Abstract.
Oxygenated
organic
molecules
(OOMs)
play
an
important
role
in
the
formation
of
atmospheric
aerosols.
Due
to
various
analytical
challenges
measuring
vapors,
uncertainties
remain
and
fate
OOMs.
The
chemical
ionization
Orbitrap
mass
spectrometer
(CI-Orbitrap)
has
recently
been
shown
be
a
powerful
technique
able
accurately
identify
gaseous
compounds
due
its
great
resolving
power.
Here
we
present
ammonium
ion
(NH4+)
based
CI-Orbitrap
as
capable
wide
range
performance
CI-(NH4+)-Orbitrap
was
compared
with
that
state-of-the-art
spectrometers,
including
nitrate
(NO3−)
CI
coupled
pressure
interfaced
long
time-of-flight
(APi-LTOF),
new
generation
proton
transfer
reaction-TOF
(PTR3-TOF),
iodide
(I−)
CI-TOF
equipped
Filter
Inlet
for
Gases
AEROsols
(FIGAERO-CIMS).
instruments
were
deployed
simultaneously
Cosmic
Leaving
OUtdoors
Droplets
(CLOUD)
chamber
at
European
Organization
Nuclear
Research
(CERN)
during
CLOUD14
campaign
2019.
Products
generated
from
α-pinene
ozonolysis
across
multiple
experimental
conditions
measured
by
spectrometers.
NH4+-Orbitrap
widest
OOMs
(i.e.,
O
≥
2),
low
oxidized
species
highly
oxygenated
volatile
(HOM).
Excellent
agreements
found
between
NO3−-LTOF
characterizing
HOMs
PTR3-TOF
less
monomeric
species.
A
semi-quantitative
information
retrieved
using
calibration
factors
derived
this
side-by-side
comparison.
As
other
spectrometry
techniques
used
campaign,
detection
sensitivity
is
greatly
affected
relative
humidity,
which
may
related
changes
efficiency
and/or
multiphase
chemistry.
Overall,
study
shows
NH4+
ion-based
chemistry
associated
high
power
analyzer
can
measure
almost
all-inclusive
compounds.
result,
it
now
possible
cover
entire
compounds,
lead
better
understanding
oxidation
processes.
Journal of Aerosol Science,
Journal Year:
2024,
Volume and Issue:
179, P. 106375 - 106375
Published: March 30, 2024
The
formation
of
aerosol
particles
in
the
atmosphere
is
driven
by
gas
to
particle
conversion
extremely
low
volatile
organic
compounds
(ELVOC),
with
a
particularly
saturation
vapor
pressure
(pSat).
Identifying
ELVOCs
and
their
chemical
structures
both
experimentally
theoretically
challenging:
Measuring
very
pSat
difficult,
computing
for
these
often
large
molecules
computationally
costly.
Moreover,
are
underrepresented
available
datasets
atmospheric
species,
which
reduces
value
statistical
models
built
on
such
data.
We
propose
an
active
learning
(AL)
approach
efficiently
identify
data
pool
species
initially
unknown
pSat.
assess
performance
our
AL
comparing
it
traditional
machine
regression
methods,
as
well
ELVOC
classification
based
molecular
properties.
proves
be
highly
efficient
method
identification
limitations
type
can
identify.
also
show
that
or
property-based
methods
adequate
tools
depending
desired
degree
efficiency.
Analytical Chemistry,
Journal Year:
2024,
Volume and Issue:
96(23), P. 9524 - 9534
Published: May 30, 2024
Quantitative
assessment
of
gas-particle
partitioning
individual
components
within
complex
atmospheric
organic
aerosol
(OA)
mixtures
is
critical
for
predicting
and
comprehending
the
formation
evolution
OA
particles
in
atmosphere.
This
investigation
leverages
previously
documented
data
obtained
through
a
temperature-programmed
desorption–direct
analysis
real-time,
high-resolution
mass
spectrometry
(TPD-DART-HRMS)
platform.
methodology
facilitates
bottom-up
construction
volatility
basis
set
(VBS)
distributions
constituents
found
three
biogenic
secondary
(SOA)
produced
ozonolysis
α-pinene,
limonene,
ocimene.
The
apparent
enthalpies
(ΔH*,
kJ
mol–1)
saturation
concentrations
(CT*,
μg·m–3)
SOA
components,
determined
as
function
temperature
(T,
K),
facilitated
an
changes
VBS
with
respect
to
T
total
loadings
(tOM,
μg·m–3).
reveal
distinct
differences
volatilities
among
monomers,
dimers,
trimers,
categorized
into
separate
bins.
At
ambient
=
298
K,
only
monomers
efficiently
partition
between
gas
particle
phases
across
broad
range
atmospherically
relevant
tOM
values
1–100
μg·m–3.
Partitioning
dimers
trimers
becomes
notable
at
>
360
K
420
respectively.
viscosity
assessed
using
calculation
approach,
incorporating
input
elemental
formulas,
ΔH*,
CT*,
particle-phase
fractions
components.
Through
this
we
are
able
accurately
estimate
variations
that
result
from
evaporation
its
These
are,
turn,
influenced
by
T.
Comparison
calculated
diffusivity
literature
reported
experimental
results
shows
close
agreement,
thereby
validating
employed
approach.
findings
underscore
significant
potential
TPD-DART-HRMS
measurements
enabling
untargeted
molecules
mixtures.
approach
quantitative
their
allows
estimation
condensed-phase
diffusion,
contributing
valuable
insights
models.
