Environmental Science & Technology,
Journal Year:
2019,
Volume and Issue:
53(4), P. 1812 - 1821
Published: Jan. 11, 2019
Water-soluble
organic
gas
(WSOG)
concentrations
are
elevated
in
homes.
However,
WSOG
sources,
sinks,
and
concentration
dynamics
poorly
understood.
We
observed
substantial
variations
23
residential
indoor
measured
real
time
a
North
Carolina,
U.S.,
home
over
several
days
with
high-resolution
time-of-flight
chemical
ionization
mass
spectrometer
equipped
iodide
reagent
ion
chemistry
(I-HR-ToF-CIMS).
Concentrations
of
acetic,
formic,
lactic
acids
ranged
from
30−130,
15−53,
2.5−360
μg
m–3,
respectively.
WSOGs,
including
acetic
formic
acids,
decreased
considerably
(∼30–50%)
when
the
air
conditioner
(AC)
cycled
on,
suggesting
that
AC
system
is
an
important
sink
for
WSOGs.
In
contrast
to
nonpolar
gases,
loss
rate
coefficients
were
compounds
high
oxygen-to-carbon
(O/C)
ratios
(e.g.,
1.6–2.2
h–1
O/C
>
0.75
was
off).
Loss
more
uncertain
but
estimated
be
1.5
h–1.
Elevated
acid
coincided
increased
human
occupancy
cooking.
report
WSOGs
emitted
cooking
cleaning
as
well
transported
outdoors.
addition
chemistry,
these
results
have
implications
exposure
health.
Atmospheric chemistry and physics,
Journal Year:
2021,
Volume and Issue:
21(11), P. 8455 - 8478
Published: June 3, 2021
Abstract.
The
atmospheric
processes
under
polluted
environments
involving
interactions
of
anthropogenic
pollutants
and
natural
emissions
lead
to
the
formation
various
complex
secondary
products.
Therefore,
characterization
oxygenated
organic
compounds
in
urban
areas
remains
a
pivotal
issue
our
understanding
evolution
carbon.
Here,
we
describe
measurements
an
iodide
chemical
ionization
time-of-flight
mass
spectrometer
installed
with
Filter
Inlet
for
Gases
AEROsols
(FIGAERO-I-CIMS)
both
gas
phase
particle
at
site
Guangzhou,
typical
megacity
southern
China,
during
autumn
2018.
Abundant
containing
two
five
oxygen
atoms
were
observed,
including
acids,
multi-functional
typically
emitted
from
biomass
burning,
oxidation
products
biogenic
hydrocarbons
aromatics.
Photochemistry
played
dominant
roles
gaseous
acids
isoprene-derived
nitrates,
while
nighttime
chemistry
contributed
significantly
monoterpene-derived
nitrates
inorganics.
Nitrogen-containing
occupied
significant
fraction
total
signal
phases,
elevated
fractions
higher
molecular
weights.
Measurements
by
FIGAERO-I-CIMS
explained
24
±
0.8
%
aerosol
measured
(AMS),
increased
more
aged
aerosol.
systematical
interpretation
spectra
area
Guangzhou
provides
holistic
view
numerous
atmosphere,
which
can
serve
as
reference
future
field
regions.
Atmospheric chemistry and physics,
Journal Year:
2018,
Volume and Issue:
18(10), P. 7149 - 7168
Published: May 24, 2018
Abstract.
Non-refractory
submicrometer
particulate
matter
(NR-PM1)
was
measured
in
the
Seoul
Metropolitan
Area
(SMA),
Korea,
using
an
Aerodyne
high-resolution
time-of-flight
aerosol
mass
spectrometer
(HR-ToF-AMS)
from
14
April
to
15
June
2016,
as
a
part
of
Korea-US
Air
Quality
Study
(KORUS-AQ)
campaign.
This
first
highly
time-resolved,
real-time
measurement
study
springtime
SMA
and
results
reveal
valuable
insights
into
sources
atmospheric
processes
that
contribute
PM
pollution
this
region.
The
average
concentration
(PM1
=
NR-PM1
+
black
carbon
(BC))
22.1
µg
m−3,
which
composed
44
%
organics,
20
sulfate,
17
nitrate,
12
ammonium,
7
BC.
