2018 TCEQ Trade Fair PFAS Presentation The Analysis
- Slides: 37
2018 TCEQ Trade Fair – PFAS Presentation The Analysis of Per and Polyfluorinated Alkyl Substances (PFAS) Challenges and Best Practices Karla Buechler – Corporate Technical Director Copyright © 2018, Test. America. All rights reserved.
PFAS - Outline Introduction to PFASs What are PFASs? Nomenclature/Chemistry Sources, Timeline, Formation Exposure, Toxicity and Risk Regulatory Review Analytical Best Practices Analytical Methods review Why so much variability? How do we reduce variability? New In Line SPE Capability Future Concerns – TOP Assay Alternative chemicals – Gen. X Capabilities and Questions? 2 Copyright © 2018, Test. America. All rights reserved.
Briefly - What are PFASs? Class of synthetic compounds containing thousands of chemicals formed from carbon chains with fluorine attached to these chains. The C-F bond is the shortest and the strongest bond in nature. PFOS and PFOA are fully fluorinated and the most common perfluorinated chemicals (PFCs). 3 Persistent and resistant to degradation Found in soil, air and groundwater. . Copyright © 2018, Test. America. All rights reserved.
Nomenclature PFAS – Broad term – completely and incompletely fluorinated PFC – Subset of PFAS completely fluorinated compounds. PFOS and PFOA are PFCs (no hydrogen atoms) PFAAs – Perfluoroalkyl acids – 2 classes PFCAs and PFSAs AFFF – Aqueous Film Forming Foam –mixture of PFCAs, PFSAs, and PFAA precursors Fluorochemicals and telomers 4 Copyright © 2018, Test. America. All rights reserved.
Chemical Structure Why is it Important? Perfluoroalkyl Carboxylate Perfluoroalkyl Sulfonate Fluorotelomer Sulfonates 5 Perfluoroalkyl Sulfonamido Amines Perfluoroalkyl Sulfonamido acetic acid amine Copyright © 2018, Test. America. All rights reserved.
Primary Sources – Point or Direct Ø Released in large quantities from primary manufacturing facilities Ø Secondary Manufacturing – incorporation of PFC raw materials into industrial and consumer products Ø The use of AFFFs to fight fires is a direct pathway to the environment – (Connection to Do. D) 6 Copyright © 2018, Test. America. All rights reserved.
Secondary Sources - Indirect Ø Commercial and consumer products have a finite lifetime. Ø Dispose to landfills Ø WWTP Ø Air emissions Ø Trace chemistry – transformation mostly degradation byproducts (TOP Assay) 7 Copyright © 2018, Test. America. All rights reserved.
Environmental Exposure Pathways Oliaei, Environ Pollut Res. (2013): 1977 -1992 8 Copyright © 2018, Test. America. All rights reserved.
Exposure, Toxicity and Risk Ø Major source of non-occupational exposure to humans is from food and air (predominately fish consumption) Ø Human and wildlife exposure can continue even though the chemicals are no longer in use, due to persistence. Ø PFOS and PFOA have half-lives in humans ranging from 2 to 9 years, depending on the study. Ø PFOA associated with liver, pancreatic, testicular, and mammary gland tumors in laboratory animals. PFOS causes liver and thyroid cancer in rats Ø PFOA and PFOS are associated with cancers in humans. Pathways are being studied. 9 Copyright © 2018, Test. America. All rights reserved.
Regulatory Challenges and New Developments Ø Lack of regulatory guidance for most matrices and most PFAS compounds Ø Wide variety of detection limits and analyte lists Ø Lack of published methods Ø What is Method 537 M? Ø What are the ASTM Methods? Ø What is the ISO Method 25101? Copyright © 2018, Test. America. All rights reserved.
PFAS – Regulatory Timeline When Who What Happened 1980 s EU 2002 US EPA 2002 3 M Discontinued making PFOS (7 other makers complied) 2006 US EPA Announced 2010 (95%)/15(100%) PFOA Stewardship Program 2008 Canada Regulated and prohibited PFOS imports to Canada 2009 UN 2010 US EPA 2010 PFOA Stewardship program - must reduce PFOA use by 95% 2015 US EPA Must 100% eliminate the use of PFOA by December 31, 2015. May 2016 US EPA PFOS and PFOA life time health limits reduced to 70 ppt each or the total if both are present. Sept 2016 NJ Groundwater directive to prevent discharge of PFOS Initiated voluntary phase out of PFOS Stockholm Convention - adds PFOS to Annex B DWQI proposed PFOA drinking water MCL of 14 ppt What started happening in 2016? 11 Copyright © 2018, Test. America. All rights reserved.
