Repeatability of the measurement of exhaled volatile metabolites using selected ion flow tube mass spectrometry

J Am Soc Mass Spectrom. 2010 Jun;21(6):1070-4. doi: 10.1016/j.jasms.2010.02.008. Epub 2010 Feb 10.


Selected ion flow tube mass spectrometry, SIFT-MS, has been used to determine the repeatability of the analysis of volatile metabolites within the breath of healthy volunteers, with emphasis on the influence of sampling methodology. Baseline instrument specific coefficients of variability for examined metabolites were as follows: acetone (1%), ammonia (1%), isoprene (2%), propanol (6%), ethanol (7%), acetic acid (7%), and hydrogen cyanide (19%). Metabolite concentration and related product ion count rate were identified as strong determinants of measurement variation. With the exception of ammonia, an orally released metabolite, variability in repeated on-line breath analysis tended to be lower for metabolites of systemic origin. Standardization of sampling technique improved the repeatability of the analysis of selected metabolites. Off-line (bag) alveolar breath sampling, as opposed to mixed (whole) breath sampling, likewise improved the repeatability of the analysis of all metabolites investigated, with the exception of acetic acid. We conclude that SIFT-MS analysis of common volatile metabolites within the breath of healthy volunteers is both reliable and repeatable. For selected metabolites, the finding that repeatability is improved through modification of sampling methodology may have implications in terms of future recommended practices.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-Propanol / analysis
  • Acetic Acid / analysis
  • Acetone / analysis
  • Adult
  • Ammonia / analysis
  • Analysis of Variance
  • Breath Tests / methods*
  • Butadienes / analysis
  • Ethanol / analysis
  • Exhalation
  • Female
  • Hemiterpenes / analysis
  • Humans
  • Hydrogen Cyanide / analysis
  • Male
  • Mass Spectrometry / methods*
  • Pentanes / analysis
  • Reproducibility of Results
  • Statistics, Nonparametric
  • Volatile Organic Compounds / analysis*


  • Butadienes
  • Hemiterpenes
  • Pentanes
  • Volatile Organic Compounds
  • isoprene
  • Acetone
  • Hydrogen Cyanide
  • Ethanol
  • Ammonia
  • 1-Propanol
  • Acetic Acid