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Scientific Articles - PTR-MS Bibliography

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Found 31 results
Title [ Year(Desc)]
Filters: Author is Jordan, Alfons  [Clear All Filters]
1996
[Taucher1996] Taucher, J., A. Hansel, A. Jordan, and W. Lindinger, "Analysis of compounds in human breath after ingestion of garlic using proton-transfer-reaction mass spectrometry", Journal of agricultural and food chemistry, vol. 44, no. 12: ACS Publications, pp. 3778–3782, 1996.
Link: http://pubs.acs.org/doi/abs/10.1021/jf960640e
Abstract
After ingestion of raw garlic, the components allyl methyl sulfide (1), allyl methyl disulfide (2), diallyl sulfide (3), diallyl disulfide (4), diallyl trisulfide (7), dimethyl sulfide (8), and acetone (9) in the breath of a test person were analyzed over a time period of about 30 h by means of proton-transfer-reaction mass spectrometry. While the concentrations of 2−7 reached maxima shortly after ingestion of garlic and declined to baseline values within the next 2−3 h, concentrations of 1, 8, and 9 increased much more slowly and showed enhanced values even 30 h after garlic consumption. The strong increase of the concentration of acetone might be indicative of enhanced metabolism of serum cholesterol, triglycerides, and total lipids in the blood stream.
1997
[Jordan1997] Jordan, A., A. Hansel, C. WARNECKE, R. Holzinger, P. Prazeller, W. Vogel, and W. Lindinger, ""On-line" Spurengasanalyse im ppt-Bereich und ihre Anwendungen auf Gebieten der Medizin, Lebensmittelforschung und Luftqualität", , no. 84: Ber. nat-.med. Verein Innsbruck, pp. 7-17, 1997.
Link: http://www.landesmuseum.at/pdf_frei_remote/BERI_84_0007-0017.pdf
1999
[Warneke1999] Warneke, C., T. Karl, H. Judmaier, A. Hansel, A. Jordan, W. Lindinger, and P. J. Crutzen, "Acetone, methanol, and other partially oxidized volatile organic emissions from dead plant matter by abiological processes: Significance for atmospheric HOx chemistry", Global Biogeochem. Cycles, vol. 13, no. 1, pp. 9–17, 1999.
Link: http://onlinelibrary.wiley.com/doi/10.1029/98GB02428/full
[Holzinger1999] Holzinger, R., C. Warneke, A. Hansel, A. Jordan, W. Lindinger, D. H. Scharffe, G. Schade, and P. J. Crutzen, "Biomass burning as a source of formaldehyde, acetaldehyde, methanol, acetone, acetonitrile, and hydrogen cyanide", Geophysical Research Letters, vol. 26, no. 8: Wiley Online Library, pp. 1161–1164, 1999.
Link: http://onlinelibrary.wiley.com/doi/10.1029/1999GL900156/full
[Fall1999] Fall, R., T. Karl, A. Hansel, A. Jordan, and W. Lindinger, "Volatile organic compounds emitted after leaf wounding: on-line analysis by proton-transfer-reaction mass spectrometry", Journal of Geophysical Research, vol. 104, no. D13: American Geophysical Union, pp. 15963–15, 1999.