What’s Up in New Jersey? 12 (12/2017) State PFOA ppt PFOS ppt Comments Source Alabama 70 70 EPA Alaska 400 ADEC California Prop 65 Proposed OEHHA Connecticut 70 70 PFNA, PFHx. A, PFPe. A, PFHp. A DPH Delaware 70 70 DNR Georgia 70 70 Proposed DPH Illinois 400 200 Iowa 70 70 Kentucky 400 200 NKWD Maine 70 70 ME DEP Maryland 70 70 Michigan 5 proposed MI DEQ Minnesota 35 27 MDH New Hampshire 70 70 DES New Jersey* 14 13 NJDEP New York 70 70 North Carolina 2000 NA DENR Ohio 400 200 Oregon 24000 300000 PFHp. A, PFNA, PFOSA Pennsylvania 70 (May lower to 6) 70 PA DEP Rhode Island 70 70 Texas 290 560 PCLs for 16 PFCs CEQ Vermont 20 20 VT DOH Washington NA TBD Listed PFOS as PBT West Virginia 400 Copyright © 2018, Test. America. All rights reserved. 200 DNR EPA
Why are PFAS an Analytical Challenge? Ø Globally distributed Ø Present at low concentrations and high Ø Contamination and analyte loss at all stages of collection and analysis Ø Lack of authentic standards Ø Unusual physical and chemical properties Ø Lack of consensus “best” method for non-DW Copyright © 2018, Test. America. All rights reserved.
PFAS Analytical Methods- Best Practices Ø Manufacturer’s methods were adopted by the environmental industry – SW-846 Method 8321 Ø EPA expanded manufacturer’s method for drinking water-Method 537 Ø Labs had to modify Method 537 in order to meet client needs for additional matrices Ø Sept 2016 EPA- Method 537 Technical Advisory Ø January 2017 Do. D QSM 5. 1 addresses PFAS 14 Copyright © 2018, Test. America. All rights reserved.
Why so much method variability? Ø Inconsistent quantitation of branched and linear isomers Ø Ø Absence of multi-lab validated methods Limited certification programs Differences in extraction efficiencies – analyte sorbent dependent External, internal and isotope dilution quantitation schemes Ø Lack of proven commercially available PT samples Ø Use of different isotopically labeled extraction surrogates Ø Lack of commercially available standard materials and true second sources Ø Target analyte losses during filtration Ø Absence of demonstrated cleanup techniques for complex matrices Ø Wide variety of container types and holding times 15 Copyright © 2018, Test. America. All rights reserved.
Show Branched and Linear Error in PFOS and PFOA Standard B and L L only 0. 99 vs 1. 20 ng/ml Sample 16 Copyright © 2018, Test. America. All rights reserved.
Study Results - NMI PT Ø 24 labs submitted results – 9 Passed Ø Test. America passed water, soil and fish tissue samples Sample Analyte Sac Lab Expected Water A PFOA 7. 91 7. 90 PFOS 3. 23 3. 00 PFOA 9. 01 10. 8 PFOS 6. 81 6. 50 PFOA 7. 00 5. 83 PFOS 290 262 PFOA 14. 2 12. 0 PFOS 23. 5 22. 0 PFOA ND ND PFOS 19. 9 20. 6 PFOA 51. 4 50. 5 PFOS 49. 2 53. 7 Water B Soil A Soil B Fish A Fish B 17 Copyright © 2018, Test. America. All rights reserved.
Sample Collection and Holding Time Studies Ø Samples should be collected in HDPE bottles fitted with unlined (no Teflon) polyethylene screw caps. Ø In addition, the sampler should avoid contact with fluoropolymers, aluminum foil, and food wrappers. Ø Samples should not be field filtered. Ø Samples must be shipped chilled Ø Limited HT study data 18 Copyright © 2018, Test. America. All rights reserved.
