10.1021/acs.analchem.6b05110.s001
Martin Breitenlechner
Martin
Breitenlechner
Lukas Fischer
Lukas
Fischer
Markus Hainer
Markus
Hainer
Martin Heinritzi
Martin
Heinritzi
Joachim Curtius
Joachim
Curtius
Armin Hansel
Armin
Hansel
PTR3: An Instrument for Studying the Lifecycle of
Reactive Organic Carbon in
the Atmosphere
American Chemical Society
2017
reaction chamber
mass resolution
gas inlet
sample gas
proton transfer reaction-time-of-flight mass spectrometer
PTR-TOF-MS
volatility compounds
reaction time
SVOC
wall losses
water molecules
Reactive Organic Carbon
First calibration tests show sensitivities
sample gas flow
H 3 O
VOC
ppbv range
18000 counts
reaction chamber design
product ions
volume
rf voltages
PTR 3 instrument
PTR-TOF
HOM
2017-04-24 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/PTR3_An_Instrument_for_Studying_the_Lifecycle_of_Reactive_Organic_Carbon_in_the_Atmosphere/4996703
We have developed
and characterized the novel PTR3, a proton transfer
reaction-time-of-flight mass spectrometer (PTR-TOF) using a new gas
inlet and an innovative reaction chamber design. The reaction chamber
consists of a tripole operated with rf voltages generating an electric
field only in the radial direction. An elevated electrical field is
necessary to reduce clustering of primary hydronium (H<sub>3</sub>O<sup>+</sup>) and product ions with water molecules present in the
sample gas. The axial movement of the ions is achieved by the sample
gas flow only. Therefore, the new design allows a 30-fold longer reaction
time and a 40-fold increase in pressure compared to standard PTR-TOF-MS.
First calibration tests show sensitivities of up to 18000 counts per
second/parts per billion and volume (cps/ppbv) at a mass resolution
of >8000 <i>m</i>/Δ<i>m</i> (fwhm). The
new inlet using center-sampling through a critical orifice reduces
wall losses of low volatility compounds. Therefore, the new PTR3 instrument
is sensitive to VOC typically present in the ppbv range as well as
to semivolatile organic compounds (SVOC) and even highly oxidized
organic molecules (HOMs) present in the parts per quadrillion per
volume (ppqv) range in the atmosphere.