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Zeitschriftenartikel zum Thema "PTR-TOF"
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Warneke, C., P. Veres, S. M. Murphy, J. Soltis, R. A. Field, M. G. Graus, A. Koss et al. „PTR-QMS versus PTR-TOF comparison in a region with oil and natural gas extraction industry in the Uintah Basin in 2013“. Atmospheric Measurement Techniques 8, Nr. 1 (26.01.2015): 411–20. http://dx.doi.org/10.5194/amt-8-411-2015.
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Abstract. Here we compare volatile organic compound (VOC) measurements using a standard proton-transfer-reaction quadrupole mass spectrometer (PTR-QMS) with a new proton-transfer-reaction time of flight mass spectrometer (PTR-TOF) during the Uintah Basin Winter Ozone Study 2013 (UBWOS2013) field experiment in an oil and gas field in the Uintah Basin, Utah. The PTR-QMS uses a quadrupole, which is a mass filter that lets one mass to charge ratio pass at a time, whereas the PTR-TOF uses a time of flight mass spectrometer, which takes full mass spectra with typical 0.1 s–1 min integrated acquisition times. The sensitivity of the PTR-QMS in units of counts per ppbv (parts per billion by volume) is about a factor of 10–35 times larger than the PTR-TOF, when only one VOC is measured. The sensitivity of the PTR-TOF is mass dependent because of the mass discrimination caused by the sampling duty cycle in the orthogonal-acceleration region of the TOF. For example, the PTR-QMS on mass 33 (methanol) is 35 times more sensitive than the PTR-TOF and for masses above 120 amu less than 10 times more. If more than 10–35 compounds are measured with PTR-QMS, the sampling time per ion decreases and the PTR-TOF has higher signals per unit measuring time for most masses. For UBWOS2013 the PTR-QMS measured 34 masses in 37 s and on that timescale the PTR-TOF is more sensitive for all masses. The high mass resolution of the TOF allows for the measurements of compounds that cannot be separately detected with the PTR-QMS, such as oxidation products from alkanes and cycloalkanes emitted by oil and gas extraction. PTR-TOF masses do not have to be preselected, allowing for identification of unanticipated compounds. The measured mixing ratios of the two instruments agreed very well (R2 ≥ 0.92 and within 20%) for all compounds and masses monitored with the PTR-QMS.
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Warneke, C., P. R. Veres, S. M. Murphy, J. Soltis, R. A. Field, M. G. Graus, A. Koss et al. „PTR-QMS vs. PTR-TOF comparison in a region with oil and natural gas extraction industry in the Uintah Basin in 2013“. Atmospheric Measurement Techniques Discussions 7, Nr. 7 (03.07.2014): 6565–93. http://dx.doi.org/10.5194/amtd-7-6565-2014.
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Abstract. Here we compare volatile organic compound (VOC) measurements using a standard Proton-Transfer-Reaction Quadrupole Mass Spectrometer (PTR-QMS) with a new Proton-Transfer-Reaction Time Of Flight Mass Spectrometer (PTR-TOF) during the Uintah Basin Winter Ozone Study 2013 (UBWOS2013) field experiment in an oil and gas field in the Uintah Basin, Utah. The PTR-QMS uses a quadrupole, which is a mass filter that lets one mass pass at a time, whereas the PTR-TOF uses a Time Of Flight mass spectrometer, which takes full mass spectra with typical 0.1 s to 1 min integrated acquisition times. The sensitivity of the PTR-QMS in units of counts per ppbv is about a factor of 10–35 times larger than the PTR-TOF, when only one VOC is measured. The sensitivity of the PTR-TOF is mass dependent because of the mass discrimination caused by the sampling duty cycle in the orthogonal-acceleration region of the TOF. For example, the PTR-QMS on mass 33 (methanol) is 35 times more sensitive than the PTR-TOF and for masses above 120 amu less than 10 times more. If more than 10–35 compounds are measured with PTR-QMS, the sampling time per ion decreases and the PTR-TOF has higher signals per unit measuring time for most masses. For UBWOS2013 the PTR-QMS measured 34 masses in 37 s and on that time-scale the PTR-TOF is more sensitive for all masses. The high mass resolution of the TOF allows for the measurements of compounds that cannot be separately detected with the PTR-QMS, such as oxidation products from alkanes and cycloalkanes emitted by oil and gas extraction. PTR-TOF masses do not have to be pre-selected allowing for identification of unanticipated compounds. The measured mixing ratios of the two instruments agreed very well (R2 ≥ 0.92 and within 20%) for all compounds and masses monitored with the PTR-QMS.
