Transcript Metoder i moderne kemi, 2000

Can a smog chamber be used
to explain why polar bears
have 8.6 ng/g of perfluoro
octanoic acid in their body?
Ole John Nielsen
Department of Chemistry
University of Copenhagen
www.cogci.dk
1
Acknowledgements
Mads P. S. Andersen
JPL-NASA, Pasadena, CA, USA
Tim. J. Wallington, Mike. P. Hurley, Jim. C. Ball
Ford Motor Company, Dearborn, MI, USA
Scott. A. Mabury
University of Toronto, Toronto, ON, Canada
2
Why am I here?
3
Outline
1. Who am I?
2. Why the interest in PerFluoro Organic Acids
(PFOAs) and FluoroTelomer alcohols (FTOHs)?
3. What are PFOA, PFCA and PFOA again?
4. Use of FTOH = CnF2n+1CH2CH2OH (straight chain)
5. Atmospheric chemistry of FTOHs
6. Environmental Impacts and Conclusions
7. Discussions
4
Who am I?
1954 Born
1973 Began at UoC (chemistry and physics)
1974 Important Atmospheric Year
1978 M.Sc. and on to do a PhD at Risø Nat. Lab.
1978-95 Risø National Laboratory
1995-96 Ford Research Center Aachen, Germany
1996-99 Risø National Laboratory
1999-? Professor at UoC
2007 Nobel Peace Prize together with Al Gore and 2500 scientists
Gas phase kinetics and reaction mechanisms - relevant to the
atmosphere – How? Why?
IPCC – Intergovernmental Panel of Climate Change
5
2. Why the interest in PerFluoro Organic Acids
(PFOAs) and FluoroTelomer alcohols (FTOHs)?
• What do you think?
• The interest in environmental chemistry is driven by?
• Health Concerns
6
Contact Us | Print Version
Perfluorooctanoic Acid (PFOA) and Fluorinated Telomers
January 12, 2005: Draft PFOA Risk Assessment submitted to EPA Science Advisory Board for Peer Review: SAB meeting February 22-23, 2005.
PFOA stands for perfluorooctanoic acid, a synthetic (man-made) chemical that does not occur naturally in the environment. PFOA is sometimes called "C8."
Companies use PFOA to make fluoropolymers, substances with special properties that have thousands of important manufacturing and industrial applications.
Consumer products made with fluoropolymers include non-stick cookware and breathable, all-weather clothing. More BASIC INFORMATION about PFOA.
EPA began its investigation because PFOA is very persistent in the environment, was being found at very low levels both in the environment and in the blood of
the general U.S. population, and caused developmental and other adverse effects in laboratory animals. EPA summarized its concerns and identified data gaps
and uncertainties about PFOA in a notice published in the Federal Register.
7
Risk Assessment
You will need Adobe Reader to view some of the files on this page. See EPA's PDF
page to learn more.
In January 2005, the EPA Office of Pollution Prevention and Toxics submitted a Draft Risk
Assessment of the Potential Human Health Effects Associated With Exposure to
Perfluorooctanoic Acid and Its Salts (PFOA) (PDF) (132pp, 450KB) to the EPA Science
Advisory Board (SAB) for formal peer review. EPA sought this early stage scientific peer
review from an outside panel of experts in order to ensure the most rigorous science is
used in the Agency's ongoing evaluation of PFOA. That draft was preliminary and did not
provide conclusions regarding potential levels of concern. The SAB reviewed the
information that was available at the time, and suggested that the PFOA cancer data are
consistent with the EPA Guidelines for Carcinogen Risk Assessment descriptor "likely to
be carcinogenic to humans."
Since its review, additional research has been conducted pertaining to the carcinogenicity
of PFOA. EPA is still in the process of evaluating this information and has not made any
definitive conclusions regarding potential risks, including cancer, at this time.
More information can be found on the SAB PFOA Review Panel Website.