Link: http://www.agu.org/pubs/crossref/1999/1999JD900144.shtml
Abstract
Volatile organic compounds (VOCs) released from vegetation, including wound-induced VOCs, can have important effects on atmospheric chemistry. The analytical methods for measuring wound-induced VOCs, especially the hexenal family of VOCs (hexenals, hexenols, and hexenyl esters), are complicated by their chemical instability and the transient nature of their formation after leaf and stem wounding. Here we demonstrate that formation and emission of hexenal family compounds can be monitored on-line using proton-transfer-reaction mass spectrometry (PTR-MS), avoiding the need for preconcentration or chromatography. These measurements allow direct analysis of the rapid emission of the parent compound, (Z)-3-hexenal, within 1–2 s of wounding of aspen leaves and then its disappearance and the appearance of its metabolites including (E)-2-hexenal, hexenols, and hexenyl acetates. Similar results were seen in wounded beech leaves and clover. The emission of hexenal family compounds was proportional to the extent of wounding, was not dependent on light, occurred in attached or detached leaves, and was greatly enhanced as detached leaves dried out. Emission of (Z)-3-hexenal from detached drying aspen leaves averaged 500 μg C g−1 (dry leaf weight). Leaf wound compounds were not emitted in a nitrogen atmosphere but were released within seconds of reintroduction of oxygen; this indicates that there are not large pools of hexenyl compounds in leaves. The PTR-MS method also allows the simultaneous detection of less abundant hexanal family VOCs including hexanal, hexanol, and hexyl acetate and VOCs formed in the light (isoprene) or during anoxia (acetaldehyde). PTR-MS may be a useful tool for the analysis of VOC emissions resulting from grazing, herbivory, and other physical damage to vegetation, from harvesting of crops, and from senescing leaves.
2001
[Holzinger2001a] Holzinger, R., A. Jordan, A. Hansel, and W. Lindinger, "Automobile emissions of acetonitrile: Assessment of its contribution to the global source", Journal of atmospheric chemistry, vol. 38, no. 2: Springer, pp. 187–193, 2001.
Link: http://www.springerlink.com/index/g3rn0j32865r9220.pdf
[Karl2001a] Karl, T., A. Guenther, A. Jordan, R. Fall, and W. Lindinger, "Eddy covariance measurement of biogenic oxygenated VOC emissions from hay harvesting", Atmospheric Environment, vol. 35, no. 3: Elsevier, pp. 491–495, 2001.
Link: http://www.sciencedirect.com/science/article/pii/S1352231000004052
Abstract
Biogenic oxygenated volatile organic compound (VOC) fluxes have been directly measured by eddy covariance using the combination of a fast response, real-time \{VOC\} sensor and an acoustic anemometer. \{VOC\} detection is based on proton-transfer reaction mass spectrometry which has currently a response time of ca. 0.8 s and the system is suitable for making nearly unattended, long-term and continuous measurements of \{VOC\} fluxes. The eddy covariance system has a detection limit, for most VOCs, of less than 0.1 mg m−2 h−1. The system was field tested above a hayfield near St. Johann, Austria where cut and drying grasses released a variety of VOCs. High fluxes were observed for about 2 days after cutting and were dominated by methanol (1–8.4 mg m−2 h−1), acetaldehyde (0.5–3 mg m−2 h−1), hexenals (0.1–1.5 mg m−2 h−1) and acetone (0.1–1.5 mg m−2 h−1). The eddy covariance measurements generally agreed with flux estimates based on enclosure measurements and surface layer gradients. The sensitivity and selectivity of the system make it suitable for quantifying the fluxes of the dominant biogenic \{VOCs\} from a variety of landscapes and sources.
[Karl2001] Karl, T., P. Prazeller, D. Mayr, A. Jordan, J. Rieder, R. Fall, and W. Lindinger, "Human breath isoprene and its relation to blood cholesterol levels: new measurements and modeling", Journal of Applied Physiology, vol. 91, no. 2, pp. 762-770, 2001.