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Müller, M., M. Graus, T. M. Ruuskanen, R. Schnitzhofer, I. Bamberger, L. Kaser, T. Titzmann et al. „First eddy covariance flux measurements by PTR-TOF“. Atmospheric Measurement Techniques 3, Nr. 2 (25.03.2010): 387–95. http://dx.doi.org/10.5194/amt-3-387-2010.
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Abstract. The recently developed PTR-TOF instrument was evaluated to measure methanol fluxes emitted from grass land using the eddy covariance method. The high time resolution of the PTR-TOF allowed storing full mass spectra up to m/z 315 with a frequency of 10 Hz. Three isobaric ions were found at a nominal mass of m/z 33 due to the high mass resolving power of the PTR-TOF. Only one of the three peaks contributed to eddy covariance fluxes. The exact mass of this peak agrees well with the exact mass of protonated methanol (m/z 33.0335). The eddy covariance methanol fluxes measured with PTR-TOF were compared to virtual disjunct eddy covariance methanol fluxes simultaneously measured with a conventional PTR-MS. The methanol fluxes from both instruments show excellent agreement.
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Müller, M., M. Graus, T. M. Ruuskanen, R. Schnitzhofer, I. Bamberger, L. Kaser, T. Titzmann et al. „First eddy covariance flux measurements by PTR-TOF“. Atmospheric Measurement Techniques Discussions 2, Nr. 6 (14.12.2009): 3265–90. http://dx.doi.org/10.5194/amtd-2-3265-2009.
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Abstract. The recently developed PTR-TOF instrument was evaluated to measure methanol fluxes emitted from grass land using the eddy covariance method. The high time resolution of the PTR-TOF allowed storing full mass spectra up to m/z 315 with a frequency of 10 Hz. Three isobaric ions were found at a nominal mass of m/z 33 due to the high mass resolving power of the PTR-TOF. Only one of the three peaks contributed to eddy covariance fluxes. The exact mass of this peak agrees well with the exact mass of protonated methanol (m/z 33.0335). The eddy covariance methanol fluxes measured with PTR-TOF were compared to virtual disjunct eddy covariance methanol fluxes simultaneously measured with a conventional PTR-MS. The methanol fluxes from both instruments show excellent agreement.
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Timkovsky, J., A. W. H. Chan, T. Dorst, A. H. Goldstein, B. Oyama und R. Holzinger. „Organic aerosol composition measurements with advanced offline and in-situ techniques during the CalNex campaign“. Atmospheric Measurement Techniques Discussions 7, Nr. 12 (12.12.2014): 12449–80. http://dx.doi.org/10.5194/amtd-7-12449-2014.
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Abstract. Our understanding of formation processes, physical properties and climate/health effects of organic aerosols is still limited in part due to limited knowledge of organic aerosol composition. We present speciated measurements of organic aerosol composition by two methods: in-situ thermal-desorption proton-transfer-reaction mass spectrometry (TD-PTR-MS) and offline two-dimensional gas chromatography with a time-of-flight mass spectrometer (GC×GC/TOF-MS). 153 compounds were identified using the GC×GC/TOF-MS, 123 of which were matched with 64 ions observed by the TD-PTR-MS. A reasonable overall correlation of 0.67 (r2) was found between the total matched TD-PTR-MS signal (sum of 64 ions) and the total matched GC×GC/TOF-MS signal (sum of 123 compounds). A reasonable quantitative agreement between the two methods was observed for most individual compounds with concentrations which were detected at levels above 2 ng m−3 using the GC×GC/TOF-MS. The analysis of monocarboxylic acids standards with TD-PTR-MS showed that alkanoic acids with molecular masses below 290 amu are detected well (recovery fractions above 60%). However, the concentrations of these acids were consistently higher on quartz filters (quantified offline by GC×GC/TOF-MS) than those suggested by in-situ TD-PTR-MS measurements, which is consistent with the semivolatile nature of the acids and corresponding positive filter sampling artifacts.
