Quantitative PFAS Analysis in Medical Devices UsingTriple Quadrupole LC/MS

Significance of the topic

Per- and polyfluoroalkyl substances (PFAS) are widely used in medical device materials for their chemical stability, low friction and biocompatibility, but their environmental persistence and potential health risks have prompted stricter regulatory control. Reliable, ultra-trace analytical methods are essential for manufacturers to screen raw materials and finished devices, demonstrate compliance with evolving regulations (e.g., EPA and REACH developments), and support material substitution to PFAS-free alternatives.

Goals and study overview

This work develops and evaluates a comprehensive UHPLC–triple quadrupole (LC/TQ) workflow to quantitatively screen 73 native PFAS in medical device materials. The study aims to deliver a PFAS-ready instrument configuration and a sample-to-result protocol that achieves ultra-low analytical background, high sensitivity (ppt-range), robust quantitation, and practical throughput for routine quality control and regulatory submissions.

Used instrumentation

• Agilent PFAS analysis UHPLC built on 1290 Infinity III platform with design changes to minimize fluorinated materials in the flow path and reduce background contamination.
• 1290 Infinity III High‑speed pump and 1290 Infinity III Hybrid Multisampler configured for Feed Injection (large-volume injections in high-organic solvent).
• Agilent 6475 triple quadrupole LC/TQ operated in negative electrospray ionization mode for targeted PFAS acquisition.
• ZORBAX RRHD Eclipse Plus C18 column (2.1 × 100 mm, 1.8 µm) for chromatographic separation.

Methodology and sample preparation

The workflow combines a targeted UHPLC–TQ method, PFAS-verified consumables, and a simple extraction protocol optimized for common medical device matrices (IV tubing, blood collection tubes, syringes):

• Sample extraction: 1 g sample extracted with 10 mL methanol, heat- and ultrasound-assisted (HUA) extraction, filtration and a 10× dilution prior to analysis.
• Calibration and standards: 73 target PFAS, 34 surrogate standards and 2 internal standards; calibration in methanol over 0.01–50 µg/L with fixed 1 µg/L surrogates/ISTDs at each level.
• LC conditions summary: mobile phase A = 5 mM ammonium acetate in water; mobile phase B = methanol; fast gradient yielding a 14.5 min run time plus 2.5 min post-time; typical flow 0.4 mL/min.
• Injection strategy: Feed Injection via Hybrid Multisampler enabled 30 µL injections of 100% MeOH extracts with feed speed set to 10% of pump flow; dedicated inner/outer wash sequences and reconditioning to minimize carryover and background.
• Quality controls: Matrix-spiked QCs at 1 µg/kg (LSQ), 10 µg/kg (MSQ) and 100 µg/kg (HSQ), analyzed in triplicate to assess LOQs, recovery and reproducibility.

Main results and discussion

• Ultra-low background: Solvent blanks showed negligible PFAS signals, indicating the PFAS‑ready UHPLC configuration and PFAS‑verified consumables effectively reduced system background to support ultra-trace analysis.
• Feed Injection optimization: A 30 µL injection volume with feed at 10% pump flow produced optimal peak shape and signal for both early- and late-eluting PFAS, demonstrating suitability of large-volume high-organic injections.
• Linearity and QC performance: All 73 analytes exhibited excellent linearity (R² > 0.992) across at least five calibration levels spanning several orders of magnitude. Surrogate recoveries were typically 70–130% and ISTD responses showed RSD ≤ 20% through the batch.
• Sensitivity (LOQs): Method limits of quantitation were established from matrix-spiked QCs. Sixty-four of 73 targets achieved LOQs at 1 µg/kg; importantly, all 40 PFAS mandated by EPA Method 1633 were quantifiable at this sensitivity in the tested matrices.
• Reproducibility: RSDs of QC recoveries were below 20% across LSQ, MSQ and HSQ levels (n = 6 per level across preparations), indicating robust reproducibility for routine application.
• Extraction efficiency: Over 87% of analytes exhibited recoveries within the 65–135% acceptance window across QC levels. Key regulated PFAS (PFOA, PFOS, PFNA, PFHxS) showed recoveries between 97–105%.

Benefits and practical use

• Streamlined workflow: The HUA methanol extraction is fast and scalable, supporting higher laboratory throughput compared with more complex cleanup procedures.
• High sensitivity with low background: PFAS‑specific UHPLC hardware plus Feed Injection permits ppt-level detection for most analytes, enabling trace-level screening of materials and finished devices.
• Regulatory support: The validated performance (linearity, LOQs, recovery, reproducibility) provides reliable quantitative data suitable for regulatory reporting and material qualification during transition to PFAS-free alternatives.
• Operational robustness: PFAS‑verified consumables, sampler wash routines and reconditioning minimize carryover and maintain low background across batches.

Future trends and potential applications

• Expanded analyte coverage: Continue extending target lists and incorporate suspect screening by high‑resolution MS to detect novel or proprietary PFAS chemistries in polymers and coatings.
• Method harmonization and standards: Adoption of standardized workflows across laboratories and harmonized QC materials will facilitate regulatory acceptance and interlaboratory comparability.
• Automation and miniaturization: On-line SPE, automated extraction, and microextraction approaches can increase throughput and reduce solvent use while maintaining sensitivity.
• Lifecycle monitoring: Routine screening of raw materials, production intermediates and finished devices to verify PFAS-free claims and support supply‑chain auditing.
• Instrument and consumable innovation: Further reduction of fluorinated flow-path components and improved sampler designs will push detection limits lower and reduce background variability.

Conclusion

The presented UHPLC–6475 TQ workflow demonstrates a practical, high-sensitivity approach for quantitative screening of 73 PFAS in medical device materials. Combining a PFAS‑optimized UHPLC configuration, Feed Injection with large-volume high‑organic injections, a simple HUA methanol extraction, and rigorous QC produced low background, excellent linearity, sub- to low‑µg/kg LOQs for the majority of targets, acceptable recoveries and good reproducibility. This protocol supports routine product screening, regulatory reporting and the industry transition to PFAS‑free materials.

Reference

1. EPA PFAS National Primary Drinking Water Regulation, 2024. Federal Register publication 2024-07773.
2. ISO 10993-12 Biological Evaluation of Medical Devices — Part 12: Sample Preparation and Reference Materials, 2021.