Link: http://jap.physiology.org/content/91/2/762.abstract
Abstract
Numerous publications have described measurements of breath isoprene in humans, and there has been a hope that breath isoprene analyses could be a noninvasive diagnostic tool to assess blood cholesterol levels or cholesterol synthesis rate. However, significant analytic problems in breath isoprene analysis and variability in isoprene levels with age, exercise, diet, etc., have limited the usefulness of these measurements. Here, we have applied proton transfer reaction-mass spectrometry to this problem, allowing on-line detection of breath isoprene. We show that breath isoprene concentration increases within a few seconds after exercise is started as a result of a rapid increase in heart rate and then reaches a lower steady state when breath rate stabilizes. Additional experiments demonstrated that increases in heart rate associated with standing after reclining or sleeping are associated with increased breath isoprene concentrations. An isoprene gas-exchange model was developed and shows excellent fit to breath isoprene levels measured during exercise. In a preliminary experiment, we demonstrated that atorvastatin therapy leads to a decrease in serum cholesterol and low-density-lipoprotein levels and a parallel decrease in breath isoprene levels. This work suggests that there is constant endogenous production of isoprene during the day and night and reaffirms the possibility that breath isoprene can be a noninvasive marker of cholesterologenesis if care is taken to measure breath isoprene under standard conditions at constant heart rate.
[Holzinger2001] Holzinger, R., A. Jordan, A. Hansel, and W. Lindinger, "Methanol measurements in the lower troposphere near Innsbruck (047° 16 N; 011° 24 E), Austria", Atmospheric Environment, vol. 35, no. 14: Elsevier, pp. 2525–2532, 2001.
Link: http://www.sciencedirect.com/science/article/pii/S1352231000004301
[Gasperi2001] Gasperi, F., G. Gallerani, A. Boschetti, F. Biasioli, A. Monetti, E. Boscaini, A. Jordan, W. Lindinger, and S. Iannotta, "The mozzarella cheese flavour profile: a comparison between judge panel analysis and proton transfer reaction mass spectrometry", Journal of the Science of Food and Agriculture, vol. 81, no. 3: Wiley Online Library, pp. 357–363, 2001.
Link: http://onlinelibrary.wiley.com/doi/10.1002/1097-0010(200102)81:3%3C357::AID-JSFA818%3E3.0.CO;2-O/full
[Karl2001b] Karl, T., P. J. Crutzen, M. Mandl, M. Staudinger, A. Guenther, A. Jordan, R. Fall, and W. Lindinger, "Variability-lifetime relationship of VOCs observed at the Sonnblick Observatory 1999�Estimation of HO-densities", Atmospheric Environment, vol. 35, no. 31: Elsevier, pp. 5287–5300, 2001.
Link: http://www.sciencedirect.com/science/article/pii/S1352231001003417
Abstract
An extensive dataset of VOC measurements was collected at the Sonnblick Observatory, Austria (3106 m) in Fall/Winter 1999/2000, showing high mixing ratios of anthropogenic and biogenic VOCs at this high altitude site due to upward mixing of air masses (Geophys. Res. Lett. 2F (2001) 507). Here we give an interpretation of proton-transfer-reaction (PTR-MS) mass scans obtained in November 1999 based on fragmentation data, GC-PTR-MS analysis and the variability-lifetime relationship, described by the power law, σ(ln(x))=Aτ−b. The variability-lifetime plot of anthropogenic VOCs gave a proportionality factor A of 1.40 and a,b exponent (sink term) of 0.44 and allowed an estimate of average HO-densities on the order of (1.5±0.4)×105 molecules cm−3. Additionally we were able to indirectly determine a diurnal HO-profile with peak values of (1.3±0.5)×106 molecules cm−3 around midday. HO-reaction rate coefficients for higher aldehydes (heptanal to nonanal) were estimated due to photochemical losses during a stagnant air episode (27 November) and from the variability-lifetime relationship. Combining long term PTR-MS analysis of VOCs and the variability-lifetime method provides a valuable tool for assessing the dominant cause of the variability in VOC concentrations. This information is essential in understanding the sources and photochemical processing of VOCs detected in ambient air at field measurement sites.
2002
[Yeretzian2002] Yeretzian, C., A. Jordan, R. Badoud, and W. Lindinger, "From the green bean to the cup of coffee: investigating coffee roasting by on-line monitoring of volatiles", European Food Research and Technology, vol. 214, no. 2: Springer, pp. 92–104, 2002.