Organics
had
atomic
oxygen-to-carbon
(O
∕
C)
ratio
0.49
organic
mass-to-carbon
(OM/OC)
1.82.
Four
distinct
OA
were
identified
via
positive
matrix
factorization
(PMF)
analysis
HR-ToF-AMS
data:
vehicle
emissions
represented
by
hydrocarbon-like
factor
(HOA;
O
C
0.15;
mass),
food
cooking
activities
cooking-influenced
(COA;
0.19;
22
secondary
(SOA)
semi-volatile
oxygenated
(SV-OOA;
0.44;
27
mass)
low-volatility
(LV-OOA;
0.91;
34
mass).
Our
indicate
air
quality
during
KORUS-AQ
influenced
strongly
formation,
with
SV-OOA,
LV-OOA
together
accounting
for
76
PM1
mass.
In
particular,
formation
sulfate
mainly
promoted
elevated
ozone
concentrations
photochemical
reactions
daytime,
whereas
SV-OOA
nitrate
contributed
both
nocturnal
processing
VOC
nitrogen
oxides,
respectively,
daytime
reactions.
addition,
lower
nighttime
temperature
gas-to-particle
partitioning
semivolatile
species
nitrate.
During
period
4
days
(from
23
May
),
increased
dramatically
accounted
up
41
intense
event
associated
large
enhancements
anthropogenic
biogenic
VOCs
(e.g.,
isoprene
toluene),
high
Ox
(
O3
NO2),
strong
solar
radiation,
stagnant
conditions,
suggesting
it
driven
local
formation.
We
have
also
investigated
evolution
mechanisms
severe
haze
episodes.
Unlike
winter
events
caused
coupled
meteorological
spring
appeared
be
regional
factors.
For
example,
there
episodes
long-range
transport
plumes
followed
calm
meteorology
accumulation
species,
leading
PM.
Overall,
our
pollutants
urban
Korea
originate
complex
emission
composition
are
controlled
various
factors,
including
emissions,
upwind
sources.
Accounts of Chemical Research,
Journal Year:
2020,
Volume and Issue:
53(8), P. 1415 - 1426
Published: July 10, 2020
ConspectusThe
complex
array
of
sources
and
transformations
organic
carbonaceous
material
that
comprises
an
important
fraction
atmospheric
fine
particle
mass,
known
as
aerosol,
has
presented
a
long
running
challenge
for
accurate
predictions
its
abundance,
distribution,
sensitivity
to
anthropogenic
activities.
Uncertainties
about
changes
in
aerosol
abundance
over
time
translate
uncertainties
their
impact
on
Earth's
climate
response
air
quality
policy.
One
limitation
our
understanding
been
lack
comprehensive
measurements
molecular
composition
volatility,
which
can
elucidate
processes
affecting
abundance.
Herein
we
describe
advances
the
development
application
Filter
Inlet
Gases
Aerosols
(FIGAERO)
coupled
field-deployable
High-Resolution
Time-of-Flight
Chemical
Ionization
Mass
Spectrometers
(HRToF-CIMS).
The
FIGAERO
HRToFCIMS
combination
broadly
probes
gas
particulate
OA
by
using
programmed
thermal
desorption
particles
collected
Teflon
filter
with
subsequent
detection
speciation
desorbed
vapors
inherently
quantitative
selected-ion
chemical
ionization.
provides
means
obtain
insights
into
volatility
components
thus
physicochemical
nature
will
govern
evolution
atmosphere.In
this
Account,
discuss
design
operation
FIGAERO,
when
HRToF-CIMS,
characterization
molecular-level
effective
laboratory
field.
We
provide
example
gleaned
from
deployment,
improve
evolution.
Specifically,
connect
profiles
equilibrium
saturation
vapor
concentration
enthalpy
vaporization
detected
components.
also
show
how
HRToF-CIMS
environmental
simulation
chamber
experiments
field
new
constraints
mechanisms
governing
secondary
formation
dynamic
associated
challenges
decomposition
during
calibration
both
axis
signal.
illustrate
additional
through
isothermal
evaporation
well
ultrafine
composition.
conclude
description
future
opportunities
needs
ability
further
science.