EPA is not waiting for all of the answers to be known before taking action, however. In
January 2006, EPA asked eight companies in the industry to commit to reducing PFOA
from facility emissions and product content by 95 percent no later than 2010, and to work
toward eliminating PFOA from emissions and product content no later than 2015. All eight
8
of the invited companies submitted commitments to the Stewardship Program by March
1,
2006. Read more information on the PFOA 2010/15 Stewardship Program.
In 2006, former Administrator Stephen L. Johnson invited the eight major
fluoropolymer and telomer manufacturers to join in a global stewardship program with
two goals:
To commit to achieve, no later than 2010, a 95% reduction, measured from a year
2000 baseline, in both facility emissions to all media of PFOA, precursor chemicals
that can break down to PFOA, and related higher homologue chemicals, and product
content levels of these chemicals.
To commit to working toward the elimination of these chemicals from emissions and
products by 2015.
Participating companies include:
Arkema, Asahi, Ciba, Clariant, Daikin, 3M, DuPont, Solvay Solexis
Submitted baseline year 2000 data on emissions and product content at the end of
October 2006.
Report annual progress toward goals each succeeding October and report progress
in terms of both U.S. and global operations.
Companies also agreed to work cooperatively with EPA and establish scientifically
credible analytical standards and laboratory methods to ensure comparability
of reporting
9
3. What are PFOAs, PFCAs and PFOA?
PerFluorinated Organic Acids
PerFluorinated Carboxylic Acids
PerFluorinated Octanoic Acid
HO
F
C
F
F
C O
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
Long chain perfluorinated acids (PFCAs/PFAs)
observed in fauna in urban and remote locations
PFOA (perfluorooctanoic acid) C7F15C(O)OH
PFNA (perfluorononanoic acid) C8F17C(O)OH
PFDA (perfluorodecanoic acid) C9F19C(O)OH
PFUA (perfluoroundecanoic acid) C10F21C(O)OH
F
F
F
F
PFPeA
10
11
In the far north...
…in Polar Bears?
HO
PFACsng/g
PFOA (8)
PFNA (9)
PFDA (10)
PFUNA (11)
PFDoA (12)
PFTrA (13)
PFTA (14)
PFPeA (15)
8.6
180
56
63
6.2
11
0.51
<0.5
F
C
F
F
C O
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
PFPeA
Martin et al., EST 38 (2004) 373.
12
Facts:
No natural sources. Water-soluble PFCA salts used in
fluoropolymer processing. Not released in major quantities.
Presence of PFCAs in remote areas suggests atmospheric
source.
The science (why) question?
Why are they here?
Where do long chain Perfluorocarboxylicacids
(PFCAs), CnF2n+1COOH come from?
Our hypothesis:
They are atmospheric degradation products from other long chain
fluorinated compounds emitted to the atmosphere
13
“Airport Foam Seeps into Creek”
Toronto Star, June 10, 2000
22,000 liters of AFFF; ~300 kg of PFOS!
14
Etobicoke Creek Fish Liver Samples; Jan 5,
2001 (spill + 7 months)
JAN17-ETOBCREEK-DOWNSTREAM
F
F
F
F
F
F
F
F
F
F
F
F
F
F
HO
%
F
F
F
F
F
F
F
F
F
F
F
F
F
C O
MRM of 12 Channels ES713 > 669
1.46e3
PFTA
100
0
JAN17-ETOBCREEK-DOWNSTREAM
MRM of 12 Channels ES613 > 569
4.46e3
PFDoA
100
%
0
JAN17-ETOBCREEK-DOWNSTREAM
MRM of 12 Channels ES563 > 519
1.82e3
PFUnA
100
%
0
JAN17-ETOBCREEK-DOWNSTREAM
MRM of 12 Channels ES513 > 469
3.03e3
PFDA
100
%
0
JAN17-ETOBCREEK-DOWNSTREAM
PFOS
100
%
0
JAN17-ETOBCREEK-DOWNSTREAM
PFOA
100
%
0
JAN17-ETOBCREEK-DOWNSTREAM
100
%
0
JAN17-ETOBCREEK-DOWNSTREAM
100
%
0
10.00
10.50
11.00
11.50
MRM of 12 Channels ES499 > 99
2.52e5
MRM of 12 Channels ES413 > 369
1.06e3
PFHxS
MRM of 12 Channels ES399 > 99
2.18e3
PFHpA
MRM of 12 Channels ES363 > 319
1.06e3
12.00
12.50
13.00
13.50
C14
C12
C11
C10
C8S
C8
C6S
C7
Time
14.00
Moody, C.A., W.C. Kwan, J.W. Martin, D.C.G. Muir, and S.A. Mabury. 2001. Determination of Perfluorinated Surfactants in Surface Water Samples
by Two Independent Analytical Techniques – Liquid Chromatography/Tandem Mass Spectrometry and 19F NMR. Analytical Chemistry. 73:2200-2206.
