1. Region 5 CRL Methods for the Analysis of Polyfluorinated Compounds (PFCs) Using a Quick Sample Extraction/Preparation Followed by UPLC/MS/MS Analysis
Lawrence B. Zintek, Danielle Kleinmaier, Dennis J. Wesolowski, Solidea Bonina# and Carolyn Acheson*
US EPA Region 5 Chicago Regional Laboratory (CRL)
#Pegasus Technical Services
*US EPA ORD/NRMRL, Cincinnati, OH.
Mention of Vendor Names Does Not Constitute Product Endorsement

2. Disclaimer
Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States government.
The views and opinions of author expressed herein do not necessarily state or reflect those of the United States government or United States Environmental Protection Agency and shall not be used for advertising or product endorsement purposes.

3. Disclaimer Continued
This work was sponsored by an agency of the United States government. Neither the United States government nor US EPA Region 5 Chicago Regional Laboratory, nor any of their employees makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights.

4. Topics PFC Workgroup Brief PFC Background
EPA Method 537- Drinking Water
CRL PFC Methods
Holding Time Study
Contamination
Sample Collection
Holding Time/Sample Requirements
Analytical Issues Observed from Review of PFAS Site QAPPs
Review Data generated by other methods/labs
Conclusion/Ongoing Work

5. EPA PFC Workgroup
Purpose: Sampling Protocol and analytical method development for solids and water other than drinking water.
Workgroup Co-Leads
OLEM/OSRTI, Region 3, ORD/SSWR
Program Offices
OLEM/OEM, OLEM/OSRTI, OW/OS&T, OW/OGWDW, OLEM/OCRC, NEIC, OCIR/RO, OPP/BEAD/ACB
Regional Offices
1,2,3,4,5,6,9,10
Office of Research and Development
NRMRL, NERL, NHEERL, NCEA

6. Brief PFC Background PFOA PFOS 6:2 FTS PFOSA (FOSA) N-EtFOSAA
PFOA/PFOS Drinking Water Health
Advisory- 70 ng/L Combined

7. Method 537 Quantitation One SRM transition
Weak approach for non-drinking water samples, no confirmatory transition and no ion ratios
Example for PFOS
Calibration Standard
Real Sample

8. Region 5 CRL PFC SOP Two SRM transitions or MRM
Stronger approach for non-drinking water samples, confirmatory transition and ion ratios
Example for PFOS, same samples
Calibration Standard Ion Ratio-1.41
Real Sample Ion Ratio-1.35
4.3% Ion Ratio Difference
(Within Tolerance)

9. EPA Method 537 Drinking Water Only 14 Analytes, all in OSRTI List
PFOS, PFOA, N-EtFOSAA, N-MeFOSAA, PFBS, PFDA, PFDoA, PFHpA, PFHxS, PFHxA, PFNA, PFTreA, PFTriA, PFUnA.
3 Surrogates
MPFHxA, MPFDA, MN-EtFOSAA
3 Internal Standards
13C-PFOA, 13C-PFOS, d3-N-MeFOSAA

10. Method 537 Quantitation/Surrogates
Internal standard quantitation (Q)
Weak approach for non-drinking water samples, may have a matrix interference that affects the internal standard resulting in bias results for anything quantitated against it.
Surrogates (S)
Compare target analyte recovery to the surrogates. Q S S S
Q, Q

11. Why not use EPA Method 537 for Matrices other than Drinking Water?
Method 537 is a drinking water method!
Not adaptable to other matrices
Only one SRM transition
Makes quantitation difficult in dirtier matrices
Less confirmatory
Require Solid Phase Extraction
Won’t work for all analytes of interest in one analysis
Pre-filter samples with particulates (Bias low results)
Limited number of surrogates to mimic the entire analyte mix
Internal Standard
May make the data worse
Blow down to dryness
Lose volatile PFCs

12. CRL PFC Methods 24 Analytes of Interest to OSRTI
External Standard Quantitation
Every compound independent of each other
2 SRM transitions (If available)
PFBA, PFPeA and PFOSA only one SRM
Ion Ratios between the 2 SRM transitions required
14 Surrogates (19 available now)
Easy sample preparation, sample manipulations to a minimum.
Basis- ASTM D7979 and D7968
Heavily single lab validated on multiple matrices
Data available

