Callback Service

Undefined

The world's leading PTR-MS company

Providing ultra-sensitive solutions for real-time trace gas analysis since 1998

Navigation

You are here

Scientific Articles - PTR-MS Bibliography

Welcome to the new IONICON scientific articles database!

Publications

Found 20 results
Title [ Year(Asc)]
Filters: First Letter Of Title is F  [Clear All Filters]
2016
[1735] Sukul, P., J. K. Schubert, P. Oertel, S. Kamysek, K. Taunk, P. Trefz, and W. Miekisch, "FEV manoeuvre induced changes in breath VOC compositions: an unconventional view on lung function tests", Scientific Reports, vol. 6, pp. 28029, Jun, 2016.
Link: http://dx.doi.org/10.1038/srep28029
Abstract
Breath volatile organic compound (VOC) analysis can open a non-invasive window onto pathological and metabolic processes in the body. Decades of clinical breath-gas analysis have revealed that changes in exhaled VOC concentrations are important rather than disease specific biomarkers. As physiological parameters, such as respiratory rate or cardiac output, have profound effects on exhaled VOCs, here we investigated VOC exhalation under respiratory manoeuvres. Breath VOCs were monitored by means of real-time mass-spectrometry during conventional FEV manoeuvres in 50 healthy humans. Simultaneously, we measured respiratory and hemodynamic parameters noninvasively. Tidal volume and minute ventilation increased by 292 and 171% during the manoeuvre. FEV manoeuvre induced substance specific changes in VOC concentrations. pET-CO2 and alveolar isoprene increased by 6 and 21% during maximum exhalation. Then they decreased by 18 and 37% at forced expiration mirroring cardiac output. Acetone concentrations rose by 4.5% despite increasing minute ventilation. Blood-borne furan and dimethyl-sulphide mimicked isoprene profile. Exogenous acetonitrile, sulphides, and most aliphatic and aromatic VOCs changed minimally. Reliable breath tests must avoid forced breathing. As isoprene exhalations mirrored FEV performances, endogenous VOCs might assure quality of lung function tests. Analysis of exhaled VOC concentrations can provide additional information on physiology of respiration and gas exchange.
[1795] Schroeder, J. R., J. H. Crawford, A. Fried, J. Walega, A. Weinheimer, A. Wisthaler, M. Müller, T. Mikoviny, G. Chen, M. Shook, et al., "Formaldehyde column density measurements as a suitable pathway to estimate near-surface ozone tendencies from space", Journal of Geophysical Research: Atmospheres, vol. 121, 2016.
Link: http://onlinelibrary.wiley.com/doi/10.1002/2016JD025419/full
Abstract
<p>In support of future satellite missions that aim to address the current shortcomings in measuring air quality from space, NASA&#39;s Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) field campaign was designed to enable exploration of relationships between column measurements of trace species relevant to air quality at high spatial and temporal resolution. In the DISCOVER-AQ data set, a modest correlation (r2&thinsp;=&thinsp;0.45) between ozone (O3) and formaldehyde (CH2O) column densities was observed. Further analysis revealed regional variability in the O3-CH2O relationship, with Maryland having a strong relationship when data were viewed temporally and Houston having a strong relationship when data were viewed spatially. These differences in regional behavior are attributed to differences in volatile organic compound (VOC) emissions. In Maryland, biogenic VOCs were responsible for &nbsp;28% of CH2O formation within the boundary layer column, causing CH2O to, in general, increase monotonically throughout the day. In Houston, persistent anthropogenic emissions dominated the local hydrocarbon environment, and no discernable diurnal trend in CH2O was observed. Box model simulations suggested that ambient CH2O mixing ratios have a weak diurnal trend (&plusmn;20% throughout the day) due to photochemical effects, and that larger diurnal trends are associated with changes in hydrocarbon precursors. Finally, mathematical relationships were developed from first principles and were able to replicate the different behaviors seen in Maryland and Houston. While studies would be necessary to validate these results and determine the regional applicability of the O3-CH2O relationship, the results presented here provide compelling insight into the ability of future satellite missions to aid in monitoring near-surface air quality.</p>
2013
[Joyce2013] Joyce, N. I., C. C. Eady, P. Silcock, N. B. Perry, and J. W. { van Klink}, "Fast Phenotyping of LFS-Silenced (Tearless) Onions by Desorption Electrospray Ionization Mass Spectrometry (DESI-MS).", J Agric Food Chem, vol. 61, no. 7: The New Zealand Institute for Plant and Food Research Limited , Private Bag 4704, Christchurch, New Zealand., pp. 1449–1456, Feb, 2013.
