EN 17892:2024

Water quality - Determination of selected per- and polyfluoroalkyl substances in drinking water - Method using liquid chromatography/tandem-mass spectrometry (LC-MS/MS)

This document specifies a method for the determination of the dissolved fraction of selected perfluoroalkyl and polyfluoroalkyl substances (PFAS) in non-filtrated drinking water using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The applicability of the method to other types of water like fresh waters (e.g. ground water, surface water) or treated wastewater can be validated separately for each individual case.
For each target compound both, eventually occurring branched isomers and the respective non-branched isomer, are quantified together. The selected set of substances determined by this method is representative for a wide variety of PFAS. This method has been validated for the analytes specified in Table 1. The list given in this table can be modified depending on the purpose and focus of the method. The lower application range of this method can vary depending on the sensitivity of the equipment used and the matrix of the samples. For many substances to which this document applies a limit of quantification (LOQ) of 1 ng/l can be achieved. Using high volume direct injection as described in part A or SPE as described in part B of the method allows lower LOQs. Analytical limitations can occur with short-chain PFAS or PFAS with more than ten carbon atoms in the carbon chain. Actual LOQs can depend on the blank values realized by individual laboratories as well.
NOTE   This document enables the analysis of those 20 PFAS which are listed in point 3 of Part B of Annex III of the EU Drinking Water Directive, EU 2020/2184 [4], for the surveillance of the parametric limit value of 0,10 µg/l for the sum of PFAS.
Furthermore, alternatives and substitutes for these PFAS substances can be analysed using this document as well.
Table 1 - Analytes for which a determination was validated in accordance with this method

Wasserbeschaffenheit - Bestimmung ausgewählter Per- und Polyfluoralkylsubstanzen in Trinkwasser - Verfahren mittels Flüssigkeitschromatographie/Tandem-Massenspektrometrie (LC-MS/MS)

Dieses Dokument legt ein Verfahren zur Bestimmung des gelösten Anteils ausgewählter Per- und Polyfluoralkylsubstanzen (PFAS) mittels Flüssigkeitschromatografie-Tandem-Massenspektrometrie (LC-MS/MS) in nicht filtriertem Trinkwasser fest. Die Anwendbarkeit des Verfahrens auf andere Wasserarten wie Süßwasser (z. B. Grundwasser, Oberflächenwasser) oder behandeltes Abwasser kann für jeden Einzelfall separat validiert werden.
Für jede Zielverbindung werden sowohl eventuell auftretende verzweigte Isomere als auch das jeweilige unverzweigte Isomer zusammen quantifiziert. Die mit diesem Verfahren ermittelte Stoffauswahl ist repräsentativ für eine Vielzahl von PFAS. Dieses Verfahren wurde für die in Tabelle 1 angegebenen Analyten validiert. Die Liste in dieser Tabelle kann je nach Zweck und Schwerpunkt des Verfahrens modifiziert werden. Der untere Anwendungsbereich dieses Verfahrens kann abhängig von der Empfindlichkeit der verwendeten Geräte und der Matrix der Proben variieren. Für zahlreiche Stoffe, für die diese Norm gilt, kann eine Bestimmungsgrenze (LOQ) von 1 ng/l erreicht werden. Die Verwendung einer Direktinjektion mit großem Probenvolumen, wie in Teil A beschrieben, oder von SPE, wie in Teil B beschrieben, ermöglicht niedrigere LOQs. Analytische Limitierungen können bei kurzkettigen PFAS oder PFAS mit mehr als zehn Kohlenstoffatomen in der Kohlenstoffkette auftreten. Tatsächlich erreichbare LOQs können auch von den Blindwerten abhängig sein, die in den einzelnen Laboren erzielt werden können.
ANMERKUNG   Dieses Dokument ermöglicht die Analyse der 20 PFAS, die in Anhang III Teil B Punkt 3 der EU-Trinkwasserrichtlinie EU 2020/2184 [4] zur Überwachung des maximal zulässigen Parameterwerts von 0,10 µg/l für die Summe der PFAS aufgeführt sind.
Darüber hinaus können mithilfe dieses Dokuments auch Alternativen und Ersatzstoffe für diese PFAS-Substanzen analysiert werden

Qualité de l'eau - Détermination de substances per- et polyfluoroalkylées sélectionnées dans l'eau potable - Méthode par chromatographie en phase liquide couplée à la spectrométrie de masse en tandem (LC-MS/MS)

Le présent document spécifie une méthode de détermination de la fraction dissoute de substances per-et polyfluoroalkylées (PFAS) sélectionnées dans l’eau potable non filtrée par chromatographie en phase liquide couplée à la spectrométrie de masse en tandem (LC-MS/MS). L’applicabilité de la méthode à d’autres types d’eau tels que les eaux douces (par exemple, eau souterraine, eau de surface) ou les eaux usées traitées, peut être validée séparément pour chaque cas individuel.
Pour chaque composé cible, les isomères ramifiés présents ainsi que les isomères non ramifiés correspondants sont quantifiés ensemble. Le groupe de substances sélectionné, déterminé par cette méthode, est représentatif d'une large gamme de PFAS. La méthode a été validée pour les analytes spécifiés dans le Tableau 1. La liste donnée dans ce tableau peut être modifiée en fonction des besoins et de l'objectif de la méthode. La limite inférieure d’application de cette méthode peut varier en fonction de la sensibilité de l’équipement utilisé et de la matrice des échantillons. Pour des nombreuses substances pour lesquelles le présent document s’applique, une limite de quantification (LQ) de 1 ng/l peut être atteinte. L’utilisation d’un grand volume en injection directe telle que décrite dans la partie A, ou de la SPE telle que décrite dans la partie B de la méthode, permet d'obtenir des LQ plus basses. Des limites analytiques peuvent survenir avec les PFAS à chaîne courte ou avec les PFAS ayant plus de dix atomes de carbone dans la chaîne carbonée. Les LQ réelles peuvent également dépendre des valeurs de blanc obtenues par chaque laboratoire.
NOTE   Le présent document permet d’analyser les 20 PFAS qui sont répertoriés au point 3 de la Partie B de l’Annexe III de la directive européenne eau potable UE 2020/2184 [4], pour la surveillance de la valeur paramétrique limite de 0,10 µg/l pour la somme des PFAS.
Par ailleurs, des alternatifs et des substituts de ces substances PFAS peuvent également être analysés en utilisant le présent document.
Tableau 1 - Analytes pour lesquels la présente méthode a été validée

