💧 Determination of selected per- and polyfluoroalkyl substances (PFAS) in unfiltered drinking water by LC-MS/MS — Part A: the sample is diluted with methanol, isotopically labelled internal standards are added and it is injected directly; Part B: the analytes are retained on a weak anion exchanger (SPE); 30 compounds validated, including the 20 PFAS of Directive (EU) 2020/2184, limit of quantification 1 ng/l for many of them, PN-EN 17892

Physicochemistry PN-EN 17892

Overview

WHAT THE STANDARD COVERS. The scope from the PKN catalogue card of PN-EN 17892:2024-11 (English version) begins with the words (our translation): “This document specifies a method for the determination of the dissolved fraction of selected perfluoroalkyl and polyfluoroalkyl substances (PFAS) in non-filtrated water intended for human consumption using liquid chromatography-tandem mass spectrometry (LC-MS/MS)” — further it repeats the content of Clause 1 described below. We read the text of the standard in the sample of SIST EN 17892:2024 (the text of EN 17892:2024 without changes) from the title page through the contents, European foreword, introduction and Clauses 1–5 up to and including 6.9 of Clause 6 (reagents). Outside the sample remain further reagents (from 6.10), Clauses 7–13 (apparatus, sampling, procedure of Parts A and B, LC-MS/MS conditions, blanks, identification, calibration, calculation, recovery, expression of results, test report) and Annexes A–B (performance data, instrumental conditions and chromatograms).

ACCORDING TO THE TEXT OF EN 17892:2024 (introduction, Clauses 1–5, 6.1–6.9). The standard was prepared by CEN/TC 230 “Water analysis” (secretariat DIN); CEN approved it on 19 May 2024. Introduction: PFAS are industrially manufactured chemicals with at least one fully fluorinated methyl or methylene carbon atom (without H, Cl, Br, I attached); according to US EPA the family comprises more than 8000 substances; perfluoroalkyl substances are persistent and accumulate in humans and the environment. Directive (EU) 2020/2184 includes PFAS as a parameter with a parametric value of 0.10 µg/l for the sum of 20 selected PFAS — perfluorinated carboxylic and sulfonic acids with a chain length of four to thirteen carbon atoms. In 2020 EFSA derived a tolerable weekly intake of 4.4 ng/kg body weight for the sum of PFOA, PFNA, PFHxS and PFOS, so these four compounds should be determinable with a limit of detection far below 0.10 µg/l. Scope (1): the dissolved fraction of selected PFAS in non-filtrated drinking water, LC-MS/MS; application to other waters (ground water, surface water, treated waste water) requires validation in each case separately; for each compound branched isomers and the linear isomer are quantified together; the method was validated for the analytes of Table 1, and the list may be modified depending on the purpose; the lower range depends on instrument sensitivity and matrix — for many substances a limit of quantification of 1 ng/l can be achieved, and lower ones with high-volume direct injection (Part A) or SPE (Part B); limitations can occur for short-chain PFAS and those with more than ten carbon atoms in the chain; actual limits also depend on the laboratory’s blanks. Note to Clause 1: the standard enables the analysis of the 20 PFAS of point 3 of Part B of Annex III of Directive 2020/2184. Table 1 lists 30 compounds: perfluorocarboxylic acids C4–C13 (PFBA, PFPeA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnDA, PFDoDA, PFTrDA), perfluorosulfonic acids C4–C13 (PFBS, PFPeS, PFHxS, PFHpS, PFOS, PFNS, PFDS, PFUnDS, PFDoDS, PFTrDS), fluorotelomer sulfonic acids 4:2, 6:2 and 8:2 FTSA, FOSA, EtFOSAA, HFPO-DA, DONA, PFMPA and 9Cl-PF3ONS. Normative references (2): ISO 5667-1, -3 and -5 (sampling), ISO 8466-1 and -2 (calibration). Definition (3.1): PFAS — fluorinated substance with at least one fully fluorinated methyl or methylene carbon atom, i.e. with a –CF3 or –CF2– group (with a few exceptions); in the broader sense also substances with chlorine and oxygen in the polyfluoroalkyl structure. Principle (4): Part A — a portion of the unfiltered sample is diluted with methanol, a solution of isotopically labelled internal standards is added and it is injected directly into LC-MS/MS; Part B — solid-phase extraction on a weak anion exchanger, similar to ISO 21675, then LC-MS/MS; online SPE on a weak anion exchanger or HLB material is permitted if it deals with the fact that long-chain PFAS adsorb on the surface of vials and tubing when the methanol content is too low — the complete method shall be validated; for additional PFAS accuracy and storage conditions of samples and reference solutions are verified (guidelines: ISO 21253-1 and -2). Interferences (5): long-chain PFAS (carboxylic acids with at least 7, sulfonic acids with at least 6 perfluorinated carbon atoms) distribute to the water/vessel and water/air interfaces — this depends on the geometry and material of the vessel, and narrow vessels with a small surface reduce it; fluoropolymer materials (PVDF, PTFE), common in LC equipment, cause blanks (e.g. PFOA) — objects of glass, steel, PEEK, PS, PP, PE, PET or silicone shall preferably be used for sampling, extraction and analysis, and sampling vessels and vials shall be checked before use; typical contamination sources in LC are vacuum degassers, frits, hoses and pump head seals — eluents may be degassed with helium, fluoropolymer frits and hoses are replaced by stainless steel or PEEK ones, seals by PE ones, and background from the instrument and mobile phases is controlled by a delay column; peak tailing and broadening indicate interferences; particles (fine SPE material in Part B, suspended matter in Part A) clog the column frits — solutions are centrifuged; matrix components suppress or enhance ionization, which is detected and corrected by isotopically labelled internal standards or by standard addition; substances with similar retention time and similar m/z may give unresolved or additional signals — the peak may be used if it can be integrated separately. Reagents (6.1–6.9): analytical or residue-analytical grade, with impurities causing blanks negligible and regularly checked; purified water checked by blank; methanol, acetonitrile, acetic acid 999 g/kg, formic acid at least 980 g/kg (SPE only), acetone (SPE only), ammonia solution at least 250 g/kg (SPE only), ammonium acetate, sodium hydroxide 1 mol/l or other.