Environmental Science & Technology,
Journal Year:
2018,
Volume and Issue:
52(16), P. 9285 - 9294
Published: Aug. 2, 2018
Organic
aerosol
(OA)
is
a
major
component
of
fine
particulate
matter
(PM2.5)
in
urban
environments.
We
performed
in-motion
ambient
sampling
from
mobile
platform
with
an
mass
spectrometer
(AMS)
to
investigate
the
spatial
variability
and
sources
OA
concentrations
Pittsburgh,
Pennsylvania,
midsize,
largely
postindustrial
American
city.
To
characterize
relative
importance
cooking
traffic
sources,
we
sampled
some
most
populated
areas
(∼18
km2)
around
Pittsburgh
during
afternoon
rush
hour
evening
mealtime,
including
congested
highways,
local
roads,
high
densities
restaurants,
background
locations.
found
greatly
elevated
(10s
μg
m–3)
vicinity
numerous
individual
restaurants
commercial
districts
containing
multiple
restaurants.
The
AMS
spectral
information
indicates
that
majority
concentration
plumes
(71%)
were
sources.
Areas
both
busy
roads
had
systematically
higher
than
only
Elevated
measured
hundreds
meters
downwind
indicating
these
can
influence
air
quality
on
neighborhood
scales.
Approximately
20%
population
(∼250
000
people)
area
lives
within
200
m
restaurant;
therefore,
restaurant
emissions
are
potentially
important
source
outdoor
PM
exposures
for
this
large
population.
Environment International,
Journal Year:
2021,
Volume and Issue:
150, P. 106426 - 106426
Published: Feb. 9, 2021
Restrictions
on
human
activities
were
implemented
in
China
to
cope
with
the
outbreak
of
Coronavirus
Disease
2019
(COVID-19),
providing
an
opportunity
investigate
impacts
anthropogenic
emissions
air
quality.
Intensive
real-time
measurements
made
compare
primary
and
secondary
aerosol
formation
Xi'an,
before
during
COVID-19
lockdown.
Decreases
mass
concentrations
particulate
matter
(PM)
its
components
observed
lockdown
reductions
32–51%.
The
dominant
contributor
PM
was
organic
(OA),
results
a
hybrid
environmental
receptor
model
indicated
OA
composed
four
(POA)
factors
(hydrocarbon-like
(HOA),
cooking
(COA),
biomass
burning
(BBOA),
coal
combustion
(CCOA))
two
oxygenated
(OOA)
(less-oxidized
OOA
(LO-OOA)
more-oxidized
(MO-OOA)).
decreased
from
over
range
17%
58%,
they
affected
by
control
measures
processes.
Correlations
aerosols/ΔCO
Ox
(NO2
+
O3)
liquid
water
content
that
photochemical
oxidation
had
greater
effect
nitrate
OOAs
than
sulfate;
however,
aqueous-phase
reaction
presented
more
complex
aerosols
at
different
relative
humidity
condition.
efficiencies
enhanced
as
increase
atmospheric
capacity.
Analyses
pollution
episodes
highlighted
importance
OA,
especially
LO-OOA,
for
Atmospheric measurement techniques,
Journal Year:
2021,
Volume and Issue:
14(5), P. 3631 - 3655
Published: May 20, 2021
Abstract.
Aerosol
intercomparisons
are
inherently
complex
as
they
convolve
instrument-dependent
detection
efficiencies
vs.
size
(which
often
change
with
pressure,
temperature,
or
humidity)
and
variations
in
the
sampled
aerosol
population,
addition
to
differences
chemical
principles
(e.g.,
inorganic-only
nitrate
inorganic
plus
organic
for
two
instruments).
The
NASA
Atmospheric
Tomography
Mission
(ATom)
spanned
four
separate
aircraft
deployments
which
remote
marine
troposphere
from
86∘
S
82∘
N
over
different
seasons
a
wide
range
of
concentrations
compositions.
Aerosols
were
quantified
set
carefully
characterized
calibrated
instruments,
some
based
on
particle
sizing
composition
measurements.
