title: Real-time metabolic monitoring with proton transfer reaction mass spectrometry.
abstract: We analysed the time evolution of several volatile organic compounds formed by the catabolism of ingested isotope-labelled ethanol using real-time breath gas analysis with proton-transfer-reaction mass spectrometry. Isotope labelling allowed distinguishing the emerging volatile metabolites from their naturally occurring, highly abundant counterparts in the human breath. Due to an extremely low detection limit of the employed technologies in the parts per trillion per volume range, it was possible to detect the emerging metabolic products in exhaled breath within ∼10 min after oral ingestion of isotope-labelled ethanol. We observed that ethanol was in part transformed into deuterated acetone and isoprene, reflecting the different fates of activated acetic acid (acetyl-coenzyme A), formed in ethanol metabolism. Using ethanol as a model clearly demonstrated the value of the here presented technique for the search for volatile markers for metabolic disorders in the exhaled breath and its potential usefulness in the diagnosis and monitoring of such diseases.
authors: Ionimed Analytik GmbH, Eduard-Bodem Gasse 3, A-6020 Innsbruck, Austria. Klaus.Winkler@ionimed.com
authors: Klaus
authors: K
authors: Winkler
authors: Jens
authors: J
authors: Herbig
authors: Ingrid
authors: I
authors: Kohl
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests / Q000379:methods; D045853:Exhalation; D005740:Gases / Q000737:chemistry; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D008659:Metabolic Diseases / Q000175:diagnosis / Q000378:metabolism; D008660:Metabolism; D008991:Monitoring, Physiologic / Q000379:methods*; D013997:Time Factors; D055549:Volatile Organic Compounds / Q000032:analysis*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005740:Gases; D055549:Volatile Organic Compounds