Laser ablation in a liquid medium as a technique for solid sampling

Abstract

A new technique for solid sampling, laser ablation in a liquid medium, has been developed and evaluated. A solid sample was held in a liquid medium contained in a flat-bottomed beaker. Laser pulses from a Q-switched Nd:YAG laser were introduced from the bottom of the beaker and were focused on the surface of the solid sample. Both the vapour and the particles produced by the laser ablation were trapped directly by the surrounding liquid, and a suspension was formed. The technique offers both time and spatial separation of the sampling and introduction and excitation processes in the laser ablation. The morphological observation of trapped particles, the evaluation of trapping efficiency and fractional ablation, and the direct introduction of the suspension into an inductively coupled argon plasma were carried out. Nearly 100% trapping efficiency and the absence of fractional ablation were obtained.