EPA CFES&ER/ORD: 537.1: SELECTED PER- AND POLYFLUORINATED ALKYL SUBSTANCES IN DRINKING WATER BY SPE AND LC/MS/MS

Summary
Analytes
Revisions
Data and Sites

Official Method Name

METHOD 537.1 DETERMINATION OF SELECTED PER- AND POLYFLUORINATED ALKYL SUBSTANCES IN DRINKING WATER BY SOLID PHASE EXTRACTION AND LIQUIDCHROMATOGRAPHY/ TANDEM MASS SPECTROMETRY (LC/MS/MS)

Current Revision

Rev. 2.0, 2020

Media

WATER

Instrumentation

Liquid Chromatography with Tandem Mass Spectrometry

Method Subcategory

Organic

Method Source

EPA CFES&ER/ORD

Citation

METHOD 537.1 DETERMINATION OF SELECTED PER- AND POLYFLUORINATED ALKYL SUBSTANCES IN DRINKING WATER BY SOLID PHASE EXTRACTION AND LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY (LC/MS/MS)

Brief Method Summary

A 250-mL water sample is fortified with surrogates and passed through an SPE cartridge containing polystyrenedivinylbenzene (SDVB) to extract the method analytes and surrogates. The compounds are eluted from the solid phase sorbent with a small amount of methanol. The extract is concentrated to dryness with nitrogen in a heated water bath, and then adjusted to a 1-mL volume with 96:4% (vol/vol) methanol:water and addition of the internal standards. A 10-µL injection is made into an LC equipped with a C18 column that is interfaced to an MS/MS. The analytes are separated and identified by comparing the acquired mass spectra and retention times to reference spectra and retention times for calibration standards acquired under identical LC/MS/MS conditions. The concentration of each analyte is determined by using the internal standard technique. Surrogate analytes are added to all Field and QC Samples to monitor the extraction efficiency of the method analytes.

Scope and Application

This is a solid phase extraction (SPE) liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the determination of selected per- and polyfluorinated alkyl substances (PFAS) in drinking water. Accuracy and precision data have been generated in reagent water and drinking water for the compounds listed in the table below.

Applicable Concentration Range

Use at least five calibration concentrations spanning a 20-fold concentration range. The suggested analyte concentrations of 4 - 160 ng/L can be used as a starting point. The lowest concentration calibration standard must be at or below the MRL, which may depend on system sensitivity.

Interferences

(A) Glassware contamination: All glassware must be meticulously cleaned. Wash glassware with detergent and tap water, rinse with tap water, followed by a reagent water rinse. Non-volumetric glassware can be heated in a muffle furnace at 400 °C for 2 h or solvent rinsed. NOTE: PFAs can adsorb to glass so polypropylene containers should be used. (B) Solutions, preservatives, SPE cartridges, and sample container contamination: Method interferences may come from many sources. All items 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 as described in Section 9.3.1. Subtracting blank values from sample results is not permitted. (C) Matrix contamination: Humic and/or fulvic material can be co-extracted during SPE and high levels can cause enhancement and/or suppression in the electrospray ionization source or low recoveries on the SPE sorbent. TOC-associated matrix effects were not generally observed.

Quality Control Requirements

CALIBRATION STANDARD (CAL), CONTINUING CALIBRATION CHECK (CCC), FIELD DUPLICATES (FD1 and FD2), FIELD REAGENT BLANK (FRB), INTERNAL (IS) STOCK STANDARD SOLUTIONS, IS STOCK STANDARD SOLUTIONS (IS SSS), LABORATORY FORTIFIED BLANK (LFB), LABORATORY FORTIFIED SAMPLE MATRIX (LFSM), LABORATORY FORTIFIED SAMPLE MATRIX DUPLICATE (LFSMD), LABORATORY REAGENT BLANK (LRB), ANALYTE PRIMARY DILUTION STANDARD (PDS) SOLUTION, INTERNAL STANDARD PRIMARY DILUTION (IS PDS) STANDARD, QUALITY CONTROL SAMPLE (QCS), STOCK STANDARD SOLUTION (SSS), SURROGATE (SUR) STANDARD SOLUTIONS, SUR STOCK STANDARD SOLUTIONS (SUR SSS), SURROGATE PRIMARY DILUTION STANDARD (SUR PDS), ANALYTE STOCK STANDARD SOLUTION (SSS),

