Autoxidation
is
a
widely
recognized
mechanism
known
to
initiate
the
degradation
of
food
and
lipids
modify
organic
matter
in
atmosphere.
Given
low
NOx
concentration
aqueous
media
(e.g.,
cloud
water
fog
droplets),
autoxidation
can
become
vital
facilitate
formation
highly
oxygenated
molecules
such
as
peroxides
(ROOH
ROOR).
Here,
we
have
identified
aqueous-phase
autoxidation-initiated
hydroperoxides
varying
precursors,
including
laboratory
model
compound
monoterpene
oxidation
products.
Our
results
show
that
ROOHs
are
suppressed
at
enhanced
precursor
oxidant
concentrations.
Furthermore,
observed
an
exponential
increase
yield
when
UV
light
with
longer
wavelengths
was
used
experiment,
comparing
UVA,
UVB,
UVC.
Water-soluble
compounds
represent
significant
fraction
ambient
component
(up
500
µM.
Thus,
important
pathway
for
water-soluble
species
ROOHs,
thereby
adding
climate
health
burden
atmospheric
particulate
matter.
Chemical Reviews,
Год журнала:
2023,
Номер
123(4), С. 1635 - 1679
Опубликована: Янв. 11, 2023
Organic
peroxides
(POs)
are
organic
molecules
with
one
or
more
peroxide
(−O–O−)
functional
groups.
POs
commonly
regarded
as
chemically
labile
termination
products
from
gas-phase
radical
chemistry
and
therefore
serve
temporary
reservoirs
for
oxidative
radicals
(HOx
ROx)
in
the
atmosphere.
Owing
to
their
ubiquity,
active
gas-particle
partitioning
behavior,
reactivity,
key
reactive
intermediates
atmospheric
multiphase
processes
determining
life
cycle
(formation,
growth,
aging),
climate,
health
impacts
of
aerosol.
However,
there
remain
substantial
gaps
origin,
molecular
diversity,
fate
due
complex
nature
dynamic
behavior.
Here,
we
summarize
current
understanding
on
POs,
a
focus
identification
quantification,
state-of-the-art
analytical
developments,
molecular-level
formation
mechanisms,
chemical
transformation
pathways,
well
environmental
impacts.
We
find
that
interactions
SO2
transition
metal
ions
generally
fast
PO
pathways
liquid
water,
lifetimes
estimated
be
minutes
hours,
while
hydrolysis
is
particularly
important
α-substituted
hydroperoxides.
Meanwhile,
photolysis
thermolysis
likely
minor
sinks
POs.
These
distinctly
different
fates,
such
reaction
OH
radicals,
which
highlights
need
understand
By
summarizing
advances
remaining
challenges
investigation
propose
future
research
priorities
regarding
fate,
Mass Spectrometry Reviews,
Год журнала:
2023,
Номер
43(5), С. 1091 - 1134
Опубликована: Июль 13, 2023
Abstract
The
Earth's
atmosphere
is
composed
of
an
enormous
variety
chemical
species
associated
with
trace
gases
and
aerosol
particles
whose
composition
chemistry
have
critical
impacts
on
the
climate,
air
quality,
human
health.
Mass
spectrometry
analysis
as
a
powerful
popular
analytical
technique
has
been
widely
developed
applied
in
atmospheric
for
decades.
allows
effective
detection,
identification,
quantification
broad
range
organic
inorganic
high
sensitivity
resolution.
In
this
review,
we
summarize
recently
mass
techniques,
methods,
applications
research
past
several
years
molecular‐level.
Specifically,
new
developments
ion‐molecule
reactors,
various
soft
ionization
unique
coupling
separation
techniques
are
highlighted.
laboratory
studies
field
measurements
focused
improving
detection
limits
traditional
emerging
volatile
compounds,
characterizing
multiphase
highly
oxygenated
molecules,
monitoring
particle
bulk
surface
compositions.
