Laser-induced breakdown spectroscopy combined with spatial heterodyne spectroscopy

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Materials Science

Background:

• Laser-induced breakdown spectroscopy (LIBS) is a powerful analytical technique for elemental analysis.
• Traditional LIBS often uses dispersive spectrometers, which can have limitations in throughput and light collection efficiency.
• Spatial heterodyne spectroscopy (SHS) offers high throughput and a compact design, making it suitable for novel applications.

Purpose of the Study:

• To evaluate the performance of a spatial heterodyne spectrometer (SHS) when coupled with laser-induced breakdown spectroscopy (LIBS).
• To investigate the potential of the combined LIBS-SHS technique for material classification and quantitative analysis.
• To assess the feasibility of developing a portable and cost-effective LIBS-SHS instrument for field use.

Main Methods:

• A modified Michelson interferometer, the spatial heterodyne spectrometer (SHS), was integrated with LIBS.
• The SHS features fixed diffraction gratings, eliminating moving parts and enhancing throughput.
• Brass standards with varying copper (Cu) and zinc (Zn) concentrations were analyzed.
• Principal component analysis (PCA) was used for material classification.
• Partial least squares regression (PLS) was employed for quantitative analysis.

Main Results:

• The LIBS-SHS system demonstrated high throughput, approximately 200 times greater than dispersive spectrometers.
• Principal component analysis (PCA) successfully classified brass samples based on their elemental composition and origin.
• Quantitative analysis using partial least squares regression (PLS) achieved good precision (RSD < 10%) and accuracy (within ± 5% of nominal concentrations).

Conclusions:

• The LIBS-SHS technique is a promising advancement for standoff material analysis, especially in low-light conditions.
• The system's ability to classify and quantify materials accurately suggests its potential for field applications.
• Further development could lead to portable, inexpensive, and rugged LIBS-SHS instruments for diverse industrial and environmental monitoring tasks.