ANALYSIS OF PER- AND POLYFLUOROALKYL SUBSTANCES (PFAS) · ANALYSIS OF PER- AND POLYFLUOROALKYL...

ANALYSIS OF PER- AND POLYFLUOROALKYL SUBSTANCES (PFAS) Jennifer Guelfo, PhD State Agencies Liaison, Brown SRP August 3, 2016

1 8/4/16

BrownUniversitySuperfundResearchProgram

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INTRODUCTION:PFASINTHENEWS

70ng/L:individuallyorincombinaAonDrinkingWaterHealthAdvisoriesforPFOA,PFOS

Whatisang/L?•  1dropin13,208,600gallons

or…

70 ng/L = 3.5 drops

INTRODUCTION:TERMINOLOGY&STRUCTURE

F

F

F

F

F

C

m

O

O-

Perfluoroalkylcarboxylates:Examples:m=2PFBAm=4PFHxAm=6PFOA

F

F

F

F

F

S

m

O

O

O-

Perfluoroalkanesulfonates:Examples:m=3PFBSm=5PFHxSm=7PFOS

4

Per=fullyfluorinatedalkyltail.

F

F

F

F

F

C

m

O

O-


F

F

F

F

F

S

m

O

O

O-


5

Polyfluoroalkylsubstances:

m=56:2FtSm=78:2FtSF

F

F

F

Fm

H

H2

S

O

O

O-

Poly=parAallyfluorinatedalkyltail.


F

F

F

F

F

C

m

O

O-


F

F

F

F

F

S

m

O

O

O-


6

Polyfluoroalkylsubstances:

m=56:2FtSm=78:2FtSF

F

F

F

Fm

H

H2

S

O

O

O-

Per + Poly = Per&polyfluoroalkylsubstances(PFAS)


PolyfluroalkylsubstancesthatcanundergotransformaAontoformperfluoroalkylacids

?

PFHxSAm (Precursor)

FHxSA (Intermediate

precursor)

? F

F

F

F

F

S

m

O

O

O-

O

O n

PFHxS

where n=6

Whatisaprecursor?

7


8

INTRODUCTION:CHEMISTRYANDUSES3

PFAScharacterisAcs:•  Chemicallystable•  Thermallystable•  Hydrophobic/lipophobic•  SurfactantproperAes•  Recalcitrantinenvironment

•  FelectronegaAve,notpolarizable•  C-Fbondstrength•  WeakintermolecularinteracAons

C ------ F δ+ δ-

PFASUses:•  Fluoropolymermanufacturing(e.g.polytetrafluoroethylene)•  FirefighAngfoams•  ElectroplaAng,papercoaAng,stain/waterrepellant,texAles,electronics,insecAcides/herbicides,adhesives,etc.

9

OVERVIEW

•  SamplepreparaAon•  Sampleanalysis

•  NovelanalyAcaltools•  Commerciallabs

•  LaboratoryQA/QC•  Standardmethods

•  Summary

Youhaveyoursample,now

what?

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SAMPLE PREPARATION

Ex: Soil + organic solvent, heat & shake

SolidsextracAon:•  Soils,plants,otherbiologicalAssue•  Nodirectanalysisofsolids•  Usesolventtoextractcompoundoffofsolid,analyzeextract•  ExtracAonmethodsvary

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SAMPLE PREPARATION

Ex: Soil + organic solvent, heat & shake

SolidsextracAon:•  Soils,plants,otherbiologicalAssue•  Nodirectanalysisofsolids•  Usesolventtoextractcompoundoffofsolid,analyzeextract•  ExtracAonmethodsvary

Ex: Load sample, elute,

analyze

SolidphaseextracAon(SPE):•  Loadlargevolumeontocartridge,eluteoffintosmaller,cleanervolume•  Concentratessample•  Notalwaysneeded-direct,largevolumeinjecAon•  Somemethodsuseit,somedonot

ANALYSIS: LC-MS/MS OVERVIEW4

Ionizing Interface (source)

