Efficient detection of emission lines for H and O and the use as an internal standard for underwater LIBS

Abstract

The effects of pulse duration on spectral emission of H and O obtained by laser-induced breakdown spectroscopy (LIBS) in bulk water have been investigated. We found distinct atomic lines of H and O by irradiating with a laser pulse of 100 ns duration or longer. The time-resolved emission spectra show that higher emission intensity and longer plasma persistence time can be obtained with the increase of pulse duration. The quantification performance by using O as an internal standard demonstrates better linearity, higher stability and lower limit of detection (LOD). The present results suggest that the use of a long ns pulse is essential for the efficient detection of atomic lines of H and O in underwater single-pulse LIBS, which can serve as a good internal standard for quantitative analysis.