The PTR3: A novel Instrument for studying the transformation of VOCs to condensing and even nucleating vapors

DSRC entrance

Armin Hansel, University of Innsbruck

Friday, December 8, 2017, 10:00 am Mountain Time
DSRC 2A305


Terrestrial plants and anthropogenic activities emit a large amount of volatile organic compounds (VOC) to the atmosphere. Their condensable oxidation products can form secondary organic aerosol (SOA), a significant component of atmospheric aerosol which is known to affect the Earth’s radiation balance by back-scattering solar radiation and by acting as cloud condensation nuclei (CCN). The quantitative assessment of such climate effects is poorly understood by a number of factors, including an incomplete understanding of how VOCs are transformed to SOA and new particles. Atmospheric oxidation processes almost exclusively form RO2 radicals as reactive intermediates whose atmospheric fate is not fully discovered yet.

Here I will present a novel instrument: The PTR3, using either H3O+(H2O)n or NH4+(NH3)n adduct ions to quantitatively ionize all RO2 radicals and all oxidized product molecules (OMs) simultaneously. Cyclohexene Ozonolysis has been chosen as a first test reaction system. For the first-time carbon closure could be achieved with a single
instrument. The sensitivity of the PTR3 technique is high enough to apply this technique not only for laboratory based studies but also for environmental measurements in real-time.

Armin Hansel is a professor at the University of Innsbruck, where he studies VOCs from anthropogenic and biogenic sources. He pioneered the development of PTR-MS as a method for fast and sensitive VOC monitoring. He is the cofounder of Ionicon Analytik GmbH and the author of over 70 publications.

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