Investigation of long-pulse Laser-Induced Breakdown Spectroscopy for analysis of the composition of rock and sediment samples submerged in seawater

The aim of this paper is to investigate the application of Laser-Induced Breakdown Spectroscopy (LIBS) to qualitatively analyze the composition of various seafloor rock samples in seawater. Well-resolved emission spectra of submerged samples were achieved by using a long laser pulse of duration 250 ns. It was found that the main elements in each rock sample could be successfully identified both in pure water and in seawater. When comparing the measurements made in pure water and in seawater, some effects of the seawater could be seen, however these effects are negligible and do not have any significant detrimental effect on the analytical value of the signal obtained. The results suggest that long-pulse LIBS may be applicable for in situ, multi-element chemical analysis of sediments and rocks in the marine environment.