Analysis of PFAS

Importance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are environmentally persistent chemicals with significant health and ecological implications. Sensitive and reliable analytical methods are essential for monitoring trace levels of PFAS in water, food, and biological samples to support regulatory compliance and risk assessment.

Objective and Overview

This application note describes a robust LC–MS method for the simultaneous quantification of short‐chain PFAS analytes, including perfluoropropanoic acid (PFPrA), perfluorobutanoic acid (PFBA), and perfluoromethylpropanoic acid (PFMPA). Utilizing Shimadzu’s Nexera X3 UHPLC system coupled with the LCMS-8060NX, the study demonstrates optimized chromatographic separation and sensitive detection under negative-mode electrospray ionization (ESI).

Methodology and Instrumentation

The reversed-phase separation was performed on a Shim-pack GIST-HP C18 column (100 × 3.0 mm, 3 µm) with a matching delay column (Shim-pack Scepter C18-120, 100 × 2.1 mm, 3 µm). The aqueous mobile phase (A) comprised 2 mmol/L ammonium acetate in water/acetonitrile (95:5), and phase B was pure acetonitrile. A gradient from 10 % to 95 % B over 16 minutes ensured efficient elution of analytes.

• Flow rate: 0.6 mL/min
• Column oven temperature: 40 °C
• Injection volume: 25 µL with multiple draw co-injection

Mass spectrometric detection employed an IonFocus ESI interface at –0.5 kV, with interface temperature at 170 °C and heat block at 300 °C. Nebulizing, drying, and heating gas flows were optimized for stable spray and desolvation.

Main Results and Discussion

The method achieved baseline resolution of target PFAS compounds within 14 minutes, with excellent peak shape and reproducibility. Limits of detection were in the low ng/L range, demonstrating the high sensitivity of the LCMS-8060NX in negative ESI mode. The use of labeled internal standards (e.g., 13C4-PFBA) improved quantitation accuracy and compensated for matrix effects.

Benefits and Practical Applications

This workflow supports high-throughput PFAS analysis in environmental monitoring, food safety, and clinical research. Key advantages include:

• Rapid turnaround with a total run time of 20 minutes
• High sensitivity for trace-level detection
• Robustness against matrix interferences

Future Trends and Opportunities

Advances in stationary phases and ionization technologies will further enhance PFAS analysis. Emerging areas include automated sample preparation, high-resolution mass spectrometry for non‐target screening, and miniaturized field-deployable LC–MS systems for on-site monitoring.

Conclusion

The described LC–MS method offers a reliable and efficient approach for the determination of short-chain PFAS. Its combination of fast separation, low detection limits, and reproducible quantitation makes it well suited for routine analysis in regulatory and research laboratories.

References

• Shimadzu Corporation. Application News 01-00150. First Edition: Sep. 2024.