Per-
and
polyfluoroalkyl
substances
(PFAS)
are
a
large
chemical
family,
numerous
species
can
co-exist
in
environmental
samples,
especially
those
impacted
by
aqueous
film-forming
foams
(AFFFs).
Given
the
limited
availability
of
standards,
capturing
total
amount
PFAS
is
challenging.
Thus,
oxidizable
precursor
assay
(TOP)
has
been
developed
to
estimate
or
precursors
perfluorocarboxylic
acids
(PFCAs).
This
study
aims
enhance
robustness
TOP
replacing
heat
activation
with
UV
activation.
We
evaluated
molar
yields
known
water
presence
Suwannee
River
natural
organic
matter
(SRNOM)
two
soils.
The
impact
was
also
soils
spiked
three
well-characterized
AFFFs,
six
AFFF-impacted
field
soils,
nine
rinse
samples
stainless-steel
pipe.
In
100
mg/L
SNROM,
6:2
fluorotelomer
sulfonate
(FTS),
8:2
FTS,
N-ethyl
perfluorooctane
sulfonamidoacetic
acid
(N-EtFOSAA)
deionized
had
good
recovery
as
PFCAs
(average
102
±
9.8%);
at
500
significantly
dropped
an
average
51
19%.
(with
4%
8.8%
OM)
individual
spikes,
101
9.4%,
except
N-EtFOSAA,
which
reduced
soil
OM.
UV-activated
assays
outperformed
heat-activated
ones,
pipe
extract
1.4~1.5×
higher
PFCA
recovery.
all
test
resulted
notable
shift
towards
longer
chain
lengths,
particularly
for
high
OM
content.
confirmed
advantages
activation,
including
shortened
exposure
time
(1
hr
vs.
6
hr)
matrix
effects
from
due
dual
functions
activating
persulfate
photodegrading
Per-
and
polyfluoroalkyl
substances
(PFAS)-containing
firefighting
foam
have
been
used
in
stationary
fire
suppression
systems
for
several
decades.
However,
there
is
a
lack
of
research
on
how
to
decontaminate
PFAS-contaminated
infrastructure
evaluate
treatment
efficiency.
This
study
assessed
the
removal
PFAS
from
stainless
steel
pipe
surfaces
using
different
cleaning
agents
(tap
water,
methanol,
aqueous
solutions
containing
10
20
wt
%
butyl
carbitol
(BC))
at
temperatures
(20
°C,
40
70
°C).
The
content
remaining
fluorine
(F)-containing
compounds
was
evaluated
first
time
time-of-flight
elastic
recoil
detection
(ToF-ERD).
results
showed
that
20%
BC
solution
heated
°C
removed
up
μg/cm2
∑PFAS
via
soaking
(targeted
analysis).
Treatment
with
2-
8-fold
more
effective
than
tap
water
10-
20-fold
°C.
Total
analysis
determined
by
combustion
ion
chromatography
higher
F-equivalent
compared
targeted
after
treatment,
indicating
presence
significant
amount
PFAS.
Surface
ToF-ERD
confirmed
partial
F
throughout
consecutive
intervals,
residual
leaving
risk
rebound
into
F-free
foams.
Furthermore,
supramolecular
assemblies
least
PFOS
molecules/nm2
were
identified
interior
surfaces.
The Science of The Total Environment,
Journal Year:
2024,
Volume and Issue:
924, P. 171292 - 171292
Published: March 2, 2024
Per-
and
polyfluoroalkyl
substances
(PFAS)
are
a
large
chemical
family,
numerous
species
can
co-exist
in
environmental
samples,
especially
those
impacted
by
aqueous
film-forming
foams
(AFFFs).
Given
the
limited
availability
of
standards,
capturing
total
amount
PFAS
is
challenging.
Thus,
oxidizable
precursor
(TOP)
assay
has
been
developed
to
estimate
via
oxidative
conversion
precursors
into
perfluorocarboxylic
acids
(PFCAs).
This
study
aims
enhance
robustness
TOP
replacing
heat
activation
with
UV
activation.