Sample Handling

Samples must be collected in a 250-mL polypropylene bottle, fitted with a polypropylene screw-cap, that contain the preservation reagent (Trizma). After collecting the sample, cap the bottle and agitate by hand until preservative is dissolved. Keep the sample sealed from time of collection until extraction. An FRB must be handled along with each sample set. Samples must be chilled during shipment and must not exceed 10 °C during the first 48 hours after collection. Sample temperature must be confirmed to be at or below 10 °C when the samples are received at the laboratory. Samples stored in the lab must be held at or below 6 °C until extraction but must not be frozen. Water samples should be extracted as soon as possible but must be extracted within 14 days. Extracts must be stored at room temperature and analyzed within 28 days after extraction.

Maximum Holding Time

sample - 14 days; extract 28 days

Relative Cost

Greater than $400

Sample Preparation Methods

This method has 18 analytes associated with it.

Analyte	Detection Level	Bias	Precision	Spiking Level
11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid(763051-92-9) 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid 11Cl-PF3OUdS Ethanesulfonic acid, 2-[(8-chloro-1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8-hexadecafluorooctyl)oxy]-1,1,2,2-tetrafluoro-	1.500 ng/L	109% Rec (ML)	3.40 % RSD (ML)	16.00 ng/L
4,8-Dioxa-3H-perfluorononanoic acid(919005-14-4) 4,8-Dioxa-3H-perfluorononanoic acid ADONA	0.880 ng/L	108% Rec (ML)	1.30 % RSD (ML)	16.00 ng/L
9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acd(756426-58-1) 9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acd 9Cl-PF3ONS	1.400 ng/L	108% Rec (ML)	8.80 % RSD (ML)	16.00 ng/L
Hexafluoropropylene oxide dimer acid(13252-13-6) HFPO-DA Hexafluoropropylene oxide dimer acid Propanoic acid, 2,3,3,3-tetrafluoro-2-(1,1,2,2,3,3,3-heptafluoropropoxy)-	1.900 ng/L	98% Rec (ML)	1.80 % RSD (ML)	16.00 ng/L
N-ethyl perfluorooctanesulfonamidoacetic acid(2991-50-6) Glycine, N-ethyl-N-[(1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluorooctyl)sulfonyl]- N-ethyl perfluorooctanesulfonamidoacetic acid N-ethyl perfluorooctanesulfonamidoacetic acid NEtFOSAA NEtFOSAA	2.800 ng/L	98% Rec (ML)	6.80 % RSD (ML)	16.00 ng/L
N-methyl perfluorooctanesulfonamidoacetic acid(2355-31-9) Glycine, N-[(1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluorooctyl)sulfonyl]-N-methyl- N-methyl perfluorooctanesulfonamidoacetic acid N-methyl perfluorooctanesulfonamidoacetic acid NMeFOSAA NMeFOSAA	2.400 ng/L	104% Rec (ML)	5.20 % RSD (ML)	16.00 ng/L
Perfluorobutanesulfonic acid(375-73-5) 1,1,2,2,3,3,4,4,4-Nonafluoro-1-butanesulfonic acid PFBS Perfluorobutanesulfonic acid	1.800 ng/L	91% Rec (ML)	6.80 % RSD (ML)	16.00 ng/L
Perfluorodecanoic acid(335-76-2) PFDA Perfluorodecanoic acid	1.600 ng/L	111% Rec (ML)	2.40 % RSD (ML)	16.00 ng/L
Perfluorododecanoic acid(307-55-1) PFDoA Perfluorododecanoic acid Perfluorolauric acid	1.200 ng/L	101% Rec (ML)	7.20 % RSD (ML)	16.00 ng/L
Perfluoroheptanoic acid(375-85-9) PFHpA Perfluoroheptanoic acid	0.710 ng/L	105% Rec (ML)	3.30 % RSD (ML)	16.00 ng/L
Perfluorohexanesulfonic acid(355-46-4) 1,1,2,2,3,3,4,4,5,5,6,6,6-Tridecafluorohexane-1-sulfonic acid PFHxS Perfluorohexanesulfonic acid	1.400 ng/L	109% Rec (ML)	6.70 % RSD (ML)	16.00 ng/L
Perfluorohexanoic acid(307-24-4) PFHxA Perfluorohexanoic acid Undecafluoro-1-hexanoic acid	1.000 ng/L	101% Rec (ML)	8.00 % RSD (ML)	16.00 ng/L
Perfluorononanoic acid(375-95-1) PFNA Perfluorononanoic acid	0.700 ng/L	110% Rec (ML)	2.60 % RSD (ML)	16.00 ng/L
Perfluorooctanesulfonic acid(1763-23-1) 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-Heptadecafluoro-1-octanesulfonic acid PFOS Perfluorooctane sulfonate Perfluorooctanesulfonic acid	1.100 ng/L	111% Rec (ML)	4.70 % RSD (ML)	16.00 ng/L
Perfluorooctanoic acid(335-67-1) Hexanoyl fluoride, 3,3,4,4,5,5,6,6,6-nonafluoro-2-oxo- PFOA Perfluoroheptanecarboxylic acid Perfluorooctanoic acid	0.530 ng/L	106% Rec (ML)	1.80 % RSD (ML)	16.00 ng/L
Perfluorotetradecanoic acid(376-06-7) PFTA Perfluoromyristic acid Perfluorotetradecanoic acid	1.100 ng/L	110% Rec (ML)	0.90 % RSD (ML)	16.00 ng/L
Perfluorotridecanoic acid(72629-94-8) PFTrDA Perfluorotridecanoic acid	0.720 ng/L	108% Rec (ML)	2.60 % RSD (ML)	16.00 ng/L
Perfluoroundecanoic acid(2058-94-8) PFUnA Perfluoroundecanoic acid	1.600 ng/L	107% Rec (ML)	2.80 % RSD (ML)	16.00 ng/L