STATUS (catalogue card as of 03.10.2026). The card of PN-EN 17892:2024-11 (English version, published 29-11-2024, 43 pages, price group S) has no “Withdrawn” header: Health, Environment and Medicine Sector, KT 122 Water Quality — Chemical Testing — Organic Substances, ICS 13.060.50, “Introduces: EN 17892:2024 [IDT]”; the card has no “Supersedes” field — this is the first edition. The PKN search (term “PN-EN 17892”, 03.10.2026) shows no other edition and no Polish version; the remaining hits are standards of the series PN-EN ISO 17892 and PKN-CEN ISO/TS 17892 on soil testing — the number alone without “ISO” distinguishes this standard from them.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, load up to 17.09.2026, read 03.10.2026). The number 17892 without “ISO” appears in 7 records at 5 laboratories: AB 311, AB 438, AB 486, AB 537, AB 578. In the current scopes on the PCA website (read 03.10.2026, issues from 18.03.2026 to 01.10.2026) all give the 2024-11 edition, AB 311 with the note “Part B”, AB 486 — “Part A”; AB 578 cites jointly its own procedure HKL/PB-03. The “Laboratories” tab (“PN-EN 17892”) shows the same 5 laboratories; checked with the tab query on the production server labcoda.pl on 03.10.2026.

WHAT THE LABORATORIES TEST (PCA items). Water intended for human consumption, at AB 311, AB 438 and AB 486 also water. All five list the same 20 compounds — perfluorocarboxylic and perfluorosulfonic acids C4–C13, i.e. the PFAS of the Directive (at AB 438 three sulfonic acids C11–C13 without abbreviations) — and the sum of PFAS “by calculation”; none of them gives compounds outside these twenty (FTSA, HFPO-DA, DONA and others of Table 1) in this item. Ranges per compound: (0.0008–0.04) µg/l (AB 578), (0.0010–0.150) µg/l (AB 486), (0.0012–0.256) µg/l (AB 537), (0.0015–0.025) µg/l (AB 311), (0.0016–0.200) µg/l (AB 438). Technique: HPLC-MS/MS. The lower limit of AB 578 — 0.8 ng/l — lies below 1 ng/l, which the standard gives as the limit of quantification achievable for many substances; with high-volume injection or SPE the standard allows lower ones.

