Evaluating off-line exhaled breath sampling techniques: a comparative study of practices for clinical implementation.

Area of Science:

• Breathomics and non-invasive diagnostics
• Analytical chemistry and mass spectrometry
• Biomedical engineering and device development

Background:

• Exhaled breath analysis using volatile organic compounds (VOCs) shows promise for disease monitoring.
• Standardization of breath sampling methods is crucial for clinical translation.
• Existing offline breath sampling techniques lack direct comparison using standardized protocols.

Purpose of the Study:

• To compare the analytical performance, reproducibility, and clinical feasibility of three widely used offline breath sampling devices: Tedlar® bags, BioVOC-2®, and ReCIVA®.
• To evaluate these devices using a standardized peppermint benchmarking protocol and comprehensive two-dimensional gas chromatography-mass spectrometry (GC×GC-MS).
• To inform the standardization of breath sampling methods in the breathomics community.

Main Methods:

• Comparison of Tedlar® bags, BioVOC-2®, and ReCIVA® using a peppermint benchmarking protocol.
• Breath sample collection from seven healthy participants post-capsule ingestion.
• Analysis using comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC-MS) to assess performance, reproducibility, and contamination.
• Clinical feasibility evaluation via focus groups.

Main Results:

• Tedlar® bags showed the lowest variability but were susceptible to contamination.
• ReCIVA® offered superior selectivity and reduced background interference but had higher variability, cost, and complexity.
• BioVOC-2® was simple to use but limited by small sample volume and manual handling variability.
• No single device was universally optimal, with trade-offs in performance, cost, and usability.

Conclusions:

• The choice of breath sampling device depends on study requirements, balancing analytical needs with practical considerations.
• Tedlar® bags are suitable for large-scale studies with strict SOPs; BioVOC-2® for targeted screening; ReCIVA® for controlled research.
• Standardized protocols and device selection are critical for advancing clinical implementation of breath analysis.
• Findings contribute to the breathomics community's standardization efforts and expand the peppermint benchmarking database.