Comparison of detection limits, for two metallic matrices, of laser-induced breakdown spectroscopy in the single and...

Limits of detection have been studied for several elements in aluminium and steel alloys, at atmospheric pressure in air, by use of the single and collinear double-pulse configurations of laser-induced breakdown spectroscopy. For this purpose, calibration plots were constructed for Mg, Al, Si, Ti, Cr, Mn, Fe, Ni, and Cu using a set of certified aluminium alloy samples and a set of certified steel samples. The investigation included optimization of the experimental conditions to furnish the best signal-to-noise ratio. Inter-pulse delay, gate width, and acquisition delay were studied. The detection limits for the elements of interest were calculated under the optimum conditions for the double-pulse configuration and compared with those obtained under the optimum conditions for single-pulse configuration. Significantly improved detection limits were achieved, for all the elements investigated, and in both aluminium and steel, by use of the double-pulse configuration. The experimental findings are discussed in terms of the measured plasma conditions (particle and electron density, and temperature).