15
Moody, C.A., J. W. Martin, W. C. Kwan, D. C. G. Muir, and S. A. Mabury. 2002. Monitoring Perfluorinated Surfactants in Biota and Surface Water
Samples Following an Accidental Fire-Fighting Foam Release into Etobicoke Creek. Environ. Sci. Technol. 36:545-551.
4. FTOH = fluorotelomer alcohol
2001 – FTOHs observed in atmosphere.
Oxidation of FTOHs could be a source of PFCA
source (against conventional wisdom in
atmospheric chemistry community).
CnF2n+1CH2CH2OH (straight chain)
4:2 FTOH = C4F9CH2CH2OH
6:2 FTOH = C6F13CH2CH2OH
8:2 FTOH = C8F17CH2CH2OH
10:2 FTOH = C10F21CH2CH2OH
16
PolyfluoroAlcohols are highly volatile!!!
10000
Log P (Pascals)
1000
100
10
1
.1
.01
50
H
H O
8:2 FTOH = 212 Pa
C H
F
C H
FF
H
F
F
Fluorotelomer Alcohols
F
F
F
F
F
F
F
F
F
F
Hydrocarbon Alcohols
F
F
150
250
350
450
550
Molecular Mass
HC data from Daubert & Danner; FTOH data from Lei et al, submitted J Chem Eng Data and
Stock et al, ES&T in press.
17
FTOH based coatings heavily used in consumer products;
F
Potential Sources?
5x106 kg/yr
40% in North America
80% are in polymers*
F
F F F F F F H H
C
OH
C
F
F F F F F F F F H H
Residual
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
CH2
F
H2C
O
O
O C
O
N
Ester
Urethane
F
F
F
F
F
F
F
F
F
F
F
F
F
F
CH2
H 2C
F
F
F
F
F
F
F
F
F
F
F
F
F
CH2
H 2C
F
F
Degradation
F
F
F
Carpet Treatment
F
F
F
F
F
F
F
CH2
H2C
OH
O
Ether
Polymer
*TRP Presentation to
USEPA OPPT. Nov 25, 2002
US Public Docket AR226-1141
F
18
Research Question:
Does atmospheric oxidation of FTOHs contribute
significantly to PFCA burden in remote locations?
Three necessary conditions:
(1) FTOH survive atmospheric transport
(2) FTOH degrade to give PFCAs
(3) Magnitude of PFCA formation must be significant
Use a FTIR Smog chamber
19
20
4. Experimental apparatus and setup
FTIR SMOG CHAMBER
o 140 L Pyrex chamber
o X/Cl2/N2/O2/black-lamps
o X/CH3ONO/NO/air/black-lamps
296 K, 700 Torr
21
22
23
24
Does atmospheric oxidation of FTOHs contribute
significantly to PFCA burden in remote locations?
Three necessary conditions:
(1) Do FTOHs survive atmospheric transport?
Measurement of k(OH+FTOH) – Why?
(2) Do FTOHs degrade to give PFCAs?
(3) Magnitude of PFCA formation must be significant?
25
UV irradiation of
FTOH/reference/CH3ONO/NO/air mixtures
FTOH = 4:2 FTOH, 6:2 FTOH, or 8:2 FTOH
reference = C2H2 or C2H4
CH3ONO  CH3O + NO
CH3O + O2  HCHO + HO2
HO2 + NO  OH + NO2
OH + FTOH  products
(1)
OH + reference  products
(2)
26
OH + FTOH  products
(1)
OH + reference  products
(2)
 d [FTOH]
k1[OH ]ss[FTOH]
dt
 d [reference ]
k2[OH] ss [reference ]
dt
Integration gives:
 [FT OH]to 
k1[OH]ss t
Ln
 [FT OH]t 
 [reference]to 
k2[OH]ss t
Ln
 [reference]t 
FTOH and reference have equal exposure to OH radicals, hence:
 [FT OH]to  k1  [reference
]to 
 Ln

Ln
]t 
 [FT OH]t  k2  [reference
27
Ln([F(CF2CF2)n(CH2)2OH]to/[F(CF2CF2)n(CH2)2OH]t)
0.6
C2H2
0.5
0.4
No discernable
difference in reactivity
of OH radicals towards
4:2, 6:2, and 8:2 FTOH
0.3
0.2
C2H4
0.1
0.0
0.0
0.5
1.0
1.5
Ln ([Reference]to/[Reference]t)
Loss of FTOH (squares = 4:2; circles = 6:2; triangles = 8:2) versus C2H2
and C2H4 on exposure to OH radicals in 700 Torr of air diluent at 296 K.
