title: Multi-capillary-column proton-transfer-reaction time-of-flight mass spectrometry.
abstract: Proton-transfer-reaction time-of-flight mass-spectrometry (PTR-TOFMS) exhibits high selectivity with a resolution of around 5000 m/Δm. While isobars can be separated with this resolution, discrimination of isomeric compounds is usually not possible. The coupling of a multi-capillary column (MCC) with a PTR-TOFMS overcomes these problems as demonstrated in this paper for the ketone isomers 3-heptanone and 2-methyl-3-hexanone and for different aldehydes. Moreover, fragmentation of compounds can be studied in detail which might even improve the identification. LODs for compounds tested are in the range of low ppbv and peak positions of the respective separated substances show good repeatability (RSD of the peak positions <3.2%). Due to its special characteristics, such as isothermal operation, compact size, the MCC setup is suitable to be installed inside the instrument and the overall retention time for a complete spectrum is only a few minutes: this allows near real-time measurements in the optional MCC mode. In contrast to other methods that yield additional separation, such as the use of pre-cursor ions other than H3O(+), this method yields additional information without increasing complexity.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Innsbruck Medical University, Anichstraße 35, A-6020 Innsbruck, Austria; Breath Research Institute, Austrian Academy of Sciences, Austria. Electronic address: veronika.ruzsanyi@i-med.ac.at.
authors.forename: Veronika
authors.initials: V
authors.lastname: Ruzsanyi
authors.forename: Lukas
authors.initials: L
authors.lastname: Fischer
authors.forename: Jens
authors.initials: J
authors.lastname: Herbig
authors.forename: Clemes
authors.initials: C
authors.lastname: Ager
authors.forename: Anton
authors.initials: A
authors.lastname: Amann
mesh_terms: D001944:Breath Tests; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007477:Ions; D011522:Protons; D012867:Skin / Q000737:chemistry / Q000378:metabolism; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D007477:Ions; D011522:Protons; D055549:Volatile Organic Compounds
keywords: Gas chromatographic separation; Multi capillary column; PTR-TOFMS; Proton transfer reaction time of flight mass spectrometry; VOCs; Volatile organic compounds