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Scientific Articles - PTR-MS Bibliography

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Found 14 results
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2016
[1789] Papurello, D., S. Silvestri, L. Tomasi, I. Belcari, F. Biasioli, and M. Santarelli, "Natural Gas Trace Compounds Analysis with Innovative Systems: PTR-ToF-MS and FASTGC", Energy Procedia, vol. 101, pp. 536–541, 2016.
Link: http://www.sciencedirect.com/science/article/pii/S1876610216312772
Abstract
<p>The technique of proton transfer reaction mass spectrometry (PTR-MS) couples a proton transfer reagent, usually H3O+, with a drift tube and mass spectrometer to determine concentrations of volatile organic compounds. Proton transfer reaction-mass spectrometry (PTR-MS) has successfully been applied to a wide variety of matrices to identify and to investigate on the behavior of trace compounds; among the possible field of applications we can find: food, air, energy, etc. Natural gas is considered as a fuel for high energy efficiencies applications such as SOFC generators. The ability to distinguish several isobaric aldehydes, ketones, isoprenoids and other compounds is impossible using PTR-MS instrument. In the present research work, PTR-ToF-MS was coupled to a prototype FastGC system allowing for a rapid (90 s) chromatographic separation of the sample headspace prior to PTR-MS analysis. The system was tested on natural gas trace compounds to individuate the major elements and to identify possible issues for the SOFC generators. In comparison to the results obtained by direct injection, FastGC provided additional information, thanks to a less drastic dilution of the sample and due to the chromatographic separation of isomers. This was achieved without increasing duration and complexity of the analysis.</p>
2015
[1825] Eichler, P., M. Müller, B. D{\textquotesingle}Anna, and A. Wisthaler, "A novel inlet system for online chemical analysis of semi-volatile submicron particulate matter", Atmospheric Measurement Techniques, vol. 8, pp. 1353–1360, mar, 2015.
Abstract
<p>We herein present a novel modular inlet system designed to be coupled to low-pressure gas analyzers for online chemical characterization of semi-volatile submicron particles. The &quot;chemical analysis of aerosol online&quot; (CHARON) inlet consists of a gas-phase denuder for stripping off gas-phase analytes, an aerodynamic lens for particle collimation combined with an inertial sampler for the particle-enriched flow and a thermodesorption unit for particle volatilization prior to chemical analysis. The denuder was measured to remove gas-phase organics with an efficiency &gt; 99.999% and to transmit particles in the 100&ndash;750 nm size range with a 75&ndash;90% efficiency. The measured average particle enrichment factor in the subsampling flow from the aerodynamic lens was 25.6, which is a factor of 3 lower than the calculated theoretical optimum. We coupled the CHARON inlet to a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) which quantitatively detects most organic analytes and ammonia. The combined CHARON-PTR-ToF-MS setup is thus capable of measuring both the organic and the ammonium fraction in submicron particles in real time. Individual organic compounds can be detected down to levels of 10&ndash;20 ng m&minus;3. Two proof-of-principle studies were carried out for demonstrating the analytical power of this new instrumental setup: (i) oxygenated organics and their partitioning between the gas and the particulate phase were observed from the reaction of limonene with ozone and (ii) nicotine was measured in cigarette smoke particles demonstrating that selected organic target compounds can be detected in submicron particles in real time.</p>
2013
[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.
Link: http://www.sciencedirect.com/science/article/pii/S0169743913001275
Abstract
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.
[Kohl2013a] Kohl, I., J. Beauchamp, F. Cakar-Beck, J. Herbig, J. Dunkl, O. Tietje, M. Tiefenthaler, C. Boesmueller, A. Wisthaler, M. Breitenlechner, et al., "Non-invasive detection of renal function via breath gas analysis: A potential biomarker for organ acceptance?", 6th International PTR-MS Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications, pp. 24, 2013.
