Analysis of Perfluorinated Compounds (PFCs) by Liquid Chromatography/Mass Spectrometry

Jia Wang

April 11, 2013

2

Perfluorinated Compounds

• Stain, oil and water resistant

• Chemical and thermo stability

• Applied to fabrics, papers, carpets, and fire-fighting foam

• Persistent, bioaccumulative and toxic

• PFOA and PFOS now on CCL3 list (Contaminant Candidate List 3)

HO S CF2(CF2)6CF3

O

O

CF3(CF2)5CF2

O

OH

3

EPA Method 537

4

Lancaster Laboratories and Thermo Fisher Scientific Participated in the Second Laboratory Demonstration of EPA Method 537

5

Compounds Analyzed

* Technical Grade: both linear and branched isomers

Name Acronym SRM TransitionAnalyte Perfluorohexanoic acid  PFHxA C6 313-269Analyte Perfluoroheptanoic acid  PFHpA C7 363-319Analyte Perfluorooctanoic acid  PFOA C8 413-369Analyte Perfluorononanoic acid  PFNA C9 463-419Analyte Perfluorodecanoic acid  PFDA C10 513-469Analyte Perfluoroundecanoic acid  PFUnA C11 563-519Analyte Perfluorododecanoic acid PFDoA C12 613-569Analyte Perfluorotridecanoic acid  PFTrDA C13 663-619Analyte Perfluorotetradecanoic acid  PFTA C14 713-669Analyte Perfluorobutanesulfonic acid  PFBS C4 299-80Analyte Perfluorohexanesulfonic acid* PFHxS C6 399-80Analyte Perfluorooctanesulfonic acid* PFOS C8 499-80Analyte N-ethyl perfluorooctanesulfonamidoacetic acid* NEtFOSAA 584-419Analyte N-methyl perfluorooctanesulfonamidoacetic acid* NMeFOSAA 570-419ISTD Perfluoro-n-[1,2,3,4-13C4]octanoic acid

13C-PFOA 417-372

ISTD Sodium perfluoro-1-[1,2,3,4-13C4]octanesulfonate13C-PFOS 503-80

ISTD N-deuteriomethylperfluoro-1-octanesulfonamidoacetic acid d3-NMeFOSAA 573-419

Surrogate Perfluoro-n-[1,2-13C2]hexanoic acid13C-PFHxA 315-270

Surrogate Perfluoro-n-[1,2-13C2]decanoic acid 13C-PFDA 515-470

Surrogate N-deuterioethylperfluoro-1-octanesulfonamidoacetic acid d5-NEtFOSAA 589-419

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• Mobile phase: 20 mM ammonium acetate and methanol

• Injection solvent: 96:4% (vol/vol) methanol:water

• Injection volume: 10 L• Flow rate: 0.3 mL/min

• Electrospray ionization (ESI): Negative

• LC gradient

Time (min) % 20 mM ammonium acetate % Methanol

0 60 40

1 60 40

25 10 90

32 10 90

32.1 60 40

37 60 40

EPA Method 537 LC and ESI-MS Conditions

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Sample Preparation

• Preservation reagent: Trizma® Preset Crystals, pH 7.0, 1.25 g/250 mL

• 250 mL water fortified with surrogates is extracted by SPE and eluted by methanol

• SPE cartridges: styrenedivinylbenzene (SDVB) sorbent, 0.5g/6mL

• The extract was concentrated to dryness and then adjusted to a 1 mL volume with 96:4% (vol/vol) methanol: water

8

PFCs Analysis Challenge

• Method interferences may be caused by contaminants in solvents, reagents, sample bottles and caps, and other sample processing hardware that lead to discrete artifacts and/or elevated baselines in the chromatograms.

• The method analytes in this method can also be found in many common laboratory supplies and equipment, such as PTFE (polytetrafluoroethylene) products, LC solvent lines, methanol, aluminum foil, SPE sample transfer lines, etc.

• All items such as these must be routinely demonstrated to be free from interferences (less than 1/3 the MRL for each method analyte) under the conditions of the analysis by analyzing laboratory reagent blanks.

• Subtracting blank values from sample results is not permitted.

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Thermo PFOA Analysis Kit

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LC System Modification

• PTFE solvent frits and tubing were replaced by PEEK solvent frits and tubing

• Degasser was replaced by PFOA free degasser • A trapping column (Thermo BDS-Hypersil, C8, 3 x 150 mm, 5 m) was

placed between the pump outlet module and autosampler to trap and separate PFCs contaminant from analytes

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• Instrument: Thermo Fisher Scientific Dionex XRS Pump, Accela Open Autosampler, and TSQ Quantum Vantage

• Analytical Column: Thermo Scientific Accucore C18 column (3 x 150 mm, 2.6 m)

• Mobile phase: 20 mM ammonium acetate and methanol

• Electrospray ionization (ESI): Negative

Time (min) % 20 mM ammonium acetate % Methanol

0 70 30

1 70 30

25 10 90

32 10 90

32.1 70 30

37 70 30

LC and ESI MS Conditions

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PFC Contaminants are Separated from Analytes - 0.1 ppb

RT: 0.00 - 28.00

0 5 10 15 20 25Time (min)

