Spectral Interference Elimination in Soil Analysis Using Laser-Induced Breakdown Spectroscopy Assisted by...

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Environmental Science

Background:

• Spectral interference complicates trace element detection in soil using Laser-Induced Breakdown Spectroscopy (LIBS).
• Accurate quantification of heavy metals in soil is crucial for environmental monitoring and risk assessment.

Purpose of the Study:

• To address spectral interference in LIBS for soil trace element analysis.
• To enhance the detection capabilities of LIBS for heavy metals in soil samples.

Main Methods:

• Application of Laser-Induced Breakdown Spectroscopy assisted by Laser-Induced Fluorescence (LIBS-LIF).
• Selective enhancement of spectral intensities for interfered lines.
• Demonstration using the Pb I 405.78 nm line as an example.

Main Results:

• Elimination of spectral interference lines was achieved.
• Improved determination coefficient (R²) from 0.6235 to 0.9802 for Pb calibration curve.
• Reduced relative standard deviation (RSD) from 10.18% to 4.77%.
• Significantly lowered limit of detection (LOD) for Pb from 24 ppm to 0.6 ppm.

Conclusions:

• LIBS-LIF effectively eliminates spectral interference in soil analysis.
• The LIBS-LIF technique substantially enhances the detection accuracy and sensitivity for trace heavy metals in soil.