28
Ln([F(CF2CF2)n(CH2)2OH]to/[F(CF2CF2)n(CH2)2OH]t)
0.6
C2H2
0.5
0.4
0.3
0.2
C2H4
0.1
0.0
0.0
0.5
1.0
Ln ([Reference]to/[Reference]t)
1.5
OH + CnF2n+1CH2CH2OH → products
(10)
OH + C2H2 → products
(11)
OH + C2H4 → products
(12)
Linear fits give k10/k11 = 1.18±0.15 and k10/k12 = 0.131±0.018.
Using k11 = 8.5 x 10-13 and k12 = 8.66 x 10-12 gives
k10 = (1.00±0.13) x 10-12 and (1.13±0.16) x 10-12 cm3 molecule-1 s-1.
Final value, k10 = (1.07±0.22) x 10-12 cm3 molecule-1 s-1.
29
FTOH Lifetime Estimate
Assuming:
atmospheric lifetime* for CH3CCl3 = 5.7 years
k(CH3CCl3 + OH) = 1.0 x 10-14 cm3 molecule-1 s-1
then
atmospheric lifetime* of F(CF2)nCH2CH2OH 
(1.0x10-14)/(1.1x10-12) x 5.7 x 365  20 days.
* with respect to reaction with OH radicals
30
Other loss mechanisms?
Photolysis – should be negligible
Rainout – estimated to be negligible
Dry deposition – lifetime estimated to be 8 years
Homogeneous reactions other than with OH - unlikely
Atmospheric lifetime determined by reaction
with OH and is approximately 20 days.
31
Ramifications of Lifetime
(1) Estimate flux of 100-1000 t yr-1 necessary to sustain
observed atmospheric concentration.
(2) FTOH have negligible GWP
(3) Spatial distribution will be inhomogeneous
(4) FTOH will be transported to remote locations. Global
average wind speed = 5 m s-1, 20 days = 8500 km.
32
20 days… Long Enough for Long Range Transport?
Assuming
5m/s winds
and a 20d
lifetime,
FTOHs could
be transported
over 8500 km
Copenhagen
to Detroit =
6500 km
33
Does atmospheric oxidation of FTOHs contribute
significantly to PFCA burden in remote locations?
Three necessary conditions:
(1) Do FTOHs survive atmospheric transport?
YES
(2) Do FTOHs degrade to give PFCAs?