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Timkovsky, J., A. W. H. Chan, T. Dorst, A. H. Goldstein, B. Oyama und R. Holzinger. „Comparison of advanced offline and in situ techniques of organic aerosol composition measurement during the CalNex campaign“. Atmospheric Measurement Techniques 8, Nr. 12 (10.12.2015): 5177–87. http://dx.doi.org/10.5194/amt-8-5177-2015.
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Abstract. Our understanding of formation processes, physical properties, and climate/health effects of organic aerosols is still limited in part due to limited knowledge of organic aerosol composition. We present speciated measurements of organic aerosol composition by two methods: in situ thermal-desorption proton-transfer-reaction mass spectrometry (TD-PTR-MS) and offline two-dimensional gas chromatography with a time-of-flight mass spectrometer (GC × GC/TOF-MS). Using the GC × GC/TOF-MS 153 compounds were identified, 123 of which were matched with 64 ions observed by the TD-PTR-MS. A reasonable overall correlation of 0.67 (r2) was found between the total matched TD-PTR-MS signal (sum of 64 ions) and the total matched GC × GC/TOF-MS signal (sum of 123 compounds) for the Los Angeles area. A reasonable quantitative agreement between the two methods was observed for most individual compounds with concentrations which were detected at levels above 2 ng m−3 using the GC × GC/TOF-MS. The analysis of monocarboxylic acids standards with TD-PTR-MS showed that alkanoic acids with molecular masses below 290 amu are detected well (recovery fractions above 60 %). However, the concentrations of these acids were consistently higher on quartz filters (quantified offline by GC × GC/TOF-MS) than those suggested by in situ TD-PTR-MS measurements, which is consistent with the semivolatile nature of the acids and corresponding positive filter sampling artifacts.
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Park, J. H., A. H. Goldstein, J. Timkovsky, S. Fares, R. Weber, J. Karlik und R. Holzinger. „Eddy covariance emission and deposition flux measurements using proton transfer reaction – time of flight – mass spectrometry (PTR-TOF-MS): comparison with PTR-MS measured vertical gradients and fluxes“. Atmospheric Chemistry and Physics 13, Nr. 3 (06.02.2013): 1439–56. http://dx.doi.org/10.5194/acp-13-1439-2013.
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Abstract. During summer 2010, a proton transfer reaction – time of flight – mass spectrometer (PTR-TOF-MS) and a quadrupole proton transfer reaction mass spectrometer (PTR-MS) were deployed simultaneously for one month in an orange orchard in the Central Valley of California to collect continuous data suitable for eddy covariance (EC) flux calculations. The high time resolution (5 Hz) and high mass resolution (up to 5000 m/Δm) data from the PTR-TOF-MS provided the basis for calculating the concentration and flux for a wide range of volatile organic compounds (VOC). Throughout the campaign, 664 mass peaks were detected in mass-to-charge ratios between 10 and 1278. Here we present PTR-TOF-MS EC fluxes of the 27 ion species for which the vertical gradient was simultaneously measured by PTR-MS. These EC flux data were validated through spectral analysis (i.e., co-spectrum, normalized co-spectrum, and ogive). Based on inter-comparison of the two PTR instruments, no significant instrumental biases were found in either mixing ratios or fluxes, and the data showed agreement within 5% on average for methanol and acetone. For the measured biogenic volatile organic compounds (BVOC), the EC fluxes from PTR-TOF-MS were in agreement with the qualitatively inferred flux directions from vertical gradient measurements by PTR-MS. For the 27 selected ion species reported here, the PTR-TOF-MS measured total (24 h) mean net flux of 299 μg C m−2 h−1. The dominant BVOC emissions from this site were monoterpenes (m/z 81.070 + m/z 137.131 + m/z 95.086, 34%, 102 μg C m−2 h−1) and methanol (m/z 33.032, 18%, 72 μg C m−2 h−1). The next largest fluxes were detected at the following masses (attribution in parenthesis): m/z 59.048 (mostly acetone, 12.2%, 36.5 μg C m−2 h−1), m/z 61.027 (mostly acetic acid, 11.9%, 35.7 μg C m−2 h−1), m/z 93.069 (para-cymene + toluene, 4.1%, 12.2 μg C m−2 h−1), m/z 45.033 (acetaldehyde, 3.8%, 11.5 μg C m−2 h−1), m/z 71.048 (methylvinylketone + methacrolein, 2.4%, 7.1 μg C m−2 h−1), and m/z 69.071 (isoprene + 2-methyl-3-butene-2-ol, 1.8%, 5.3 μg C m−2 h−1). Low levels of emission and/or deposition (<1.6% for each, 5.8% in total flux) were observed for the additional reported masses. Overall, our results show that EC flux measurements using PTR-TOF-MS is a powerful new tool for characterizing the biosphere-atmosphere exchange including both emission and deposition for a large range of BVOC and their oxidation products.