Kakovost vode - Določanje izbranih perfluoroalkilnih in polifluoroalkilnih snovi (PFAS) v pitni vodi - Metoda s tekočinsko kromatografijo s tandemsko masno spektrometrijo (LC-MS/MS)

V predlaganem dokumentu bo določena metoda za določevanje vsote izbranih perfluoroalkilnih in polifluoroalkilnih snovi (PFAS) v pitni vodi s tekočinsko kromatografijo s tandemsko masno spektrometrijo (LC MS/MS).
Metoda zajema najmanj snovi, potrebne za izračun »vsote perfluoroalkilnih in polifluoroalkilnih snovi« v skladu s točko 3 dela B dodatka III nove evropske direktive o pitni vodi (osnutek). Direktiva o pitni vodi (DWD) trenutno vključuje perfluoralkilne kisline C4 do C13 in perfluoralkil sulfonske kisline C4 do C13.
Druge matrice, kot je podtalnica, in dodatne snovi, kot sta HFPO-DA (GenX) in ADONA ali perfluoralkansulfonamidi (FASA), bodo vključene, če je to mogoče. Spodnje področje uporabe metode se lahko razlikuje glede na občutljivost uporabljene opreme in matrico vzorca. Za večino spojin, za katere se uporablja ta dokument, je mogoče doseči mejo količinskega določanja ≥ 0,2 ng/l. Dejanske ravni so lahko odvisne od slepih ravni, ki jih doseže posamezen laboratorij.
Uporabnost metode za druge spojine, ki niso navedene v dodatku direktive o pitni vodi, ali za druge vrste vode ni izključena, vendar naj bi jo posebej potrdili za vsak posamezen primer.

General Information

• Status: Published
• Publication Date: 18-Jun-2024
• ICS: 13.060.50 - Examination of water for chemical substances
• Technical Committee: CEN/TC 230 - Water analysis
• Drafting Committee: CEN/TC 230/WG 1 - Physical and biochemical methods
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 19-Jun-2024
• Due Date: 31-Jan-2023
• Completion Date: 19-Jun-2024
• Ref Project: SIST EN 17892:2024 - Water quality - Determination of selected per- and polyfluoroalkyl substances in drinking water - Method using liquid chromatography/tandem-mass spectrometry (LC-MS/MS)

Overview

EN 17892:2024 (CEN) specifies a validated analytical method for the determination of selected per‑ and polyfluoroalkyl substances (PFAS) in drinking water using liquid chromatography coupled to tandem mass spectrometry (LC‑MS/MS). The standard targets the dissolved fraction in non‑filtrated drinking water and enables analysis of the 20 PFAS listed for surveillance under the EU Drinking Water Directive (EU 2020/2184). The method supports compliance monitoring for the parametric limit of 0.10 µg/L (sum of PFAS) and can be adapted and validated for other water matrices (groundwater, surface water, treated wastewater) on a case‑by‑case basis.

Key Topics and Requirements

• Analytes: Method validated for a representative set of PFAS (including common compounds such as PFOA, PFOS, PFHxS, PFNA) as listed in Table 1 of the standard. Branched and linear isomers of each target are quantified together.
• Analytical techniques: LC‑MS/MS is the required detection technique; instrumental conditions, chromatograms and performance data are addressed in annexes.
• Two procedural routes:
  • Part A - High‑volume direct injection for lower limits of quantification (LOQs).
  • Part B - Solid‑phase extraction (SPE) for pre‑concentration and improved sensitivity.
• Performance levels: Typical LOQs around 1 ng/L for many analytes; achievable LOQs depend on instrument sensitivity, sample matrix and laboratory blank levels.
• Quality control: Requirements for sampling, blank determination, calibration (external and internal standards), recovery assessment, identification criteria and calculation of results.
• Limitations: Potential analytical challenges with short‑chain PFAS and PFAS with more than ten carbon atoms; actual LOQs depend on laboratory blank values.

Applications

• Regulatory monitoring to demonstrate compliance with the EU Drinking Water Directive and national limits.
• Routine surveillance and trend analysis by water utilities and public health laboratories.
• Environmental monitoring and research where sensitive quantification of PFAS in aqueous matrices is required.
• Validation and implementation of laboratory LC‑MS/MS methods for PFAS screening and targeted quantification.