Link: http://dx.doi.org/10.1021/jf304444s
Abstract
Fast MS techniques have been applied to the analysis of sulfur volatiles in Allium species and varieties to distinguish phenotypes. Headspace sampling by proton transfer reaction (PTR) MS and surface sampling by desorption electrospray ionization (DESI) MS were used to distinguish lachrymatory factor synthase (LFS)-silenced (tearless; LFS-) onions from normal, LFS-active (tear-inducing; LFS+), onions. PTR-MS showed lower concentrations of the lachrymatory factor (LF, 3) and dipropyl disulfide 12 from tearless onions. DESI-MS of the tearless onions confirmed the decreased LF 3 and revealed much higher concentrations of the sulfenic acid condensates. Using DESI-MS with MS(2) could distinguish zwiebelane ions from thiosulfinate ions. DESI-MS gave reliable fast phenotyping of LFS+ versus LFS- onions by simply scratching leaves and recording the extractable ions for <0.5 min. DESI-MS leaf compound profiles also allowed the rapid distinction of a variety of Allium cultivars to aid plant breeding selections.
[Manikam2013] Manikam, S., and R. Vani, "Feasibility of using combined Proton Transfer Reaction Mass Spectrometry (PTR-MS) technique and biochemical analyses to assess the quality of broccoli florets during postharvest storage, handling and temperature treatments", : University of Otago, 2013.
Link: http://oatd.org/oatd/record?record=handle%5C:10523%5C%2F4127
Abstract
The objective of this research was to gain a better understanding of the relationship between changes in volatiles release, colour and biochemical markers (i.e. pigment content, antioxidant levels, activity of enzymes and oxidative damage levels) during postharvest storage and mechanical damage. This study attempted to find potential volatile markers, using Proton Transfer Reaction Mass Spectrometry (PTR-MS), that were statistically correlated with biochemical and physiological changes associated with postharvest storage and mechanical damage. Multivariate statistical analysis and regression analysis using Partial Least Squares Regression (PLSR) was used to evaluate possible correlations. It is hypothesized that volatile markers in combination with biochemical analyses can be used to assess quality changes during postharvest storage and handling of broccoli. The intensity of protonated volatile organic compounds with the mass ions m/z 33 and m/z 49 were tentatively identified as methanol and methanethiol. While both increased, methanol was the dominant volatile detected. The increase of these mass ions was observed at the onset of senescence (Day 3, 23 °C), at which point chlorophyll breakdown was initiated, resulting in colour change from green to yellow. Validations were carried out using cytokinin 6-benzylaminopurine (BAP) which delays the onset of senescence for several days. Application of BAP delayed senescence in a concentration dependent manner, with 50 ppm or above BAP slowed the rate of senescence, as determined by chlorophyll loss measurement. Application of BAP also slowed the rate of methanol release. Colour change as a marker for the onset of senescence was validated using markers of oxidative damage and defence, which are known to be key indicators of the onset and progression of senescence. Depending on the BAP concentrations, measurements of antioxidant enzymes, non-enzymatic antioxidants and markers of oxidative damage confirmed that senescence was delayed. To further determine if the release of methanol was due to major cellular disruption, which occurs during senescence, broccoli florets at different stages of senescence were subjected to severe mechanical damage and the damaged tissues were monitored for up to six hours. In addition, broccoli florets were subjected to different temperature treatments ranging from -18 to 100 °C to simulate different types of cellular and metabolic disruption. The stage of senescence prior to mechanical damage was the critical factor determining the cellular and metabolic integrity of broccoli samples six hours following the damage event although mechanical damage accelerated the breakdown of photosynthetic pigments, the inactivation of antioxidant enzymes, the degradation of non-enzymatic antioxidants and increases in the levels of oxidative damage and methanol. The temperature treatments (-18, 50, 70 and 100 °C) disrupted cellular metabolism as evidenced by changes in the activities of several enzymes (POD, SOD, CAT and AAO) and led to significant increases in…
[Kohl2013b] Kohl, I., J. Beauchamp, F. Cakar-Beck, J. Herbig, J.. Dunkl, O. Tietje, M. Tiefenthaler, C. Boesmueller, A. Wisthaler, M. Breitenlechner, et al., "First observation of a potential non-invasive breath gas biomarker for kidney function.", J Breath Res, vol. 7, no. 1: Ionimed Analytik GmbH, Eduard Bodem Gasse 3, A-6020 Innsbruck, Austria., pp. 017110, Mar, 2013.