Link: http://www.springerlink.com/index/1t5671mp5tu83meu.pdf
Abstract
A proton-transfer-reaction mass spectrometer (PTR-MS) was used for fast-response measurements of volatile organic compounds (VOCs) onboard the NOAA research vessel Ronald H. Brown during leg 2 (4 March–23 March) of the INDOEX 1999 cruise. In this paper, we present a first overview of the distribution of acetonitrile, methanol, acetone, and acetaldehyde over a broad spatial extent of the Indian Ocean (19°N–13°S, 67°E–75°E). The prevailing atmospheric circulation during the winter monsoon transported polluted air from India and the Middle East over the Indian Ocean to meet pristine southern hemispheric air at the intertropical convergence zone (ITCZ). The chemical composition of air parcels changed according to their geographic origin, which was traced by backtrajectory analysis. The relative abundance of acetonitrile, a selective tracer for biomass burning, to that of carbon monoxide, a general tracer for incomplete combustion, reflected the signature of biomass burning or fossil fuel combustion. This indicated a strong biomass burning impact in W-India, mixed pollution sources in NE-India, and the dominance of fossil fuel combustion in the Middle East. Biomass burning impacted air was rich in methanol (0.70–1.60 ppbv), while acetone (0.80–2.40 ppbv) and acetaldehyde (0.25–0.50 ppbv) were elevated in all continental air masses. Pollution levels decreased toward the ITCZ resulting in minima for methanol, acetone, and acetaldehyde of 0.50, 0.45, and 0.12 ppbv, respectively. The observed abundances suggest that there are unidentified sources of acetone and acetaldehyde in biomass burning impacted air masses and in remote marine air.
2003
[Yeretzian2003] Yeretzian, C., A. Jordan, and W. Lindinger, "Analysing the headspace of coffee by proton-transfer-reaction mass-spectrometry", International Journal of Mass Spectrometry, vol. 223: Elsevier, pp. 115–139, 2003.
Link: http://www.sciencedirect.com/science/article/pii/S1387380602007856
Abstract
An extensive analysis of the headspace (HS) of coffee brew using proton-transfer-reaction mass-spectrometry (PTR-MS) is presented. In particular, we present a set of methods that link mass spectral peaks, as observed in PTR-MS, to chemical compounds in the HS of coffee. Combining all this information, a tentative assignment and rough quantification of liquid coffee HS is presented. Coffee was chosen because it contains a large number of chemically diverse volatile organic compounds (VOCs), representing a challenging system for on-line analysis by PTR-MS.
[Karl2003] Karl, T., C. Yeretzian, A. Jordan, and W. Lindinger, "Dynamic measurements of partition coefficients using proton-transfer-reaction mass spectrometry (PTR–MS)", International Journal of Mass Spectrometry, vol. 223: Elsevier, pp. 383–395, 2003.
Link: http://www.sciencedirect.com/science/article/pii/S1387380602009272
Abstract
Liquid–gas partition coefficients (HLC) of volatile organic compounds (VOCs) in water–air systems are determined using a novel dynamic approach by coupling a stripping cell directly to a proton-transfer-reaction mass spectrometer (PTR–MS). Two complementary set-ups are evaluated, one suited for determining HLCs of highly volatile compounds (<10 M/atm), the second adapted for medium to low volatile compounds (∼10–1000 M/atm). We validated the method using 2-butanone, investigated the temperature dependence of various HLCs and applied the stripping technique to a series of VOCs. Compared to alternative state-of-the-art techniques the present approach has the advantage of being simple, fast and less prone to artefacts. Furthermore, it allows to quantify volatile compounds in the headspace without calibration or addition of standards.
[Pollien2003b] Pollien, P., A. Jordan, W. Lindinger, and C. Yeretzian, "Liquid–air partitioning of volatile compounds in coffee: dynamic measurements using proton-transfer-reaction mass spectrometry", International Journal of Mass Spectrometry, vol. 228, no. 1: Elsevier, pp. 69–80, 2003.