Link: http://www.ionicon.com/sites/default/files/uploads/doc/contributions_ptr_ms_Conference_6.pdf
Abstract
Breath gas analysis is an emerging field that attempts to link components in exhaled breath gas with state-of-health or illness [1]. This is based on the premise that disease in the body will elicit abnormal biochemical reactions which in turn produce chemical compounds that might be excreted by the body - at least in part - via exhalation. We used PTR-MS to directly sample and analyse selected VOC constituents in the exhaled breath of patients (n=96) undergoing kidney transplantation. Breath samples were taken before surgery and then over an extended period thereafter. Comparison of PTR-MS data with routine blood-serum data revealed a specific compound (ion trace) at m/z 115 that correlated with creatinine in blood serum and daily urine production, which are the current generally-accepted markers for kidney function. PTR-TOF analyses revealed that this compound had an exact molecular mass of 114.104 u and a chemical composition of C7H14O. Subsequent analyses using PTR-QqQ-MS suggested the compound to be a C7-ketone or branched C7-aldehyde. It is hoped that the results of this study will provide impetus to other researchers in the field to further delve into the nature of this compound and its possible biochemical production routes to ascertain the eligibility of this compound for potential use in future routine breath analysis for renal function assessment.
2012
[Nolscher2012a] Nölscher, AC., V. Sinha, S. Bockisch, T. Klüpfel, and J. Williams, "A new method for total OH reactivity measurements using a fast Gas Chromatographic Photo-Ionization Detector (GC-PID)", Atmospheric Measurement Techniques Discussions, vol. 5, no. 3: Copernicus GmbH, pp. 3575–3609, 2012.
Link: http://www.atmos-meas-tech-discuss.net/5/3575/2012/
Abstract
The primary and most important oxidant in the atmosphere is the hydroxyl radical (OH). Currently OH sinks, particularly gas phase reactions, are poorly constrained. One way to characterize the overall sink of OH is to measure directly the ambient loss rate of OH, the total OH reactivity. To date direct measurements of total OH reactivity have been either performed using a Laser Induced Fluorescence (LIF) system ("pump-and-probe" or "flow reactor") or the Comparative Reactivity Method (CRM) with a Proton Transfer Reaction Mass Spectrometer (PTR-MS). Both techniques require large, complex and expensive detection systems. This study presents a feasibility assessment for CRM total OH reactivity measurements using a new detector, a Gas Chromatographic Photo-Ionization Detector (GC-PID). Such a system is smaller, more portable, less power consuming and less expensive than other total OH reactivity measurement techniques. Total OH reactivity is measured by the CRM using a competitive reaction between a reagent (here pyrrole) with OH alone and in the presence of atmospheric reactive molecules. The new CRM method for total OH reactivity has been tested with parallel measurements of the GC-PID and the previously validated PTR-MS as detector for the reagent pyrrole during laboratory experiments, plant chamber and boreal field studies. Excellent agreement of both detectors was found when the GC-PID was operated under optimum conditions. Time resolution (60–70 s), sensitivity (LOD 3–6 s−1) and overall uncertainty (25% in optimum conditions) for total OH reactivity were equivalent to PTR-MS based total OH reactivity measurements. One drawback of the GC-PID system was the steady loss of sensitivity and accuracy during intensive measurements lasting several weeks, and a possible toluene interference. Generally, the GC-PID system has been shown to produce closely comparable results to the PTR-MS and thus in suitable environments (e.g. forests) it presents a viably economical alternative for groups interested in total OH reactivity observations.
2011
[Raseetha2011] Raseetha, S., SP. Heenan, I. Oey, DJ. Burritt, and N. Hamid, "A new strategy to assess the quality of broccoli ( Brassica oleracea L. italica) based on enzymatic changes and volatile mass ion profile using Proton Transfer Reaction Mass Spectrometry (PTR-MS)", Innovative Food Science & Emerging Technologies, vol. 12, no. 2: Elsevier, pp. 197–205, 2011.
Link: http://www.sciencedirect.com/science/article/pii/S1466856410001128