Precision Descriptor Notes:	LCMRLs and DLs for each method analyte are presented. Precision and accuracy are presented for four water matrices: reagent water; chlorinated (finished) ground water; chlorinated (finished) surface water; and private well water. The performance of this method was demonstrated by multiple laboratories. The authors wish to acknowledge the work of 1) EPA Region 2 in Edison, NJ., 2) Eurofins Eaton Analytical, LLC in Monrovia, CA, and 3) New Jersey Department of Health in Ewing, NJ.
Detection Level Note:	Minimum Reporting Level (MRL) is the lowest analyte concentration that meets Data Quality Objectives (DQOs) that are developed based on the intended use of this method. The single laboratory lowest concentration MRL (LCMRL) is the lowest true concentration for which the future recovery is predicted to fall, with high confidence (99%), between 50 and 150% recovery. Single laboratory LCMRLs for analytes in this method range from 0.53-6.3 ng/L. The procedure used to determine the LCMRL is described elsewhere.

Precision Descriptor Notes:

LCMRLs and DLs for each method analyte are presented. Precision and accuracy are presented for four water matrices: reagent water; chlorinated (finished) ground water; chlorinated (finished) surface water; and private well water. The performance of this method was demonstrated by multiple laboratories. The authors wish to acknowledge the work of 1) EPA Region 2 in Edison, NJ., 2) Eurofins Eaton Analytical, LLC in Monrovia, CA, and 3) New Jersey Department of Health in Ewing, NJ.

Detection Level Note:

Minimum Reporting Level (MRL) is the lowest analyte concentration that meets Data Quality Objectives (DQOs) that are developed based on the intended use of this method. The single laboratory lowest concentration MRL (LCMRL) is the lowest true concentration for which the future recovery is predicted to fall, with high confidence (99%), between 50 and 150% recovery. Single laboratory LCMRLs for analytes in this method range from 0.53-6.3 ng/L. The procedure used to determine the LCMRL is described elsewhere.

Revision	PDF/Link
Rev. 2.0, 2020
Rev. 1.0, 2018

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EPA CFES&ER/ORD: 537.1: SELECTED PER- AND POLYFLUORINATED ALKYL SUBSTANCES IN DRINKING WATER BY SPE AND LC/MS/MS

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