Who should use this standard

• Accredited water testing laboratories and contract analytical services
• Drinking water utilities and distribution system operators
• Public health and environmental protection agencies
• Consultants, researchers and manufacturers involved in PFAS monitoring and mitigation

Related standards and references

• EU Drinking Water Directive (EU 2020/2184) - for regulatory context and parametric limits
• CEN/TC 230 “Water analysis” publications - for related water quality methods and guidance

Keywords: EN 17892:2024, PFAS, LC‑MS/MS, drinking water, SPE, direct injection, limit of quantification, EU Drinking Water Directive, water quality monitoring.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2024
Kakovost vode - Določanje izbranih perfluoroalkilnih in polifluoroalkilnih snovi
(PFAS) v pitni vodi - Metoda s tekočinsko kromatografijo s tandemsko masno
spektrometrijo (LC-MS/MS)
Water quality - Determination of selected per- and polyfluoroalkyl substances in drinking
water - Method using liquid chromatography/tandem-mass spectrometry (LC-MS/MS)
Wasserbeschaffenheit - Bestimmung ausgewählter Per- und Polyfluoralkylsubstanzen in
Trinkwasser - Verfahren mittels Flüssigkeitschromatographie/Tandem-
Massenspektrometrie (LC-MS/MS)
Qualité de l'eau - Détermination de substances per- et polyfluoroalkylées sélectionnées
dans l'eau potable - Méthode par chromatographie en phase liquide couplée à la
spectrométrie de masse en tandem (LC-MS/MS)
Ta slovenski standard je istoveten z: EN 17892:2024
ICS:
13.060.20 Pitna voda Drinking water
13.060.50 Preiskava vode na kemične Examination of water for
snovi chemical substances
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 17892
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2024
EUROPÄISCHE NORM
ICS 13.060.50
English Version
Water quality - Determination of selected per- and
polyfluoroalkyl substances in drinking water - Method
using liquid chromatography/tandem-mass spectrometry
(LC-MS/MS)
Qualité de l'eau - Détermination de substances per- et Wasserbeschaffenheit - Bestimmung ausgewählter
polyfluoroalkylées sélectionnées dans l'eau potable - Per- und Polyfluoralkylsubstanzen in Trinkwasser -
Méthode par chromatographie en phase liquide Verfahren mittels
couplée à la spectrométrie de masse en tandem (LC- Flüssigkeitschromatographie/Tandem-
MS/MS) Massenspektrometrie (LC-MS/MS)
This European Standard was approved by CEN on 19 May 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17892:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 8
3 Terms and definitions . 8
4 Principle . 9
5 Interferences . 9
5.1 Sampling . 9
5.2 Background contamination . 9
5.3 Interferences encountered during liquid chromatography and mass spectrometry 10
6 Reagents . 10
7 Apparatus . 12
8 Sampling . 14
9 Procedure . 14
9.1 Part A: Method using direct injection . 14
9.1.1 General. 14
9.1.2 Sampling . 14
9.1.3 Sample preparation . 14
9.2 Part B: Method using SPE . 15
9.2.1 General. 15
9.2.2 Sampling . 15
9.2.3 Sample preparation . 15
9.2.4 Extraction . 16
9.3 LC MS/MS operating conditions . 17
9.4 Blank determination . 20
9.4.1 General. 20
9.4.2 Method using direct injection. 20
9.4.3 Method using SPE . 20
9.5 Identification . 20
9.6 Calibration . 21
9.6.1 General requirements . 21
9.6.2 Calibration using an external standard . 22
9.6.3 Calibration using an internal standard . 23
9.6.4 Calibration check . 24
10 Calculation . 24
10.1 Use of a calibration curve to determine concentration . 24
10.2 Calculation of concentration using calibration with external standards . 24
10.3 Calculation of concentration using calibration with internal standards . 25
10.4 Treatment of results outside the calibration range . 25
10.5 Quantification of branched isomers . 25
11 Determination of analyte recovery . 26
11.1 Recovery . 26
11.2 Recovery of internal standards . 27
12 Expression of results . 27
13 Test report . 27
Annex A (informative) Performance data . 28
Annex B (informative) Instrumental conditions and chromatograms . 35
Bibliography . 41
European foreword
This document (EN 17892:2024) has been prepared by the Technical Committee CEN/TC 230 “Water
analysis”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by December 2024, and conflicting national standards shall
be withdrawn at the latest by December 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
Introduction
Per- and polyfluoroalkyl substances (PFAS) are industrially manufactured chemicals, that contain at least
one fully fluorinated methyl or methylene carbon atom (without any H/Cl/Br/I atom attached to it) [1].
This definition is also chosen in the document (see 3.1). According to the United States Environmental
Protection Agency (U.S. EPA), PFAS is a chemical family consisting of more than 8 000 individual
substances [2]. They are a group of widely used man-made chemicals. The perfluoroalkyl substances are
persistent and can accumulate over time in humans and in the environment. Because of their special
properties and stability, some of these compounds were widely used in industry, as components in
firefighting foams or for consumer products and can now be found ubiquitous as background
contamination in the environment [3].
PFAS - especially the shorter-chain - can enter the water cycle as a result of manufacture, application and
disposal. PFAS are included in the EU Drinking Water Directive EU 2020/2184 [4] as parameter to be
under surveillance with a maximum parametric limit value of 0,10 µg/l for the sum of 20 selected PFAS,
i.e. the perfluorinated carbonic acids as well as the perfluorinated sulfonic acids with chain length of four
to thirteen carbon atoms.
Longer-chain compounds such as PFOA, PFNA, PFHxS, and PFOS accumulate in the blood and the liver,
and their half-lives in the human body amount to several years. In 2020 the European Food Safety
