title: Monoterpene separation by coupling proton transfer reaction time-of-flight mass spectrometry with fastGC.
abstract: Proton transfer reaction mass spectrometry (PTR-MS) is a well-established technique for real-time analysis of volatile organic compounds (VOCs). Although it is extremely sensitive (with sensitivities of up to 4500 cps/ppbv, limits of detection <1 pptv and the response times of approximately 100 ms), the selectivity of PTR-MS is still somewhat limited, as isomers cannot be separated. Recently, selectivity-enhancing measures, such as manipulation of drift tube parameters (reduced electric field strength) and using primary ions other than H3O(+), such as NO(+) and O2 (+), have been introduced. However, monoterpenes, which belong to the most important plant VOCs, still cannot be distinguished so more traditional technologies, such as gas chromatography mass spectrometry (GC-MS), have to be utilised. GC-MS is very time consuming (up to 1 h) and cannot be used for real-time analysis. Here, we introduce a sensitive, near-to-real-time method for plant monoterpene research-PTR-MS coupled with fastGC. We successfully separated and identified six of the most abundant monoterpenes in plant studies (α- and β-pinenes, limonene, 3-carene, camphene and myrcene) in less than 80 s, using both standards and conifer branch enclosures (Norway spruce, Scots pine and black pine). Five monoterpenes usually present in Norway spruce samples with a high abundance were separated even when the compound concentrations were diluted to 20 ppbv. Thus, fastGC-PTR-ToF-MS was shown to be an adequate one-instrument solution for plant monoterpene research.
authors.affiliation: Department of Environment, Earth and Ecosystems, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK. dusan.materic@open.ac.uk.
authors.forename: Dušan
authors.initials: D
authors.lastname: Materić
authors.affiliation: IONICON Analytik, Eduard-Bodem-Gasse 3, 6020, Innsbruck, Austria.
authors.forename: Matteo
authors.initials: M
authors.lastname: Lanza
authors.affiliation: IONICON Analytik, Eduard-Bodem-Gasse 3, 6020, Innsbruck, Austria.
authors.forename: Philipp
authors.initials: P
authors.lastname: Sulzer
authors.affiliation: IONICON Analytik, Eduard-Bodem-Gasse 3, 6020, Innsbruck, Austria.
authors.forename: Jens
authors.initials: J
authors.lastname: Herbig
authors.affiliation: Department of Environment, Earth and Ecosystems, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK.
authors.forename: Dan
authors.initials: D
authors.lastname: Bruhn
authors.affiliation: Department of Life, Health and Chemical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Turner
authors.affiliation: Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK.
authors.forename: Nigel
authors.initials: N
authors.lastname: Mason
authors.affiliation: Department of Environment, Earth and Ecosystems, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK.
authors.forename: Vincent
authors.initials: V
authors.lastname: Gauci
mesh_terms: D000080462:Acyclic Monoterpenes; D000475:Alkenes / Q000032:analysis / Q000302:isolation & purification; D000081008:Bicyclic Monoterpenes; D001643:Bridged Bicyclo Compounds / Q000032:analysis / Q000302:isolation & purification; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D039821:Monoterpenes / Q000032:analysis* / Q000302:isolation & purification; D028222:Picea / Q000737:chemistry*; D028223:Pinus / Q000737:chemistry*; D011522:Protons; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000302:isolation & purification; D014835:Volatilization
chemical_list: D000080462:Acyclic Monoterpenes; D000475:Alkenes; D000081008:Bicyclic Monoterpenes; D001643:Bridged Bicyclo Compounds; D039821:Monoterpenes; D011522:Protons; D055549:Volatile Organic Compounds; C509595:myrcene; C010789:beta-pinene; C030218:3-carene
keywords: FastGC; Monoterpenes; PTR-MS; Pinene; Plant VOCs; VOC