National foreword

This British Standard is the UK implementation of ISO 21675:2019.

The UK participation in its preparation was entrusted to Technical Committee EH/3/2, Physical chemical and biochemical methods.

A list of organizations represented on this committee can be obtained on request to its secretary.

This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2019.

Foreword

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This document was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 2, Physical, chemical and biochemical methods.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

1 Scope

This document specifies a method for the determination of selected perfluoroalkyl and polyfluoroalkyl substances (PFAS) in non‑filtrated waters, for example drinking water, natural water (fresh water and sea water) and waste water containing less than 2 g/l solid particulate material (SPM) using liquid chromatography-tandem mass spectrometry (LC‑MS/MS). The compounds monitored by this method are typically the linear isomers. The group of compounds determined by this method are representative of a wide variety of PFAS. The analytes specified in Table 1 can be determined by this method. The list can be modified depending on the purpose for which the method is intended. The lower application range of this method can vary depending on the sensitivity of the equipment used and the matrix of the sample. For most compounds to which this document applies ≥0,2 ng/l as limit of quantification can be achieved. Actual levels can depend on the blank levels realized by individual laboratory.

The applicability of the method to further substances, not listed in Table 1, or to further types of water is not excluded, but is intended to be validated separately for each individual case.

NOTE 1 PFAS is used in this document to describe the analytes monitored. Many of the compounds in Table 1 are perfluoroalkyl and are also considered polyfluoroalkyl substances.

NOTE 2 The linear PFAS isomers are specified in this document. The branched isomers can be present in environmental samples, especially for PFOS. Annex E provides an example of an analytical approach to the chromatographic and spectroscopic separation of individual isomers.

2 Normative references

3 Terms and definitions

4 Principle

5 Interferences

5.1 Interferences with sampling and extraction

5.2 Interferences with LC‑MS/MS

6 Reagents

6.1

6.2

6.3

6.4

6.5

6.6

6.7

6.8

6.9 Preparation of the solutions

6.10

6.11

6.12

6.13

7 Apparatus

7.1 Sample bottles

7.2

7.3

7.4

7.5

7.6

7.7

7.8

7.9

7.10

7.11

7.12

7.13

7.14

7.15 pH indicator paper.

8 Sampling

9 Procedure

9.1 Solid-phase extraction

9.2 LC‑MS/MS operating conditions

9.3 Blank determination

9.4 Identification

10 Calibration

10.1 General requirements

10.2 Calibration using an external standard

10.3 Calibration using an internal standard

11 Calculation

11.1 Use of a calibration curve to determine concentration

11.2 Calculation of concentration using calibration with external standards

11.3 Calculation of concentration using calibration with internal standards

11.4 Treatment of results outside the calibration range

12 Determination of analyte recovery

12.1 Recovery

12.2 Recovery of internal standards

13 Expression of results

14 Test report

Bibliography

BS ISO 21675:2019

Water quality. Determination of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in water. Method using solid phase extraction and liquid chromatography-tandem mass spectrometry (LC-MS/MS)

Current

Published:

31 Oct 2019