Biomass
burning
organic
aerosol
(BBOA),
containing
brown
carbon
chromophores,
plays
a
critical
role
in
atmospheric
chemistry
and
climate
forcing.
However,
the
effects
of
evaporation
on
BBOA
volatility
viscosity
under
different
environmental
conditions
remain
poorly
understood.
This
study
focuses
molecular
characterization
laboratory-generated
proxies
from
wood
pyrolysis
emissions.
The
initial
mixture,
"pyrolysis
oil
(PO
While
biomass
burning
(BB)
is
the
largest
source
of
fine
particles
in
atmosphere,
influence
relative
humidity
(RH)
and
photochemistry
on
BB
secondary
organic
aerosol
(BB-SOA)
formation
aging
remains
poorly
constrained.
These
effects
need
to
be
addressed
better
capture
comprehend
evolution
BB-SOA
atmosphere.
Cresol
(C7H8O)
used
as
a
proxy
investigate
these
effects.
It
emitted
directly
from
has
been
identified
significant
SOA
precursor
residential
wood-burning
emissions.
The
gas-
particle-phase
signal
intensities
are
investigated
using
online
mass
spectrometers.
An
increase
yield
7%
observed
when
RH
rises
0.5–20
70–87%.
At
elevated
RH,
nitrogen-containing
compounds
due
processes.
This
linked
net
decrease
viscosity,
enabling
formed
greater
extent
at
presence
nitrogen
oxides.
results
highlight
importance
particle
water
content
for
molecular
compounds.
Geophysical Research Letters,
Journal Year:
2024,
Volume and Issue:
51(3)
Published: Feb. 4, 2024
Abstract
Aerosol
water
affects
the
physicochemical
properties
and
mass
concentration
of
organic
aerosols
(OA),
but
it
is
typically
omitted
by
air
quality,
weather,
climate
models.
We
compare
two
classes
simplified
models
to
estimate
OA
uptake
gas–particle
partitioning
compounds.
One
class
uses
a
single‐hygroscopicity‐parameter
(
κ
)
approach
while
other
based
on
reduced‐complexity
Binary
Activity
Thermodynamics
(BAT)
model.
show
that
BAT‐based
two‐dimensional
volatility
basis
set
(VBS)
model
always
predicts
higher
at
elevated
relative
humidity
(RH),
for
example,
∼16%
80%
RH,
than
any
variation
‐based
method
considered—even
when
BAT‐VBS
lower
uptake.
The
main
reason
being
captures
variations
in
effective
saturation
organics
C
*)
with
feature
VBS
methods
lack.
framework
offers
an
efficient,
RH‐sensitive
treatment
modeling.
Environmental Science Atmospheres,
Journal Year:
2023,
Volume and Issue:
4(1), P. 88 - 103
Published: Nov. 29, 2023
This
study
investigates
the
effects
of
temperature
and
relative
humidity
on
formation
secondary
organic
aerosol
from
Δ
3
-carene,
a
prevalent
monoterpene
in
boreal
forests.
Atmospheric measurement techniques,
Journal Year:
2024,
Volume and Issue:
17(17), P. 5413 - 5428
Published: Sept. 13, 2024
Abstract.
Oxygenated
organic
molecules
(OOMs)
play
an
important
role
in
the
formation
of
atmospheric
aerosols.
Due
to
various
analytical
challenges
with
respect
measuring
vapors,
uncertainties
remain
regarding
and
fate
OOMs.
The
chemical
ionization
Orbitrap
(CI-Orbitrap)
mass
spectrometer
has
recently
been
shown
be
a
powerful
technique
that
is
able
accurately
identify
gaseous
compounds
due
its
greater
resolution.
Here,
we
present
ammonium-ion-based
CI-Orbitrap
(NH4+-Orbitrap)
as
capable
wide
range
performance
NH4+-Orbitrap
compared
state-of-the-art
spectrometers,
including
nitrate-ion-based
pressure
interface
coupled
time-of-flight
(NO3--LTOF),
new
generation
proton
transfer
reaction-TOF
(PTR3-TOF),
iodide-based
CI-TOF
equipped
Filter
Inlet
for
Gases
AEROsols
(I−-CIMS).
instruments
were
deployed
simultaneously
Cosmic
Leaving
OUtdoors
Droplets
(CLOUD)
chamber
at
European
Organization
Nuclear
Research
(CERN)
during
CLOUD14
campaign
2019.
Products
generated
from
α-pinene
ozonolysis
under
experimental
conditions
measured
by
spectrometers.
was
widest
OOMs
(i.e.,
O
≥
2),
less-oxidized
species
highly
oxygenated
(HOMs).
Excellent
agreement
found
between
NO3--LTOF
characterizing
HOMs
PTR3-TOF
monomeric
species.
OOM
concentrations
estimated
using
calibration
factors
derived
high
time-series
correlations
side-by-side
measurements.
As
other
spectrometry
techniques
used
this
campaign,
detection
sensitivity
greatly
affected
relative
humidity,
which
may
related
changes
efficiency
and/or
multiphase
chemistry.
Overall,
study
shows
NH4+-ion-based
chemistry
associated
resolution
analyzer
can
measure
almost
all
inclusive
compounds.
result,
it
now
possible
cover
entire
compounds,
lead
better
understanding
oxidation
processes.