Investigating the CO2 pressure effect on underwater laser-induced plasma emission of Eu and Yb

Abstract

Laser-induced breakdown spectroscopy (LIBS) is an emerging analytical technique for in situ determination of elements in natural resources. The technique is employed for the study of two rare earth elements (Eu and Yb) in aqueous solutions at pressures ranging from ambient to 250 bar. Underwater plasma is created at ambient and elevated pressures to record LIBS spectra from their solutions using Nd:YAG laser operated at its fundamental wavelength of 1064 nm. The effect of CO2 pressure on the characteristic spectral signatures of these two rare earth elements is presented. Variation of intensity, integrated intensity, and width of selected emission lines with CO2 pressure is explained. The technique could potentially be used for the detection of rare earth elements in oceanic, carbon sequestration, and geothermal fluids.