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Scientific Articles - PTR-MS Bibliography

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[Northway2004] Northway, MJ., JA. De Gouw, DW. Fahey, RS. Gao, C. Warneke, JM. Roberts, and F. Flocke, "Evaluation of the role of heterogeneous oxidation of alkenes in the detection of atmospheric acetaldehyde", Atmospheric Environment, vol. 38, no. 35: Elsevier, pp. 6017–6028, 2004.
Unexpectedly high values for acetaldehyde have been observed in airborne measurements using a proton-transfer-reaction mass spectrometry instrument. The acetaldehyde values increase with increasing ambient ozone levels with a ratio up to 5 pptv acetaldehyde per ppbv of ozone in the free troposphere. The elevated values of acetaldehyde cannot easily be explained from known tropospheric chemistry. Here, we investigate the possibility that the elevated acetaldehyde signals are due to a sampling artifact. Laboratory experiments show that the elevated signals are not due to changes of the ion chemistry in the instrument, or from the instrument materials reacting with ozone. The heterogeneous oxidation of a number of unsaturated organic compounds is investigated as a possible source for a chemical artifact produced in the instrument inlet. The products of the heterogeneous reactions are consistent with gas phase chemistry, and the ozonolysis of some alkenes does produce acetaldehyde when they have the appropriate hydrocarbon structure. The amount of reactive material in the free troposphere expected to accumulate in the aircraft inlet is unknown, and the exact origin of reactive compounds that contribute to the artifact production remains unresolved.
[Stroud2001] Stroud, CA., JM. Roberts, PD. Goldan, WC. Kuster, PC. Murphy, EJ. Williams, D. Hereid, D. Parrish, D. Sueper, M. Trainer, et al., "Isoprene and its oxidation products, methacrolein and methylvinyl ketone, at an urban forested site during the 1999 Southern Oxidants Study", Journal of Geophysical Research: Atmospheres (1984–2012), vol. 106, no. D8: Wiley Online Library, pp. 8035–8046, 2001.
[Stroud2002] Stroud, CA., JM. Roberts, EJ. Williams, D. Hereid, WM. Angevine, FC. Fehsenfeld, A. Wisthaler, A. Hansel, M. Martinez-Harder, H. Harder, et al., "Nighttime isoprene trends at an urban forested site during the 1999 Southern Oxidant Study", Journal of Geophysical Research: Atmospheres (1984–2012), vol. 107, no. D16: Wiley Online Library, pp. ACH–7, 2002.
[1] Measurements of isoprene and its oxidation products, methacrolein, methyl vinyl ketone and peroxymethacrylic nitric anhydride, were conducted between 13 June and 14 July 1999, at the Cornelia Fort Airpark during the Nashville intensive of the Southern Oxidant Study. Trends in isoprene and its oxidation products showed marked variability from night-to-night. The reaction between isoprene and the nitrate radical was shown to be important to the chemical budget of isoprene and often caused rapid decay of isoprene mixing ratios in the evening. Trends in methacrolein, methyl vinyl ketone, and peroxymethacrylic nitric anhydride were steady during the evening isoprene decay period, consistent with their slow reaction rate with the nitrate radical. For cases when isoprene sustained and even increased in mixing ratio throughout the night, the observed isoprene oxidation rates via the hydroxyl radical, ozone, and the nitrate radical were all small. Sustained isoprene mixing ratios within the nocturnal boundary layer give a unique opportunity to capture hydroxyl radical photochemistry at sunrise as isoprene was observed to rapidly convert to its first stage oxidation products before vertical mixing significantly redistributed chemical species. The observed nighttime isoprene variability at urban, forested sites is related to a complex coupling between nighttime boundary layer dynamics and chemistry.
[DeGouw2003a] De Gouw, JA., PD. Goldan, C. Warneke, WC. Kuster, JM. Roberts, M. Marchewka, SB. Bertman, AAP. Pszenny, and WC. Keene, "Validation of proton transfer reaction-mass spectrometry (PTR-MS) measurements of gas-phase organic compounds in the atmosphere during the New England Air Quality Study (NEAQS) in 2002", Journal of geophysical research, vol. 108, no. D21: American Geophysical Union, pp. 4682, 2003.
Organic compounds were measured by proton transfer reaction-mass spectrometry (PTR-MS) on board the National Oceanic and Atmospheric Administration's research ship Ronald H. Brown during the New England Air Quality Study (NEAQS) in July and August of 2002. PTR-MS has the potential to measure many important organic species with a fast time response, but its validity has not been proven sufficiently. The results obtained by PTR-MS during NEAQS were compared with those from (oxygenated) hydrocarbon measurements by gas chromatography/mass spectrometry (GC-MS), peroxyacyl nitrate measurements by gas chromatography/electron capture detection, and carboxylic acid measurements by mist chamber/ion chromatography. The PTR-MS and GC-MS data for methanol, acetonitrile, acetone, isoprene, benzene, and toluene agreed within the measurement uncertainties. The comparison for C8 aromatics and acetaldehyde was less quantitative due to calibration inaccuracies. In addition, PTR-MS measured the sum of methyl vinyl ketone and methacrolein at 71 amu, the sum of C9 aromatics at 121 amu, and the sum of monoterpenes at 81 and 137 amu. The PTR-MS signal at 61 amu was found to correlate well with data for acetic acid. The signal at 73 amu correlated reasonably well with methyl ethyl ketone data, but the quantitative disagreement suggested interference from other species, possibly methyl glyoxal. The signal at 77 amu correlated well with data for peroxyacetyl nitrate, and the sensitivity inferred from the field data agreed within 30% with the results from laboratory calibrations. Finally, the signal at 105 amu was attributed to styrene and peroxy isobutyryl nitrate. These results prove that many important organic species can be measured accurately and with a fast response time by PTR-MS.

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Selected PTR-MS related Reviews

F. Biasioli, C. Yeretzian, F. Gasperi, T. D. Märk: PTR-MS monitoring of VOCs and BVOCs in food science and technology, Trends in Analytical Chemistry 30 (7) (2011).

J. de Gouw, C. Warneke, T. Karl, G. Eerdekens, C. van der Veen, R. Fall: Measurement of Volatile Organic Compounds in the Earth's Atmosphere using Proton-Transfer-Reaction Mass Spectrometry. Mass Spectrometry Reviews, 26 (2007), 223-257.

W. Lindinger, A. Hansel, A. Jordan: Proton-transfer-reaction mass spectrometry (PTR–MS): on-line monitoring of volatile organic compounds at pptv levels, Chem. Soc. Rev. 27 (1998), 347-375.


Lists with PTR-MS relevant publications of the University of Innsbruck can be found here: Atmospheric and indoor air chemistry, IMR, Environmental Physics and Nano-Bio-Physics


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