13. Reporting Limit (Water) Reporting Limit (Soil)
Region 5 CRL PFC SOP Reporting Limits/Surrogates
Analyte
Reporting Limit (Water)
Reporting Limit (Soil)
Surrogate
(ng/L)
(ng/Kg)
PFTreA 10 25
New
PFTriA
PFDoA X
PFUnA
PFDA
PFDS
PFOS 50
PFNA
PFNS
PFOA
PFHpS
PFHxS
PFHpA
PFHxA
PFBS
PFPeS
PFPeA
125
PFBA
FOSA
4:2 FTS
6:2 FTS
8:2 FTS
NEtFOSAA
NMeFOSAA

14. CRL PFC SOP Water Sample Preparation
5 mL water sample in Polypropylene Tube
Add “Spikes”
Add 5 mL MeOH
Shake- 30 seconds
Filter through Polypropylene Filter Unit
Add 10 mL acetic acid
Analyze

15. CRL PFC SOP Sludge Sample Preparation
5 mL Sludge sample in PP tube
Add “Spikes”
Add 5 mL MeOH
Add 20 mL NH4OH, Shake, check if basic, pH 9-10.
Mix for 2 minutes
Decant the liquid and filter through Polypropylene Filter Unit
Add 50 mL acetic acid
Analyze

16. CRL PFC SOP Soil/Biosolid Sample Preparation
2 gram sample (sub-sample)
Add “Spikes”
10 ml of methanol:water (50:50) -shake/vortex for ~ 2 minutes.
Add 20 mL NH4OH, shake/vortex for ~ 2 minutes, check if basic, pH 9-10.
Tumble for 1 hr
Centrifuge
Decant the liquid and Filter through Polypropylene Filter Unit
Add 50 mL acetic acid
Analyze

17. NC Sludge Sample Before Extraction NC Sludge Sample After Extraction
Sludge samples
NC Sludge Sample Before Extraction
NC Sludge Sample After Extraction

18. Matrices Used to do Single Lab Validation using CRL PFC SOP for Water
Reagent Water
Chicago River Water
Ground Water: Silurian-Dolomite Aquifer
Sewage Treatment Plant I (STP) Effluent
STP I Influent
STP II (Effluent with supplemental sewage)
STP III (Effluent with supplemental sewage)

19. Matrices Used to do Single Lab Validation using CRL PFC SOP for Soil
Ottawa Sand
Four ASTM Soils
Sand
Lean Clay
Fat Clay
Silt

20. MPFBA (Surrogate) Recovery Data in Water Samples Over Last 19 Months
Example of a Control Chart displaying recoveries for data collected with CRL Water Method

21. CRL PFC Water SOP Precision and Accuracy
Includes target and surrogate analytes (ASTM D7979).
Samples- 101 Blanks, 97 MRLs, 102 BSs, 189 MSs and 416 samples.
Accuracy
Average Recovery: 99.2%
Precision (Standard Deviation)
Average Precision: ±6.08%

22. CRL PFC Soil SOP Precision and Accuracy
Includes target and surrogate analytes (ASTM D7968).
Samples- 37 Blanks, 31 MRLs, 42 BSs, 26 MSs and 138 samples.
Accuracy
Average Recovery: 90.3%
Precision (Standard Deviation)
Average Precision: ±15.8%

23. Holding Time Study in POTW Influent
Compare concentrations sampling the same spiked bottles over 27 days (Aliquot, not using the entire sample)
Amber Glass
Polypropylene
HDPE
Losses over time with each sampling container
Drastic differences between reagent water and POTW influent recovery results.

24. Holding Time- Polypropylene tubes (POTW Influent)

25. Holding Time- Amber Glass Bottles (POTW Influent)

26. Holding Time- HDPE Bottles (POTW Influent)

27. Holding Time Study in POTW Influent using Entire Sample
Spiked into POTW influent and monitored.
Polypropylene- Eighteen separate spiked samples prepared to use the entire sample. Small sample size – 5 mL.
Pyrex Glass- Twelve separate spiked samples prepared to use the entire sample. Small sample size – 5 mL.
Corroborates that the entire sample must be used.