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Herbig, Jens, Markus Müller, Simon Schallhart, Thorsten Titzmann, Martin Graus und Armin Hansel. „On-line breath analysis with PTR-TOF“. Journal of Breath Research 3, Nr. 2 (01.06.2009): 027004. http://dx.doi.org/10.1088/1752-7155/3/2/027004.
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Park, J. H., A. H. Goldstein, J. Timkovsky, S. Fares, R. Weber, J. Karlik und R. Holzinger. „Eddy covariance emission and deposition flux measurements using proton transfer reaction-time of flight-mass spectrometry (PTR-TOF-MS): comparison with PTR-MS measured vertical gradients and fluxes“. Atmospheric Chemistry and Physics Discussions 12, Nr. 8 (15.08.2012): 20435–82. http://dx.doi.org/10.5194/acpd-12-20435-2012.
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Abstract. During summer 2010, a proton transfer reaction-time of flight-mass spectrometer (PTR-TOF-MS) and a standard proton transfer reaction mass spectrometer (PTR-MS) were deployed simultaneously for one month in an orange orchard in the Central Valley of California to collect continuous data suitable for eddy covariance (EC) flux calculations. The high time resolution (5 Hz) and high mass resolution (up to 5000 m Δ m−1) data from the PTR-TOF-MS provided the basis for calculating the concentration and flux for a wide range of volatile organic compounds (VOC). Throughout the campaign, 664 mass peaks were detected in mass-to-charge ratios between 10 and 1278. Here we present PTR-TOF-MS EC fluxes of the 27 ion species for which the vertical gradient was simultaneously measured by PTR-MS. These EC flux data were validated through spectral analysis (i.e. co-spectrum, normalized co-spectrum, and ogive). Based on inter-comparison of the two PTR instruments, no significant instrumental biases were found in either mixing ratios or fluxes, and the data showed agreement within 5% on average for methanol and acetone. For the measured biogenic volatile organic compounds (BVOC), the EC fluxes from PTR-TOF-MS were in agreement with the qualitatively inferred flux directions from vertical gradient measurements by PTR-MS. For the 27 selected ion species reported here, the PTR-TOF-MS measured total (24 h) mean net flux of 299 μg C m−2 h−1. The dominant BVOC emissions from this site were monoterpenes (m/z 81.070 + m/z 137.131 + m/z 95.086, 34%, 102 μg C m−2 h−1) and methanol (m/z 33.032, 18%, 72 μg C m−2 h−1). The next largest fluxes were detected at the following masses (attribution in parenthesis): m/z 59.048 (mostly acetone, 12.2%, 36.5 μg C m−2 h−1), m/z 61.027 (mostly acetic acid, 11.9%, 35.7 μg C m−2 h−1), m/z 93.069 (para-cymene + toluene, 4.1%, 12.2 μg C m−2 h−1), m/z 45.033 (acetaldehyde, 3.8%, 11.5 μg C m−2 h−1), m/z 71.048 (methylvinylketone + methacrolein, 2.4%, 7.1 μg C m−2 h−1), and m/z 69.071 (isoprene + 2-methyl-3-butene-2-ol, 1.8%, 5.3 μg C m−2 h−1). Low levels of emission and/or deposition (<1.6% for each, 5.8% in total flux) were observed for the additional reported masses. Overall, our results show that EC flux measurements using PTR-TOF-MS is a powerful new tool for characterizing the biosphere-atmosphere exchange including both emission and deposition for a large range of BVOC and their oxidation products.
