Abstract.
Humic-like
Substances
(HULIS)
encompass
a
continuum
of
molecular
weight
(MW)
ranges,
yet
our
understanding
how
HULIS
characteristics
vary
with
MW
is
still
limited
and
not
well-established.
In
this
study,
combination
ultrafiltration
solid-phase
extraction
protocols
was
employed
to
fractionate
the
high
(HMW,
>1
kDa)
low
(LMW,
<
1kDa)
fractions
from
ambient
aerosols
collected
during
summer
winter
at
rural
site.
Subsequently,
comprehensive
characterization
by
using
total
organic
carbon,
high-performance
size
exclusion
chromatography
(HPSEC),
UV-vis
fluorescence
spectroscopy,
Fourier-transform
infrared
spectroscopy
(FTIR),
negative
electrospray
ionization
resolution
mass
spectrometry
(ESI-
HRMS)
were
conducted.
The
results
revealed
that
HMW
dominated
larger-sized
chromophores,
substantially
constituting
higher
fraction
carbon
UV
absorption
254
nm
than
LMW
HULIS.
While
both
shared
similar
fluorophore
types
functional
groups,
former
exhibited
levels
humification
greater
presence
polar
groups
(e.g.,
-COOH,
>C=O).
HRMS
analysis
further
unveiled
formulas
within
generally
featured
smaller
sizes
but
degrees
unsaturation
aromaticity
compared
those
fractions.
This
observation
suggests
possibility
small
molecules
assembling
form
through
intermolecular
weak
forces.
Moreover,
contained
proportion
CHON
fewer
CHO
compounds
HULIS,
unique
primarily
characterized
lignin-like
species,
displayed
prevalence
N-enriched
highly
aromatic
species.
Additionally,
more
lipids-like
compounds,
while
distinct
tannin-like
compounds.
These
findings
provide
valuable
insights
into
distribution,
optical
properties,
molecular-level
in
atmospheric
aerosols,
thereby
advancing
their
sources,
composition,
environmental
implications.
Atmospheric chemistry and physics,
Journal Year:
2025,
Volume and Issue:
25(6), P. 3647 - 3667
Published: March 27, 2025
Abstract.
To
understand
the
spatial
variation
of
optical
and
structural
properties
water-soluble
brown
carbon
its
influencing
factors
in
China,
light
absorption,
fluorescence,
Fourier
transform
infrared
(FTIR)
spectrum
organic
(WSOC)
different
regions
China
are
measured
following
same
analytical
methods.
The
average
absorption
coefficients
mass
efficiencies
WSOC
at
365
nm
(Abs365
MAE365)
rank
from
high
to
low
as
northwest
>
southwest
north
east
regional
site,
with
higher
values
northern
than
southern
sites
inland
areas
coastal
areas.
resolved
by
spectra-based
positive
matrix
factorization
model
abundance
aromatic
O−H
C=C
functional
groups
determined
FTIR
both
indicate
that
compounds
significant
light-absorbing
substances
have
a
impact
on
fluorophores.
Multiple
linear
regression
analysis
shows
fluorophores
identified
fluorescence
spectra
combined
parallel
factor
(PARAFAC)
contribute
about
62
%–93
%
all
sites,
which
humic-like
substance
(HULIS)
contributes
most,
especially
highly
oxygenated
HULIS
(29
%–50
%)
long
emission
wavelengths.
Combustion
source
emissions
atmospheric
chemical
processes
impacts
some
sites.
Moreover,
relative
humidity
(RH)
can
also
affect
MAE365
WSOC,
decreasing
increase
RH
when
RH<60
remaining
relatively
unchanged
RH>60
%.
Taken
together,
this
study
promotes
better
understanding
heterogeneity
their
China.
Abstract.
To
understand
the
spatial
variation
of
optical
and
structural
properties
water-soluble
brown
carbon
its
influencing
factors
in
China,
light
absorption,
fluorescence,
Fourier
transform
infrared
(FTIR)
spectrum
organic
(WSOC)
different
regions
China
are
measured
following
same
analytical
methods.
