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Scientific Articles - PTR-MS Bibliography

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Found 8 results
Title [ Year(Asc)]
Filters: Author is Armin Wisthaler  [Clear All Filters]
[1816] Liu, X., G. L. Huey, R. J. Yokelson, V. Selimovic, I. J. Simpson, M. Müller, J. L. Jimenez, P. Campuzano-Jost, A. J. Beyersdorf, D. R. Blake, et al., "Airborne measurements of western U.S. wildfire emissions: Comparison with prescribed burning and air quality implications", Journal of Geophysical Research: Atmospheres, vol. 122, pp. 6108–6129, jun, 2017.
<p>Wildfires emit significant amounts of pollutants that degrade air quality. Plumes from three wildfires in the western U.S. were measured from aircraft during the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) and the Biomass Burning Observation Project (BBOP), both in summer 2013. This study reports an extensive set of emission factors (EFs) for over 80 gases and 5 components of submicron particulate matter (PM1) from these temperate wildfires. These include rarely, or never before, measured oxygenated volatile organic compounds and multifunctional organic nitrates. The observed EFs are compared with previous measurements of temperate wildfires, boreal forest fires, and temperate prescribed fires. The wildfires emitted high amounts of PM1 (with organic aerosol (OA) dominating the mass) with an average EF that is more than 2 times the EFs for prescribed fires. The measured EFs were used to estimate the annual wildfire emissions of carbon monoxide, nitrogen oxides, total nonmethane organic compounds, and PM1 from 11 western U.S. states. The estimated gas emissions are generally comparable with the 2011 National Emissions Inventory (NEI). However, our PM1 emission estimate (1530 &plusmn; 570 Gg yr&minus;1) is over 3 times that of the NEI PM2.5 estimate and is also higher than the PM2.5 emitted from all other sources in these states in the NEI. This study indicates that the source of OA from biomass burning in the western states is significantly underestimated. In addition, our results indicate that prescribed burning may be an effective method to reduce fine particle emissions.</p>
[1833] Müller, M., P. Eichler, B. D'Anna, W. Tan, and A. Wisthaler, "Direct Sampling and Analysis of Atmospheric Particulate Organic Matter by Proton-Transfer-Reaction Mass Spectrometry", Analytical Chemistry, sep, 2017.
<p>We report on a new method for analyzing atmospheric submicrometer particulate organic matter which combines direct particle sampling and volatilization with online chemical ionization mass spectrometric analysis. Technically, the method relies on the combined use of a CHARON (&ldquo;Chemical Analysis of Aerosol Online&rdquo;) particle inlet and a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS). Laboratory studies on target analytes showed that the ionization conditions in the PTR-ToF-MS lead to extensive fragmentation of levoglucosan and cis-pinonic acid, while protonated oleic acid and 5α-cholestane molecules remain intact. Potential problems and biases in quantitative and qualitative analyses are discussed. Side-by-side atmospheric comparison measurements of total particulate organic mass and levoglucosan with an aerosol mass spectrometer (AMS) were in good agreement. Complex and clearly distinct organic mass spectra were obtained from atmospheric measurements in three European cities (Lyon, Valencia, Innsbruck). Data visualization in reduced-parameter frameworks (e.g., oxidation state of carbon vs carbon number) revealed that the CHARON-PTR-ToF-MS technique adds significant analytical capabilities for characterizing particulate organic carbon in the Earth&rsquo;s atmosphere. Positive matrix factorization (PMF) was used for apportioning sources of atmospheric particles in late fall in Innsbruck. The m/z signatures of known source marker compounds (levoglucosan and resin acids, polycyclic aromatic hydrocarbons, nicotine) in the mass spectra were used to assign PMF factors to biomass burning, traffic, and smoking emission sources.</p>
[1824] Eichler, P., M. Müller, C. Rohmann, B. Stengel, J. Orasche, R. Zimmermann, and A. Wisthaler, "Lubricating Oil as a Major Constituent of Ship Exhaust Particles", Environmental Science {&} Technology Letters, vol. 4, pp. 54–58, jan, 2017.
