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The improvement of laser-induced breakdown spectroscopy

Name
Timur
Surname
Labutin
Scientific organization
Lomonosov Mosocow State University
Academic degree
Ph. D.
Position
senior researcher
Scientific discipline
Chemistry & Chemical technologies
Topic
The improvement of laser-induced breakdown spectroscopy
Abstract
The achievements in the determination of trace amounts of components in environmental samples (soils, ores, natural
waters, etc.) and construction materials by application of enhanced variant of laser-induced breakdown spectrometry are considered. Our results are critically compared with the state-of-the art in the field.
Keywords
laser induced breakdown spectrosocopy, analytical spectrosocpy, direct analysis, laser ablation
Summary

High-power pulsed laser radiation is used both for sample evaporation and excitation in laser-induced breakdown spectroscopy (LIBS), and the spectra of laser-induced plasma are used for quantitative and qualitative analysis. Fully optical excitation and detection provide the possibilities of local and remote analysis of light and heavy elements. The key advantages of the method that account for its high efficiency are demonstrated, in particular, a small amount of analyzed material, the absence of sample preparation, the possibility of local and remote analysis of either one or several elements. However, similarly to other direct methods matrix effects, sensitivity, and reproducibility are the main limitation the LIBS practical application. This study was carried out on improving the LIBS technique to overcome these problems, especially for geological samples and constructional materials.

We used a variety of techniques for increasing LIBS sensitivity including the use of different laser harmonics, double pulses, and a special mode of camera operation. We also suggested several approaches of improving the reproducibility of the analytical LIBS signal. We focused on algorithm of "internal" standard selection to correct pulse to pulse fluctuations, matrix effect, changing the laser parameters and environmental conditions. Application of these enhancements has led to a significant improvement in the detection limits for the number of elements, which are import markers in natural materials. The achieved limits of detection for most elements in geochemical samples are critically evaluated. We have shown that the possibilities of LIBS for quantitative determination of metals (Ni, Cr, Mn, Al, V, Ti) and nonmetal (Si, C) in high and low alloy steels are met the requirements of existing regulatory documents.