Link: http://dx.doi.org/10.1088/1752-7155/7/1/017110
Abstract
We report on the search for low molecular weight molecules-possibly accumulated in the bloodstream and body-in the exhaled breath of uremic patients with kidney malfunction. We performed non-invasive analysis of the breath gas of 96 patients shortly before and several times after kidney transplantation using proton-transfer-reaction mass spectrometry (PTR-MS), a very sensitive technique for detecting trace amounts of volatile organic compounds. A total of 642 individual breath analyses which included at least 41 different chemical components were carried out. Correlation analysis revealed one particular breath component with a molecular mass of 114 u (unified atomic mass units) that clearly correlated with blood serum creatinine, which is the currently accepted marker for assessing the function of the kidney. In particular, daily urine production showed good correlation with the identified breath marker. An independent set of seven samples taken from three patients at the onset of dialysis and three controls with normal kidney function confirmed a significant difference in concentration between patients and controls for a compound with a molecular mass of 114.1035 u using high mass resolving proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOF-MS). A chemical composition of CHO was derived for the respective component. Fragmentation experiments on the same samples using proton-transfer-reaction triple-quadrupole tandem mass spectrometry (PTR-QqQ-MS) suggested that this breath marker is a C-ketone or a branched C-aldehyde. Non-invasive real-time monitoring of the kidney function via this breath marker could be a possible future procedure in the clinical setting.
[1591] Maihom, T., E. Schuhfried, M. Probst, J. Limtrakul, T. D. Märk, and F. Biasioli, "Fragmentation of allylmethylsulfide by chemical ionization: dependence on humidity and inhibiting role of water.", J Phys Chem A, vol. 117, pp. 5149–5160, Jun, 2013.
Link: http://dx.doi.org/10.1021/jp4015806
Abstract
<p>We report on a previously unknown reaction mechanism involving water in the fragmentation reaction following chemical ionization. This result stems from a study presented here on the humidity-dependent and energy-dependent endoergic fragmentation of allyl methyl sulfide (AMS) upon protonation in a proton transfer reaction-mass spectrometer (PTR-MS). The fragmentation pathways were studied with experimental (PTR-MS) and quantum chemical methods (polarizable continuum model (PCM), microhydration, studied at the MP2/6-311+G(3df,2p)//MP2/6-31G(d,p) level of theory). We report in detail on the energy profiles, reaction mechanisms, and proton affinities (G4MP2 calculations). In the discovered reaction mechanism, water reduces the fragmentation of protonated species in chemical ionization. It does so by direct interaction with the protonated species via covalent binding (C3H5(+)) or via association (AMS&middot;H(+)). This stabilizes intermediate complexes and thus overall increases the activation energy for fragmentation. Water thereby acts as a reusable inhibitor (anticatalyst) in chemical ionization. Moreover, according to the quantum chemical (QC) results, when water is present in abundance it has the opposite effect and enhances fragmentation. The underlying reason is a concentration-dependent change in the reaction principle from active inhibition of fragmentation to solvation, which then enhances fragmentation. This amphoteric behavior of water is found for the fragmentation of C3H5(+) to C3H3(+), and similarly for the fragmentation of AMS&middot;H(+) to C3H5(+). The results support humidity-dependent quantification efforts for PTR-MS and chemical ionization mass spectrometry (CIMS). Moreover, the results should allow for a better understanding of ion-chemistry in the presence of water.</p>
[Edtbauer2013] Edtbauer, A., E. Hartungen, A. Jordan, P. Sulzer, S. Juerschik, S. Feil, G. Hanel, S. Jaksch, L. Maerk, and T. D. Maerk, "From Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) to Universal Trace Gas Analysis with Selective-Reagent-Ionization Mass Spectrometry (SRI-MS) in Kr+ mode", CONFERENCE SERIES, pp. 76, 2013.
