for Cr and 15.2 mg x g(-1) for Sr in soil respectively. These results are better than the data reported in literature, indicating that the established LIBS method is suitable for the determination of heavy metal in soil.