Managing Artifacts Ø The field crew – personnel hygiene, clothing, food products, sunscreens and insect repellants Ø Sampling equipment – avoid fluoropolymer bailers, pump bladders, tubing, valves etc. Ø Sample collection – wash hands, wear nitrile gloves, do not filter samples, add field QC samples routinely Ø Avoid detergents Ø Avoid food or drink on-site Ø Limit visitors during sample collection Copyright © 2018, Test. America. All rights reserved.
Sources of Artifacts USEPA Study, March 2009 EPA/600/R-09/033 Copyright © 2018, Test. America. All rights reserved.
Managing Loss/Adsorption Ø Many PFAS are surface active, which cause them to stratify, adsorb to surfaces Ø Extraction type – whole bottle or subsample play a more significant role then material type Ø PFAS can adsorb to the filtration equipment. PFAS in the dissolved phase can also adsorb to the filter material Ø Unless the samples are analyzed immediately adsorption to glass vials may occur Copyright © 2018, Test. America. All rights reserved.
How can we mitigate analytical variability? Ø Apply tandem mass spectrometry technology Ø Implement an isotope dilution quantitation scheme Ø Compensate for losses with matrix recovery correction Ø Share our knowledge Ø Invest resources in multilab validation 22 Copyright © 2018, Test. America. All rights reserved.
What is Isotope Dilution? Ø Most accurate and precise calibration method available Ø Partial loss of analyte during preparation is compensated for since chemical interferences are not an issue Ø Allows for matrix recovery correction – what affects the native analyte will equally affect the isotope Ø Correction for signal drift Ø Improved qualitative identification – RT shifts 23 Copyright © 2018, Test. America. All rights reserved.
Method 537 M – In Line SPE Ø What is it? § Dilute a water sample with methanol and inject a large volume onto a modified UPLC Ø What are the advantages? § Simplicity – reduced sample manipulation § Reduced sample volume (5 mls) § Speed, reduced TAT § Increased capacity § Reduced risk of laboratory background artifacts 24 Copyright © 2018, Test. America. All rights reserved.
What are Precursors and Why Do We Care? Ø Thousands of precursors used in industrial and consumer products Ø Some biotransform to make PFAAs Ø Some are fluorotelomers Ø Most are ionic, either positive, negative or both Ø Fate and transport – complex process Copyright © 2018, Test. America. All rights reserved.
What is the TOP Assay? A new PFAS sample preparation technique Ø Conceptually simple chemistry Quantified Transformation Ø Used with 537 M not 537 Ø Pre and Post results Ø Indicates unidentified PFAS Unknown Potential 26 Copyright © 2018, Test. America. All rights reserved.
How Does it Work in the Environment? Give me an example: PFOA Biotransformation PFAA Precursors Inflow Low levels of discrete compounds are detected 13 PFOS Outflow High levels of discrete compounds are detected, which can include PFOA and PFOS Copyright © 2018, Test. America. All rights reserved.
TOP – How Does it Work in the Laboratory? OH • PFAA Precursors 85°C OH • 85°C 28 Copyright © 2018, Test. America. All rights reserved. PFOA + other PFCAs
PFCA Pattern – Me-FOSA Precursor 80 PFOA 70 PFBA 60 PFPe. A 50 PFHx. A ppt 40 PFHp. A PFOA 30 PFNA 20 10 0 11 Copyright © 2018, Test. America. All rights reserved.
PFCA Pattern – 8: 2 FTS PFHp. A 100 90 80 PFBA 70 PFPe. A ppt 60 PFHx. A PFHp. A 50 PFOA 40 PFNA 30 20 10 0 12 Copyright © 2018, Test. America. All rights reserved.
What Do the Results Mean? TOP Assay measures total PFCA 31 Precursor Pre - TOP Post - TOP % Oxidation FOSA 32. 68 ND 100% Me. FOSAA 19. 38 ND 100% Et. FOSAA 18. 83 ND 100% 6: 2 FTS 31. 69 ND 100% 8: 2 FTS 26. 37 ND 100% PFCA Pre – TOP Post - TOP Total PFBA 24. 94 27. 16 109% PFPe. A 23. 38 28. 55 122% PFHx. A 26. 49 34. 87 132% PFHp. A 23. 10 25. 14 109% PFOA 23. 72 58. 71 248% Total 122 Total 174 Copyright © 2018, Test. America. All rights reserved.