Authority (EFSA) has derived a tolerably weekly intake (TWI) for the sum of the four substances PFOA,
PFNA, PFHxS and PFOS of 4,4 ng/kg body weight based on epidemiological studies and the most sensitive
effect on the human immune system [5].
Due to the low TWI the EFSA recommends for the four substances PFOA, PFNA, PFHxS, and PFOS, the
analysis of at least these four EFSA-PFAS should be possible with a limit of detection far below the
maximum parametric limit value of 0,10 µg/l.
WARNING — Persons using this document should be familiar with usual laboratory practice. This
document does not purport to address all of the safety problems, if any, associated with its use. It is the
responsibility of the user to establish appropriate safety and health practices.
IMPORTANT — It is absolutely essential that tests conducted in accordance with this document be
carried out by suitably qualified staff.
1 Scope
This document specifies a method for the determination of the dissolved fraction of selected
perfluoroalkyl and polyfluoroalkyl substances (PFAS) in non-filtrated drinking water using liquid
chromatography-tandem mass spectrometry (LC-MS/MS). The applicability of the method to other types
of water like fresh waters (e.g. ground water, surface water) or treated wastewater can be validated
separately for each individual case.
For each target compound both, eventually occurring branched isomers and the respective non-branched
isomer, are quantified together. The selected set of substances determined by this method is
representative for a wide variety of PFAS. This method has been validated for the analytes specified in
Table 1. The list given in this table can be modified depending on the purpose and focus of the method.
The lower application range of this method can vary depending on the sensitivity of the equipment used
and the matrix of the samples. For many substances to which this document applies a limit of
quantification (LOQ) of 1 ng/l can be achieved. Using high volume direct injection as described in part A
or SPE as described in part B of the method allows lower LOQs. Analytical limitations can occur with
short-chain PFAS or PFAS with more than ten carbon atoms in the carbon chain. Actual LOQs can depend
on the blank values realized by individual laboratories as well.
NOTE This document enables the analysis of those 20 PFAS which are listed in point 3 of Part B of Annex III of
the EU Drinking Water Directive, EU 2020/2184 [4], for the surveillance of the parametric limit value of 0,10 µg/l
for the sum of PFAS.
Furthermore, alternatives and substitutes for these PFAS substances can be analysed using this document
as well.
Table 1 — Analytes for which a determination was validated in accordance with this method
a) b)
Analyte IUPAC name Formula Abbreviation CAS-RN
Perfluoro-n- 2,2,3,3,4,4,4-Heptafluorobutanoic
C4HF7O2 PFBA 375–22–4
butanoic acid acid
Perfluoro-n- 2,2,3,3,4,4,5,5,5-
C5HF9O2 PFPeA 2706–90–3
pentanoic acid Nonafluoropentanoic acid
Perfluoro-n- 2,2,3,3,4,4,5,5,6,6,6-
C HF O PFHxA 307–24–4
6 11 2
hexanoic acid Undecafluorohexanoic acid
Perfluoro-n- 2,2,3,3,4,4,5,5,6,6,7,7,7-
C HF O PFHpA 375–85–9
7 13 2
heptanoic acid Tridecafluoroheptanoic acid
Perfluoro-n- 2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-
C HF O PFOA 335–67–1
8 15 2
octanoic acid Pentadecafluorooctanoic acid
Perfluoro-n- 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-
C9HF17O2 PFNA 375–95–1
nonanoic acid Heptadecafluorononanoic acid
2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,
Perfluoro-n-
10,10-Nonadecafluorodecanoic C10HF19O2 PFDA 335–76–2
decanoic acid
acid
2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,
Perfluoro-n-
10,11,11,11- C11HF21O2 PFUnDA 2058–94–8
undecanoic acid
Heneicosafluoroundecanoic acid
2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,
Perfluoro-n-
11,11,12,12,12- C12HF23O2 PFDoDA 307–55–1
dodecanoic acid
Tricosafluorododecanoic acid
a) b)
Analyte IUPAC name Formula Abbreviation CAS-RN
2,2,3,3,4,4,5,5,6,6,7,7,8,8,
Perfluoro-n-
9,9,10,10,11,11,12,12, 13,13,13- C13HF25O2 PFTrDA 72629–94–8
tridecanoic acid
Pentacosa-fluorotridecanoic acid
Perfluoro-n- 1,1,2,2,3,3,4,4,4-Nonafluorobutane-
C4HF9O3S PFBS 375–73–5
butanesulfonic acid 1-sulfonic acid
Perfluoro-n- 1,1,2,2,3,3,4,4,5,5,5-
pentanesulfonic Undecafluoropentane-1-sulfonic C5HF11O3S PFPeS 2706–91–4
acid acid
1,1,2,2,3,3,4,4,5,5,6,6,6-
Perfluoro-n-
Tridecafluorohexane-1-sulfonic C6HF13O3S PFHxS 355–46–4
hexanesulfonic acid
acid
Perfluoro-n- 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-
heptanesulfonic Pentadecafluoroheptane-1-sulfonic C7HF15O3S PFHpS 375–92–8
acid acid
1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-
Perfluoro-n-
Heptadecafluorooctane-1-sulfonic C8HF17O3S PFOS 1763–23–1
octanesulfonic acid
acid
1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-
Perfluoro-n-
Nonaadecafluorononane-1-sulfonic
C9HF19O3S PFNS 68259–12–1
nonanesulfonic acid
acid
1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,
Perfluoro-n-
10,10-Heneicosafluorodecane-1- C HF O S PFDS 335–77–3
10 21 3
decanesulfonic acid
sulfonic acid
1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,
Perfluoro-n-
9,9,10,10,11,11,11-
undecanesulfonic C HF O S PFUnDS 749786-16-1
11 23 3
Tricosafluoroundecane-1-sulfonic
acid
acid
1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,
Perfluoro-n-
10,11,11,12,12,12-
dodecanesulfonic C12HF25O3S PFDoDS 79780-39-5
Pentacosafluorododecane-1-
acid
sulfonic acid
1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,
Perfluoro-n-
10,11,11,12,12,13,13,13-
tridecanesulfonic C HF O S PFTrDS 791563-89-8
13 27 3
Heptacosafluorotridecane-1-
acid
sulfonic acid
4:2 Fluorotelomer 3,3,4,4,5,5,6,6,6-Nonafluorohexane-
C H F O S 4:2 FTSA 757124–72–4
6 5 9 3
sulfonic acid 1-sulfonic acid
3,3,4,4,5,5,6,6,7,7,8,8,8-
6:2 Fluorotelomer