This
study
aims
provide
critical
evaluation
inlet
transmissions
impacting
intercomparisons,
quantification
during
ATom,
focus
mass
spectrometer
(AMS).
volume
determined
physical
instruments
(aerosol
microphysical
properties,
AMP,
2.7
nm
4.8
µm
optical
diameter)
is
compared
detail
that
derived
measurements
AMS
single
soot
photometer
(SP2).
Special
attention
was
paid
characterize
upper
end
size-dependent
transmission
in-field
calibrations,
we
show
be
accurate
comparisons
across
inevitably
cuts.
Observed
between
campaigns
emphasize
importance
characterizing
each
instrument
field
meaningful
interpretation
comparisons.
Good
agreement
(regression
slope
=0.949
1.083
ATom-1
ATom-2,
respectively;
SD
=0.003)
found
composition-based
(including
AMS-quantified
sea
salt)
AMP
after
applying
transmission.
captured,
average,
95±15
%
standard
PM1
(referred
URG
Corp.
cut
1
cyclone
operated
at
its
nominal
efficiency).
These
results
support
absence
significant
unknown
biases
appropriateness
accuracy
estimates
total
mostly
aged
air
masses
encountered
ATom.
ranges
(and
their
altitude
dependence)
by
complementary
(such
soluble
acidic
gases
aerosol,
SAGA,
analysis
laser
spectrometry,
PALMS)
investigated
inform
use
future
studies.
Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences,
Journal Year:
2020,
Volume and Issue:
378(2183), P. 20190319 - 20190319
Published: Sept. 27, 2020
Airborne
particulate
matter
(PM)
is
a
pollutant
of
concern
not
only
because
its
adverse
effects
on
human
health
but
ability
to
reduce
visibility
and
soil
buildings
materials.
It
can
be
regarded
as
suite
pollutants
since
PM
covers
very
wide
range
particle
sizes
also
has
diverse
chemical
composition.
Historically,
much
the
arose
from
coal
burning
was
measured
black
smoke.
However,
in
second
half
twentieth
century
developed
countries,
there
reduction
smoke
emissions
steadily
became
dominated
by
carbonaceous
particles
road
traffic
exhaust
secondary
pollutants,
ammonium
salts
organic
carbon.
This
exemplified
composition
fine
(referred
2.5
)
London,
Delhi
Beijing.
Steadily,
control
strategies
have
addressed
more
tractable
sources
emissions,
so
previously
unconventional
emerged
been
seen
make
significant
contribution
airborne
concentrations.
Among
these
are
non-exhaust
traffic,
cooking
aerosol
wood
The
size
distribution
hugely
diverse,
ranging
newly
formed
few
nanometres
diameter
through
tens
micrometres
diameter.
There
great
deal
interest
ultrafine
(nano)
suspicions
enhanced
toxicity,
decrease
source,
regional
nucleation
processes
become
bigger
relative
contributors
number,
mass.
article
part
discussion
meeting
issue
‘Air
quality,
past
present
future’.
Journal of Geophysical Research Atmospheres,
Journal Year:
2021,
Volume and Issue:
126(16)
Published: Aug. 6, 2021
Abstract
To
investigate
the
chemical
compositions,
sources,
and
aging
processes
of
submicron
particles
(PM
1
),
a
comprehensive
field
campaign
was
conducted
in
Guangzhou
urban
area
China
during
autumn
(October–November)
2018.
The
average
mass
concentration
PM
35.6
±
20.8
µg
m
−3
,
which
mainly
contributed
by
organic
aerosols
(OA,
42%),
then
followed
sulfate
(25%)
inorganic
nitrate
(11%).
found
to
be
main
driving
component
(up
∼50%)
account
for
fast
increase
polluted
periods
autumn.
promotion
effects
sulfate,
aerosol
liquid
water
content,
acidity
on
formation
were
systematically
discussed.
Source
apportionment
results
showed
72%
OA
secondary
(SOA),
28%
primary
(POA),
including
vehicle
emission
related
hydrocarbon‐like
(HOA,
16%),
nitrogen‐containing
(NOA,
3%)
cooking
(COA,
8%).
explore
OA,
dynamic
variations
its
oxidation
level
as
function
ambient
photochemical
age
are
shown.