Link: http://www.ionicon.com/sites/default/files/uploads/doc/contributions_ptr_ms_Conference_6.pdf
2012
[Tasin2012] Tasin, M., L. Cappellin, and F. Biasioli, "Fast direct injection mass-spectrometric characterization of stimuli for insect electrophysiology by proton transfer reaction-time of flight mass-spectrometry (PTR-ToF-MS).", Sensors (Basel), vol. 12, no. 4: IASMA Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy. marco.tasin@slu.se, pp. 4091–4104, 2012.
Link: http://dx.doi.org/10.3390/s120404091
Abstract
Electrophysiological techniques are used in insect neuroscience to measure the response of olfactory neurons to volatile odour stimuli. Widely used systems to deliver an olfactory stimulus to a test insect include airstream guided flow through glass cartridges loaded with a given volatile compound on a sorbent support. Precise measurement of the quantity of compound reaching the sensory organ of the test organism is an urgent task in insect electrophysiology. In this study we evaluated the performances of the recent realised proton transfer reaction-time of flight mass-spectrometry (PTR-ToF-MS) as a fast and selective gas sensor. In particular, we characterised the gas emission from cartridges loaded with a set of volatile compounds belonging to different chemical classes and commonly used in electrophysiological experiments. PTR-ToF-MS allowed a fast monitoring of all investigated compounds with sufficient sensitivity and time resolution. The detection and the quantification of air contaminants and solvent or synthetic standards impurities allowed a precise quantification of the stimulus exiting the cartridge. The outcome of this study was twofold: on one hand we showed that PTR-ToF-MS allows monitoring fast processes with high sensitivity by real time detection of a broad number of compounds; on the other hand we provided a tool to solve an important issue in insect electrophysiology.
[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).
2011
[Stavrakou2011] Stavrakou, T., A. Guenther, A. Razavi, L. Clarisse, C. Clerbaux, P-F. Coheur, D. Hurtmans, F. Karagulian, M. De Mazière, C. Vigouroux, et al., "First space-based derivation of the global atmospheric methanol emission fluxes", Atmospheric chemistry and physics, vol. 11, no. 10: Copernicus GmbH, pp. 4873–4898, 2011.
Link: http://www.atmos-chem-phys.net/11/4873/2011/acp-11-4873-2011.html
Abstract
This study provides improved methanol emission estimates on the global scale, in particular for the largest methanol source, the terrestrial biosphere, and for biomass burning. To this purpose, one complete year of spaceborne measurements of tropospheric methanol columns retrieved for the first time by the thermal infrared sensor IASI aboard the MetOp satellite are compared with distributions calculated by the IMAGESv2 global chemistry-transport model. Two model simulations are performed using a priori biogenic methanol emissions either from the new MEGANv2.1 emission model, which is fully described in this work and is based on net ecosystem flux measurements, or from a previous parameterization based on net primary production by Jacob et al. (2005). A significantly better model performance in terms of both amplitude and seasonality is achieved through the use of MEGANv2.1 in most world regions, with respect to IASI data, and to surface- and air-based methanol measurements, even though important discrepancies over several regions are still present. As a second step of this study, we combine the MEGANv2.1 and the IASI column abundances over continents in an inverse modelling scheme based on the adjoint of the IMAGESv2 model to generate an improved global methanol emission source. The global optimized source totals 187 Tg yr−1 with a contribution of 100 Tg yr−1 from plants, only slightly lower than the a priori MEGANv2.1 value of 105 Tg yr−1. Large decreases with respect to the MEGANv2.1 biogenic source are inferred over Amazonia (up to 55 %) and Indonesia (up to 58 %), whereas more moderate reductions are recorded in the Eastern US (20–25 %) and Central Africa (25–35 %). On the other hand, the biogenic source is found to strongly increase in the arid and semi-arid regions of Central Asia (up to a factor of 5) and Western US (factor of 2), probably due to a source of methanol specific to these ecosystems which is unaccounted for in the MEGANv2.1 inventory. The most significant error reductions achieved by the optimization concern the derived biogenic emissions over the Amazon and over the Former Soviet Union. The robustness of the derived fluxes to changes in convective updraft fluxes, in methanol removal processes, and in the choice of the biogenic a priori inventory is assessed through sensitivity inversions. Detailed comparisons of the model with a number of aircraft and surface observations of methanol, as well as new methanol measurements in Europe and in the Reunion Island show that the satellite-derived methanol emissions improve significantly the agreement with the independent data, giving thus credence to the IASI dataset.
