HR: 08:02h
AN: A51H-01 INVITED    [Abstracts]
TI: High Resolution PTR-TOFMS: A New Instrument for Organic Compound Measurements
AU: * Hansel, A
EM: armin.hansel@uibk.ac.at
AF: Institute of Ion Physics and Applied Physics, University of Innsbruck, Technikerstrasse 25, Innsbruck, 6020, Austria
AU: Graus, M
EM: martin.graus@uibk.ac.at
AF: Institute of Ion Physics and Applied Physics, University of Innsbruck, Technikerstrasse 25, Innsbruck, 6020, Austria
AU: Mueller, M
EM: markus.mueller@uibk.ac.at
AF: Institute of Ion Physics and Applied Physics, University of Innsbruck, Technikerstrasse 25, Innsbruck, 6020, Austria
AU: Wisthaler, A
EM: armin.wisthaler@uibk.ac.at
AF: Institute of Ion Physics and Applied Physics, University of Innsbruck, Technikerstrasse 25, Innsbruck, 6020, Austria
AB: Over the last decade proton transfer reaction mass spectrometry (PTR-MS) has become very popular in many scientific fields. PTR-MS allows for the quantitative detection of volatile organic compounds (VOCs) at pptv-level virtually in real time. Monitoring of VOCs with a time resolution of typically a second per compound has, for instance, enabled the tracking of pollution plumes by air-borne measurements, thus revealing the photo- chemical fate of pollutants. It has also been employed in direct eddy covariant flux measurements. This rapidity, however, has been achieved at the cost of the number of compounds to be analyzed and compound selectivity. Conventional PTR-MS can, for example, not distinguish between hydrocarbons and their oxygenated isobaric species, e.g. between naphthalene and octanal or between isoprene and furan. In a mass range up to 200 Dalton, such a task would require a mass resolving power of 5500. The use of a time of flight (TOF) instead of a quadrupole mass analyzer in PTR-MS provides a sufficient high mass resolution to identify the atomic composition of product ions by their exact mass and their characteristic isotope patterns. In addition PTR-TOF-MS can record full mass spectra within a fraction of a second which is a dramatically increase in duty cycle. At the University of Innsbruck a high resolution PTR-TOFMS has recently been developed, coupling a PTR-ion source and a high resolution TOFMS. We achieved a mass resolving power of 6000 (FWHM), and a detection limit of tens to a few hundreds of pptv if integrating mass spectra for one minute. First results and future directions will be discussed in this paper.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0365 Troposphere: composition and chemistry
DE: 0394 Instruments and techniques
DE: 0452 Instruments and techniques
DE: 0454 Isotopic composition and chemistry (1041, 4870)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting