Determining concentration patterns of volatile compounds in exhaled breath by PTR-MS
K Schwarz1, W Filipiak, A Amann
1Department of Operative Medicine, Innsbruck Medical University, Anichstraße 35, A-6020 Innsbruck, Austria. Breath Research Unit of the Austrian Academy of Sciences, Dammstrasse 22, A-6850 Dornbirn, Austria.
Journal of Breath Research
|March 9, 2011
Summary
Proton-transfer-reaction mass spectrometry (PTR-MS) allows rapid breath analysis. This study calibrates 21 compounds, accounting for fragmentation, to improve quantitative accuracy in complex exhaled breath samples.
Area of Science:
- Analytical Chemistry
- Biomedical Engineering
- Environmental Science
Background:
- Proton-transfer-reaction mass spectrometry (PTR-MS) offers rapid analysis of exhaled breath without sample preparation.
- PTR-MS spectra can be complex due to unseparated compounds and protonated molecule fragmentation, hindering quantitative interpretation.
- Existing methods often lack comprehensive calibration for multiple compounds and their fragmentation patterns.
Purpose of the Study:
- To calibrate 21 key compounds for exhaled breath analysis using PTR-MS.
- To quantify fragmentation patterns of these compounds under specific conditions.
- To develop a method for accurate quantitative analysis of complex breath mixtures using PTR-MS.
Main Methods:
- Calibration of 21 pure compounds diluted in nitrogen.
- Determination of fragmentation patterns under dry, CO(2)-free conditions.
- Development of a linear optimization approach using the simplex algorithm for mixture analysis.
Main Results:
- Calibration factors and fragmentation proportions were determined for 21 compounds.
- Eleven compounds exhibited substantial fragmentation (>10%).
- A method was established to simulate mixture spectra and determine concentrations from observed spectra.
Conclusions:
- Accounting for fragmentation is crucial for accurate PTR-MS quantification of exhaled breath.
- The developed calibration and analysis method improves the reliability of PTR-MS for breath analysis.
- This approach enables more precise determination of volatile organic compounds in complex biological samples.
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