[1509] Goldstein, A. H., J. F. Karlik, S. Fares, E. Ormeno Lafuente, D. Gentner, J-H. Park, R. Weber, and M. McKay, "Flux Measurements of Biogenic Precursors to Ozone and Particulate Matter in the Central Valley", Report for the California Air Resources Board and the California Environmental Protection Agency, Aug, 2011.
Link: http://nature.berkeley.edu/ahg/pubs/ARB FR 2011 CITRUS Final Report Contract 06-329.pdf
2010
[Mueller2010] Müller, M., M. Graus, TM. Ruuskanen, R. Schnitzhofer, I. Bamberger, L. Kaser, T. Titzmann, L. Hoertnagl, G. Wohlfahrt, T. Karl, et al., "First eddy covariance flux measurements by PTR-TOF", Atmospheric Measurement Techniques, vol. 3, pp. 387–395, 2010.
Link: http://adsabs.harvard.edu/abs/2010AMT.....3..387M
Abstract
We have developed a High-Temperature Proton-Transfer-Reaction Mass Spectrometer (HT-PTR-MS) in which both the ion source and the ion drift tube can be continuously operated at temperatures up to 250 °C. The instrument was characterized in a high E/N-mode (130 Td) and in a low E/N-mode (87 Td) at an operating temperature of 200 °C. Instrumental sensitivities and 2σ-detection limits were on the order of 50–110 cps/ppb and 100 ppt (1 s signal integration time), respectively. The HT-PTR-MS is primarily intended for measuring "sticky" or semi-volatile trace gases. Alternatively, it may be coupled to a particle collection/thermal desorption apparatus to measure particle-bound organics in near real-time. In view of these applications, we have measured instrumental response times for a series of reference compounds. 1/e2-response times for dimethyl sulfoxide, ammonia and monoethanolamine were in the sub-second to second regime. 1/e2-response times for levoglucosan, oxalic acid and cis-pinonic acid ranged from 8 to 370 s.
[1493] Langford, B.., P.. K. Misztal, E.. Nemitz, B.. Davison, C.. Helfter, T.. A. M. Pugh, A.. R. MacKenzie, S.. F. Lim, and C.. N. Hewitt, "Fluxes and concentrations of volatile organic compounds from a South-East Asian tropical rainforest", Atmospheric Chemistry and Physics, vol. 10, pp. 8391–8412, 2010.
Link: http://www.atmos-chem-phys.net/10/8391/2010/
Abstract
<p>As part of the OP3 field study of rainforest atmospheric chemistry, above-canopy fluxes of isoprene, monoterpenes and oxygenated volatile organic compounds were made by virtual disjunct eddy covariance from a South-East Asian tropical rainforest in Malaysia. Approximately 500 hours of flux data were collected over 48 days in April&ndash;May and June&ndash;July 2008. Isoprene was the dominant non-methane hydrocarbon emitted from the forest, accounting for 80% (as carbon) of the measured emission of reactive carbon fluxes. Total monoterpene emissions accounted for 18% of the measured reactive carbon flux. There was no evidence for nocturnal monoterpene emissions and during the day their flux rate was dependent on both light and temperature. The oxygenated compounds, including methanol, acetone and acetaldehyde, contributed less than 2% of the total measured reactive carbon flux. The sum of the VOC fluxes measured represents a 0.4% loss of daytime assimilated carbon by the canopy, but atmospheric chemistry box modelling suggests that most (90%) of this reactive carbon is returned back to the canopy by wet and dry deposition following chemical transformation. The emission rates of isoprene and monoterpenes, normalised to 30 &deg;C and 1000 μmol m&minus;2 s&minus;1 PAR, were 1.6 mg m&minus;2 h&minus;1 and 0.46mg m&minus;2 h&minus;1 respectively, which was 4 and 1.8 times lower respectively than the default value for tropical forests in the widely-used MEGAN model of biogenic VOC emissions. This highlights the need for more direct canopy-scale flux measurements of VOCs from the world&#39;s tropical forests.</p>
[Vlasenko2010] Vlasenko, A., AM. Macdonald, SJ. Sjostedt, and JPD. Abbatt, "Formaldehyde measurements by Proton transfer reaction–Mass Spectrometry (PTR-MS): correction for humidity effects", Atmospheric Measurement Techniques Discussions, vol. 3, no. 2: Copernicus GmbH, pp. 965–988, 2010.