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Wu, Caihong, Chaomin Wang, Sihang Wang, Wenjie Wang, Bin Yuan, Jipeng Qi, Baolin Wang et al. „Measurement report: Important contributions of oxygenated compounds to emissions and chemistry of volatile organic compounds in urban air“. Atmospheric Chemistry and Physics 20, Nr. 23 (02.12.2020): 14769–85. http://dx.doi.org/10.5194/acp-20-14769-2020.
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Abstract. Volatile organic compounds (VOCs) play important roles in the tropospheric atmosphere. In this study, VOCs were measured at an urban site in Guangzhou, one of the megacities in the Pearl River Delta (PRD), using a gas chromatograph–mass spectrometer/flame ionization detection (GC–MS/FID) and a proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS). Diurnal profile analyses show that stronger chemical removal by OH radicals for more reactive hydrocarbons occurs during the daytime, which is used to estimate the daytime average OH radical concentration. In comparison, diurnal profiles of oxygenated volatile organic compounds (OVOCs) indicate evidence of contributions from secondary formation. Detailed source analyses of OVOCs, using a photochemical age-based parameterization method, suggest important contributions from both primary emissions and secondary formation for measured OVOCs. During the campaign, around 1700 ions were detected in PTR-ToF-MS mass spectra, among which there were 462 ions with noticeable concentrations. VOC signals from these ions are quantified based on the sensitivities of available VOC species. OVOC-related ions dominated PTR-ToF-MS mass spectra, with an average contribution of 73 % ± 9 %. Combining measurements from PTR-ToF-MS and GC–MS/FID, OVOCs contribute 57 % ± 10 % to the total concentration of VOCs. Using concurrent measurements of OH reactivity, OVOCs measured by PTR-ToF-MS contribute greatly to the OH reactivity (19 % ± 10 %). In comparison, hydrocarbons account for 21 % ± 11 % of OH reactivity. Adding up the contributions from inorganic gases (48 % ± 15 %), ∼ 11 % (range of 0 %–19 %) of the OH reactivity remains `missing”, which is well within the combined uncertainties between the measured and calculated OH reactivity. Our results demonstrate the important roles of OVOCs in the emission and evolution budget of VOCs in the urban atmosphere.
Dissertationen zum Thema "PTR-TOF"
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Sonderfeld, Hannah [Verfasser]. „Charakterisierung und Einsatz eines PTR-ToF-MS zur Messung von flüchtigen organischen Verbindungen / Hannah Sonderfeld“. Wuppertal : Universitätsbibliothek Wuppertal, 2014. http://d-nb.info/1050188357/34.
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2
Barber, Shane Brian. „Improving PTR-ToF-MS : implementation of a radio frequency ion funnel and an investigation into buffer-gas doping“. Thesis, University of Leicester, 2015. http://hdl.handle.net/2381/35978.
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Volatile organic compounds (VOCs) are ubiquitous in the Earth’s atmosphere. VOCs are produced from biogenic sources such as forests, or anthropogenic sources such as fossil fuel combustion. Many areas of research involve measuring VOCs, from atmospheric science, to medical science and homeland security with implications for health, the environment, and safety. It is crucial that VOCs are detected quickly and with a high sensitivity: proton transfer reaction - mass spectrometry (PTR-MS) offers a solution and potential enhancements of the PTR-MS technique are discussed here. A drift tube capable of simultaneously functioning as an ion funnel is demonstrated in PTR-MS for the first time enabling a much higher proportion of ions to exit the drift tube and enter the mass spectrometer than would otherwise be the case. An increase in the detection sensitivity for VOCs of up to two orders of magnitude and an increase in Limit of Detection of one order of magnitude is delivered, allowing lower concentrations of VOCs to be detected. An alternate way to change how the drift tube behaves is to alter the buffer gas. The collision energy within the drift tube is investigated in order to ascertain what advantages changing the buffer gas from nitrogen to argon yields with respect to sensitivity and fragmentation of analytes. For several compounds, the sensitivity is increased and fragmentation reduced. If sensitivity can be increased and/or fragmentation reduced within a complex mixture of analyte ions, then analysis of these mixtures will be simplified. Finally, a standard PTR-MS instrument is compared with the ion funnel equipped PTR-MS instrument in an urban, megacity (ClearfLo campaign, London, UK) in order to test the instrument and enhanced sensitivity for field measurements.
