About event
From apparent temperature to fully self-calibrated Laser Induced Breakdown Spectroscopy
Although several important applications of Laser-Induced Breakdown Spectroscopy (LIBS) have been demonstrated in recent decades and many others are ongoing in various fields of science, LIBS struggles to be accepted as a powerful analytical tool by a large part of the analytical chemistry community. This is mainly due to the fact that the best use of LIBS requires a strong theoretical foundation and deep knowledge of the physical processes involved in plasma generation and the resulting analytical emission spectra. Despite these challenges, there are applications where LIBS can be the only tool to use, such as chemical analysis in harsh environments and the exploration of planets and planetoids.
In this lecture, the effects of theoretical assumptions and the consequent operational restrictions during LIBS will be critically discussed to assess their real impact on elemental analysis. In this context, it will be shown that, beyond the rigorous treatment of plasma theories, the use of apparent element distributions can be exploited to build virtual Local Thermodynamic Equilibrium (LTE) conditions to be applied to plasma composition. In this approximation, the use of a fully self-calibrated approach will be discussed, where all information (instrument calibration and element composition) is obtained directly from the measured spectrum without the need for any previous experimental calibration. In this way, all restrictions due to reproducibility, deterioration of instrumental response, matrix-matching issues, and experiment stability can be neglected. The advantages and limitations of such an approach will be discussed with experiments on volcanic ash, meteorites, and gemstones.