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(7), С. 3322 - 3331
Опубликована: Фев. 7, 2024
Ozonolysis
of
alkenes
is
known
to
produce
reactive
intermediates─stabilized
Criegee
intermediates
(SCIs),
and
their
subsequent
bimolecular
reactions
with
various
carboxylic
acids
can
form
α-acyloxyalkyl
hydroperoxides
(AAHPs),
which
considered
a
major
class
organic
peroxides
in
secondary
aerosol
(SOA).
Despite
atmospheric
health
importance,
the
molecular-level
identification
aerosols
highly
challenging,
preventing
further
assessment
environmental
fate.
Here,
we
synthesize
20
atmospherically
relevant
AAHPs
through
liquid-phase
ozonolysis,
two
types
monoterpene-derived
SCIs
from
either
α-pinene
or
3-carene
are
scavenged
by
10
different
diverse
structures.
These
identified
individually
liquid
chromatography
coupled
high-resolution
mass
spectrometry.
were
previously
thought
decompose
quickly
an
aqueous
environment
such
as
cloud
droplets,
but
demonstrate
here
that
hydrolysis
rates
compound-dependent
rate
constants
differing
2
orders
magnitude.
In
contrast,
aqueous-phase
formation
between
SCI
vary
only
within
factor
2–3.
Finally,
synthesized
SOA
SOA,
contributing
∼0.3%
total
mass.
Our
results
improve
current
understanding
useful
for
more
accurate
fate
impact.
Environmental Science & Technology,
Год журнала:
2022,
Номер
56(20), С. 14249 - 14261
Опубликована: Сен. 30, 2022
High
molecular
weight
dimeric
compounds
constitute
a
significant
fraction
of
secondary
organic
aerosol
(SOA)
and
have
profound
impacts
on
the
properties
lifecycle
particles
in
atmosphere.
Although
different
formation
mechanisms
involving
reactive
intermediates
and/or
closed-shell
monomeric
species
been
proposed
for
particle-phase
dimers,
their
relative
importance
remains
debate.
Here,
we
report
unambiguous
experimental
evidence
important
role
acyl
peroxy
radicals
(RO2)
small
but
non-negligible
contribution
from
stabilized
Criegee
(SCIs)
dimers
during
ozonolysis
α-pinene,
one
most
precursors
biogenic
SOA.
Specifically,
find
that
RO2-involved
reactions
explain
50-80%
total
oxygenated
dimer
signals
(C15-C20,
O/C
≥
0.4)
20-30%
less
(O/C
<
signals.
In
particular,
they
contribute
to
70%
C15-C19
ester
formation,
likely
mainly
via
decarboxylation
diacyl
peroxides
arising
RO2
cross-reactions.
comparison,
SCIs
play
minor
esters
react
noticeably
with
abundant
C9
C10
carboxylic
acids
carbonyl
products
form
C19
C20
peroxides,
which
are
prone
transformation
more
stable
without
peroxide
functionality.
This
work
provides
clearer
view
pathways
α-pinene
oxidation
would
help
reduce
uncertainties
future
atmospheric
modeling
budget,
properties,
health
climate
Environmental Science Atmospheres,
Год журнала:
2024,
Номер
4(5), С. 519 - 530
Опубликована: Янв. 1, 2024
Secondary
organic
aerosols
(SOAs)
originating
from
the
oxidation
of
biogenic
volatile
compounds
such
as
monoterpenes
by
atmospheric
oxidants
(
e.g.
OH,
ozone,
and
NO
3
),
constitute
a
widespread
source
in
atmosphere.
Environmental Science & Technology,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 19, 2025
Fenton-like
reactions
between
organic
peroxides
and
transition-metal
ions
in
the
atmospheric
aqueous
phase
have
profound
impacts
on
chemistry,
composition,
health
effects
of
aerosols.
However,
kinetics,
mechanisms,
key
influencing
factors
such
remain
poorly
understood.