What Conclusions Can We Draw? Ø PFAA precursors are present in environmental samples and many AFFF products Ø Implies treatment strategies must remove precursors and end points Ø Presence impacts our treatment strategies and our risk assessments Ø Potentially increases future risk as precursors are biotransformed Ø Presence impacts our decisions for AFFF formulations Ø AFFF manufacturers should reduce the content of PFOA etc. 21 Copyright © 2018, Test. America. All rights reserved.
Fluorinated Replacement Chemicals Ø Since 2000, on-going industrial transition to replace LC PFCAs, PFSAs and precursors Ø Many alternative chemicals are in use – below regulatory radar Ø Unclear whether they are safe for humans or the environment Ø Du. Pont developed patented Gen. X technology - enables them to make fluoropolymers without PFOA Ø Gen. X is not a chemical it is a process Copyright © 2018, Test. America. All rights reserved.
Replacement Chemicals CAS # Name Synonym Source 73606 -19 -6 F-53 B (Major component) 6: 2 CL-PFESA or 9 CLPF 3 ONS TBD PFOS replacement Chenguang, China chemical 83329 -89 -9 F-53 B (Minor component) 8: 2 CL-PFESA or 11 CLPF 3 OUd. S TBD PFOS replacement Chenguang, China chemical ADONA or DONA NH 4 TBD PFOS replacement chemical 958445 -44 -8 Use Manufacturer 3 M and Dyneon 13252 -13 -6 PFPr. OPr. A HFPO-DA Gen. X PFOA replacement Du. Pont/Chemours chemical 62037 -80 -3 PFPr. OPr. A NH 4 HFPO-DA NH 4 Gen. X PFOA replacement Du. Pont/Chemours chemical 3330 -15 -2 PFPr. A ether HFPO-DA ether Gen. X PFOA replacement Du. Pont/Chemours chemical Copyright © 2018, Test. America. All rights reserved.
Test. America Capabilities Ø Test. America Sacramento is EPA approved for Method 537 in drinking water and ISO 25101 in NYS Ø Sacramento is QSM 5. 1 Table B-15 approved for Method 537 M Ø Sacramento, Denver and Burlington Labs are NELAP approved for Method 537 M. Ø 7 LCMSMS instruments capable of PFAS testing Ø Sacramento has successfully implemented the TOP Assay 35 Copyright © 2018, Test. America. All rights reserved.
Future Concerns Ø We need a consensus “best” method. Ø Analyte lists are growing for discrete methods, may lead to forensics. Ø LC PFASs are being replaced by SC PFASs and little is know about the toxicity Ø On-going data variability must be improved Ø We need an effective field screening technique. 36 Copyright © 2018, Test. America. All rights reserved.
Thank you for attending The Analysis of Polyfluorinated Alkyl Substances (PFAS) Including PFOS and PFOA Questions Copyright © 2018, Test. America. All rights reserved.
- Tceq trade fair
- Fair trade not free trade
- Pfas sunscreen
- Pfas nemp 2020
- Pfas
- Sonnet
- Foul is fair and fair is foul literary device
- Assonance in macbeth
- Foul is fair and fair is foul
- Syntax rhetorical device
- Fair is foul and foul is fair significato
- Examples of fair is foul and foul is fair in macbeth
- B a f c j e
- Is free trade fair? discuss
- Qatar karta
- Fair and unfair trade
- Make trade fair
- New trade theory
- Fair trade technology
- Trade fair dialogue
- Nike fair trade
- Fair trade prodcuts
- Fair trade minerals
- Coffee commodity chain
- Responsability fair trade fund
- Fair trade coffee facts and figures
- Fair trade calgary
- Fair trade quiz
- Fairtrade marks
- Trade vocabulary
- Fair trade facts
- What is fair trade coffee why is it an ethical issue
- Science fair powerpoint presentation examples
- Science fair powerpoint presentation examples
- Trade diversion and trade creation
- Umich
- Trade diversion and trade creation
- The trade in the trade-to-gdp ratio