(3) Magnitude of PFCA formation must be significant
34
(A) before irradiation
0.25
0.20
0.15
FTIR study of 4:2
FTOH oxidation
0.10
0.05
0.00
0.25
CF3(CF2)3CH2CHO
0.20
is the major primary
0.10
atom and OH
radical initiated
0.15
IR Absorbance
product from Cl
(B) 10 sec irradiation
0.05
0.00
0.08
(C) Product
0.06
0.04
0.02
oxidation of 4:2 FTOH
0.00
(D) CF3(CF2)3CH2CHO
0.15
0.10
0.05
0.00
35
700
900
1100
1300
1500
-1
1700
1900
FTOH Oxidation mechanism
CnF2n+1CH2CH2OH + OH  CnF2n+1CH2C(•)HOH + H2O
CnF2n+1CH2C(•)HOH + O2  CnF2n+1CH2CHO + HO2
36
CnF2n+1CH2CHO is
reactive …
Gives secondary
products …
[CF3(CF2)3CH2CHO] / [CF3(CF2)3CH2CH2OH]0
0.5
0.4
0.3
0.2
0.1
0.0
0.0
0.2
0.4
0.6
0.8
1.0
 [CF3(CF2)3CH2CH2OH] / [CF3(CF2)3CH2CH2OH]0
37
0.25
0.4
0.20
CF3(CF2)3CHO
0.3
0.15
CF3(CF2)3CH2COOH
0.2
0.10
0.1
0.05
UNKNOWN
0.0
[UNKNOWN] / [CF3(CF2)3CH2CH2OH]0
[products] / [CF3(CF2)3CH2CH2OH]0
0.5
Secondary products:
CF3(CF2)3CHO,
CF3(CF2)3CH2COOH,
CF3(CF2)3C(O)OOH
0.00
0.0
0.2
0.4
0.6
0.8
1.0
 [CF3(CF2)3CH2CHO] / [CF3(CF2)3CH2CH2OH]0
38
FTOH Oxidation mechanism
CnF2n+1CH2CH2OH + OH  CnF2n+1CH2C(•)HOH + H2O
CnF2n+1CH2C(•)HOH + O2  CnF2n+1CH2CHO + HO2
CnF2n+1CH2CHO + OH + O2  CnF2n+1CH2C(O)OO + H2O
CnF2n+1CH2C(O)OO + NO  CnF2n+1CH2C(O)O + NO2
CnF2n+1CH2C(O)O  CnF2n+1CH2 + CO2
CnF2n+1CH2 + O2  CnF2n+1CH2O2
CnF2n+1CH2O2 + NO  CnF2n+1CH2O + NO2
CnF2n+1CH2O + O2  CnF2n+1CHO + HO2
39
0.25
0.4
0.20
CF3(CF2)3CHO
0.3
0.15
CF3(CF2)3CH2COOH
0.2
0.10
0.1
0.05
UNKNOWN
0.0
[UNKNOWN] / [CF3(CF2)3CH2CH2OH]0
[products] / [CF3(CF2)3CH2CH2OH]0
0.5
Secondary products:
C4F 9CHO,
C4F9CH2COOH
C4F9C(O)OOH
Secondary
products are
reactive …
0.00
0.0
0.2
0.4
0.6
0.8
1.0
 [CF3(CF2)3CH2CHO] / [CF3(CF2)3CH2CH2OH]0
40
0.60
Tertiary products
include:
0.50
(A) before irradiation
0.40
0.30
0.20
COF2, CF3OH
0.10
C4F9COOH
0.80
0.00
(B) 8.5 minutes irradiation
0.60
Conclusion of FTIR
experiments:
simulated
atmospheric
oxidation of 4:2
FTOH (in absence
of NOx) gives a
small (few %) yield
of C4F9COOH
IR Absorbance
0.40
0.20
0.00
0.08
(C) residual
0.06
0.04
0.02
0.00
0.30
(D) CF3(CF2)3COOH
0.20
0.10
0.00
1400
1600
1800
3500
-1
Wavenumber (cm )
41
FTIR data shows that in gas phase:
in absence of NOx
4:2 FTOH   C4F9CHO  C4F9COOH
in presence of NOx
4:2 FTOH   C4F9CHO  C4F9COOH
Likely explanation, presence of HO2 radicals in absence of NOx
Well established that CH3C(O)O2 + HO2 gives acetic acid and
peracetic acid, ,presumably CxF2x+1C(O)O2 + HO2 reaction gives
CxF2x+1COOH and CxF2x+1COOOH.
Product study of CxF2x+1C(O)O2 + HO2 (x=1-4) to test this idea.
42
Method
CnF2n+1C(O)O2 and HO2 radicals generated by UV irradiation of
CnF2n+1CHO/H2/Cl2 mixtures in 100-700 Torr of air at 296±2 K:
Cl2 + h  2Cl
Cl + CnF2n+1CHO  CnF2n+1CO + HCl
CnF2n+1CO + O2 + M  CnF2n+1C(O)O2 + M
Cl + H2  H + HCl
H + O2 + M  HO2 + M
CnF2n+1C(O)O2 + HO2  products
CnF2n+1C(O)O2 + CnF2n+2C(O)O2  products
As [H2]o/CnF2n+1CHO]o , products/products ,
43
0.5
0.4
Absorbance10
0.3
A: Before UV
0.2
0.1
0.0
0.4
0.10
0.3
B: After UV
0.2
0.05
0.1
0.00
0.0
C: C2F5C(O)OH
E: CF3OH
D: COF2
1700
1800
IR spectra obtained
before (A) and after
(B) 55 s of irradiation
of a mixture of 18.8
mTorr C2F5C(O)H,
218 mTorr Cl2 and
2.8 Torr H2 in 700
Torr of air. The
consumption of
C2F5C(O)H was 63%.