Tridecafluorooctane-1-sulfonic C H F O S 6:2 FTSA 27619–97–2
8 5 13 3
sulfonic acid
acid
3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,
8:2 Fluorotelomer
10-Heptadecafluorodecane-1- C H F O S 8:2 FTSA 39108–34–4
10 5 17 3
sulfonic acid
sulfonic acid
1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-
Perfluorooctanesulf
Heptadecafluoro-1- C H F NO S FOSA 754–91–6
8 2 17 2
onamide
octanesulfonamide
a) b)
Analyte IUPAC name Formula Abbreviation CAS-RN
2-
N-ethyl
[Ethyl(1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,
perfluorooctanesulf C12H8F17NO4S EtFOSAA 2991–50–6
8-heptadecafluorooctylsulfonyl)
onamidoacetic acid
amino]acetic acid
2,3,3,3-Tetrafluoro-2-(1,1,2,2,3,3,3-
Hexafluoropropylen
heptafluoropropoxy)propanoic C6HF11O3 HFPO-DA 13252–13–6
e oxide dimer acid
acid
2,2,3-Trifluoro-3-[1,1, 2,2,3,3-
4,8-Dioxa-3H-
hexafluoro-3-(tri-
perfluorononanoic C H F O DONA 919005–14–4
7 2 12 4
fluoromethoxy)propoxy]
acid
propanoic acid
Perfluoro-3-
2,2,3,3-Tetrafluoro-3- PFMPA
methoxypropanoic C HF O 377–73–1
4 7 3
(trifluoromethoxy)pro-panoic acid (PF4OPeA)
acid
9-Chlorohexa-
2-(6-Chloro-1,1,2,2, 3,3,4,4,5,5,6,6-
decafluoro-3-
dodeca-fluorohexoxy)-1,1,2,2- C8HClF16O4S 9Cl-PF3ONS 73606–19–6
oxanonane-1-
tetrafluoroethanesulfonic acid
sulfonic acid
a)
IUPAC: International Union of Pure and Applied Chemistry
b)
CAS-RN: Chemical Abstract Services Registry Number
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 5667-1, Water quality — Sampling — Part 1: Guidance on the design of sampling programmes and
sampling techniques
ISO 5667-3, Water quality — Sampling — Part 3: Preservation and handling of water samples
ISO 5667-5, Water quality — Sampling — Part 5: Guidance on sampling of drinking water from treatment
works and piped distribution systems
ISO 8466-1, Water quality — Calibration and evaluation of analytical methods — Part 1: Linear calibration
function
ISO 8466-2, Water quality — Calibration and evaluation of analytical methods and estimation of
performance characteristics — Part 2: Calibration strategy for non-linear second-order calibration
functions
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
per- and polyfluoroalkyl substance
PFAS
fluorinated substance that contains at least one fully fluorinated methyl or methylene carbon atom
(without any H/Cl/Br/I atom attached to it), i.e. with a few noted exceptions, any chemical with at least
a perfluorinated methyl group (–CF3) or a perfluorinated methylene group (–CF2–)
Note 1 to entry: The term is used in the broader sense for substances that contain chlorine and oxygen in a
polyfluoroalkyl structure as well [1].
4 Principle
Part A of this document comprises a method using direct injection liquid chromatography coupled with
tandem mass-spectrometry detection (LC-MS/MS): An aliquot of the unfiltrated water sample is diluted
with methanol and amended with a solution of isotopically labelled internal standards. The diluted water
sample is injected directly into the analysis system. The identification and quantitative determination of
the substances listed in Table 1 is performed using LC-MS/MS.
Part B of this document comprises a method using a solid-phase extraction protocol similar to ISO 21675
before LC-MS/MS measurement: The analytes listed in Table 1 are extracted from the water sample by
solid-phase extraction using a weak anion exchange sorbent. The identification and quantitative
determination of the substances in the extract is performed using LC-MS/MS.
Online solid-phase extraction protocols can be applied if they use weak anion exchange sorbents or
hydrophilic-lipophilic balanced (HLB) SPE material and deal with the fact that long chain PFAS are
adsorbed on the surface of vials and tubing if the methanol content is too low. The complete method shall
be validated.
The method can be used to determine additional PFAS. Accuracy shall be tested and verified for each case
as well as storage conditions of both samples and reference solutions. Criteria to be fulfilled depend on
the specification for the analysis. ISO 21253-1 and ISO 21253-2 can be used as guidelines.
5 Interferences
5.1 Sampling
Long chain PFAS (e.g. perfluoroalkyl carboxylic acids with x ≥ 7 and perfluoroalkane sulfonic acids with
x ≥ 6; x being the number of perfluorinated C-atoms in the chain) may distribute to the water/vessel and
water/air interfaces. These interferences depend on the geometry and material of the sample vessels and
can be reduced by minimizing the sample surface, e.g. by using narrow vessels with a small surface area.
5.2 Background contamination
Efforts should be taken to minimize background levels in materials and reagents. Handling of unavoidable
blank values is described in 9.4.
Low molecular residuals in fluoropolymer-containing materials such as polyvinylidene fluoride or
polyvinylidene difluoride (PVDF), polytetrafluoroethylene (PTFE), etc., which are often used in LC-
equipment, may cause blank values, e.g. in the case of PFOA. In order to minimize these contributions to
blank values, objects made of glass, steel, polyether ether ketone (PEEK), polystyrene (PS),
polypropylene (PP), polyethylene (PE), poly(ethylene terephthalate) (PET) or silicone shall preferably
be used for sampling, extraction and analysis. Sampling vessels (7.1) and sample vials (7.11) shall be
checked for possible blank values before use.
Typical contamination sources in the LC-system include vacuum degassers, frits and hoses as well as
pump head seals. In the case of such interferences, degassing of the eluents, for example, can be carried
out using helium instead of vacuum degassers. Fluoropolymer frits and hoses shall be replaced by frits
and hoses made of stainless steel or PEEK. If available, pump head seals made of PE shall be used.
Background contamination, originating from the instrument and/or mobile phases can be controlled by
using a delay column (7.13.3).