We
evaluated
molar
yields
known
water
presence
varying
levels
Suwannee
River
natural
organic
matter
(SRNOM)
two
soils.
The
impact
was
also
soils
spiked
three
well-characterized
AFFFs,
six
AFFF-impacted
field
soils,
nine
rinse
samples
stainless-steel
pipe.
In
100
mg/L
SNROM,
6:2
fluorotelomer
sulfonate
(FTS),
8:2
FTS,
N-ethyl
perfluorooctane
sulfonamidoacetic
acid
(N-EtFOSAA)
deionized
had
good
recovery
as
PFCAs
(average
102
±
9.8
%);
at
500
significantly
dropped
an
average
51
19
%.
(with
4
%
8.8
matter)
individual
spikes,
101
9.4
%,
except
N-EtFOSAA,
which
reduced
soil
(OM).
UV-activated
assays
outperformed
heat-activated
ones,
pipe
extract
1.4-1.5×
higher
PFCA
recovery.
almost
all
test
resulted
notable
shift
towards
longer
chain
lengths,
particularly
for
high
OM
content.
confirmed
advantages
activation,
including
shortened
exposure
time
(1
h
vs.
6
h)
matrix
effects
from
due
dual
functions
activating
persulfate
photodegrading
OM.
Analytical and Bioanalytical Chemistry,
Journal Year:
2024,
Volume and Issue:
416(29), P. 6799 - 6808
Published: Oct. 12, 2024
Abstract
Organofluorine
mass
balance
approaches
are
increasingly
applied
to
investigate
the
occurrence
of
per-
and
polyfluoroalkyl
substances
(PFAS)
other
organofluorines
in
environmental
samples
more
comprehensively.
Usually,
complex
prevent
identification
quantification
every
fluorine-containing
molecule.
Consequently,
large
unidentified
fractions
between
fluorine
sum
parameters
such
as
extractable
organic
(EOF)
quantified
analytes
frequently
reported.
We
propose
using
oxidative
conversion
separate
(unidentified)
weakly
fluorinated
compounds
(e.g.,
pesticides,
pharmaceuticals)
from
PFAA-precursors
(perfluoroalkyl
chain
lengths
≥
C
6
).
show
with
three
organofluorine
model
(flufenamic
acid,
diflufenican,
pantoprazole)
that
CF
3
-groups
or
aromatic
can
be
quantitatively
converted
inorganic
fluoride
trifluoroacetic
acid
(TFA)
by
applying
PhotoTOP
oxidation
(UV/TiO
2
The
principle
separation
mixtures
is
demonstrated
together
PFAA-precursor
6:2/6:2
fluorotelomer
mercaptoalkyl
phosphate
diester
(FTMAP).
After
oxidation,
products
F
−
TFA
were
separated
PFCAs
(>
4
)
SPE,
analyzed
individually.
Closed
balances
both
without
addition
matrix
achieved.
Eventually,
was
verified
total
measurements
combustion
ion
chromatography
(CIC).
proposed
methods
should
considered
a
proof
concept
potentially
explain
EOF,
especially
if
low
content
pharmaceuticals,
their
transformation
contribute
largely
EOF.
Future
studies
needed
applicability
complexity
samples.
Graphical
Many
"smart"
and
"fitness"
watch
bands
are
advertised
to
contain
fluoroelastomers,
a
type
of
synthetic
rubber
designed
be
resilient
against
skin
oils
sweat.
Fluoroelastomers,
which
considered
polymeric
form
per-
polyfluoroalkyl
substances
(PFAS),
have
historically
involved
the
use
shorter-chain
PFAS
as
surfactants
in
polymerization
process.
In
this
study,
22
were
analyzed
across
numerous
brands
price
points
for
presence
PFAS.
Products
first
screened
total
fluorine
using
particle-induced
gamma-ray
emission
spectroscopy
on
surface
these
bands,
15
contained
F
concentrations
>1%
fluorine,
suggesting
widespread
fluoroelastomers
product
category.
Watch
then
underwent
solvent
extraction
targeted
LC-MS/MS
analysis
20
Perfluorohexanoic
acid
(PFHxA)
was
most
frequently
detected
compound
with
from