Link: http://www.sciencedirect.com/science/article/pii/S1387380603001970
Abstract
Recently we introduced a dynamic approach to determine Henry’s law constants (HLCs) of volatile organic compounds (VOCs) in water, and applied it to a series organic compounds dissolved in pure water. Here, we first discuss a further development of the original approach such that it can be applied to complex liquid food systems (coffee). Second, we examine the impact of non-volatile constituents on the HLC. More specifically, we evaluate the impact of non-volatile coffee constituents on the HLC of 2-methylpropanal, 3- and 2-methylbutanal, dimethylsulfide, dimethyldisulfide and ethyl-2-methylbutyrate. Finally, we demonstrate that the concentration on the VOC in solution does not affect the HLC, over the investigated concentration range of 10−4 to 10 ppm.
2005
[Mestres2005] Mestres, M., N. Moran, A. Jordan, and A. Buettner, "Aroma release and retronasal perception during and after consumption of flavored whey protein gels with different textures. 1. in vivo release analysis.", J Agric Food Chem, vol. 53, no. 2: Deutsche Forschungsanstalt fuer Lebensmittelchemie, Lichtenbergstrasse 4, D-85748 Garching, Germany., pp. 403–409, Jan, 2005.
Link: http://pubs.acs.org/doi/abs/10.1021/jf048596n
Abstract
The influence of gel texture on retronasal aroma release during mastication was followed by means of real-time proton-transfer reaction mass spectrometry and compared to sensory perception of overall aroma intensity. A clear correlation was found between individual-specific consumption patterns and the respective physicochemical release patterns in vivo. A modified data analysis approach was used to monitor the aroma changes during the mastication process. It was found that the temporal resolution of the release profile played an important role in adequate description of the release processes. On the basis of this observation, a hypothesis is presented for the observed differences in intensity rating.
2009
[Petersson2009] Petersson, F., P. Sulzer, C. A. Mayhew, P. Watts, A. Jordan, L. Märk, and T. D. Märk, "Real-time trace detection and identification of chemical warfare agent simulants using recent advances in proton transfer reaction time-of-flight mass spectrometry.", Rapid Commun Mass Spectrom, vol. 23, no. 23: Institut für Ionenphysik und Angewandte Physik, Leopold Franzens Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria., pp. 3875–3880, Dec, 2009.
Link: http://dx.doi.org/10.1002/rcm.4334
Abstract
This work demonstrates for the first time the potential of using recent developments in proton transfer reaction mass spectrometry for the rapid detection and identification of chemical warfare agents (CWAs) in real-time. A high-resolution (m/Deltam up to 8000) and high-sensitivity (approximately 50 cps/ppbv) proton transfer reaction time-of-flight mass spectrometer (PTR-TOF 8000 from Ionicon Analytik GmBH) has been successfully used to detect a number of CWA simulants at room temperature; namely dimethyl methylphosphonate, diethyl methylphosphonate, diisopropyl methylphosphonate, dipropylene glycol monomethyl ether and 2-chloroethyl ethyl sulfide. Importantly, we demonstrate in this paper the potential to identify CWAs with a high level of confidence in complex chemical environments, where multiple threat agents and interferents could also be present in trace amounts, thereby reducing the risk of false positives. Instantaneous detection and identification of trace quantities of chemical threats using proton transfer reaction mass spectrometry could form the basis for a timely warning system capability with greater precision and accuracy than is currently provided by existing analytical technologies.
2010
[Jordan2010] Jordan, A., P. Sulzer, S. Juerschik, S. Jaksch, G. Hanel, E. Hartungen, H. Seehauser, L. Maerk, S. Haidacher, R. Schottkowsky, et al., "Extremely high mass resolution and sensitivity-comparison of two novel proton transfer reaction time-of-flight mass spectrometers (PTR-TOFMS)", Verhandlungen der Deutschen Physikalischen Gesellschaft, vol. -, no. Hanver 2010 issue, pp. -, 2010.
