ISO 25101-2009 PDF

Full title and description

ISO 25101:2009 — Water quality — Determination of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) — Method for unfiltered samples using solid phase extraction and liquid chromatography/tandem mass spectrometry (HPLC‑MS/MS). This standard specifies a laboratory method for measuring the linear isomers of PFOS and PFOA in unfiltered water matrices (drinking water, groundwater, surface water and seawater) using SPE enrichment and LC‑MS/MS analysis.

Abstract

ISO 25101:2009 defines a solid‑phase extraction (SPE) followed by liquid chromatography with tandem mass spectrometry procedure for the determination of PFOS and PFOA in unfiltered aqueous samples. The method is intended to quantify the linear isomers (branched isomers may be reported separately) and gives application ranges for PFOS and PFOA with recommended sample handling for environmental monitoring laboratories.

General information

• Status: Published / active.
• Publication date: March 2009 (2009‑03).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 13.060.50 (Water quality).
• Edition / version: Edition 1 (2009).
• Number of pages: 19 pages (approx.).

Scope

The standard applies to the determination of the linear isomers of PFOS and PFOA in unfiltered drinking water, groundwater and surface water (fresh and sea water) using SPE combined with HPLC‑MS/MS. Reportable concentration ranges stated in the document cover approximately 2.0 ng/L to 10 000 ng/L for PFOS and 10 ng/L to 10 000 ng/L for PFOA; higher concentrations can be analysed after proper dilution or sample‑size adjustment. The method focuses on unfiltered samples (i.e., including particulate‑bound fractions) and gives guidance on sample preparation, internal standards and chromatographic/mass spectrometric conditions.

Key topics and requirements

• Target analytes: linear isomers of PFOS and PFOA; option to report non‑linear (branched) isomers separately.
• Sample type: unfiltered water samples (drinking, ground, surface and sea water).
• Sample preparation: solid phase extraction (SPE) for enrichment and cleanup.
• Analytical technique: liquid chromatography coupled with tandem mass spectrometry (LC‑MS/MS / HPLC‑MS/MS) using appropriate internal standards and MRM transitions.
• Performance characteristics: defined application ranges, limits of quantification dependent on instrumentation and matrix, and recommendations for calibration and quality controls.
• Reporting and interpretation: guidance on isomer reporting, blanks, recoveries and matrix effects for environmental monitoring purposes.

Typical use and users

Primary users are accredited environmental and commercial analytical laboratories, water utilities, regulatory agencies and research institutions conducting PFOS/PFOA monitoring in water. The method is used for routine monitoring, source investigations and research where quantification of PFOS and PFOA in unfiltered aqueous matrices is required. Laboratories frequently adapt the protocol for their instrumentation while following the standard’s quality control and validation guidance.

Related standards

ISO 25101:2009 is one of several international/regional methods for PFAS analysis in water. Notable related documents include ISO 21675:2019 (broader method for many PFAS in non‑filtrated waters using SPE + LC‑MS/MS) and regulatory methods such as U.S. EPA methods (for example EPA Method 533 and EPA Method 537.1 for drinking water and EPA Method 1633 for multi‑matrix PFAS analysis). Laboratories commonly reference these complementary standards and regulatory methods when selecting analyte lists, limits of quantification and reporting conventions.

Keywords

PFOS, PFOA, PFAS, water quality, solid phase extraction (SPE), LC‑MS/MS, HPLC‑MS/MS, unfiltered samples, environmental monitoring, method validation.

FAQ

Q: What is this standard?

A: ISO 25101:2009 is an international laboratory method specifying SPE followed by LC‑MS/MS for the determination of PFOS and PFOA in unfiltered water samples (drinking, ground and surface waters).

Q: What does it cover?

A: It covers sample handling for unfiltered waters, SPE enrichment, chromatographic and MS/MS parameters, calibration and quality control recommendations, and application/concentration ranges for PFOS and PFOA.

Q: Who typically uses it?

A: Accredited environmental testing laboratories, water utilities, regulators and researchers monitoring PFOS/PFOA in environmental and potable water supplies.

Q: Is it current or superseded?

A: ISO 25101:2009 remains a published method for PFOS and PFOA. Since its publication, broader and updated PFAS methods (for example ISO 21675:2019 and various EPA methods) have been published that cover larger lists of PFAS and updated performance requirements; laboratories and regulators therefore often choose the method that best fits their analyte list and regulatory context. ISO 25101 itself is still a valid reference for targeted PFOS/PFOA analysis unless a national/regulatory body specifies a different mandated method.

Q: Is it part of a series?

A: It is part of the body of water‑quality analytical standards and sits alongside other ISO and regional methods for PFAS and trace organic analysis (for example ISO 21675:2019 and several EPA and EN/CEN methods). These documents together support PFAS monitoring programs across jurisdictions.

Q: What are the key keywords?

A: PFOS, PFOA, PFAS, SPE, LC‑MS/MS, water quality, unfiltered samples, method, environmental monitoring.