Abstract
The shelf life of high quality horticultural products such as broccoli is relatively short, thereby limiting their potential for export and long distance trade. To assess the quality and the shelf life of vegetables, a reliable, accurate and high-throughput technique is required. In this study, an approach that profiled enzyme activities and volatile mass ions was used. The possible relationship between volatile mass ions and changes in the activity of enzymes that influence quality of broccoli (i.e., peroxidase/POD and ascorbate oxidase/AAO) during post-harvest storage (25 °C for 6 days) was investigated. Proton Transfer Reaction Mass Spectometry (PTR-MS) was used to scan and quantify volatile mass ions in broccoli during storage, with m/z ratio of between 20 and 180. In this study, the effect of severe wounding on enzyme activities and the volatile profile was simulated by incubating crushed broccoli florets at different time intervals (2, 4 and 6 h). Based on one-way ANOVA, changes in enzyme activities were more influenced by incubation time after crushing rather than days of storage. POD activity gradually decreased over six days of storage, while AAO activity gradually decreased over 3 to 4 days, followed by an increase in activity until the sixth day of storage. Based on Partial Least Square Regression type 1 (PLSR 1) model, a good correlation between PTR-MS volatile mass ions fingerprints and enzymatic activity in broccoli florets that varied with days of storage and incubation time after crushing was found for POD and not for AAO.
[Pleil2011] Pleil, J. D., "Non invasive biomedical analysis. Breath networking session at PittCon 2011, Atlanta, Georgia", Journal of Breath Research, vol. 5, no. 2: IOP Publishing, pp. 029001, 2011.
Link: http://iopscience.iop.org/1752-7163/5/2/029001
Abstract
This was the second year that our breath colleagues organized a networking session at the Pittsburgh Conference and Exposition, or 'PittCon' (www.pittcon.org/). This time it was called 'Non Invasive Biomedical Analysis' to broaden the scope a bit, but the primary focus remained on exhaled breath diagnostics. As reported last year in the Journal of Breath Research, PittCon continues to be one of the largest international conferences for analytical chemistry and instrumentation, typically attracting about 25 000 attendees and 1 000 commercial exhibitors (Pleil 2010). This year the conference was held in Georgia, USA, at the Georgia World Congress Center in the city of Atlanta.
2010
[Jordan2010c] Jordan, A., G. Hanel, E. Hartungen, P. Sulzer, H. Seehauser, S. Haidacher, R. Schottkowsky, C. Lindinger, L. Märk, and TD. Märk, "Novel Developments in Proton-Transfer-Reaction Mass-Spectrometry (PTR-MS): Switchable Reagent Ions (PTR+ SRI-MS) and ppqv Detection Limit", : IONICON Analytik, 2010.
Link: http://www.technologynetworks.com/images/news/uploadedimages/poster2.pdf
2009
[1494] Hewitt, C.. N., A.. R. MacKenzie, P.. Di Carlo, C.. F. Di Marco, J.. R. Dorsey, M.. Evans, D.. Fowler, M.. W. Gallagher, J.. R. Hopkins, C.. E. Jones, et al., "Nitrogen management is essential to prevent tropical oil palm plantations from causing ground-level ozone pollution", Proceedings of the National Academy of Sciences, 2009.
Link: http://www.pnas.org/content/early/2009/10/16/0907541106.abstract
Abstract
<p>More than half the world&#39;s rainforest has been lost to agriculture since the Industrial Revolution. Among the most widespread tropical crops is oil palm (Elaeis guineensis): global production now exceeds 35 million tonnes per year. In Malaysia, for example, 13% of land area is now oil palm plantation, compared with 1% in 1974. There are enormous pressures to increase palm oil production for food, domestic products, and, especially, biofuels. Greater use of palm oil for biofuel production is predicated on the assumption that palm oil is an &ldquo;environmentally friendly&rdquo; fuel feedstock. Here we show, using measurements and models, that oil palm plantations in Malaysia directly emit more oxides of nitrogen and volatile organic compounds than rainforest. These compounds lead to the production of ground-level ozone (O3), an air pollutant that damages human health, plants, and materials, reduces crop productivity, and has effects on the Earth&#39;s climate. Our measurements show that, at present, O3 concentrations do not differ significantly over rainforest and adjacent oil palm plantation landscapes. However, our model calculations predict that if concentrations of oxides of nitrogen in Borneo are allowed to reach those currently seen over rural North America and Europe, ground-level O3 concentrations will reach 100 parts per billion (109) volume (ppbv) and exceed levels known to be harmful to human health. Our study provides an early warning of the urgent need to develop policies that manage nitrogen emissions if the detrimental effects of palm oil production on air quality and climate are to be avoided.</p>