Link: https://www.etde.org/etdeweb/details_open.jsp?osti_id=21329230
Abstract
Since many years PTR-MS is a well established technique in trace gas analysis with its major advantages of having very short response times of below 100ms and outstanding detection limits in the single digit pptv region. However, the quadrupole mass filter based instruments used so far cannot separate isobaric compounds due to lack of mass resolution. To overcome this problem Ionicon developed the so called PTR-TOF 8000 instrument, which couples the well established PTR ionization technique with a high resolution time-of-flight (TOF) mass analyzer. In contrast to a quadrupole based PTR-MS where only one nominal mass at a time can be monitored, the PTR-TOF acquires whole mass spectra in split-seconds at a resolution of up to 8.000 m/{delta}m (FWHM). As there might be applications where an enormous mass resolution is not necessarily needed, but the sensitivity has to be as high as possible, we now developed an instrument (called PTR-TOF 2000) that performs with an enhanced sensitivity at the expense of a somewhat lower mass resolution.
2011
[Jordan2011] Jordan, A., P. and Watts, and C. A. Mayhew, "Detection and Identification of Illicit and Hazardous Substances with Proton-Transfer-Reaction Mass Spectrometry (PTR-MS)", : IONICON Analytik, 2011.
Link: http://blog.ionicon.com/wp-content/uploads/2011/08/future-security-ionicon-extended_abstract.pdf
[Juerschik2011] Juerschik, S., P. Sulzer, A. Jordan, L. Maerk, and M. D Tilmann, "Sprengstoffe und Drogen–PTR-MS in der Spurenanalytik", Nachrichten aus der Chemie, vol. 59, no. 11, pp. 1087–1088, 2011.
Link: http://www.degruyter.com/view/j/nachrchem.2011.59.11/nachrchem.2011.59.11.1087/nachrchem.2011.59.11.1087.xml
2012
[Sulzer2012c] Sulzer, P., A. Edtbauer, E. Hartungen, S. Juerschik, A. Jordan, G. Hanel, S. Feil, S. Jaksch, L. Märk, and T. D. Märk, "From conventional proton-transfer-reaction mass spectrometry (PTR-MS) to universal trace gas analysis", International Journal of Mass Spectrometry, vol. 321: Elsevier, pp. 66–70, 2012.
Link: http://www.sciencedirect.com/science/article/pii/S1387380612001704
Abstract
We present here a slightly modified PTR-MS instrument that is not only capable to ionize trace compounds in air via proton-transfer-reactions (PTR) but is also able to ionize via charge-transfer-reactions (CTR) with help of reagent ions (Kr+ in particular) possessing higher ionization energies than common air constituents. This means that with minor adaptations a common PTR-MS instrument can be used for the analysis of nearly all available substance classes by using both PTR and/or CTR ionization. Especially in environmental research, the field of application where PTR-MS is used most widely, now not only trace volatile organic compounds (benzene, toluene, etc.) but additionally also very important (inorganic) substances, such as CO, CO2, CH4, NOx, and SO2, can be detected and quantified with the same instrument. As all ionizing agents are produced in a hollow cathode discharge ion source with good purity no additional mass filter is needed for reagent ion selection (as in other analytical methods employed) and remaining reagent ion impurities can be clearly distinguished from isobaric sample compounds due to the high mass resolution of the time-of-flight mass spectrometer used in the present PTR-MS instrument (PTR-TOF 8000). We present data obtained with various gas standards ranging from a “classical” PTR-MS aromatics mixture to samples containing molecules possessing ionization energies all the way up to 14 eV (CO).
[Sulzer2012b] Sulzer, P., A. Jordan, E. Hartungen, and T. Maerk, "Ionisation method for a universal gas analyzer", , no. EP2606505A1, 2012.