The
average
absorption
coefficients
mass
efficiencies
WSOC
at
365
nm
(Abs365
MAE365)
rank
from
high
to
low
as
northwest
>
southwest
north
east
regional
site,
with
higher
values
Northern
than
Southern
sites,
inland
areas
coastal
areas.
resolved
by
positive
matrix
factorization
model
combined
spectra
abundant
aromatic
O-H
C=C
functional
groups
determined
FTIR
both
indicate
that
compounds
important
light-absorbing
substances
WSOC,
which
also
have
a
significant
impact
on
fluorophores.
Multiple
linear
regression
analysis
shows
identified
fluorophores
fluorescence
parallel
factor
contribute
about
62–93
%
all
humic-like
substance
(HULIS)
contributes
most,
especially
highly‑oxygenated
HULIS
(29
%–50
%)
long
emission
wavelengths.
Combustion
source
emissions
atmospheric
chemical
processes
impacts
some
sites.
Moreover,
relative
humidity
(RH)
can
affect
MAE365
decreasing
increase
RH
when
<
60
remaining
relatively
unchanged
%.
Taken
together,
this
study
promotes
better
understanding
heterogeneity
their
China.
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(6), P. 3769 - 3783
Published: March 27, 2024
Abstract.
Humic-like
substances
(HULIS)
encompass
a
continuum
of
molecular
weight
(MW)
ranges,
yet
our
understanding
how
HULIS
characteristics
vary
with
MW
is
still
limited
and
not
well
established.
In
this
study,
combination
ultrafiltration
solid-phase
extraction
protocols
was
employed
to
fractionate
the
high
(HMW;
>
1
kDa)
low
(LMW;
<
fractions
from
ambient
aerosols
collected
during
summer
winter
at
rural
site.
Subsequently,
comprehensive
characterization
using
total
organic
carbon,
high-performance
size
exclusion
chromatography
(HPSEC),
UV-visible
(UV-vis)
fluorescence
spectroscopy,
Fourier
transform
infrared
spectroscopy
(FTIR),
negative
electrospray
ionization
high-resolution
mass
spectrometry
(ESI–HRMS)
were
conducted.
The
results
revealed
that
HMW
dominated
by
larger-sized
chromophores,
substantially
constituting
higher
fraction
carbon
UV
absorption
254
nm
than
LMW
HULIS.
While
both
shared
similar
fluorophore
types
functional
groups,
former
exhibited
levels
humification
greater
presence
polar
groups
(e.g.,
−COOH;
C=O).
HRMS
analysis
further
unveiled
formulas
within
generally
featured
smaller
sizes
but
degrees
unsaturation
aromaticity
compared
those
fractions.
This
observation
suggests
possibility
small
molecules
assembling
form
through
intermolecular
weak
forces.
Moreover,
contained
proportion
CHON
fewer
CHO
compounds
HULIS,
unique
primarily
characterized
lignin-like
species,
displayed
prevalence
N-enriched
highly
aromatic
species.
Additionally,
more
lipid-like
compounds,
while
distinct
tannin-like
compounds.
These
findings
provide
valuable
insights
into
distribution,
optical
properties,
molecular-level
in
atmospheric
aerosols,
thereby
advancing
their
sources,
composition,
environmental
implications.
Research Square (Research Square),
Journal Year:
2023,
Volume and Issue:
unknown
Published: Sept. 28, 2023
Abstract
In
this
study,
hydroxypropyl
Methylcellulose
(HPMC)
with
lower
viscosity
was
obtained
by
electron
beam
irradiation
(EBI),
and
its
physical
modifiers
for
pharmaceutical
powders
investigated
when
it
used
during
spray
drying.
After
HPMC
irradiated
at
a
dose
of
150
kGy,
the
main
structure
not
affected,
substitution
degree
methoxy
destroyed
significantly.
As
increased
from
10
to
molecular
weight
decreased
continuously.
The
results
drying
showed
that
could
quickly
migrate
surface
liquid
medicine
cover
droplets
atomization,
which
improved
hygroscopicity
softening
point
spray-dried
powder.
And
powder
water
content
is
lower.
prepared
into
particles,
dissolution
rate
particles
faster.