Using
an
situ
field‐deployed
flow
reactor,
heterogeneous
reaction
rate
coefficients
POA
with
OH
radicals
(
)
estimated
4.0–5.4
×
10
−13
cm
3
molecules
−1
s
is
equivalent
lifetime
>2
weeks.
long
supports
gas
phase
major
pathway
aging.
uptake
coefficient
0.76–0.84,
underlining
that
can
taken
up
efficiently
aerosols.
Atmospheric measurement techniques,
Journal Year:
2019,
Volume and Issue:
12(3), P. 1429 - 1439
Published: March 5, 2019
Abstract.
The
Filter
Inlet
for
Gases
and
AEROsols
(FIGAERO)
is
an
inlet
specifically
designed
to
be
coupled
with
the
Aerodyne
High-Resolution
Time-of-Flight
Chemical
Ionization
Mass
Spectrometer
(HR-ToF-CIMS).
FIGAERO-HR-ToF-CIMS
provides
simultaneous
molecular
information
relating
both
gas-
particle-phase
samples
has
been
used
extract
vapour
pressures
(VPs)
of
compounds
desorbing
from
filter
whilst
giving
quantitative
concentrations
in
particle
phase.
However,
such
extraction
measured
components
requires
use
appropriate,
well-defined,
reference
compounds.
Vapour
homologous
series
polyethylene
glycols
(PEG)
((H-(O-CH2-CH2)n-OH)
n=3
n=8),
covering
a
range
(VP)
(10−1
10−7
Pa)
that
are
atmospherically
relevant,
have
shown
reproduced
well
by
different
techniques,
including
Knudsen
Effusion
Spectrometry
(KEMS).
This
first
which
number
pressure
measurement
techniques
found
agreement,
indicating
utility
as
calibration
standard,
providing
ideal
set
benchmark
accurate
characterization
FIGAERO
extracting
chambers
real
atmosphere.
To
demonstrate
this,
single-component
mixture
measurements
made
using
two
instruments
based
on
new
determined
PEG
series.
VP
values
extracted
agree
those
KEMS
reported
literature,
validating
this
approach
data
FIGAERO.
method
then
applied
chamber
measurements,
known
products
estimated.
Atmospheric chemistry and physics,
Journal Year:
2020,
Volume and Issue:
20(21), P. 12721 - 12740
Published: Nov. 4, 2020
Abstract.
Although
secondary
particulate
matter
is
reported
to
be
the
main
contributor
of
PM2.5
during
haze
in
Chinese
megacities,
primary
particle
emissions
also
affect
concentrations.
In
order
improve
estimates
contribution
sources
number
and
mass
concentrations,
we
performed
source
apportionment
analyses
using
both
chemical
fingerprints
size
distributions
measured
at
same
site
urban
Beijing
from
April
July
2018.
Both
methods
resolved
factors
related
emissions,
including
vehicular
cooking
which
together
make
up
76
%
24
total
organic
aerosol
(OA)
mass,
respectively.
Similar
types,
particles
(1.6±1.1
µg
m−3;
2.4±1.8×103
cm−3
5.5±2.8×103
for
two
traffic-related
components),
(2.6±1.9
m−3
5.5±3.3×103
cm−3)
aerosols
(51±41
4.2±3.0×103
cm−3),
were
by
methods.
Converted
concentrations
components
comparable
with
those
fingerprints.
Size
distribution
separated
into
a
component
mode
diameter
20
nm
(“traffic-ultrafine”)
100
(“traffic-fine”).
Consistent
similar
day-
nighttime
diesel
vehicle
estimated
area,
traffic-fine
particles,
hydrocarbon-like
OA
(HOA,
factor
resulting
fingerprints)
black
carbon
(BC)
showed
diurnal
patterns,
higher
night
morning
than
afternoon
when
boundary
layer
higher.
Traffic-ultrafine
highest
rush-hour
period,
suggesting
prominent
role
local
gasoline
emissions.
absence
new
formation,
our
results
show
that
vehicular-related
(14
30
ultrafine
fine
respectively)
cooking-activity-related
(32
%)
dominate
concentration,
while
(over
80
governs
non-heating
season
Beijing.