Link: http://www.atmos-meas-tech-discuss.net/3/965/2010/amtd-3-965-2010.html
Abstract
Formaldehyde measurements can provide useful information about photochemical activity in ambient air, given that HCHO is formed via numerous oxidation processes. Proton transfer reaction mass spectrometry (PTR-MS) is an online technique that allows measurement of VOCs at the sub-ppbv level with good time resolution. PTR-MS quantification of HCHO is hampered by the humidity dependence of the instrument sensitivity, with higher humidity leading to loss of PTR-MS signal. In this study we present an analytical, first principles approach to correct the PTR-MS HCHO signal according to the concentration of water vapor in sampled air. The results of the correction are validated by comparison of the PTR-MS results to those from a Hantzsch fluorescence monitor which does not have the same humidity dependence. Results are presented for an intercomparison made during a field campaign in rural Ontario at Environment Canada's Centre for Atmospheric Research Experiments.
2009
[Graus2009] Graus, M., M. Müller, and A. Hansel, "Field performance and identification capability of the Innsbruck PTR-TOF", EGU General Assembly Conference Abstracts, vol. 11, pp. 10200, 2009.
Link: http://adsabs.harvard.edu/abs/2009EGUGA..1110200G
Abstract
Over the last one and a half decades Proton Transfer Reaction Mass Spectrometry (PTR-MS) [1, 2] has gained recognition as fast on-line sensor for monitoring volatile organic compounds (VOC) in the atmosphere. Sample collection is very straight forward and the fact that no pre-concentration is needed is of particular advantage for compounds that are notoriously difficult to pre-concentrate and/or analyze by gas chromatographic (GC) methods. Its ionization method is very versatile, i.e. all compounds that perform exothermic proton transfer with hydronium ions - and most VOCs do so - are readily ionized, producing quasi-molecular ions VOC.H+. In the quasi-molecular ion the elemental composition of the analyte compound is conserved and allows, in combination with some background knowledge of the sample, conclusions about the identity of that compound. De Gouw and Warneke (2007) [3] summarized the applicability of PTR-MS in atmospheric chemistry but they also pointed out shortcomings in the identification capabilities. Goldstein and Galbally (2007) [4] addressed the multitude of VOCs potentially present in the atmosphere and they emphasized the gasphase-to-aerosol partitioning of organic compounds (volatile and semi-volatile) in dependence of carbon-chain length and oxygen containing functional groups. In collaboration with Ionicon and assisted by TOFWERK we developed a PTR time-of-flight (PTR-TOF) instrument that allows for the identification of the atomic composition of oxygenated hydrocarbons by exact-mass determination. A detection limit in the low pptv range was achieved at a time resolution of one minute, one-second detection limit is in the sub-ppbv range. In 2008 the Innsbruck PTR-TOF was field deployed in the icebreaker- and helicopter based Arctic Summer Cloud Ocean Study (ASCOS) to characterize the organic trace gas composition of the High Arctic atmosphere. During the six-week field campaign the PTR-TOF was run without problems even under harsh conditions in the open water and during ice breaking. Continuous time-series of full mass spectra with a one minute time resolution were recorded throughout the campaign between August 2nd and September 7th 2008 running up to a net VOC data set of 745 hours. Over 370 mass peaks have been separated, about 340 show signal intensities above the 30 minute detection limit of  3pptv. Additionally we analyzed samples from nine helicopter based soundings providing vertical VOC profiles up to 3000 m.a.s.l. The performance of the newly developed instrument will be discussed and ASCOS data will be shown. Acknowledgment: The ASCOS expedition was arranged by the Swedish Polar Research Secretariat (SPRS) and was an effort within the framework of SWEDARCTIC 2008. For more information on ASCOS see http://ascos.se/. We thank the ASCOS organizers - Caroline Leck and Michael Tjernström - all ASCOS participants, the SPRS and the Oden crew for the excellent team work and Armin Wisthaler for his assistance in planning and preparations. The TOF-MS system was funded by the University of Innsbruck (Uni Infrastruktur Programm). The development project was financially supported by the Austrian Research Funding Association (FFG). [1] Hansel, A.; Jordan, A.; Holzinger, R.; Prazeller, P.; Vogel, W.; Lindinger, W. International Journal of Mass Spectrometry and Ion Processes 1995, 149-150, 609-619. [2] Lindinger, W.; Hansel, A.; Jordan, A. Chemical Society Review 1998, 27, 347-375. [3] De Gouw, J. A.; Warneke, C. Mass Spectrometry Reviews 2007, 26, 223-257. [4] Goldstein, A. H.; Galbally, I. E. Environmental Science and Technology 2007, 41, 154-1521.