[Bajtarevic2009] Bajtarevic, A., C. Ager, M. Pienz, M. Klieber, K. Schwarz, M. Ligor, T. Ligor, W. Filipiak, H. Denz, M. Fiegl, et al., "Noninvasive detection of lung cancer by analysis of exhaled breath.", BMC Cancer, vol. 9: Department of Operative Medicine, Innsbruck Medical University, A-6020 Innsbruck, Austria. amel.bajtarevic@i-med.ac.at, pp. 348, 2009.
Link: http://dx.doi.org/10.1186/1471-2407-9-348
Abstract
{Lung cancer is one of the leading causes of death in Europe and the western world. At present, diagnosis of lung cancer very often happens late in the course of the disease since inexpensive, non-invasive and sufficiently sensitive and specific screening methods are not available. Even though the CT diagnostic methods are good, it must be assured that "screening benefit outweighs risk, across all individuals screened, not only those with lung cancer". An early non-invasive diagnosis of lung cancer would improve prognosis and enlarge treatment options. Analysis of exhaled breath would be an ideal diagnostic method, since it is non-invasive and totally painless.Exhaled breath and inhaled room air samples were analyzed using proton transfer reaction mass spectrometry (PTR-MS) and solid phase microextraction with subsequent gas chromatography mass spectrometry (SPME-GCMS). For the PTR-MS measurements, 220 lung cancer patients and 441 healthy volunteers were recruited. For the GCMS measurements, we collected samples from 65 lung cancer patients and 31 healthy volunteers. Lung cancer patients were in different disease stages and under treatment with different regimes. Mixed expiratory and indoor air samples were collected in Tedlar bags, and either analyzed directly by PTR-MS or transferred to glass vials and analyzed by gas chromatography mass spectrometry (GCMS). Only those measurements of compounds were considered, which showed at least a 15% higher concentration in exhaled breath than in indoor air. Compounds related to smoking behavior such as acetonitrile and benzene were not used to differentiate between lung cancer patients and healthy volunteers.Isoprene, acetone and methanol are compounds appearing in everybody's exhaled breath. These three main compounds of exhaled breath show slightly lower concentrations in lung cancer patients as compared to healthy volunteers (p < 0.01 for isoprene and acetone
2006
[Inomata2006a] Inomata, S., H. Tanimoto, N. Aoki, J. Hirokawa, and Y. Sadanaga, "A novel discharge source of hydronium ions for proton transfer reaction ionization: design, characterization, and performance.", Rapid Commun Mass Spectrom, vol. 20, no. 6: Atmospheric Environment Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. ino@nies.go.jp, pp. 1025–1029, 2006.
Link: http://dx.doi.org/10.1002/rcm.2405
Abstract
A novel ion source based on direct current (d.c.) discharge has been developed for proton transfer reaction ionization operated at relatively high ion drift tube pressure. The shape and geometry of the ion source are designed to maximize overall ion intensity and to minimize interference from sample air. The initial performance of the technique, including speciation and intensity of reagent ions, their stability, and the impact of artifact signals, is evaluated by means of a proton transfer reaction time-of-flight mass spectrometer (PTR-TOFMS) newly built in our laboratory. Intensities of the hydronium (H(3)O(+)) ions are typically (5-7) x 10(5) counts for a 1-min integration time with a duty cycle of approximately 1%. The fluctuations of the ion signals over a period of hours are within 4%. Although the formation of artifact ions from sample air (NO(+) and O(2) (+)), which react with volatile organic compounds (VOCs) and subsequently cause fragmentation, is observed as background signals in addition to hydronium and mono- and di-hydrate H(3)O(+) ions, intensities of both NO(+) and O(2) (+) ions are only approximately 0.5% of those of H(3)O(+) ions. Using our PTR-TOFMS system at a drift tube pressure of approximately 5 Torr, the detection sensitivities are significantly improved and the detection limits for propene, acetaldehyde, acetone, isoprene, benzene, toluene, and p-xylene are estimated to be at the sub-ppbv level for 1-min integration.