0

1000

1000

1000

100

Rel

ativ

e A

bund

ance

0

1000

1000

10024.4423.86

20.1415.4721.80

25.5018.0912.7512.75

13.0615.48

16.1714.9715.47

15.9314.9118.09

18.6817.8918.24

17.74 18.6116.74

20.13

19.71

NL: 4.30E4TIC MS EPA537-Cal3-21

NL: 3.89E2TIC F: - c ESI SRM ms2 298.898 [79.907-79.909] MS EPA537-Cal3-21

NL: 1.27E3TIC F: - c ESI SRM ms2 312.918 [268.981-268.983] MS EPA537-Cal3-21

NL: 2.39E4TIC F: - c ESI SRM ms2 314.913 [269.944-269.946] MS EPA537-Cal3-21

NL: 1.26E3TIC F: - c ESI SRM ms2 362.917 [318.968-318.970] MS EPA537-Cal3-21

NL: 2.44E2TIC F: - c ESI SRM ms2 398.893 [79.907-79.909] MS EPA537-Cal3-21

NL: 2.12E3TIC F: - c ESI SRM ms2 412.911 [368.960-368.962] MS EPA537-Cal3-21

PFBS

PFHxA

PFHxA-SUR

PFHpA

PFHxS*

PFOA

* Technical grade

PFOA Contaminant

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RT: 0.00 - 28.00

0 5 10 15 20 25Time (min)

0

1000

1000

1000

100

Rel

ativ

e A

bund

ance

0

1000

1000

10020.14

20.4519.7222.51

21.80

21.3321.9620.49

21.80

22.2121.5023.25

23.8422.6123.25

23.5622.9524.46

23.83

NL: 2.73E4TIC F: - c ESI SRM ms2 414.908 [369.937-369.939] MS EPA537-Cal3-21

NL: 1.80E3TIC F: - c ESI SRM ms2 462.910 [418.966-418.968] MS EPA537-Cal3-21

NL: 1.52E2TIC F: - c ESI SRM ms2 498.888 [79.873-79.875] MS EPA537-Cal3-21

NL: 1.16E4TIC F: - c ESI SRM ms2 502.892 [79.860-79.862] MS EPA537-Cal3-21

NL: 1.28E3TIC F: - c ESI SRM ms2 512.912 [468.993-468.995] MS EPA537-Cal3-21

NL: 2.50E4TIC F: - c ESI SRM ms2 514.902 [469.969-469.971] MS EPA537-Cal3-21

NL: 1.40E3TIC F: - c ESI SRM ms2 562.907 [518.998-519.000] MS EPA537-Cal3-21

PFC Contaminants are Separated from Analytes - 0.1 ppb

PFOA-IS

PFNA

PFOS*

PFOS-IS

PFDA

PFDA-SUR

NMeFOSAA-IS

* Technical grade

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RT: 0.00 - 28.00

0 5 10 15 20 25Time (min)

0

1000

1000

1000

100

Rel

ativ

e A

bund

ance

0

1000

1000

10023.87

24.2323.3923.86

23.44 24.2224.46

24.5824.10

24.44

24.7524.0625.50

25.9325.13

26.40

25.93

NL: 4.44E2TIC F: - c ESI SRM ms2 569.909 [418.919-418.921] MS EPA537-Cal3-21

NL: 3.91E4TIC F: - c ESI SRM ms2 572.916 [418.937-418.939] MS EPA537-Cal3-21

NL: 4.69E2TIC F: - c ESI SRM ms2 583.907 [418.968-418.970] MS EPA537-Cal3-21

NL: 4.30E4TIC F: - c ESI SRM ms2 588.928 [418.931-418.933] MS EPA537-Cal3-21

NL: 1.73E3TIC F: - c ESI SRM ms2 612.914 [568.984-568.986] MS EPA537-Cal3-21

NL: 1.53E3TIC F: - c ESI SRM ms2 662.905 [618.968-618.970] MS EPA537-Cal3-21

NL: 1.17E3TIC F: - c ESI SRM ms2 712.904 [668.934-668.936] MS EPA537-Cal3-21

PFC Contaminants are Separated from Analytes - 0.1 ppb

NMeFOSAA

PFUnA

NEtFOSAA-SUR

NEtFOSAA

PFDoA

PFTrDA

PFTA

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• PFC acquisition and analysis was performed using software with built-in workflows for streamlining method development and routine analysis.

TraceFinder Software

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Compound Database

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Method Development

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Method Development

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Data Review – PFOA

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Data Review – PFOS

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Data Review – PFOS

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Report View

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Unregulated Contaminant Monitoring Rules 3 (UCMR3)

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UCMR 3 Contaminants and Corresponding Analytical Methods - PFCs

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Thermo Has Helped Customer to Receive UCMR3 Certification for EPA Method 537

• EPA coordinates a Laboratory Approval Program for the contaminants. UCMR 3 requires laboratories have EPA approval to analyze PWS samples.

• Thermo Fisher Scientific has developed TraceFinder method for EPA method 537 UCMR3 analysis. Our customer has used this TraceFinder method for EPA method 537 UCMR3 application and PT samples analysis, and received EPA certification

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• Thermo Fisher Scientific offers PFOA analysis kit to reduce and separate PFCs contaminants from analytes

• Thermo Fisher Scientific and Lancaster Labs had previously participated in the second laboratory demonstration of EPA Method 537

• Thermo Fisher Scientific has developed TraceFinder method for EPA method 537 UCMR3 analysis. Customer has used this TraceFinder method for EPA method 537 UCMR3 analysis and received EPA certification

Summary

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Thank You for Your Attention

Questions?