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Scientific Articles - PTR-MS Bibliography

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Found 3 results
Title [ Year(Asc)]
Filters: Author is Mayhew, Chris A  [Clear All Filters]
[Steele2011] Steele, D. A., R. D. Short, P. Brown, and C. A. Mayhew, "On the Use of SIFT-MS and PTR-MS Experiments to Explore Reaction Mechanisms in Plasmas of Volatile Organics: Siloxanes", Plasma Processes and Polymers, vol. 8, no. 4: Wiley Online Library, pp. 287–294, 2011.
Selected ion flow tube mass spectrometry (SIFT-MS) and proton transfer reaction mass spectrometry (PTR-MS) are used to explore ion-molecule reactions in low temperature and pressure plasmas of hexamethyldisiloxane. These techniques shed new light on possible reactions taking place within such plasma environments and validate many of the reaction pathways previously advocated based upon plasma-phase MS. However, SIFT-MS and PTR-MS results draw attention to the possible importance of the H3O+ ion in initiating the formation of oligomeric ions, a point previously missed in plasma-MS studies.
[OHara2009] O'Hara, M. E., T. H. Clutton-Brock, S. Green, S. O'Hehir, and C. A. Mayhew, "Mass spectrometric investigations to obtain the first direct comparisons of endogenous breath and blood volatile organic compound concentrations in healthy volunteers", International Journal of Mass Spectrometry, vol. 281, no. 1: Elsevier, pp. 92–96, 2009.
Volatile organic compounds (VOCs) in breath could be clinically useful for the early detection and diagnosis of diseases, physiological disorders and therapeutic monitoring. However, it is crucial to compare the reliability and precision of breath measurements with those from blood if endogenous VOCs on breath are to be used as biomarkers. Few studies have been undertaken to investigate this, none of which relate to endogenous VOCs in freely breathing subjects. Here we establish the reliability and precision of breath measurements to determine endogenous VOC concentrations in comparison to blood measurements in order to assess the viability of using breath measurements for potential diagnostic and screening purposes. Acetone and isoprene concentration levels in the breath, radial arterial blood and peripheral venous blood and in vivo arterial blood/breath ratios for freely breathing subjects have been determined using mass spectrometric techniques. Mean (range) breath concentrations in parts per billion by volume are 1090 (515–2335) for acetone and 465 (308–702) for isoprene. The mean (range) blood concentrations are: for acetone in radial arterial blood 26 (10–73) μmol/l and in peripheral venous blood 18 (9–39) μmol/l; for isoprene in radial arterial blood 6.8 (3.7–11) μmol/l and in peripheral venous blood 14 (5.5–30) μmol/l. Arterial blood/breath ratios mean (range) are 580 (320–860) for acetone and 0.38 (0.19–0.58) for isoprene. An important finding is that the coefficients of repeatability as a percentage of mean are less than 30% in breath but greater than 70% in blood. This study suggests that breath VOC measurements could provide a more consistent measure for investigating underlying physiological function or pathology than single blood measurements.
[Kennedy2003] Kennedy, R. A., C. A. Mayhew, R. Thomas, and P. Watts, "Reactions of H< sub> 3 O< sup>+ with a number of bromine containing fully and partially halogenated hydrocarbons", International Journal of Mass Spectrometry, vol. 223: Elsevier, pp. 627–637, 2003.
The thermal bimolecular rate coefficients and product ion branching ratios for the reactions of H3O+ with the bromine containing molecules CH3Br, CH2Br2, CH2FBr, CHF2Br, CHFBr2, CH2BrCl, CHBrCl2, CHBr2Cl, CH3CH2Br, CH2BrCH2Cl, CH2BrCH2Br, CF3CF2Br and CF2BrCF2Br at 300 K are reported. H3O+ reacts with an experimental rate coefficient (kexp) close to the collisional value (kc≈10−9 cm3 molecule−1 s−1) with CHFBr2, CHBrCl2, CHBr2Cl, CH2BrCH2Cl, and CH2BrCH2Br, at a decreased efficiency with CH3CH2Br (kexp/kc≈0.3). The other neutral reactant molecules, CH3Br, CH2FBr, CHF2Br, CF3CF2Br, and CF2BrCF2Br react through a three-body associative process. There is no observable reaction with CH2Br2 and CH2BrCl. Mechanistic arguments are given that go some way to explaining the observed range in both reactivity and reaction pathways.

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Selected PTR-MS related Reviews

F. Biasioli, C. Yeretzian, F. Gasperi, T. D. Märk: PTR-MS monitoring of VOCs and BVOCs in food science and technology, Trends in Analytical Chemistry 30 (7) (2011).

J. de Gouw, C. Warneke, T. Karl, G. Eerdekens, C. van der Veen, R. Fall: Measurement of Volatile Organic Compounds in the Earth's Atmosphere using Proton-Transfer-Reaction Mass Spectrometry. Mass Spectrometry Reviews, 26 (2007), 223-257.

W. Lindinger, A. Hansel, A. Jordan: Proton-transfer-reaction mass spectrometry (PTR–MS): on-line monitoring of volatile organic compounds at pptv levels, Chem. Soc. Rev. 27 (1998), 347-375.


Lists with PTR-MS relevant publications of the University of Innsbruck can be found here: Atmospheric and indoor air chemistry, IMR, Environmental Physics and Nano-Bio-Physics


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