[Eerdekens2009a] Eerdekens, G., L. Ganzeveld, V-G. J de Arellano, T. Klüpfel, V. Sinha, N. Yassaa, J. Williams, H. Harder, D. Kubistin, M. Martinez, et al., "Flux estimates of isoprene, methanol and acetone from airborne PTR-MS measurements over the tropical rainforest during the GABRIEL 2005 campaign", Atmospheric Chemistry and Physics, vol. 9, no. 13: Copernicus GmbH, pp. 4207–4227, 2009.
Link: http://www.atmos-chem-phys.net/9/4207/2009/acp-9-4207-2009.html
Abstract
Tropical forests are a strong source of biogenic volatile organic compounds (BVOCs) to the atmosphere which can potentially impact the atmospheric oxidation capacity. Here we present airborne and ground-based BVOC measurements representative for the long dry season covering a large area of the northern Amazonian rainforest (6–3° N, 50–59° W). The measurements were conducted during the October 2005 GABRIEL (Guyanas Atmosphere-Biosphere exchange and Radicals Intensive Experiment with the Learjet) campaign. The vertical (35 m to 10 km) and diurnal (09:00–16:00) profiles of isoprene, its oxidation products methacrolein and methyl vinyl ketone and methanol and acetone, measured by PTR-MS (Proton Transfer Reaction Mass Spectrometry), have been used to empirically estimate their emission fluxes from the forest canopy on a regional scale. The mixed layer isoprene emission flux, inferred from the airborne measurements above 300 m, is 5.7 mg isoprene m−2 h−1 after compensating for chemistry and  6.9 mg isoprene m−2 h−1 taking detrainment into account. This surface flux is in general agreement with previous tropical forest studies. Inferred methanol and acetone emission fluxes are 0.5 mg methanol m−2 h−1 and 0.35 mg acetone m−2 h−1, respectively. The BVOC measurements were compared with fluxes and mixing ratios simulated with a single-column chemistry and climate model (SCM). The inferred isoprene flux is substantially smaller than that simulated with an implementation of a commonly applied BVOC emission algorithm in the SCM.
2008
[Vlasenko2008] Vlasenko, A., I. J. George, and J. P. D. Abbatt, "Formation of volatile organic compounds in the heterogeneous oxidation of condensed-phase organic films by gas-phase OH.", J Phys Chem A, vol. 112, no. 7: Department of Chemistry and Southern Ontario Centre for Atmospheric Aerosol Research, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada., pp. 1552–1560, Feb, 2008.
