Rapid Analysis of Inorganic Species in Herbaceous Materials Using Laser-Induced Breakdown Spectroscopy

Area of Science:

• Biomass thermochemical conversion
• Analytical chemistry
• Spectroscopy

Background:

• Inorganic compounds (ash) in biomass hinder thermochemical conversion processes.
• Conventional ash analysis methods (ICP-OES/MS) are time-consuming and reagent-intensive.

Purpose of the Study:

• To evaluate Laser-Induced Breakdown Spectroscopy (LIBS) as a rapid alternative for biomass inorganic analysis.
• To compare LIBS performance against established Inductively Coupled Plasma-Optical Emission Spectrometry/Mass Spectrometry (ICP-OES/MS) methods.

Main Methods:

• Analysis of 12 biomass samples, including six standard reference materials.
• Comparison of LIBS data with three ICP-OES/MS analytical methods.
• Measurement of elements: Al, Ca, Fe, Mg, Mn, P, K, Na, Si.

Main Results:

• LIBS achieved comparable accuracy to ICP-OES methods, with concentrations measurable to ~100 ppm uncertainty.
• Germanium (Ge) demonstrated utility as an internal standard for improved LIBS accuracy.
• LIBS proved effective for rapid total ash determination in biomass.

Conclusions:

• LIBS is a viable, rapid, and cost-effective technique for biomass inorganic analysis.
• LIBS offers advantages over ICP-OES/MS, including minimal sample preparation and no reagent consumption.
• LIBS data suggests potential unreliability in certain acid-digestion ICP-OES methods for Na and Al analysis.