Is Your Next Sip Safe? A Simple, Rapid Method for Measuring volatile PFAS in Juices.

Significance of the topic

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants with growing regulatory and public-health scrutiny. While most routine PFAS monitoring targets aqueous matrices, volatile PFAS in foods and beverages represent an emerging exposure route with direct implications for consumer safety and brand integrity. Rapid, reliable analytical methods that address volatile PFAS in complex beverage matrices are therefore important for regulatory compliance, product stewardship, and risk assessment.

Objectives and study overview

This study developed and evaluated a headspace solid-phase microextraction (HS-SPME) coupled to triple quadrupole gas chromatography/mass spectrometry (GC/MS/MS) method to quantify ten volatile PFAS in juices. Key aims were to: establish a fast, low‑prep workflow suitable for complex beverage matrices; demonstrate calibration performance and method precision/accuracy; evaluate matrix effects in several commercial juices; and determine the necessity of isotope-labelled internal standards for reliable quantitation.

Methods and experimental workflow

The method combined HS-SPME sampling of 10 mL juice/water aliquots with GC separation and MRM detection on a triple quadrupole MS. Isotope-dilution quantitation was used, with labelled internal standards spiked into each vial prior to extraction. An eight-point aqueous calibration (1–2000 ng/L for most targets) was prepared in reagent water containing 2% (w/v) NaCl to enhance headspace extraction. Method validation used reagent-water laboratory control samples (LCS), spiked and unspiked commercial juices (two carton apple juices from different brands, one plastic-bottled apple juice, and one berry blend carton juice), and routine calibration checks (ICV/CCV). The study emphasized evaluation of matrix effects and the assignment of compound-specific isotopically labelled internal standards.

• Targets: ten volatile PFAS across chemical classes including perfluoroalkyl iodides (PFIs), fluorotelomer iodides (FTIs), fluorotelomer acrylates (FTACs), fluorotelomer methacrylates (FTMACs), fluorotelomer alcohols (FTOHs) and perfluoroalkane sulfonamides (FASAs).
• Sample prep: 10 mL sample, 2% NaCl (w/v), internal standards at 100 ng/L in calibrators; vortex then HS-SPME.
• SPME: 50/30 µm DVB/CAR/PDMS fiber; incubation 5 min; extraction 30 min at 50 °C with 300 rpm agitation; desorption 7 min at 240 °C.
• GC: splitless injection, He carrier, injection port 240 °C, SH‑I‑624Sil MS capillary column (30 m × 0.25 mm × 1.40 µm), oven program from 40 °C (7 min) ramped to 190 °C then to 300 °C final hold.
• MS/MS: Shimadzu GCMS‑TQ8040 NX in MRM mode, interface 280 °C, ion source 200 °C, loop time 0.5 s.

Used instrumentation

• Nexis GC-2030 gas chromatograph.
• Shimadzu GCMS-TQ8040 NX triple quadrupole mass spectrometer.
• AOC-6000 Plus autosampler with HS-SPME module and appropriate SPME fiber.

Key results and discussion

Calibration and system performance:

• Calibration curves for all targets produced good linearity with R2 ≥ 0.993 across the specified ranges (most targets 1–2000 ng/L).
• Initial calibration verification (ICV) and continuing calibration verifications (CCV) met method criteria: measured accuracies within 70–130% of expected.
• Method blanks showed no quantifiable contamination, indicating low background and suitable cleanliness for trace analysis.

Precision and accuracy in reagent water (LCS):

• Replicate LCS analyses (n=4) fortified at 100 ng/L yielded mean recoveries of 83–115% and %RSDs of 0.6–6.8%, meeting the established acceptance criteria (70–130% recovery; ≤20 %RSD).

Matrix effects and juice analyses:

• Significant matrix effects were observed in juice samples for several targets, underlining the challenge of complex beverage matrices for volatile PFAS quantitation.
• Compounds lacking corresponding isotopically labelled internal standards could not be quantified reliably in those matrices. Assignment of a matched labelled internal standard for each analyte markedly improved accuracy and precision (example: 8:2 FTMAC quantitation was accurate only when quantified with 8:2 FTMAC‑d5 rather than a different labelled analogue).
• Unspiked commercial juices contained no target PFAS at quantifiable levels in this dataset.
• Spiked juice recoveries across four beverage matrices averaged 69–120% with %RSDs below 12, meeting the method performance criteria for complex matrices once analyte‑specific isotope standards were applied.

Overall interpretation: The HS‑SPME GC/MS/MS workflow delivered robust calibration behavior and reproducible results in clean matrices, and—crucially—acceptable performance in complex juice matrices when each target had a matched isotopically labelled internal standard. The approach is therefore suited to volatile PFAS that are not amenable to LC/MS, provided matrix effects are compensated by appropriate internal standards.

Practical benefits and applicability

• Minimal sample preparation and headspace extraction reduce solvent use and handling time compared with liquid extraction approaches.
• GC/MS/MS in MRM mode offers selective, sensitive detection for volatile PFAS classes (FTOHs, FTACs, FTMACs, FTIs, PFIs, FASAs) that are challenging for LC/MS workflows.
• Method demonstrated applicability across a range of commercial juices and is likely transferable to similar beverages (sports drinks, vitamin waters) with validation and matched internal standards.

Future trends and potential uses

• Broader adoption will depend on availability and cost of isotopically labelled internal standards; development of labelled standards for more volatile PFAS will improve quantitation across matrices.
• Extension of method scopes to other beverage and food matrices, and interlaboratory validation, would support regulatory monitoring and industry surveillance programs.
• Automation of HS-SPME workflows and improvements in SPME fiber chemistry could increase throughput and lower detection limits.
• Integration with risk-assessment frameworks and occurrence studies will be important as regulations evolve and consumer concern grows.

Conclusion

The described HS‑SPME GC/MS/MS method provides a rapid, low‑prep approach for detecting and quantifying a suite of volatile PFAS in juices. The method shows strong linearity, acceptable precision and accuracy in reagent-water controls, and satisfactory performance in complex juice matrices when analyte-matched isotopically labelled internal standards are used. Absence of quantifiable native PFAS in the tested commercial juices suggests low occurrence for the compounds and batches studied, but routine monitoring and broader matrix evaluation are recommended to confirm generalizability.

References

1. Alazaiza M. Y., Alzghoul T. M., Ramu M. B., Amr S. S. A., & Abushammala M. F. (2025). PFAS Contamination and Mitigation: A Comprehensive Analysis of Research Trends and Global Contributions. Case Studies in Chemical and Environmental Engineering, 101127.
2. US Food and Drug Administration. Per- and Polyfluoroalkyl Substances (PFAS). (2024, June 26). FDA guidance and informational material on PFAS in food and beverages.
3. Milberg. Florida’s Natural PFAS Lawsuit Disputes “Natural” Claim. (2023, September 26). News summary of litigation highlighting industry and public concern over PFAS in juices.