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Vesin, Aude. „Suivi temportel des niveaux de concentration en atmosphère intérieure lors de l'application d'insecticides ménagers“. Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4710/document.
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L'étude du comportement dynamique des substances actives pendant l'épandage de produits insecticides ménagers commerciaux dans les atmosphères intérieures nécessite le développement et l'adaptation de procédures analytiques de mesure en ligne ayant une résolution temporelle élevée. Un HS-PTR-MS et un HR-ToF-AMS ont par conséquent été utilisés pour mesurer les contaminants à la fois en phase gazeuse et particulaire. Les substances actives ciblées par cette étude appartiennent à la famille des pyréthrinoïdes, présentes dans différentes formulations commerciales du type diffuseurs électriques et sprays aérosols, qui ont été appliqués dans une pièce d'étude simulant une atmosphère réelle dans la maison expérimentale MARIA du Centre Scientifique et Technique du Bâtiment. Les résultats de ces mesures montrent des pics de concentration compris entre 1,5 et 8,5 µg.m-3, après 8 heures de branchement des diffuseurs électriques. Les pics de concentration des substances actives après l'application des sprays peuvent atteindre plusieurs dizaines de µg.m-3. La ventilation et la sédimentation des aérosols apparaissent comme des mécanismes majeurs d'élimination des polluants du compartiment air. Par ailleurs, une distribution importante des substances actives avec les surfaces de la pièce (murs, sol, plafond, particules en suspension et poussières) est observée. L'évaluation de l'exposition par inhalation aux produits insecticides étudiés montre qu'il n'existe a priori pas de risque pour la santé. Néanmoins, une évaluation intégrée, prenant en compte toutes les voies d'exposition est nécessaire avant de conclure à une absence de risque sanitaireThe study of the dynamic behaviour of the active substances during the application of commercial household insecticide products in indoor atmospheres requires the development of the adaptation of on-line analytical procedures with high time resolution. A HS-PTR-MS and a HR-ToF-AMS have therefore been used to measure contaminants both in the gaseous and particulate phase. The active substances targeted by this study belong to the pyrethroids, which are present in different commercial formulations like electric vaporizers and sprays that were applied in a full-scale test room simulating a real atmosphere in the experimental house MARIA of the French scientific and technical centre for building. The results of these measurements show that peak concentrations during a 8h-emission of electric vaporizers range from 1,5 et 8,5 µg.m-3. The peak concentrations of active substances during spraying can reach several dozens of µg.m-3. Ventilation and deposition of aerosols are major elimination mechanisms of pollutants from the air compartment. Moreover, an important distribution of active substances with the surfaces of the room (walls, floor, ceiling, suspended particles and dust) is observed. The evaluation of inhalation exposure to the studied insecticide products show that adverse effects are not likely to occur. Nevertheless, to conclude that these products are safe, it is necessary to perform an integrated evaluation, taking into account all exposure routes
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Hayeck, Nathalie. „Contamination des wafers et de l'atmosphère des salles blanches de la micro-électronique : développement analytique et étude in-situ“. Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4734/document.
