Fast and sensitive trace metal analysis in aqueous solutions by laser-induced breakdown spectroscopy using wood slice substrates

Abstract

To perform fast and sensitive trace metal analysis in aqueous solutions by laser-induced breakdown spectroscopy (LIBS) based on only one single-pulse laser system, a wood slice has been used as a liquid absorber to transform liquid sample analysis to solid sample analysis using LIBS. High detection sensitivity and good reproducibility can be achieved with this approach. Calibration curves for five metal elements, Cr, Mn, Cu, Cd, and Pb under trace concentrations, have been obtained, and the limits of their detection were determined to be in the range of 0.029–0.59 mg L − 1 , 2–3 orders better than those obtained by directly analyzing liquid samples where the laser was focused on a liquid surface. The wood slice was very easy to handle and thus, the whole analysis process took only 4–5 min for each sample. This approach provides a more practical approach for fast and sensitive metal element analysis in aqueous solutions using LIBS, which is especially useful for monitoring toxic heavy metals in water.