Elemental Analyzer-Interface-Off-Axis Integrated Cavity Output Spectroscopy (EA-OA-ICOS): A Universal Coupling for...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Isotope Geochemistry

Background:

• Traditional elemental analysis-isotope ratio mass spectrometry (EA-IRMS) for δ¹³C analysis is effective but can be resource-intensive.
• There is a need for more efficient and environmentally friendly analytical techniques for stable isotope analysis.

Purpose of the Study:

• To introduce and validate an innovative coupling of a custom elemental analyzer (EA) with an off-axis integrated cavity output spectroscopy (OA-ICOS) laser for δ¹³C analysis.
• To demonstrate the accuracy, efficiency, and compatibility of the EA-OA-ICOS system as an alternative to EA-IRMS.

Main Methods:

• Development of a dedicated interface to couple a combustion-based elemental analyzer with an OA-ICOS laser.
• Combustion of solid organic samples and subsequent analysis of δ¹³C using the coupled EA-OA-ICOS system.
• Comparison of EA-OA-ICOS results with conventional EA-IRMS using international standards and two different commercial EAs.

Main Results:

• The EA-OA-ICOS system achieved high accuracy for δ¹³C measurements (standard deviations ± 0.22‰) and carbon content (% C ± 0.24%).
• EA-OA-ICOS analysis of international standards yielded mean values and standard deviations comparable to EA-IRMS.
• The developed interface proved universal and compatible with different commercial elemental analyzers, showing highly comparable results.

Conclusions:

• The innovative EA-OA-ICOS coupling provides an efficient, accurate, and eco-friendly alternative for δ¹³C analysis of solid organic samples.
• This method is robust and adaptable to various commercially available elemental analyzers, making it accessible for routine laboratory use.