Lithium ion detection in liquid with low detection limit by laser-induced breakdown spectroscopy

Area of Science:

• Analytical Chemistry
• Materials Science
• Spectroscopy

Background:

• Lithium (Li) is crucial for battery fabrication, necessitating rapid detection methods for industrial applications.
• Traditional methods like atomic absorption spectroscopy and ICP-MS are accurate but too slow for in situ control due to complex sample preparation.
• Fast, on-site monitoring of lithium ions in aqueous solutions is essential for industrial processes.

Purpose of the Study:

• To develop a rapid, quantitative method for detecting lithium ions (Li+) in water.
• To utilize laser-induced breakdown spectroscopy (LIBS) with filter paper enrichment for improved lithium detection sensitivity.
• To establish a feasible online monitoring system for lithium ion concentration.

Main Methods:

• Quantitative analysis of Li+ in water using laser-induced breakdown spectroscopy (LIBS) targeting the Li I 670.79 nm spectral line.
• Sample preparation involving filter paper as an adsorption substrate for concentrating lithium ions from water.
• Development of a calibration curve using polynomial function fitting for predicting Li+ concentration.

Main Results:

• Achieved a low limit of detection (LOD) of 18.4 ppb for Li+ using filter paper enrichment, significantly lower than previously reported.
• Obtained a high correlation coefficient (R²) of 99% and a prediction error below 2%, demonstrating method reliability.
• Direct detection of Li+ in water without enrichment yielded a higher LOD of 10.5 ppm, highlighting the benefit of filter paper substrate.
• Plasma imaging revealed distinct morphologies and evolution on water versus filter paper surfaces.

Conclusions:

• Laser-induced breakdown spectroscopy (LIBS) with filter paper enrichment offers a fast and sensitive method for quantitative Li+ detection in water.
• The developed method is feasible for fast and online monitoring of lithium ions in industrial settings.
• This study provides valuable experimental and theoretical insights for the rapid quantitative detection of lithium ions in liquids.