Quadripole 1 (Q1)Analyzer

Q2 Collision

Cell

Quadripole 3 (Q3) Analyzer

Ion detector

HPLC Pump

Controller

Mobile phases

Auto- sampler

Valve

Sample Injection

Column

Tandem mass spectrometer (MS/MS)

High performance liquid chromatography (HPLC)

Desktop Computer HPLC system control MS/MS

system control

Liquidchromatographytandemmassspectrometry(LC-MS/MS)

12 12

ANALYSIS: LC-MS/MS OVERVIEW

Ionizing Interface (source)

Quadripole 1 (Q1)Analyzer

Q2 Collision

Cell

Quadripole 3 (Q3) Analyzer

Ion detector

HPLC Pump

Controller

Mobile phases

Auto- sampler

Valve

Sample Injection

Column

Tandem mass spectrometer (MS/MS)

High performance liquid chromatography (HPLC)

Desktop Computer HPLC system control MS/MS

system control

Liquidchromatographytandemmassspectrometry(LC-MS/MS)

13

14

ANALYSIS: LC-MS/MS OVERVIEW HPLCSeparaAon

+

T0

T1

T2MS/MS

• Separatescompoundmixtures• CharacterisAcretenAonAmes• Step1incompoundID

AcceptedtoolforPFASanalysis

• UniquefragmentaAonpaderns• Parent-daughtercombos=definiAveID,sensiAveanalysis

MS/MSDetecAon

- --

- --

Parentionized

MS1:analyzesparentmol.wt.

Collisioncell:parentfragmentaAon

MS2:analyzesdaughtermol.wt

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ANALYSIS: DATA AND QUANTIFICATION

Retention time

Peak

inte

nsity

PFHpA

PFOA

PFNA

Dataanalysis/quanAficaAon:•  Generally,concentraAonsdeterminedbycomparisonofcompoundresponsetocalibraAoncurve•  ExactmethodofquanAfyingconcentraAonmaydifferbetweenlabs•  Examples:externalcalibraAon,internalstandard,isotopediluAon

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QUALITY ASSURANCE/QUALITY CONTROL Methodblanks:checksforcontaminaAonduringsamplepreparaAon;~2/30samples+aierelevatedsamples

Laboratorycontrol:addsknownamt.compoundtocleanmatrix;ensurestestmethodisworking;~1/30samples

Matrixspike:addsknownamt.compoundtofieldsample;testsmatrixinterferences;~1/30samples

Duplicate:testsanalyAcalprecision;~1/30samples

CalibraAoncheck:ValidatesexisAngcalibraAon;frequencyvariese.g.1/10samplesandatbatchendforEPA53710

ng/L

STANDARD METHODS FOR PFAS5-7

17

•  PFAA=perfluoroalkylacids•  FASAA=perfluoroalkylsulfonamidoaceAcacid

•  n:3acid=n:3saturatedacid•  FTUCA=fluorotelomerunsaturatedcarboxylicacid•  FTCA=flurotelomercarboxylicacid

MethodName Method537 ASTMD7979-16 ASTMD7968-14

MatrixDrinkingwater

Water,influent/effluentwastewater,sludge Soil

CompoundClasses PFAA,FASAAPFAA,n:3acid,FTUCA,FTCA

PFAA,n:3acid,FTUCA,FTCA

Samplecontainer PolypropylenePolypropylene PolypropyleneSamplevolume 250mL 5mL 2g,adjustifneededExtracAon SPE None 50:50H2O:MeOHFiltering None Polypropylene PolypropyleneReporAngLimits 2.9-14ng/L 10-300ng/L 25-750ng/kgHoldingTimes 14days 28days 28days