In
this
study,
we
synthesized
a
series
monoterpene-derived
α-acyloxyalkyl
hydroperoxides
(AAHPs),
an
important
class
formed
from
Criegee
intermediates
during
ozonolysis
alkenes,
investigated
their
with
iron
phase.
We
found
that
AAHPs
are
essentially
chemically
inert
to
Fe3+
but
highly
reactive
toward
Fe2+.
The
aqueous-phase
reaction
rate
constant
Fe2+
(kIIAAHP+Fe(II))
was
determined
range
11.0
±
0.8
150.0
3.3
M–1
s–1,
depending
positively
solution
pH
(1–3),
water
content
(50%–90%),
temperature
(8–25
°C).
Meanwhile,
kIIAAHP+Fe(II)
value
is
linearly
correlated
O/C
ratio
AAHPs,
which
allows
for
estimation
reactivity
based
oxygenation
level.
addition,
decomposition
via
predominantly
yields
alkoxy
(RO)
radicals
production
yield
OH
smaller
than
16%.
Similar
several
abundant
including
pinonic
acid-derived
AAHP
exhibit
high
low
dissolved
α-pinene
secondary
aerosol.
A
quantitative
analysis
measured
kinetics
suggests
even
dominant
drivers
behind
transformation
atmosphere,
would
significantly
affect
multiphase
chemistry
aerosol
impacts.
Exposure
to
airborne
particulate
matter
(PM)
has
been
attributed
millions
of
deaths
annually.
However,
the
PM
components
responsible
for
observed
health
effects
remain
unclear.
Oxidative
potential
(OP)
gained
increasing
attention
as
a
key
property
that
may
explain
toxicity.
Using
online
measurement
methods
impinge
particles
OP
quantification
within
seconds,
we
reveal
60
99%
reactive
oxygen
species
(ROS)
and
in
secondary
organic
aerosol
combustion-generated
have
lifetime
minutes
hours
ROS
activity
ambient
decays
substantially
before
offline
analysis.
This
implies
current
underestimate
true
PM.
We
demonstrate
short-lived
activate
different
toxicity
pathways
upon
direct
deposition
onto
reconstituted
human
bronchial
epithelia.
Therefore,
suggest
future
air
pollution
studies
should
include
quantification,
allowing
more
accurate
assessments
links
between
effects.
The Journal of Physical Chemistry A,
Год журнала:
2022,
Номер
126(32), С. 5386 - 5397
Опубликована: Авг. 3, 2022
1,2,4-Trioxolanes,
known
as
secondary
ozonides
(SOZs),
are
key
products
of
ozonolysis
biogenic
terpenoids.
Functionalized
terpenoid-derived
SOZs
readily
taken
up
into
atmospheric
aerosols;
however,
their
condensed-phase
fates
remain
unknown.
Here,
we
report
the
results
a
time-dependent
mass
spectrometric
investigation
liquid-phase
C10
and
C13
synthesized
by
monoterpene
alcohol
(α-terpineol)
in
water:acetone
(1:1
=
vol:vol)
mixtures.
Isomerization
Criegee
intermediates
bimolecular
reaction
with
acetone
produced
SOZs,
respectively,
which
were
detected
Na+-adducts
positive-ion
electrospray
spectrometry.
Use
CD3COCD3,
D2O,
H218O
solvents
enabled
identification
three
types
(aldehyde,
ketone,
lactol)
other
products.
These
surprisingly
stable
(1:1)
mixtures
at
T
298
K,
some
persisting
for
least
week.
Theoretical
calculations
supported
high
stability
lactol-type
SOZ
formed
from
aldehyde-type
via
intramolecular
rearrangement.
The
present
suggest
that
can
persist
condensed
phases,
potentially
until
they
delivered
to
epithelial
lining
fluid
pulmonary
alveoli
inhaled
particulate
matter,
where
may
exert
hitherto
unrecognized
adverse
health
effects.