Direct Analysis of Fatty Acid Vapors in Breath by Electrospray Ionization and Atmospheric Pressure Ionization-Mass Spectrometry
- 26 September 2008
- journal article
- research article
- Published by American Chemical Society (ACS) in Analytical Chemistry
- Vol. 80 (21), 8210-8215
- https://doi.org/10.1021/ac801185e
Abstract
Real time analysis of human breath is achieved in an atmospheric pressure ionization mass spectrometer (API-MS) by negatively charging exhaled vapors via contact with an electrospray cloud. The spectrum observed is dominated by a wide range of deprotonated fatty acids, including saturated chains up to C14. Above C14, the background from cutaneous sources becomes dominant. We also tentatively identify a series of unsaturated fatty acids (C7-C10), ketomonocarboxylic acids (C6-C10), and a family of aldehydes. The ionization probability of large fatty acids increases drastically when the humidity changes from 20% to 95%. Accordingly, distinguishing lung vapors (humid) from those in the background (dry) requires special precautions. Estimated fatty acid vapor concentrations in breath based on our measurements ( approximately 100 ppt) are in fair agreement with values expected from blood concentrations in the range for which data are available (C3-C6).Keywords
This publication has 35 references indexed in Scilit:
- Exhaled methyl nitrate as a noninvasive marker of hyperglycemia in type 1 diabetesProceedings of the National Academy of Sciences of the United States of America, 2007
- Gas-phase ions of solute species from charged droplets of solutionsProceedings of the National Academy of Sciences of the United States of America, 2007
- Selected ion flow tube mass spectrometry (SIFT-MS) for on-line trace gas analysisMass Spectrometry Reviews, 2005
- A comparison of the metabolism of eighteen-carbon 13C-unsaturated fatty acids in healthy womenJournal of Lipid Research, 2004
- Validation of deuterium labeled fatty acids for the measurement of dietary fat oxidation: a method for measuring fat-oxidation in free-living subjectsInternational Journal of Obesity, 2001
- Analysis of volatile emissions from porcine faeces and urine using selected ion flow tube mass spectrometryBioresource Technology, 2000
- Method for the Collection and Assay of Volatile Organic Compounds in BreathAnalytical Biochemistry, 1997
- Physiology and pathophysiology of organic acids in cerebrospinal fluidJournal of Inherited Metabolic Disease, 1993
- Quantitative Analysis of Urine Vapor and Breath by Gas-Liquid Partition ChromatographyProceedings of the National Academy of Sciences of the United States of America, 1971
- Ueber die Abhängigkeit der Siedetemperatur vom LuftdruckEuropean Journal of Inorganic Chemistry, 1883