Silica Nanoparticle and Microwave Plasma Torch Effects on Laser-Induced Breakdown Spectroscopy

Area of Science:

• Analytical Chemistry
• Materials Science
• Spectroscopy

Background:

• Laser-induced breakdown spectroscopy (LIBS) is a key elemental analysis technique.
• Enhancing LIBS sensitivity for trace element detection remains a challenge.
• Silica nanoparticles and microwave plasma torches (MPT) offer potential improvements.

Purpose of the Study:

• To investigate the synergistic effects of silica nanoparticles and MPT on LIBS spectral signals of titanium (Ti).
• To optimize nanoparticle concentration and explore plasma dynamics.
• To evaluate the performance of nanoparticle-enhanced laser-induced breakdown spectroscopy (NELIBS) combined with MPT (MPT-NELIBS) for quantitative Ti detection.

Main Methods:

• Optimized laser energy and varied silica nanoparticle concentrations.
• Employed finite-difference time-domain (FDTD) simulations to model electric field intensity.
• Conducted time-resolved experiments to analyze emission spectra evolution.
• Utilized microwave plasma torch (MPT) to extend plasma lifetime.

Main Results:

• Silica nanoparticles increased plasma electron density, enhancing emission intensity and signal-to-noise ratio (SNR).
• MPT extended plasma lifetime, improving accumulated emission signals.
• MPT-NELIBS demonstrated substantial improvements in spectral intensity and SNR, reducing nanoparticle dependency.
• Achieved a determination coefficient (R^2) of 0.999 and a limit of detection (LOD) of 0.14 ppm for Ti.

Conclusions:

• The combination of silica nanoparticles and MPT in NELIBS significantly enhances titanium detection sensitivity.
• MPT-NELIBS offers a robust method for highly sensitive trace element analysis.
• This technique shows great potential for quantitative elemental detection in various samples.