Optimized breath analysis: customized analytical methods and enhanced workflow for broader detection of VOCs

Area of Science:

• Biomedical analysis
• Analytical chemistry
• Biomarker discovery

Background:

• Volatile organic compounds (VOCs) in breath are promising biomarkers for clinical use.
• Translating VOC biomarkers requires robust identification and validation protocols.
• Previous work identified 148 breath-borne VOCs using a developed collection and analysis method.

Purpose of the Study:

• To develop a complementary analytical method for detecting and identifying additional VOCs in breath.
• To upgrade the methodology for identifying 'on-breath' features using statistical metrics (standard deviation, t-test, ROC curve).

Main Methods:

• Utilized thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) with a PEG phase column.
• Enhanced VOC identification through grouping, spectral library creation, retention indexing, and quality checks.
• Applied three statistical metrics to compare breath and background samples for feature identification.

Main Results:

• 621 features were statistically determined as 'on-breath' by at least one metric.
• 38 on-breath VOCs were confidently identified by comparison with chemical standards.
• The total number of confirmed on-breath VOCs increased to 186.

Conclusions:

• Presents an updated methodology for high-confidence VOC identification in breath.
• Identified a new set of commonly occurring on-breath VOCs.
• Significantly expands the repertoire of known breath-borne VOC biomarkers.