PreservaAon5g/Lbuffer,cooled<10oC Cooled,<6oC Cooled,<6oC

QuanAficaAon Internalstd. Externalcal.+recoveryofisotopelabeledPFAS

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COMMERCIAL LAB AVAILABILITY

Laboratory Method Matrices Compound Classes Aqueous RL*

Axys Internal

Water, Solid, Air, Tissue, Serum, Urine

PFAA, FTS, FASA, FASAA, PAP, FTCA 1-80 ng/L

Eurofins EPA 537 or direct injection

Water, Solid, Tissue, Products PFAA, FTS, FASAA 2-10 ng/L

Test America Mod EPA 537 Water, Solid PFAA, FTS, FASA, FASAA, FASE 2-100 ng/L

Vista Mod EPA 537 Water, Solid, Tissue

PFAA, FTS, FASA, FASE, FASAA 1-40 ng/L

* Reporting limit (RL) range encompass all compound classes; RLs for all labs were below EPA HA levels for PFOS/PFOA

•  PFAA=perfluoroalkylacids•  FTS=fluorotelomersulfonates•  PAP=polyfluoroalkylphosphateesters

•  FASA=perfluroalkylsulfonamides•  FTCA=fluorotelomercarboxylicacid

•  FASE=perfluoroalkylsulfonamidoethanol

•  FASAA=perfluoroalkylsulfonamidoaceAcacid

•  FTUCA=fluorotelomerunsaturatedcarboxylicacid

19

OTHER ANALYTICAL TOOLS: TOP ASSAY8

Totaloxidizableprecursorassay:

PFCAs0+PFSAsPrecursors

Add:60mMKS2O8125mMNaOH

React:6hrs850C

HeatedoxidaAveconversion

TotalPrecursors=PFAAfinal–PFAA0

PFCAsfinal+PFSAs

•  BulkprecursorquanAficaAon=totalamt.precursorspresent•  DoesnotidenAfyindividualprecursorcompoundspresent

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OTHER ANALYTICAL TOOLS: PIGE

Par\cleinducedgamma-rayemission(PIGE):

•  Spectroscopicmeasurementof19Fnuclei•  Measurestotalfluorine-helpingtocompletePFASmassbalance•  Applicabletosoil,products(e.g.paper),geologicformaAons,etc.

IonbeamCharacterisAc

γ-ray@197keV

SUMMARY

Summary•  PrimarytoolfordetecAon/quanAficaAon:LC-MS/MS•  SampleextracAon/preparaAontechniquesvary•  Commercialavailabilityofcompoundclasses/matrices

varies•  HighpotenAalforbackgroundissuesàQA/QC!

Inthefuture•  DiversificaAonoftargetcompounds•  Needforcomparisonacrosslabs/

methods•  Commercialdevelopmentofnovel

techniques(e.g.TOP)21

REFERENCES

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1.  Buck, Robert C., et al. "Perfluoroalkyl and polyfluoroalkyl substances in the environment: terminology, classification, and origins." Integrated environmental assessment and management 7.4 (2011): 513-541.

2.  Place, Benjamin J., and Jennifer A. Field. "Identification of novel fluorochemicals in aqueous film-forming foams used by the US military." Environmental science & technology 46.13 (2012): 7120-7127.

3.  Kissa, Erik, ed. Fluorinated surfactants and repellents. Vol. 97. CRC Press, 2001. 4.  McMaster, Marvin C. LC/MS: a practical user's guide. John Wiley & Sons, 2005. 5.  Shoemaker, J. A. "Method 537. Determination of selected perfluorinated alkyl acids in

drinking water by solid phase extraction and liquid chromatography/tandem mass spectrometry (LC/MS/MS)." (2009).

6.  ASTM D7979-16 Standard Test Method for Determination of Perfluorinated Compounds in Water, Sludge, Influent, Effluent and Wastewater by Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS), ASTM International, West Conshohocken, PA, 2016.

7.  ASTM D7968-14 Standard Test Method for Determination of Perfluorinated Compounds in Soil by Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS), ASTM International, West Conshohocken, PA, 2014.

8.  Houtz, Erika F., and David L. Sedlak. "Oxidative conversion as a means of detecting precursors to perfluoroalkyl acids in urban runoff." Environmental science & technology 46.17 (2012): 9342-9349.

9.  Srivastava, A., et al. "Determination of fluorine concentrations in soil samples using proton induced gamma-ray emission." Journal of Radioanalytical and Nuclear Chemistry 302.3 (2014): 1461-1464.

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