Therefore,
modified
exhibits
better
properties.
low
suitable
modification
materials
drying,
expected
be
developed
as
excipient
in
traditional
Chinese
other
industries.
Abstract.
Humic-like
Substances
(HULIS)
encompass
a
continuum
of
molecular
weight
(MW)
ranges,
yet
our
understanding
how
HULIS
characteristics
vary
with
MW
is
still
limited
and
not
well-established.
In
this
study,
combination
ultrafiltration
solid-phase
extraction
protocols
was
employed
to
fractionate
the
high
(HMW,
>1
kDa)
low
(LMW,
<
1kDa)
fractions
from
ambient
aerosols
collected
during
summer
winter
at
rural
site.
Subsequently,
comprehensive
characterization
by
using
total
organic
carbon,
high-performance
size
exclusion
chromatography
(HPSEC),
UV-vis
fluorescence
spectroscopy,
Fourier-transform
infrared
spectroscopy
(FTIR),
negative
electrospray
ionization
resolution
mass
spectrometry
(ESI-
HRMS)
were
conducted.
The
results
revealed
that
HMW
dominated
larger-sized
chromophores,
substantially
constituting
higher
fraction
carbon
UV
absorption
254
nm
than
LMW
HULIS.
While
both
shared
similar
fluorophore
types
functional
groups,
former
exhibited
levels
humification
greater
presence
polar
groups
(e.g.,
-COOH,
>C=O).
HRMS
analysis
further
unveiled
formulas
within
generally
featured
smaller
sizes
but
degrees
unsaturation
aromaticity
compared
those
fractions.
This
observation
suggests
possibility
small
molecules
assembling
form
through
intermolecular
weak
forces.
Moreover,
contained
proportion
CHON
fewer
CHO
compounds
HULIS,
unique
primarily
characterized
lignin-like
species,
displayed
prevalence
N-enriched
highly
aromatic
species.
Additionally,
more
lipids-like
compounds,
while
distinct
tannin-like
compounds.
These
findings
provide
valuable
insights
into
distribution,
optical
properties,
molecular-level
in
atmospheric
aerosols,
thereby
advancing
their
sources,
composition,
environmental
implications.
Abstract.
Humic-like
Substances
(HULIS)
encompass
a
continuum
of
molecular
weight
(MW)
ranges,
yet
our
understanding
how
HULIS
characteristics
vary
with
MW
is
still
limited
and
not
well-established.
In
this
study,
combination
ultrafiltration
solid-phase
extraction
protocols
was
employed
to
fractionate
the
high
(HMW,
>1
kDa)
low
(LMW,
<
1kDa)
fractions
from
ambient
aerosols
collected
during
summer
winter
at
rural
site.
Subsequently,
comprehensive
characterization
by
using
total
organic
carbon,
high-performance
size
exclusion
chromatography
(HPSEC),
UV-vis
fluorescence
spectroscopy,
Fourier-transform
infrared
spectroscopy
(FTIR),
negative
electrospray
ionization
resolution
mass
spectrometry
(ESI-
HRMS)
were
conducted.
The
results
revealed
that
HMW
dominated
larger-sized
chromophores,
substantially
constituting
higher
fraction
carbon
UV
absorption
254
nm
than
LMW
HULIS.
While
both
shared
similar
fluorophore
types
functional
groups,
former
exhibited
levels
humification
greater
presence
polar
groups
(e.g.,
-COOH,
>C=O).
HRMS
analysis
further
unveiled
formulas
within
generally
featured
smaller
sizes
but
degrees
unsaturation
aromaticity
compared
those
fractions.
This
observation
suggests
possibility
small
molecules
assembling
form
through
intermolecular
weak
forces.
Moreover,
contained
proportion
CHON
fewer
CHO
compounds
HULIS,
unique
primarily
characterized
lignin-like
species,
displayed
prevalence
N-enriched
highly
aromatic
species.
Additionally,
more
lipids-like
compounds,
while
distinct
tannin-like
compounds.
These
findings
provide
valuable
insights
into
distribution,
optical
properties,
molecular-level
in
atmospheric
aerosols,
thereby
advancing
their
sources,
composition,
environmental
implications.
