Reduce PFAS Background with the Agilent PFAS Analysis HPLC Conversion Kit

Topic Importance

Per- and polyfluoroalkyl substances (PFAS) represent persistent pollutants that accumulate in water and biota. Trace-level analysis of PFAS is critical for regulatory compliance and public health monitoring. High-sensitivity LC/MS/MS methods require minimal background contamination to achieve low quantification limits.

Study Aims and Overview

This work evaluates the Agilent PFAS Analysis HPLC Conversion Kit, a ready-to-install solution designed to replace PFAS-containing components in HPLC systems and to incorporate an InfinityLab PFC delay column. The aim is to assess background reduction in LC/MS/MS workflows and to ensure robust trace-level PFAS detection in environmental water samples.

Methodology and Instrumentation

• Key modifications: substitution of PTFE, PFA, and FEP components with polypropylene (PP), PEEK, and ETFE in solvent lines, bottle caps, and inline filters.
• Implementation steps: bypass of degasser, installation of PFC delay column before autosampler, and deployment of multiwash tubing.
• Mobile phases: water and methanol with 5–20 mM ammonium acetate or 0.1% acetic acid.
• Gradient program and injection parameters optimized for PFAS separation.

Instrumentation

• LC: Agilent 1290 Infinity II/III High Speed Pump and Multisampler with multiwash option.
• Analytical column: ZORBAX Eclipse Plus C18 RRHD, 2.1 × 50 mm, 1.8 µm, with PFC delay column (4.6 × 30 mm).
• MS: Agilent G6495C triple quadrupole in negative dynamic MRM mode.
• Auxiliary components: InfinityLab Quick Change inline filters, PEEK fittings, and polypropylene Stay Safe bottle caps.

Results and Discussion

The conversion kit significantly lowers PFAS background across 38 targeted analytes. Systems without modification exhibited high baseline levels, hindering ppb-level quantification. Replacing fluoropolymer parts alone reduced background for most analytes; combining material swaps with the PFC delay column reduced residual signals below detection limits (<2 fg for PFHpA and <7 fg for PFNA). Calibration linearity improved (R² > 0.999), and blank injections confirmed effective delay of mobile phase–derived contaminants.

Benefits and Practical Applications

• Enhanced sensitivity and reliability for regulatory methods (US EPA 533, 537.1, ISO 21675).
• Modular design allows retrofitting existing HPLC platforms dedicated to PFAS analysis.
• Trace-level detection supports water quality monitoring and compliance testing.
• Reduced downtime via easy installation and maintenance of non-fluorinated components.

Future Trends and Applications

Advancements may include broader compatibility with diverse LC modules, integration of automated background monitoring, and development of next-generation delay columns for ultra-high-pressure systems. Adoption of fully fluorine-free fluidics could further minimize contamination in emerging environmental, food, and biological PFAS analyses.

Conclusion

The Agilent PFAS Analysis HPLC Conversion Kit offers a comprehensive solution for minimizing PFAS background in LC/MS workflows. By replacing fluorinated materials and incorporating a PFC delay column, laboratories can achieve superior sensitivity and compliance with stringent trace-level regulations.

References

1. Wang Z, DeWitt J, Higgins C, Cousins I. A Never-Ending Story of Per- and Polyfluoroalkyl Substances (PFASs)? Environ Sci Technol. 2017;51(5):2508–18.
2. US EPA Method 533. Determination of PFAS in Drinking Water by Isotope Dilution SPE and LC/MS/MS. 2019.
3. US EPA Method 537.1. Selected Per- and Polyfluoroalkyl Substances in Drinking Water by SPE and LC/MS/MS. 2020.
4. US EPA Method 8327. PFAS using External Standard Calibration and MRM LC/MS/MS. 2019.
5. ISO 21675:2019 Water Quality—Determination of PFAS in Water by SPE and LC/MS/MS.
6. Agilent Technologies. More Sensitive Quantification of PFAS by LC/MS with the 1260 Infinity II Hybrid Multisampler. Application note 5994-6994EN, 2024.