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La miniaturisation et la complexification croissante des composants microélectroniques induit une sensibilisation et une fragilisation accrue des composants vis-à-vis des contaminations présentes dans les zones de productions appelées “salles blanches”. Dans ces espaces, le contrôle actuel de la contamination organique n’est pas suffisant puisqu’il ne permet pas d’éviter la contamination de surface des plaquettes de silicium et des optiques des robots de production utilisés pour la photolithographie. Un contrôle accru des concentrations des contaminants organiques dans les atmosphères des salles blanches devient donc nécessaire et de nouvelles méthodes analytiques doivent être développées et validées. Dans le cadre de ce travail, des méthodes d’analyse ont été développées et validées afin de disposer d’une gamme d’outils permettant un suivi rigoureux des contaminations. Ces outils permettent d’identifier et de quantifier les contaminations surfaciques des plaquettes de silicium par des composés organiques semi-volatils (phtalates et organophosphorés) mais aussi de déterminer les concentrations de composés organiques volatils présents dans l’atmosphère des salles blanches. Ces méthodes font appel aux technologies du WOS/ATD-GC-MS « Wafer Outgassing System/Automated Thermal Desorber–Gas Chromatography–Mass Spectrometry » et de la DART-ToF-MS « Direct Analysis in Real Time-Time of Flight–Mass Spectrometry » pour les analyses de surfaces et au PTR-ToF-MS « Proton Transfer Reaction – Time of Flight - Mass Spectrometry » pour l’analyse de l’atmosphèreThe recent advances in the miniaturization and complexification of microelectronic components induce an increase in the sensitivity of these components regarding the organic contamination present in the production zone called “clean room”. Although, the control of organic contamination in the clean room is very rigorous it does not avoid the contamination of silicon wafer surfaces and robot lenses used in the photolithography process. The later implies that new analytical methodologies should be developed and validated. In this work, analytical methods were developed and validated in order to have a panel of tools which allows careful monitoring of organic contaminants. These tools allow the identification and quantitation of the contamination of silicon wafer surface by semi-volatiles organic compounds (phthalates and organophosphates) and the determination of volatile organic compounds concentrations in the clean room atmosphere. These methods uses the WOS/ATD-GC-MS « Wafer Outgassing System/Automated Thermal Desorber–Gas Chromatography–Mass Spectrometry » technology and the DART-ToF-MS « Direct Analysis in Real Time-Time of Flight–Mass Spectrometry » technology for wafer surface analysis and the PTR-ToF-MS « Proton Transfer Reaction – Time of Flight - Mass Spectrometry » technology for gas-phase analysis
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Derstroff, Bettina [Verfasser]. „Investigation of oxygenated and intermediate volatility organic compounds (OVOCs/IVOCs) with a Proton Transfer Reaction - Time Of Flight - Mass Spectrometer (PTR-TOF-MS) / Bettina Derstroff“. Mainz : Universitätsbibliothek Mainz, 2017. http://d-nb.info/1138803103/34.
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Lokajová, Aneta. „Analýza produktů elektrického výboje ve směsích vody a etanolu“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401875.
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The thesis is focused on electrical discharge in liquid solutions, in particular in ethanol solutions. In the theoretical section, the plasma is defined along with its important parameters, types of plasma generation and usage of plasma technologies. Main part is focused on the discharges in water solutions. Electric discharges in liquid solutions enable physical processes (shock waves, UV radiaton, electric current) as well as chemical ones (generation of radicals and ions). Both types of the processes are used in many fields – medicine (tool sterilization, destruction of pathogens), consumer technologies (surface adjustemen, processing of the textiles, surface clearing) of environmental protection (clearing water, decomposition of organic compounds). Goal of the thesis was to analyze discharge products on ethanol solution. Multiple samples were measured and concentration od selected products was monitored during the measurement – ethanol, acetone and acetaldehyde. PTR-TOF-MS method was used to collect and analyze the data. This method is well used thanks to quick response and immediate measurement. It produce the reset accurate enough for our purpose. It would be more efficient to use this method in combination with another analytical metohod in the future research, e.g. gas chromatography.
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Suarez-Bertoa, Ricardo, Michael Clairotte, Bertold Arlitt, Shigeru Nakatani, Leslie Hill, Klaus Winkler, Charlotte Kaarsberg et al. „Intercomparison of ethanol, formaldehyde and acetaldehyde measurements from a flex-fuel vehicle exhaust during the WLTC“. Elsevier, 2017. https://publish.fid-move.qucosa.de/id/qucosa%3A73222.
