Correction of self-absorption effect in calibration-free laser-induced breakdown spectroscopy by an internal...

Area of Science:

• Atomic and Molecular Spectroscopy
• Plasma Physics
• Analytical Chemistry

Background:

• Calibration-free laser-induced breakdown spectroscopy (CF-LIBS) is powerful but affected by self-absorption in optically thick plasmas.
• Self-absorption, especially for strong lines of major elements, degrades CF-LIBS performance.
• Existing correction methods, like the curve of growth, are complex to implement.

Purpose of the Study:

• To propose a simplified and effective procedure for correcting self-absorption effects in CF-LIBS.
• To enhance the accuracy of plasma temperature and material composition analysis in CF-LIBS.
• To overcome the limitations of traditional self-absorption correction methods.

Main Methods:

• Developed the Internal Reference for Self-Absorption Correction (IRSAC) method.
• Selected an internal reference spectral line for each species, minimally affected by self-absorption.
• Compared other spectral line intensities of the same species to the reference line to estimate self-absorption.
• Employed a regressive algorithm for optimal self-absorption correction.

Main Results:

• The IRSAC method significantly simplifies the correction procedure for self-absorption.
• The self-absorption effect on the selected reference line is negligible due to high excitation energy.
• IRSAC leads to more regular points on the Boltzmann plot.
• Improved accuracy in evaluating plasma temperature and material composition compared to basic CF-LIBS.

Conclusions:

• IRSAC offers a practical and accurate solution for self-absorption correction in CF-LIBS.
• The method enhances the reliability and performance of CF-LIBS analysis.
• IRSAC is a valuable advancement for elemental analysis using laser-induced breakdown spectroscopy.