Link: http://pubs.acs.org/doi/abs/10.1021/jp0772979
Abstract
The yield of volatile organic compounds (VOCs) from the heterogeneous oxidation of condensed-phase organic and hydrocarbon soot films by gas-phase OH has been studied in a coated-wall flow tube at room temperature. Simultaneously, OH concentrations are measured using a chemical-ionization mass spectrometer (CIMS) operated in negative ion mode and VOCs are measured using a commercial proton-transfer-reaction mass spectrometer (PTR-MS). It is observed that a variety of aldehydes/carbonyls and carboxylic acids are formed. Specifically, detailed experiments were conducted with stearic acid, where products are observed that contain as many as 13 carbon atoms with the average carbon number of the products between 3 and 5. The yield of VOCs, relative to the loss of OH radicals, is strongly dependent on the partial pressure of O2 in the carrier gas, ranging from 0.08 +/- 0.03 in a nominally pure He carrier gas to 0.34 +/- 0.14 in 6 Torr of pure O2. Yields from other organics are somewhat lower than those from stearic acid, ranging in conditions of pure O2 from 0.10 +/- 0.04 for BES (bis(ethylhexyl)sebacate), to 0.03 +/- 0.01 for n-hexane soot, to 0.01 +/- 0.005 for pyrene. Under atmospheric conditions, OH oxidation of select organics may be an efficient source of small VOCs. In particular, formic acid is formed in significant yield from all the surfaces.
2006
[Tamas2006] Tamas, G., C. J. Weschler, Z. Bako-Biro, D. P. Wyon, and P. Strøm-Tejsen, "Factors affecting ozone removal rates in a simulated aircraft cabin environment", Atmospheric environment, vol. 40, no. 32: Elsevier, pp. 6122–6133, 2006.
Link: http://www.sciencedirect.com/science/article/pii/S1352231006005152
Abstract
Ozone concentrations were measured concurrently inside a simulated aircraft cabin and in the airstream providing ventilation air to the cabin. Ozone decay rates were also measured after cessation of ozone injection into the supply airstream. By systematically varying the presence or absence of people, soiled T-shirts, aircraft seats and a used HEPA filter, we have been able in the course of 24 experiments to isolate the contributions of these and other factors to the removal of ozone from the cabin air. In the case of this simulated aircraft, people were responsible for almost 60% of the ozone removal occurring within the cabin and recirculation system; respiration can only have been responsible for about 4% of this removal. The aircraft seats removed about 25% of the ozone; the loaded HEPA filter, 7%; and the other surfaces, 10%. A T-shirt that had been slept in overnight removed roughly 70% as much ozone as a person, indicating the importance of skin oils in ozone removal. The presence of the used HEPA filter in the recirculated airstream reduced the perceived air quality. Over a 5-h period, the overall ozone removal rate by cabin surfaces decreased at ∼3% h−1. With people present, the measured ratio of ozone's concentration in the cabin versus that outside the cabin was 0.15–0.21, smaller than levels reported in the literature. The results reinforce the conclusion that the optimal way to reduce people's exposure to both ozone and ozone oxidation products is to efficiently remove ozone from the air supply system of an aircraft.
2003
[Biasioli2003a] Biasioli, F., F. Gasperi, E. Aprea, L. Colato, E. Boscaini, and TD. Maerk, "Fingerprinting mass spectrometry by PTR-MS: heat treatment vs. pressure treatment of red orange juice - a case study", International journal of mass spectrometry, vol. 223: Elsevier, pp. 343–353, 2003.
Link: http://www.sciencedirect.com/science/article/pii/S1387380602008709
Abstract
Proton transfer reaction mass spectrometry (PTR-MS) is more and more applied to rather different fields of research and applications showing interesting performances where high sensitivity and fast monitoring of volatile organic compounds (VOCs) are required. Based on this technique and aiming at the realisation of an automatic system for routine applications in food science and technology, we tested here a novel approach for fingerprinting mass spectrometric detection and analysis of complex mixtures of VOCs. In particular, we describe and discuss corresponding head space (HS) sampling methods and possible data analysis techniques. As a first test case we studied here the properties of four red orange juices processed by different stabilisation methods starting from the same industrial batch: untreated juice, thermal pasteurised (flash and standard) juice and high pressure stabilised juice. We demonstrate the possibility of a fast automatic discrimination/classification of the samples with the further advantage, compared to the use of electronic noses, of useful information on the mass of the discriminating compounds. Moreover, first comparisons with discriminative analysis by a sensory panel shows evidence that there is a correlation between the ability of the PTR-MS to distinguish different juice samples and that of a panel of trained judges with the obvious advantages of an instrumental approach.
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.

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

 

Download the latest version of the IONICON publication database as BibTeX.