Alkaline-hydrolysis Method for PFAS in Textiles and Textiles Products by Xevo™ TQ-S micro with ACQUITY™ UPLC™ H-Class Plus System

Significance of the topic

Per- and polyfluoroalkyl substances (PFAS) in textiles present a direct exposure route for consumers and a persistent environmental risk. Reliable detection of both non-polymeric PFAS and side‑chain fluorinated polymers in coated or chemically treated textile matrices is essential for regulatory compliance, product safety, and supply‑chain transparency. The alkaline hydrolysis approach enables conversion of precursor species into quantifiable perfluorinated acids and improves extract cleanliness, reducing instrument contamination and analytical artefacts common with methanolic extractions.

Objectives and study overview

This application note evaluated an optimized alkaline hydrolysis extraction (based on EN 17681‑1:2025) combined with LC‑MS/MS analysis (ACQUITY UPLC H‑Class Plus with Xevo TQ‑S micro) for a broad panel of 30 PFAS plus internal standards. Key aims were to: extract PFAS across C4–C14 including side‑chain fluorinated polymers, minimize matrix contamination and instrument fouling, establish method linearity and recovery, and identify practical recommendations to mitigate analytical artefacts.

Methodology and sample preparation

The extraction protocol used methanolic aqueous sodium hydroxide (alkaline hydrolysis) to cleave precursor moieties and release terminal perfluorinated carboxylic acids (PFCAs). The sample preparation workflow was optimized with emphasis on:

• controlled temperature during reaction and neutralization,
• adjustment to near‑neutral pH before workup,
• high‑speed refrigerated centrifugation to remove particulates and coagulates, and
• deep freezing of the clarified extract to stabilize it for extended autosampler storage (>24 h).

These steps produced clear extracts free of visible dispersions, settleable solids or particulates and reduced potential mineralization/co‑precipitation caused by NaOH acting on textile additives (dyes, surfactants, crosslinkers, etc.). A divert valve strategy was implemented in the LC method to exclude early‑eluting non‑PFAS material from entering the MS inlet, protecting the source and reducing contamination.

Used instrumentation

• ACQUITY UPLC H‑Class Plus System fitted with PFAS kit and SMFTN.
• Xevo TQ‑S micro triple quadrupole mass spectrometer (ESI negative, MRM acquisition).
• Columns: XBridge BEH C18, 4.6 × 100 mm, 5 µm (analytical); ACQUITY BEH C18 AX, 2.1 × 100 mm (isolator).
• Autosampler vials: polypropylene.
• Data system: MassLynx (SCN 1050).

Representative LC conditions: column 40 °C, sample tray 20 °C, injection 10 µL, flow 0.3 mL/min, mobile phases 5 mM ammonium acetate in water (A) and in acetonitrile (B), 18‑min gradient total runtime. MS source: capillary 0.5 kV, desolvation 300 °C, desolvation gas flow 900 L/hr, cone gas 50 L/hr, source 100 °C.

Main results and discussion

The method detected all 30 target PFAS across the tested calibration range (0.5–50 ng/mL) with robust linearity (R2 > 0.95) and residuals within ±15%. Key findings include:

• Recoveries for the 30 PFAS generally ranged between 60–110%, demonstrating reliable quantification in complex textile matrices.
• Cromatographic separation achieved high resolution in an 18‑minute run, including separation of closely related analytes such as FTOHs and FTS homologues.
• Clear extracts markedly reduced matrix load across chromatography and MS, leading to improved baseline stability and extended autosampler stability (>24 h).
• Certain fluorotelomer sulfonate (FTS) homologues showed apparent recoveries exceeding 150%. Cross‑system verification suggested this was an analytical artefact, likely caused by matrix‑enhanced ionization, co‑extracted components, or multi‑component effects in a single run rather than true chemical enrichment.

Practical mitigations recommended to address enhanced responses include use of matrix‑matched calibration, structurally similar or isotopically labeled internal standards, selection of alternative product ions, and further ESI source optimization.

Benefits and practical applications

The optimized alkaline hydrolysis approach offers several operational and analytical advantages:

• Inclusion of side‑chain fluorinated polymers in the analyte scope by converting bound precursors to measurable PFCAs.
• Generation of particle‑free, stable extracts that minimize instrument fouling and extend maintenance intervals.
• Improved analytical sensitivity, reproducibility, and accuracy across high‑matrix textile samples.
• Compatibility with routine laboratory throughput — short LC runtime (~18 min), stable autosampler storage (>24 h), and reliable quantitative performance across 30 PFAS.

These features support PFAS monitoring in textiles for regulatory testing, product screening, supplier surveillance and quality assurance workflows.

Future trends and potential uses

Expected developments and opportunities include:

• Wider adoption of standardized alkaline hydrolysis methods (EN 17681‑1 and equivalents) to harmonize textile PFAS testing globally.
• Greater use of isotopically labeled internal standards and matrix‑matched calibrations to correct for matrix effects and artefacts (especially for FTS/FTOH groups).
• Instrumentation advances such as improved isolator columns, automated divert/cleaning cycles, and source designs minimizing matrix enhancement.
• Method expansion to quantify polymeric and oligomeric PFAS fractions and to link analytical outputs with lifecycle and exposure assessments.
• Regulatory drivers prompting routine industry screening and supplier audits, increasing demand for robust, high‑throughput methods.

Conclusion

Adapting the EN 17681‑1:2025 alkaline hydrolysis extraction for textiles and coupling it with an ACQUITY UPLC H‑Class Plus / Xevo TQ‑S micro LC‑MS/MS workflow provides a sensitive, reproducible and instrument‑protective method for comprehensive PFAS analysis. The approach effectively includes side‑chain fluorinated polymers, produces clear extracts that reduce matrix interferences, and yields reliable quantification across a broad PFAS panel when appropriate calibration strategies are applied. Laboratories should implement matrix matching and isotopically labeled standards and consider source and ionization optimizations to minimize specific artefacts (e.g., elevated FTS responses).

References

1. EN 17681‑1:2025. Textiles and Textile Products – Per and polyfluoroalkyl substances (PFAS) – Part 1: Analysis of an alkaline extract using liquid chromatography and tandem mass spectrometry.
2. OECD (2021). Reconciling Terminology of the Universe of Per‑ and Polyfluoroalkyl Substances: Recommendations and Practical Guidance.
3. OECD (2022). Synthesis Report on Understanding Side‑Chain Fluorinated Polymers and their Life Cycle. ENV/CBC/MONO(2022)35.
4. Per‑ and Polyfluoroalkyl Substances (PFAS) in Consumer Products: An Overview of the Occurrence, Migration, and Exposure Assessment. Molecules. 2025 Feb 21;30(5):994.