2004
[Roberts2004] Roberts, DD., P. Pollien, C. Yeretzian, C. Lindinger, KD. Deibler, J. Delwiche, and , "Nosespace analysis with proton-transfer-reaction mass spectrometry: intra-and interpersonal variability", Handbook of flavor characterization: sensory analysis, chemistry, and physiology, vol. -, pp. 151–162, 2004.
Link: http://www.crcnetbase.com/doi/abs/10.1201/9780203912812.ch10
2002
[Stroud2002] Stroud, CA., JM. Roberts, EJ. Williams, D. Hereid, WM. Angevine, FC. Fehsenfeld, A. Wisthaler, A. Hansel, M. Martinez-Harder, H. Harder, et al., "Nighttime isoprene trends at an urban forested site during the 1999 Southern Oxidant Study", Journal of Geophysical Research: Atmospheres (1984–2012), vol. 107, no. D16: Wiley Online Library, pp. ACH–7, 2002.
Link: http://onlinelibrary.wiley.com/doi/10.1029/2001JD000959/full
Abstract
[1] Measurements of isoprene and its oxidation products, methacrolein, methyl vinyl ketone and peroxymethacrylic nitric anhydride, were conducted between 13 June and 14 July 1999, at the Cornelia Fort Airpark during the Nashville intensive of the Southern Oxidant Study. Trends in isoprene and its oxidation products showed marked variability from night-to-night. The reaction between isoprene and the nitrate radical was shown to be important to the chemical budget of isoprene and often caused rapid decay of isoprene mixing ratios in the evening. Trends in methacrolein, methyl vinyl ketone, and peroxymethacrylic nitric anhydride were steady during the evening isoprene decay period, consistent with their slow reaction rate with the nitrate radical. For cases when isoprene sustained and even increased in mixing ratio throughout the night, the observed isoprene oxidation rates via the hydroxyl radical, ozone, and the nitrate radical were all small. Sustained isoprene mixing ratios within the nocturnal boundary layer give a unique opportunity to capture hydroxyl radical photochemistry at sunrise as isoprene was observed to rapidly convert to its first stage oxidation products before vertical mixing significantly redistributed chemical species. The observed nighttime isoprene variability at urban, forested sites is related to a complex coupling between nighttime boundary layer dynamics and chemistry.
2001
[Fay2001] Fay, L. B., C. Yeretzian, and I. Blank, "Novel mass spectrometry methods in flavour analysis", CHIMIA International Journal for Chemistry, vol. 55, no. 5: Swiss Chemical Society, pp. 429–434, 2001.
Link: http://www.ingentaconnect.com/content/scs/chimia/2001/00000055/00000005/art00009
Abstract
Flavour research is a demanding domain in terms of analytical methodology as key odorants usually occur in trace amounts, often embedded in extracts containing volatile compounds at much higher concentrations. Since its early days, GC-MS has been a key tool in flavour laboratories enabling characterisation of thousands of volatile components in food products. However, as flavour chemists delve deeper into the understanding of flavour generation and delivery, there is a need for more powerful methodologies adapted to their specific needs. This paper will present two techniques that allow flavour separation and characterisation, namely GC-TOFMS and MS/MS. Moreover, APCI-MS, PTR-MS and REMPI-TOFMS will be discussed as they enable direct investigation of volatile compounds without any chromatographic step, thus studying release of flavour compounds during food processing or food consumption.

Featured Articles

Download Contributions to the International Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications:

 

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).
Link

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.
Link

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.
Link

 

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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