5.3 Interferences encountered during liquid chromatography and mass spectrometry
Peak tailing, peak fronting and/or broadened peaks are indicative of interferences in chromatography.
Particles in the measurement solution, e.g. fine fractions of the SPE material in case of analytical
protocol B of this document or solid phase matter in the sample in case of analytical protocol A of this
document, can block the inlet sieves or frits, respectively, of the LC column and result in interferences
due to the increase in pressure; in such cases the measurement solutions shall be centrifuged (7.10) prior
to the analysis.
Sample matrix components can affect the ionization of the target substances. This may result in
suppression or enhancement of the ionization. Such matrix interferences can be detected and corrected
by using authentic isotopically labelled internal standards or by the standard addition method.
Substances with similar retention times that can produce ions with similar mass to charge ratios (m/z)
to those produced by the target analytes may interfere with the determination. These interferences may
lead to incompletely resolved signals and/or additional signals in the mass chromatograms of target
substances. Depending on their levels in the sample, such substances may affect the accuracy and
precision of the results. If the peak of interest can be separately integrated from interferences, it can be
used.
6 Reagents
As far as available, analytical grade or residue-analytical grade reagents shall be used. The content of
impurities contributing to blank values or causing interfering signals shall be negligible. This shall be
checked in regular intervals (9.4).
Reagents, solvents, and water used as eluents shall be suitable for LC and mass spectrometry.
6.1 Water, H O.
Purified laboratory water can be used. The quality of water shall be checked using the blank
determination procedure given in 9.4.
6.2 Methanol, CH OH.
6.3 Acetonitrile, CH CN.
6.4 Acetic acid, w(CH COOH), 999 g/kg.
6.5 Formic acid, w(HCOOH), minimum 980 g/kg (SPE method only)
6.6 Acetone, C H O (SPE method only).
3 6
6.7 Ammonia solution, w(NH ), minimum 250 g/kg (SPE method only).
6.8 Ammonium acetate, CH COONH .
3 4
6.9 Sodium hydroxide solution, NaOH, 1 mol/l or other suitable concentration.
6.10 Sulfuric acid, H SO , 1 mol/l or other suitable concentration.
2 4
6.11 Solid phase material, mixed-mode material (weak anion exchanger on a polymer base with
reversed-phase moiety) (SPE and online SPE method only), HLB-type material (“Hydrophilic-Lipophilic
balanced” polymer material) (online SPE alternative only).
6.12 Elution solution for solid phase extraction, mixture of methanol (6.2) and ammonia (6.7), with
approximately 1 g/kg NH . (SPE method only).
6.13 Nitrogen, or other inert gas for the concentration of extracts, purity of at least 999,9 g/kg.
6.14 Operational gases for the mass spectrometer, in accordance with the specifications of the
instrument manufacturer.
6.15 Reference substances, as given in Table 1.
Use only reference substances or solutions containing mainly non-branched isomers. The content of non-
branched isomers shall be certified.
NOTE Solutions of single reference substances or mixed solutions of various combinations are commercially
available.
WARNING It is essential for laboratories which purchase the substances individually, to take into
account the contribution of the counter ion when constituting the solution of the reference substance.
6.16 Internal standard substances, as given in Table 3.
Make sure that the internal standard substances do not contain detectable concentrations of the
substances to be determined. This shall be checked.
NOTE Suitable solutions are commercially available.
6.17 Preparation of the solutions
Calculate all solutions with regard to the content of the neutral substance.
Store the solutions between (4 ± 3) °C (or colder), protected against evaporation. These solutions are
stable for at least one year. Store the solutions in the dark. Bring them to room temperature prior to use
(i.e. before dilution or spiking or injection). For some compounds, sonication and/or vortexing is
recommended.
6.17.1 Individual or mixed solutions of the reference substances
Solutions of the reference substances (6.15) in methanol (6.2) or other suitable water miscible solvents,
e.g. mass concentration of 50 µg/ml each.
6.17.2 Individual or mixed solutions of internal standard substances
Solutions of internal standard substances (6.16) in methanol (6.2) or other suitable water miscible
solvents, e.g. mass concentration of 50 µg/ml each.
6.17.3 Stock solution (reference substances)
Prepare a solution of the reference substances with a mass concentration of e.g. 0,5 µg/ml each.
NOTE Suitable solutions are commercially available.
Dilute the solution of the reference substances (6.17.1) with methanol (6.2) in a suitable volumetric
flask (7.3). The concentration in the stock solution should be appropriate for the preparation of
calibration solutions according to 6.17.6. Due to the calibration range it may be necessary to prepare an
additional dilution of the stock solution by a factor of 10.
Check the mass concentrations of the substances in the stock solution regularly using a control
standard (6.17.7) (see 9.6.4).
6.17.4 Stock solution (internal standard substances)
Prepare a solution of the internal standard substances with a mass concentration of e.g. 1 µg/ml each.
Dilute the solution of the internal standard substances (6.17.2) with methanol (6.2) in a suitable
volumetric flask (7.3). The concentration in the stock solution should be appropriate for the preparation
of calibration solutions according to 6.17.6.
6.17.5 Spiking solution (internal standard substances)
Prepare a solution of the internal standard substances with a mass concentration of e.g. 0,1 µg/ml each.
