ptr-ms: Proton Transfer Reaction Mass Spectrometer

The Proton Transfer Reaction Mass Spectrometer (PTR-MS) measures gas-phase compounds in ambient air and headspace samples before using chemical ionization to produce positively charged molecules, which are detected with a time-of-flight (TOF) mass spectrometer. This ionization method uses a gentle proton transfer reaction method between the molecule of interest and protonated water, or hydronium ion (H3O+), to produce limited fragmentation of the parent molecule. The ions produced are primarily positively charged with the mass of the parent ion, plus an additional proton. Ion concentration is determined by adding the number of ions counted at the molecular ion’s mass-to-charge ratio to the number of air molecules in the reaction chamber, which can be identified according to the pressure levels in the reaction chamber. The PTR-MS allows many volatile organic compounds in ambient air to be detected at levels from 10–100 parts per trillion by volume (pptv). The response time is 1 to 10 seconds.

Measurements

Related Publications

2018

Liu Y, R Seco, S Kim, A Guenther, A Goldstein, F Keutsch, S Springston, T Watson, P Artaxo, R Souza, K McKinney, and S Martin. 2018. "Isoprene photo-oxidation products quantify the effect of pollution on hydroxyl radicals over Amazonia." Science Advances, 4(4), eaar2547, 10.1126/sciadv.aar2547.

Koss A, K Sekimoto, J Gilman, V Selimovic, M Coggon, K Zarzana, B Yuan, B Lerner, S Brown, J Jimenez, J Krechmer, J Roberts, C Warneke, R Yokelson, and J de Gouw. 2018. "Non-methane organic gas emissions from biomass burning: identification, quantification, and emission factors from PTR-ToF during the FIREX 2016 laboratory experiment." Atmospheric Chemistry and Physics, 18(5), 10.5194/acp-18-3299-2018.

Palm B, S de Sá, D Day, P Campuzano-Jost, W Hu, R Seco, S Sjostedt, J Park, A Guenther, S Kim, J Brito, F Wurm, P Artaxo, R Thalman, J Wang, L Yee, R Wernis, G Isaacman-VanWertz, A Goldstein, Y Liu, S Springston, R Souza, M Newburn, M Alexander, S Martin, and J Jimenez. 2018. "Secondary organic aerosol formation from ambient air in an oxidation flow reactor in central Amazonia." Atmospheric Chemistry and Physics, 18(1), doi:10.5194/acp-18-467-2018.

2017

Zaveri R, J Shilling, A Zelenyuk, J Liu, D Bell, E D'Ambro, C Gaston, J Thornton, A Laskin, P Lin, J Wilson, R Easter, J Wang, A Bertram, S Martin, J Seinfeld, and D Worsnop. 2017. "Growth kinetics and size distribution dynamics of viscous secondary organic aerosol." Environmental Science & Technology, 52(3), 10.1021/acs.est.7b04623.

2016

Kontkanen J, P Paasonen, J Aalto, J Bäck, P Rantala, T Petäjä, and M Kulmala. 2016. "Simple proxies for estimating the concentrations of monoterpenes and their oxidation products at a boreal forest site." Atmospheric Chemistry and Physics, 16(20), 10.5194/acp-16-13291-2016.

Watson TB. 2016. Proton Transfer Time-of-Flight Mass Spectrometer Instrument Handbook. Ed. by Robert Stafford, DOE ARM Climate Research Facility. DOE/SC-ARM-TR-160.

2004

Jobson BT, CM Berkowitz, WC Kuster, PD Goldan, EJ Williams, F Fehsenfeld, E Apel, TG Karl, WA Lonneman, and D Riemer. 2004. "Hydrocarbon source signatures in Houston, Texas: Influence of the petrochemical industry." Journal of Geophysical Research – Atmospheres, 109(D24), D24305, 10.1029/2004jd004887.


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