Link: http://www.freepatentsonline.com/EP2421024.html
[Maerk2012] Märk, L., A. Jordan, C. Lindinger, E. Hartungen, A. Edtbauer, S. Juerschik, P. Sulzer, and T. D. Märk, "More than one order of magnitude higher sensitivities with Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry", : IONICON Analytik, 2012.
Link: http://www.ionicon.com/sites/default/files/uploads/doc/poster_ionicon_asms_ptr_tofms_series_performance_improvements.pdf
2013
[Sulzer2013a] Sulzer, P., B. Agarwal, S. Juerschik, M. Lanza, A. Jordan, E. Hartungen, G. Hanel, L. Märk, T. D. Märk, R. González-Méndez, et al., "Applications of switching reagent ions in proton transfer reaction mass spectrometric instruments for the improved selectivity of explosive compounds", International Journal of Mass Spectrometry, vol. 354–355: Elsevier, 2013.
Link: http://www.sciencedirect.com/science/article/pii/S1387380613001735
Abstract
<p>Here we demonstrate the use of a switchable reagent ion proton transfer reaction mass spectrometry (SRI-PTR-MS) instrument to improve the instrument&#39;s selectivity for the detection of the explosive compounds 2,4,6 trinitrotoluene (TNT), 1,3,5 trinitrobenzene (TNB), pentaerythritol tetranitrate (PETN), and cyclotrimethylenetrinitramine (RDX). Selectivity is improved owing to the production of different product ions resulting from changes in the reagent ion-molecule chemistry. To be of use as an analytical tool for homeland security applications, it is important that the reagent ions (and hence product ions) can be rapidly changed (within seconds) from H3O+ to another dominant ion species if the technology is to be acceptable. This paper presents measurements that show how it is possible to rapidly switch the reagent ion from H3O+ to either O2+ or NO+ to enhance selectivity for the detection of the four explosives named above. That switching reagent ions can be done quickly results from the fact that the recombination energies of O2+ and NO+ are less than the ionisation potential of H2O, i.e. charge transfer cannot occur which otherwise would result in ions that can react efficiently with water (e.g. H2O+ + H2O &rarr; H3O+ + OH) leading to H3O+ becoming the dominant reagent ion. Reaction processes observed are non-dissociative charge transfer (O2+ with TNT and TNB), dissociative charge transfer (O2+ with TNT) and adduct formation (NO+ with PETN and RDX). O2+ is found to be unreactive with PETN and RDX, and under the conditions operating in the reaction region of the PTR-MS only a low signal associated with NO+&middot;TNT was observed. No NO+&middot;TNB was detected.</p>
[Lanza2013] Lanza, M., J. W. Acton, S. Jürschik, P. Sulzer, K. Breiev, A. Jordan, E. Hartungen, G. Hanel, L. Märk, C. A. Mayhew, et al., "Distinguishing two isomeric mephedrone substitutes with selective reagent ionisation mass spectrometry (SRI-MS)", Journal of Mass Spectrometry, vol. 48, no. 9, pp. 1015–1018, 2013.
Link: http://dx.doi.org/10.1002/jms.3253
Abstract
The isomers 4-methylethcathinone and N-ethylbuphedrone are substitutes for the recently banned drug mephedrone. We find that with conventional proton transfer reaction mass spectrometry (PTR-MS), it is not possible to distinguish between these two isomers, because essentially for both substances, only the protonated molecules are observed at a mass-to-charge ratio of 192 (C12H18NO+). However, when utilising an advanced PTR-MS instrument that allows us to switch the reagent ions (selective reagent ionisation) from H3O+ (which is commonly used in PTR-MS) to NO+, O2+ and Kr+, characteristic product (fragment) ions are detected: C4H10N+ (72 Da) for 4-methylethcathinone and C5H12N+ (86 Da) for N-ethylbuphedrone; thus, selective reagent ionisation MS proves to be a powerful tool for fast detection and identification of these compounds. Copyright © 2013 John Wiley & Sons, Ltd.

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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).
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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.
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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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