Dilute the stock solution (6.17.4) with methanol (6.2) in a suitable volumetric flask (7.3). The
concentration in the spiking solution should be appropriate for spiking the samples according to 9.2.3.
6.17.6 Calibration solutions
Prepare the calibration solutions by diluting the stock solutions accordingly (6.17.3, 6.17.4). Add the
same amounts of internal standards to each calibration solution. The mass concentrations of the internal
standards in the calibration solutions shall lie in the midrange of the calibration curve.
Prepare calibration solutions with mass concentrations of the substances to be determined and of the
internal standard substances in an appropriate calibration range.
For the direct injection method (9.1), add e.g. 200 μl of stock solution 6.17.3 and 100 μl of stock solution
6.17.4 into a 1 ml sample vial (7.11) and add methanol (6.2) and water (6.1) to generate a final volumetric
mixture of water to methanol in the ratio of 1:1 (e.g. given the afore mentioned example: add 200 μl of
methanol and 500 μl of water).
6.17.7 Control standard
Solution of the target substances prepared independently of the stock solution of the reference
substances (6.17.3) and used for testing the calibration in accordance with 9.6.4, e.g. certified standard
solution from a second source. If available, the control standard should contain the relevant compounds
in the form of a mixture of non-branched and branched isomers. Thus the position of branched isomers
in the chromatogram can be verified. The content of non-branched isomers shall be certified.
NOTE Suitable solutions are commercially available.
7 Apparatus
The equipment or any parts of it, which come into contact with the water sample or the extract shall be
free of residues which might cause blank values (see Clause 5).
7.1 Sampling vessels, depending on the sample volume e.g. PE/PP/PS/PET centrifuge tubes, volume
10 ml (method part A), graduated and with screw closure or PE/PP/PS/PET/glass vessels, volume
100 ml (method part B) with suitable closures.
Blanks of vessels can be minimized by rinsing with methanol and subsequent drying. Glassware can be
heated to > 500 °C, e.g. overnight, for cleaning purposes.
7.2 Measuring cylinder, nominal volume 50 ml, e.g. graduated measuring cylinder in accordance with
ISO 4788.
7.3 Volumetric flasks, nominal volumes 10 ml, 50 ml and 100 ml, e.g. ISO 1042 — A 50 — C one-mark
volumetric flasks.
7.4 Pipettes, with polypropylene tips.
7.5 SPE Cartridges, made of polypropylene, with polyethylene frits, packed with solid phase
material (6.11). (SPE alternative only). In case of online SPE other suitable PFAS-free materials are
acceptable.
NOTE Ready-to-use cartridges are commercially available.
7.6 Reservoir column, nominal volume e.g. 70 ml, with adaptor for cartridges (7.5), made of
polypropylene. (SPE method only).
7.7 Vacuum or pressure equipment, for carrying out the extraction. (SPE method only).
7.8 Sample tubes, made of glass or polypropylene, for collecting and concentrating the eluate, e.g. test
tube, nominal volume 10 ml, with glass stopper NS 14. (SPE method only).
7.9 Device for concentrating the extracts, e.g. apparatus for blowing off with nitrogen (6.13). (SPE
method only).
NOTE The application of rotary evaporators can cause elevated blank values.
7.10 Centrifuge, suitable for centrifugation of sampling vessels (7.1) or sample tubes (7.8) to avoid solid
matter in the measuring solution without filtering.
7.11 Sample vials, suitable for the sample feeding system, e.g. beaded rim bottles, nominal volume 1 ml,
made of polypropylene, with polyethylene Snap-On caps (see Clause 5). Sample vials shall be checked for
their contribution to blank values (9.4).
7.12 LC column, with pre-column, if appropriate (see Annex B for examples).
7.13 Liquid chromatograph, coupled with mass spectrometer, consisting of the following components.
7.13.1 Degassing equipment, e.g. ultrasonic bath.
7.13.2 Analytical pump system, low-pulsation, suitable for binary gradient elution.
7.13.3 Delay column, attached between the solvent mixer and the injection valve to
chromatographically separate background contaminants, originating from the instrument and/or mobile
phases, from the injected sample.
7.13.4 LC autosampler.
7.13.5 Column oven for separating column, e.g. temperature controlled column compartment.
7.13.6 Mass spectrometric detector (MS), tandem mass spectrometer with electrospray ionization
(ESI).
For the procedure described in this document, other MS techniques can be used, e.g. high resolution mass
spectrometry, provided the identification and quantitation of the analytes have been verified and
documented for the respective applications. Criteria to be fulfilled depend on the specification for the
respective analysis. ISO 21253-1 and ISO 21253-2 can be used as guidelines.
8 Sampling
Take samples as specified in ISO 5667-1, ISO 5667-3, ISO 5667-5.
Use only clean sampling vessels (7.1) for sampling and fill them as described in 9.1.2 for direct injection
or as described in 9.2.2 for SPE enrichment.
Store the water sample at (4 ± 3) °C until it is processed, but no longer than 60 d. For longer storage the
sample can be frozen and kept at ≤ −15 C for at least 180 d [6].
9 Procedure
9.1 Part A: Method using direct injection
9.1.1 General
The samples are mixed with methanol, transferred to sample vials, spiked with internal standards and
are then analysed by LC-MS/MS using one mass transition for quantification and a second mass transition
for confirmation, if available.
9.1.2 Sampling
Water samples are collected in suitable sampling vessels (7.1). At least half of the vessel shall be left
empty.
9.1.3 Sample preparation
In the lab the sample is mixed in the sample vessel with methanol to achieve a methanol content between
30 % and 50 %. Thus, adsorption of target PFAS to vessel walls or their enrichment at the liquid/air