<p>A proton-transfer-reaction time-of-flight mass spectrometer combined with the novel CHARON (&ldquo;chemical analysis of aerosol online&rdquo;) aerosol inlet was used for characterization of submicrometer particulate organic matter in ship engine exhaust. Particles were sampled from diluted and cooled exhaust of a marine test bench engine that was operated on residual heavy fuel oil (HFO) and low-sulfur distillate marine gas oil (MGO), respectively. In both fuel operation modes, exhaust particle mass spectra were dominated by polycycloalkanes in the C20-to-C39 range, which are typical main constituents of lubricating oils. Exhaust particle mass spectra were closely reproduced when the engine&rsquo;s lubricant oil was directly measured in aerosolized form. We report emission profiles of lubricant oil hydrocarbons as a function of their volatility and as a function of their carbon atom number. Total emissions of lubricant oil amounted to 183 and 74 mg kW&ndash;1 h&ndash;1 for HFO and MGO combustion, respectively. These values resemble typical oil loss rates of marine four-stroke trunk piston engines in which most of the lubricant is known to be lost through the combustion chamber and the tailpipe. We conclude that marine trunk piston engines are generally prone to high emissions of particles mainly composed of unburned lubricating oil.</p>
[Ciesa2013] Ciesa, F., J. Dalla Via, A. Wisthaler, A. Zanella, W. Guerra, T. Mikoviny, T. D. Märk, and M. Oberhuber, "Discrimination of four different postharvest treatments of ‘Red Delicious’ apples based on their volatile organic compound (VOC) emissions during shelf-life measured by proton transfer reaction mass spectrometry (PTR-MS)", Postharvest Biology and Technology, vol. 86, pp. 329 - 336, 2013.
Abstract Storage methods extend the postharvest life of apples from weeks to up to one year; however, these methods also alter the production of volatile organic compounds (VOCs), which amongst others, are important for aroma attributes. While the impact of storage on particular aroma components has been established, high throughput methods for determining the storage history during shelf-life are elusive. Here we show the potential of proton transfer reaction-mass spectrometry (PTR-MS), an MS-based metabolic fingerprinting technique, for characterizing fruit in the postharvest chain. The \{VOC\} fingerprint of apples (Malus&#xa0;×&#xa0;domestica Borkh. ‘Red Delicious’) was analyzed by PTR-MS during four weeks of shelf-life ripening after storage under four different storage conditions: \{ULO\} (ultra-low oxygen), DCA-CF (dynamic controlled atmosphere monitored by chlorophyll fluorescence), \{RLOS\} (repeated low oxygen stress) and 1-MCP (1-methylcyclopropene) in ULO. \{PTR\} fingerprint mass spectra of the apple headspace, obtained in short time without sample preparation or preconcentration, were sufficient to discriminate the four storage conditions during shelf-life. Moreover, we were able to monitor the changes in quality-critical \{VOC\} classes, including esters and terpenes, during shelf-life and observe the differential impact of the storage history on these VOCs. This work emphasizes the potential of PTR-MS as a valuable addition to targeted GC–MS-based approaches in postharvest research.
[Mueller2013] Müller, M., T. Mikoviny, W. Jud, B. D'Anna, and A. Wisthaler, "A new software tool for the analysis of high resolution PTR-TOF mass spectra", Chemometrics and Intelligent Laboratory Systems, vol. 127, pp. 158 - 165, 2013.
Abstract The High Resolution Proton-Transfer-Reaction Time-of-Flight Mass Spectrometer (HR PTR-TOF-MS) is a powerful analytical tool used by various scientific communities for real-time measurements of volatile organic compounds (VOC). The analysis of \{HR\} PTR-TOF-MS data is, however, particularly demanding because of the large amount of complex data being generated. Based on recently developed or described mathematical methods, we have produced a new software tool, the PTR-TOF Data Analyzer, which greatly facilitates the data analysis process. The new software solution allows for i) a combined Poisson counting statistics and dead time correction of ion count rates, ii) accurate mass axis calibration, iii) an iterative residual peak analysis that detects up to 5 isobaric peaks per unit m/z, iv) time series analysis of both low and high mass and time resolution data and v) visualization of analysis results for fast quality assurance checks. After having been successfully tested by a group of users with different application needs, the PTR-TOF Data Analyzer is made generally available to the scientific community. This will improve the user-friendliness of the PTR-TOF-MS technique and facilitate scientific work with this new analytical mass spectrometer.