1900
2000
3500
3600
3700
-1
Wavenumber (cm )
44
PFCAs are
products of
CxF2x+1C(O)O2 +
HO2 reaction
Offers
reasonable
explanation of
observed PFCA
formation in 4:2
FTOH expts.
45
Branching ratios in reactions of RC(O)O2 with HO2 radicals under ambient conditions (700-760 Torr, 2962K).
RC(O)O2
Reference
Products
RC(O)OOH+O2
RC(O)OH+O3
RC(O)O+O2+OH
CH3C(O)O2
0.40 0.16
0.20  0.08
0.40  0.16
[21]
CF3C(O)O2
0.09  0.04
0.38  0.04
0.56  0.05
This work
C2F5C(O)O2
< 0.06
0.24  0.04
0.76  0.04
[27]
C3F7C(O)O2
< 0.03
0.10  0.02
 0.90
This work
C4F9C(O)O2
< 0.03
0.08  0.02
 0.90
This work
46
O
O
O +
CF3
HO2
CF2
O
CF2
O
CF3
a
O
H
O
CF2
O
O
H
b
H
CF3
O
O
O
C2F5C(O)OOH + O 2
O
O
O
c
O
O
O
CF3
CF2
O
CF3
CF2
O
O
O
H
O
C2F5C(O)OH + O 3
C2F5C(O)O + O 2 + OH
47
48
Does atmospheric oxidation of FTOHs contribute
significantly to PFCA burden in remote locations?
Three necessary conditions:
(1) Do FTOHs survive atmospheric transport?
YES
(2) Do FTOHs degrade to give PFCAs?
YES
(3) Magnitude of PFCA formation must be significant
49
FTOH flux into Northern Hemisphere = 100-1000 t yr-1
Assume molar PFCA yield from FTOH of 1-10%
Hence, PFCA flux = 1-100 t yr-1
Assume even spatial distribution
Hence, PFCA flux to Arctic = 0.1 - 10 t yr-1
Persistent organochlorine pesticides arctic loading =1.8 t yr-1
Organochlorine pesticides detectable in polar bears at a
similar concentration to PFCAs ( 100-1000 ng/g)
Order of magnitude calculations suggest atmospheric
oxidation of FTOHs is plausible explanation of PFCAs in
remote areas.
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Does atmospheric oxidation of FTOHs contribute
significantly to PFCA burden in remote locations?
Three necessary conditions:
(1) Do FTOHs survive atmospheric transport?
YES
(2) Do FTOHs degrade to give PFCAs?
YES
(3) Magnitude of PFCA formation must be significant
Looks plausible … more work …
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Concentration of PFOA (in molecule cm-3) at 50 m. altitude in the
University of Michigan 3D model (IMPACT) for January and July.
The color scale extends from (A) 0 to 1.2x103 and (B) 0 to 3x103 molecule cm-3.
UIUC 2D model
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Conclusions
1. The available evidence suggests, that the
atmospheric oxidation of FTOHs makes a
significant contribution to the PFCA burden in
remote locations.
2. This is just the tip of the ice berg
3. The automobile industry uses large
quantities of fluoropolymers but little, if any,
FTOHs. Vehicles do not appear to be a
source of PFCAs 
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The ”smog” quartet
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The Atmospheric Science Group
Dk
F
Dk
US
Dk
Dk
Ch
Dk
Rus
Dk
Dk
D
Fin
Dk
Est
Est
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Extra slides
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8:2 FTOH = C8F17CH2CH2OH
PFNA = C8F17C(O)OH
PFOA = C7F15C(O)OH
Research Question:
Does atmospheric oxidation of FTOHs contribute
significantly to PFCA burden in remote locations?
Three necessary conditions:
(1) FTOH survive atmospheric transport
(2) FTOH degrade to give PFCAs
(3) Magnitude of PFCA formation must be significant
Use a FTIR Smog chamber
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