interface is minimized. The corresponding dilution factor can be adjusted either using the graduation of
the vessel or by weighing the vessel before and after sampling. The dilution factor shall be considered
when calculating the amount of PFAS in the sample. The volume contraction that occurs when methanol
and water are mixed can be neglected.
Dilution of the entire sample amount with methanol as described above is necessary to avoid loss of long-
chain analytes with carbon chain length of more than ten carbon atoms. If the analytical scope does not
comprise such analytes, an aliquot of the sample may be transferred to the sample vial and may be diluted
with methanol therein.
For a methanol content of e.g. ∼50 % in the injection solution e.g. 4 ml of methanol (6.2) are added to
5 ml of sample volume in the sampling vessel (7.1) and mixed properly. Then an aliquot of 900 µl is
transferred to a sample vial (7.11) and 100 µl of internal standard spiking solution (6.17.5) is added. Mix
and centrifuge if necessary. Analyse within 28 d. If for large volume injection the methanol content is
adjusted to less than 50 %, the sample shall be analysed within 24 h.
The concentration of the internal standard in the sample is recommended to be in the midrange of the
calibration curve. The volume of internal standard solution added should not be smaller than 5 µl.
An alternative sample preparation may be as follows: Fill the vessel completely at the sampling point. In
the laboratory, transfer the whole sample from the sample vessel (7.1) to a sample mixing vessel and add
the same quantity of methanol to the emptied sample vessel. Shake the vessel and add the methanol used
for rinsing to the sample in the mixing vessel. Thus, the methanol content in the mixing vessel is 50 %.
The dilution shall be considered as described in 9.1.3.
WARNING The quality of methanol is crucial to avoid blank values. PFAS contamination in methanol
will contribute substantially to blank values when the sample is diluted as described above.
9.2 Part B: Method using SPE
9.2.1 General
Use SPE as an alternative method where sensitivity of the direct measurement is not sufficient. The entire
unfiltrated water sample is mixed with internal standards. The analytes listed in Table 1 and the
respective internal standards listed in Table 3 are enriched from the water sample by solid-phase
extraction at a weak anion exchange sorbent and eluted with methanol and ammoniacal methanol.
Identification and quantitative determination are performed by LC-MS/MS.
9.2.2 Sampling
Water samples are collected in suitable sampling vessel (7.1). The volume collected should be nearly the
volume needed for enrichment (usually between 50 ml and 100 ml). A second sample can be taken in
reserve to allow for repeat analysis. The entire sample shall be extracted to avoid losses of target analytes
due to sorption to the sampling vessel (7.1).
9.2.3 Sample preparation
Calculate the exact sample amount e.g. by weighing the filled sampling vessel (7.1) and subtraction of the
weight of the empty vessel after transferring the sample to the SPE tube. The pH value of the sample is
adjusted with sodium hydroxide solution (6.9) or sulfuric acid (6.10) at a suitable value, as recommended
by the manufacturer of the SPE material used. The same amount of internal standard (IS) spiking solution
(6.17.5) is added to each sample (e.g. 40 µl). The concentration of the internal standard in the sample is
recommended to be in the midrange of the calibration curve after SPE enrichment. It should be at least
three times the corresponding level of the limit of quantification.
Proceed as described in 9.2.4.
Extraction of the entire sample amount as described above is necessary to avoid loss of long-chain
analytes with carbon chain length of more than ten carbon atoms due to sorption to the sampling vessel.
If the analytical scope does not comprise such analytes, an aliquot of the sample may be extracted without
rinsing the sampling vessel with methanol as described in 9.2.4.
For online solid-phase extraction it is required to take a subsample. Dilution of the entire sample as
described for the direct injection would lead to lowered extraction efficiencies.
When using mixed-mode material (6.11), a possibility is to proceed as follows: Fill sampling vessels to
around 90 %. To take a subsample transfer the whole sample to a second vessel. Rinse the complete inner
surface of the first vessel is immediately twice with methanol (using 5 % of its nominal volume) and add
the methanol to the second vessel. Record the sample amounts by weighing or by volume. Shake the
vessel well and immediately transfer an aliquot to an autosampler vial. Add internal standard spiking
solution and close the autosampler vial. The whole content of this vial (including the methanol rinsing)
shall be transferred to the online SPE cartridge to obtain good recoveries of long chain PFAS.
Using HLB-type material (6.11) for online solid-phase extraction, samples shall be acidified with formic
acid (6.5) prior to subsampling as described to promote the neutral form and thus increase the extraction
efficiency.
NOTE An alternative sample preparation for online solid-phase extraction using HLB-type material (6.11) can
be to analyse each sample with two independent injections: For the first injection use an aliquot of the acidified
sample. With this analysis, the short-chain components are quantified. For the second injection prepare the
sampling solution as described in 9.1.3 for the direct injection method by mixing with methanol. With this analysis,
the long-chain components are quantified.
9.2.4 Extraction
Use at least 60 mg of the solid phase material (6.11) for a sample volume of e.g. 50 ml.
For cleaning and conditioning, successively pour at least 2
...