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An intercomparison exercise of the world-harmonized light-duty vehicle test procedure (WLTP) aiming at measuring ethanol, formaldehyde and acetaldehyde emissions from a flex-fuel light-duty vehicle using E85 was conducted in the Vehicle Emission Laboratory (VELA) at the European Commission Joint Research Centre (EC-JRC), Ispra, Italy. The instruments used during the intercomparison allowed online measurements of these compounds directly from the diluted exhaust. Measurements were done either in real time or immediately after the test. The measurement and analysis of exhaust emissions over the world-harmonized light-duty vehicle test cycle was done by means of Fourier transform infrared spectroscopy (FTIR), proton transfer reaction-mass spectrometry (PTR-Qi-ToF-MS), photoacoustic spectroscopy (PAS) and gas chromatography (GC). Results showed that online systems can perform measurements from the vehicle diluted exhaust assuring a good repeatability (within instrument variance) and reproducibility (between instrument variance) of the results. Measurements from all the instruments were in good agreement (|Z-score| < 2). Results showed that online systems can perform measurements from the vehicle diluted exhaust assuring the reproducibility and repeatability of the results. Results obtained measuring at the tailpipe using a FTIR were in good agreement with those acquired measuring at the constant volume sampler (CVS). Considering the low sensitivity of the current technique used to measure hydrocarbons emissions towards oxygenated compounds (flame ionization detector; FID), non-methane organic gases (NMOG) were calculated applying their FID response factors to the measured emissions of ethanol, acetaldehyde and formaldehyde. NMOG resulted to be up to 74% higher than measured non-methane hydrocarbons (NMHC).
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Fojtíková, Nikola. „Diagnostika plazmatu generovaného v atmosféře simulující podmínky na Marsu“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-445140.
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The aim of the diploma thesis was the diagnostics of plasma generated in the atmosphere simulating conditions on Mars. This diploma thesis is focused on the simulation of Mars’ atmosphere at atmospheric pressure and normal laboratory temperature. Due to the similar conditions of Mars' atmosphere with Earth, this planet has been explored in the past as well as up to now. Mars' atmosphere is composed mostly of carbon dioxide, which makes up more than 90 % of Mars' atmosphere. A glow discharge generated in a special reactor at atmospheric pressure at a flow of pure CO2 was used to simulate the atmosphere of Mars. Part of the measurement was performed only in pure CO2 with changing current of 20, 25, 30, 35 and 40 mA. Part of the measurements was focused on the study of the effect of the addition of various gases, such as nitrogen, hydrogen and methane, at changes in their flow rates of 1, 2, 3, 4 and 5 sccm. The products formed in the special reactor were analysed using a mass spectrometer with proton ionization and with a flight time analyser. Optical emission spectrometry was used for plasma diagnostics and composition. Mainly simple aliphatic hydrocarbons, alcohols, aldehydes, and ketones were detected. With increasing flow rates of the individual gases, more complex aromatic compounds with higher molecular weights were formed. Corresponding mass and optical emission spectra were measured simultaneously.
Buchteile zum Thema "PTR-TOF"
1
Farneti, Brian. „Direct Injection Analysis of Fruit VOCs by PTR-ToF-MS: The Apple Case Study“. In Methods in Molecular Biology, 213–23. New York, NY: Springer New York, 2018. http://dx.doi.org/10.1007/978-1-4939-7643-0_15.
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2
Costa, Corrado, Cosimo Taiti, Maria Concetta Strano, Giuseppe Morone, Francesca Antonucci, Stefano Mancuso, Salvatore Claps et al. „Multivariate Approaches to Electronic Nose and PTR–TOF–MS Technologies in Agro-Food Products“. In Electronic Noses and Tongues in Food Science, 73–82. Elsevier, 2016. http://dx.doi.org/10.1016/b978-0-12-800243-8.00008-1.
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3
Kohl, Ingrid, Jens Herbig, Jürgen Dunkl, Armin Hansel, Martin Daniaux und Michael Hubalek. „Smokers Breath as Seen by Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-TOF-MS)“. In Volatile Biomarkers, 89–116. Elsevier, 2013. http://dx.doi.org/10.1016/b978-0-44-462613-4.00006-4.
Der volle Inhalt der QuelleKonferenzberichte zum Thema "PTR-TOF"
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Carr, Liesl, Luke Bryant, Ahmed Yousuf, Rebecca Cordell, Michael Wilde, Salman Siddiqui, Paul Monks und Christopher Brightling. „Relationship between Volatile Organic Compounds (VOCs) in exhaled breath determined by Proton Transfer Reaction Time of Flight Mass Spectrometry (PTR-TOF-MS), clinical characteristics and airway inflammation in COPD“. In ERS International Congress 2018 abstracts. European Respiratory Society, 2018. http://dx.doi.org/10.1183/13993003.congress-2018.pa2013.
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