The Influence of Acquisition Delay for Calibration-Free Laser-Induced Breakdown Spectroscopy.

Area of Science:

• Analytical Chemistry
• Materials Science
• Spectroscopy

Background:

• Slag analysis is crucial for industrial processes.
• Laser-Induced Breakdown Spectroscopy (LIBS) offers rapid elemental analysis.
• Calibration-Free LIBS (CF-LIBS) requires careful optimization for accuracy.

Purpose of the Study:

• To optimize the Calibration-Free LIBS (CF-LIBS) method for slag analysis.
• To investigate factors affecting LIBS spectral measurements of slag.
• To determine the optimal acquisition time for accurate elemental quantification.

Main Methods:

• Time-resolved LIBS spectra acquisition from slag samples.
• Analysis of factors influencing CF-LIBS, including self-absorption and local thermodynamic equilibrium.
• Calculation of plasma temperature and electron density using Saha-Boltzmann plots and Stark broadening.
• Application of an automatic spectral line elimination algorithm.

Main Results:

• Element concentrations varied significantly with acquisition time.
• Early acquisition times were affected by continuous spectra, while late times suffered from self-absorption.
• Optimal accuracy was achieved with a gate delay time between 1.5 μs and 2 μs.

Conclusions:

• The gate delay time is a critical parameter for accurate LIBS analysis of slag.
• Minimizing spectral interferences and self-absorption is essential for reliable elemental quantification.
• Optimized LIBS parameters enhance the applicability of CF-LIBS for industrial slag characterization.