[Kolarik2010] Kolarik, B., P. Wargocki, A. Skorek-Osikowska, and A. Wisthaler, "The effect of a photocatalytic air purifier on indoor air quality quantified using different measuring methods", Building and Environment, vol. 45, no. 6, pp. 1434 - 1440, 2010.
The effect on indoor air quality of an air purifier based on photocatalytic oxidation (PCO) was determined by different measuring techniques: sensory assessments of air quality made by human subjects, Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) and chromatographic methods (Gas Chromatography/Mass Spectrometry and High-Pressure Liquid Chromatography with \{UV\} detection). The experiment was conducted in a simulated office, ventilated with 0.6 h−1, 2.5 h−1 and 6 h−1, in the presence of additional pollution sources (carpet, chipboard and linoleum). At the lowest air change rate, additional measurements were made with no pollution sources present in the office. All conditions were tested with the photocatalytic air purifier turned on and off. The results show that operation of the air purifier in the presence of pollutants emitted by building materials and furniture improves indoor air quality, as documented by sensory assessments made by human subjects. It also reduces concentrations of many chemical compounds present in the air as documented by the PTR-MS technique. For the lowest ventilation, results from measurements using the chromatographic methods have similar tendency, however many of the 50 compounds that were targeted for analysis were not detected at all, independent of whether the purifier was on or off. For the two conditions with higher ventilation the results were inconclusive.
[Bunge2008] Bunge, M., N. Araghipour, T. Mikoviny, J. Dunkl, R. Schnitzhofer, A. Hansel, F. Schinner, A. Wisthaler, R. Margesin, and T. D. Maerk, "On-Line Monitoring of Microbial Volatile Metabolites by Proton Transfer Reaction-Mass Spectrometry", Applied and Environmental Microbiology, vol. 74, no. 7, pp. 2179–2186, 2008.
A method for analysis of volatile organic compounds (VOCs) from microbial cultures was established using proton transfer reaction-mass spectrometry (PTR-MS). A newly developed sampling system was coupled to a PTR-MS instrument to allow on-line monitoring of VOCs in the dynamic headspaces of microbial cultures. The novel PTR-MS method was evaluated for four reference organisms: Escherichia coli, Shigella flexneri, Salmonella enterica, and Candida tropicalis. Headspace VOCs in sampling bottles containing actively growing cultures and uninoculated culture medium controls were sequentially analyzed by PTR-MS. Characteristic marker ions were found for certain microbial cultures: C. tropicalis could be identified by several unique markers compared with the other three organisms, and E. coli and S. enterica were distinguishable from each other and from S. flexneri by specific marker ions, demonstrating the potential of this method to differentiate between even closely related microorganisms. Although the temporal profiles of some VOCs were similar to the growth dynamics of the microbial cultures, most VOCs showed a different temporal profile, characterized by constant or decreasing VOC levels or by single or multiple peaks over 24 h of incubation. These findings strongly indicate that the temporal evolution of VOC emissions during growth must be considered if characterization or differentiation based on microbial VOC emissions is attempted. Our study may help to establish the analysis of VOCs by on-line PTR-MS as a routine method in microbiology and as a tool for monitoring environmental and biotechnological processes.
[Bunge2007] Bunge, M., N. Araghipour, T. Mikoviny, J. Dunkl, A. Hansel, A. Wisthaler, F. Schinner, T. D. Maerk, and R. Margesin, "An On-line PTR-MS System for the Sensitive Real-time Detection of Volatile Metabolites from Microbial Cultures", International Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications, vol. 3, 2007.

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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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