Development of a laser-induced breakdown spectrometer and evaluation of alternative detection systems

Abstract

Laser induced breakdown spectroscopy (LIBS), a relatively recent analytical technique in relation to other atomic spectrometric techniques more used and developed, is based on the incidence of a laser radiation over a small region of the sample promoting its ablation, plasma formation and light emission characteristic of sample constituents. Due to its various advantages over other atomic spectrometric techniques, as direct analysis of practically any sample, practically non-destructive and micro-region analysis, LIBS has been subject of various international research projects seeking the development, still incipient, of this technique. This project proposes the construction of a LIBS instrument using three detection systems: one employing advanced technology, based on an Echelle type monocromator and a bidimensional array of intensified charge coupled device (ICCD) type detectors; and two low cost alternative detection systems, the first based on an acouto optical tunable filter (AOTF) and a photomultiplier and the second based on a low resolution diffraction grating and a linear array of photodiodes. The alternative detection systems will be evaluated by using the LIBS instrument to develop quantitative methods for determination of interest elements in metal alloy samples, eventually using multivariate calibration to compensate possible losses of spectral resolution. (AU)