Simple method for liquid analysis by laser-induced breakdown spectroscopy (LIBS)

Area of Science:

• Analytical Chemistry
• Spectroscopy

Background:

• Laser-induced breakdown spectroscopy (LIBS) is a rapid in situ multi-element analysis technique.
• LIBS faces challenges in liquid sample analysis due to splashing and contamination issues.

Purpose of the Study:

• To introduce and evaluate a novel capillary mode for quantitative elemental analysis of liquids using LIBS.
• To address the limitations of traditional LIBS methods for liquid samples.

Main Methods:

• Utilized a Nd:YAG laser (10 Hz repetition rate) for analyzing sodium chromate (Na2CrO4) solutions.
• Implemented a capillary mode to contain the liquid sample during laser-induced plasma generation.
• No sample preparation was required.

Main Results:

• The capillary mode significantly reduced liquid splashing and prevented optical component contamination.
• Quantitative analysis of Cr and Na in solution showed improved accuracy compared to other methods.
• Excellent linear calibration curves (R² > 0.998) were obtained for Cr and Na.
• Limits of detection (LODs) were 28.9 mg/L for Cr and 1.0 mg/L for Na.

Conclusions:

• The proposed capillary mode offers a practical and simple approach to enhance the accuracy of LIBS elemental analysis in liquids.
• This method overcomes key technical difficulties associated with LIBS analysis of aqueous solutions.