WHERE A SEEMINGLY CORRECT RESULT IS EASY. At sampling: long-chain PFAS adsorb on the walls and at the water surface — a vessel with a large surface lowers the result for PFOS and longer acids without any signal (5.1); the sample is not filtered — the standard determines the dissolved fraction in the unfiltered sample (1, 4). At the blank: PTFE and PVDF parts in the instrument or in the vessels give PFOA and other compounds in the blank and raise the result, therefore vessels and vials are checked before use (5.2). At measurement: matrix components suppress or enhance ionization — this is detected and corrected by isotopically labelled internal standards or by standard addition (5.3); with online SPE, at too low a methanol content, long-chain PFAS adsorb on vials and tubing (4). At calculation: the sum of PFAS is a calculated quantity — each of the 20 components is a separate measurement of this method, and branched isomers count together with the linear one (1); the result of the sum depends on how components below the limit of quantification were treated, and we did not read that clause (10, 12). At the result: the upper limit of the AB 311 range (0.025 µg/l per compound) is four times lower than the parametric value of the sum (0.10 µg/l); the treatment of results outside the calibration range is described in 10.4, which we did not read.

WHAT WE DO NOT GIVE. We did not read Clauses 7–13 and the annexes, so we do not give the sample volume and dilution in Part A, sorbent and elution in Part B, chromatographic conditions and MRM transitions, identification criteria, calibration procedure, quantification of branched isomers or precision data. We give the value 0.10 µg/l and the sum of 20 PFAS following the introduction and the note to Clause 1 of the standard — we did not read the text of the Directive or of the Polish regulation for this entry.

Method principle

PFAS dissolved in unfiltered drinking water are separated by liquid chromatography and detected by tandem mass spectrometry, with quantification against isotopically labelled internal standards, which compensate for the suppression or enhancement of ionization by the matrix. In Part A the sample is only diluted with methanol and injected (sensitivity comes from a large injection volume), in Part B the analytes are concentrated by solid-phase extraction on a weak anion exchanger.

Applications

• Drinking water — the 20 PFAS of Directive (EU) 2020/2184 (sum, parametric value 0.10 µg/l) and further compounds of Table 1, 30 validated in total (Clause 1)
• PFOA, PFNA, PFHxS and PFOS with a limit of detection far below 0.10 µg/l — recommendation following from the EFSA assessment (introduction)
• Ground water, surface water and treated waste water — only after separate validation (Clause 1); in the accreditation scopes of 5 laboratories at PCA — drinking water and water

Key parameters

Standard

Standard number

PN-EN 17892:2024-11

Title (PL)

Jakość wody — Oznaczanie wybranych substancji per- i polifluoroalkilowych (PFAS) w wodzie przeznaczonej do spożycia — Metoda z wykorzystaniem chromatografii cieczowej/tandemowej spektrometrii mas (LC-MS/MS)

Title (EN)

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

Step-by-step procedure

1. Sampling

   Narrow vessels of permitted materials, checked for blanks; the sample is not filtered (sampling according to ISO 5667-1, -3, -5). PN-EN 17892:2024-11 current (PKN catalogue card as of 03.10.2026).

2. Part A — direct injection

   Dilute a portion of the sample with methanol, add the solution of isotopically labelled internal standards, inject into LC-MS/MS; details (9.1) outside the sample read.

3. Part B — solid-phase extraction

   Isolate the analytes on a weak anion exchanger (similar to ISO 21675), determine in the extract by LC-MS/MS; details (9.2) outside the sample read.

4. Blanks and background control

   Regularly check water, reagents, vessels and instrument; separate instrument background with a delay column; centrifuge solutions with particles.

5. Result

   Each compound separately (isomers together), sum of PFAS by calculation; calibration, calculation and expression of results (9.6, 10, 12) outside the sample read.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The standard requires familiarity with usual laboratory practice and testing by suitably qualified staff; safety practices are established by the user (warning in the introduction)
• Methanol, acetonitrile and acetone are flammable and toxic; formic acid and ammonia solution — corrosive; work in a fume hood

Frequently asked questions