28. Whole Sample Influent (Polypropylene tubes- 31 days)

29. Whole Sample Influent (Compare Glass to Polypropylene)

30. Contamination (Be cautious!)
Teflon® Containing Materials
Waterproof Field Books
Plastic Clipboards, binders, or spiral hard cover books
Post-it Notes
Chemical (blue) ice packs
Tyvek®
Glass Pipettes-PFC contaminated- PFBA, PFPeA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA

31. Contamination (Be cautious!)
New clothing or water resistant, waterproof, or stain-treated clothing, clothing containing Gore-Tex™
LDPE containers
Decon 90
Water from an on-site well
Aluminum Foil

32. Sample Collection
Collect a 5.0 mL sample, grab would be best, in a graduated 15 mL polypropylene BD Falcon tube in the field so that the whole sample is processed in the lab (NO ALIQUOTING). 
In order to have accurate volumes, the weight of the 15 mL polypropylene BD Falcon tube may be taken before and after sampling in order to get an exact volume. The density of water is assumed to be 1.0 g/mL unless the exact density of the water sample is known, then that conversion should be used.

33. Holding time/Sample Requirements
28 Days
Required to collect a separate sample for each QC Sample (Co-located). Collecting in one container in the field and transferring to other containers may lead to low biased results.
Have to prepare and use the entire sample.
Take a couple extra samples in case re-extract required.

34. Analytical Issues Observed from Review of PFAS Site QAPPs: Environmental Water
Matrix – environmental water (groundwater, surface water, wastewater from treatment)
Method – options
No EPA approved method – cross agency workgroup is working on methods
ASTM D7979
Common for labs to cite “Modified Method 537”. This term is meaningless.
Other methods may be acceptable
Ask for the SOP and performance data
Compare to level of information in Method 537 or ASTM method
Is QC similar to other methods?
Is aliquot or whole sample used?

35. Analytical Issues Observed from Review of PFAS Site QAPPs: Solids
Matrix – solids (soil and sediment)
Method – options
No EPA approved method – cross agency workgroup is working on methods
ASTM D7968
Common for labs to cite “Modified Method 537”. Even more meaningless since solid matrices.
Other methods may be acceptable
Ask for the SOP and performance data
Compare to level of information in Method 537 or ASTM method
Is QC similar to other methods?
Is sample dried before extraction?

36. Analytical Issues Observed from Review of PFAS Site QAPPs: Common and Outstanding Issues
Unwilling to share complete SOPs
Label their methods as confidential business information
Share redacted SOPs
Without seeing SOPs, not possible to have confidence in data.
Do not supply performance data
Performance Data Benchmarks to look for
Method precision and accuracy data for 4 matrices, 7 replicates
ASTM D precision and accuracy data for at least 5 matrices, 6 replicates
Agency should expect similar level of data
DoD accreditation
Not clear what data are required to obtain accreditation
Not clear if EPA was consulted on accreditation criteria
Critical to thoroughly review QAPP to determine if SOPs used are sufficient

37. If You Review Data Generated by Other Methods
Previously Published methods on PFCs
EPA Method 537, ASTM D7979 or D7968, Journal?
Are they really following the methods they cite?
Using the entire sample?
Many sample manipulations involved?
Pre-filter?
Complicated Sample Preparation?
Batch QC-Surrogates, duplicates, matrix spikes, reporting limit checks?
Ongoing Method Performance in Real Matrices?
Quantitation?
SRM or MRM, Ion Ratios?
Isotope dilution, are they getting single digit, or lower, recoveries of their isotopes and correcting the data? (Turn a bad method into a so-so method! Reference- Phrase from EPA/OW/OS&T)
Equilibration time of the isotopes in the sample?
Are the isotopes at a similar concentration as their reporting range?

38. Conclusion/Ongoing work
Use Entire Sample
Quick and robust analyses
Multi-lab validating methods
Internal EPA (now)
External
Plan is to place in SW-846
Updated ASTM D7979 (Waters/sludges, not drinking water!) and D7968 (Soils).

39. More Information
Contact: Dennis Wesolowski, US EPA Region 5 Chicago Regional Lab Director
Contact: Larry Zintek, Chemist
Contact: Robert Thompson, Chemist and Sample Coordinator