Targeted Quantitation of Legacy and Emerging Per- and Polyfluoroalkyl Substances (PFAS) in Water Using the Agilent 6470 Triple Quadrupole LC/MS System

Importance of the topic

The widespread use and persistence of legacy and emerging per- and polyfluoroalkyl substances PFAS in drinking and surface waters pose significant environmental and human health concerns. Their resistance to degradation and potential bioaccumulation require sensitive, reliable analytical strategies to support regulatory monitoring and remediation efforts.

Objectives and study overview

This work presents a comprehensive workflow for targeted quantitation of over 100 native and isotopically labeled PFAS in water matrices. Leveraging solid phase extraction SPE and triple quadrupole LC/MS/MS, the study aims to simplify routine laboratory testing by combining sample cleanup, chromatographic separation, and mass spectrometric detection into a single, robust method.

Methodology

Water samples were adjusted to pH ~3 and spiked with surrogate and native PFAS mixes. SPE using weak anion exchange WAX cartridges provided cleanup and 250-fold concentration. Extracts were analyzed on an Agilent 1290 Infinity II LC coupled to a 6470 Triple Quadrupole MS operating in negative ion mode with dynamic MRM. Calibration utilized isotope dilution across a wide concentration range, with 1/x or quadratic weighting as needed.

Used instrumentation

• Agilent 1290 Infinity II UHPLC with PFC-Free Conversion Kit and ZORBAX RRHD Eclipse Plus C18 column
• Agilent 6470 Triple Quadrupole LC/MS with Agilent Jet Stream ion source
• Vac Elut SPS 24 manifold and SampliQ WAX SPE cartridges

Main results and discussion

Method detection limits for 60 PFAS ranged from 0.14 to 14 ng/L, with 51 compounds below 0.6 ng/L. Interbatch precision in drinking and surface water was 2.2–19.9% RSD and recoveries 72–120%. PFOS exhibited an MDL of 0.27 ng/L, below the EU annual average quality standard of 0.65 ng/L. Over 93 hours and 300 injections, response ratios for representative PFAS showed ≤3.1% RSD and retention time stability ≤0.10% RSD, confirming robustness.

Benefits and practical applications

• Comprehensive coverage of regulated and emerging PFAS in a single method
• High sensitivity and wide dynamic range suitable for trace-level monitoring
• Streamlined workflow with ready-to-use electronic method and database support
• Demonstrated applicability to routine analysis in environmental laboratories

Future trends and opportunities

As regulatory frameworks evolve to include additional PFAS species, this flexible LC/MS/MS approach can be expanded by updating MRM transitions from curated databases. Integration of high-resolution MS and automated SPE could further improve throughput and screening capabilities. Ongoing developments in robust, PFC-free instrumentation will continue to reduce background interference.

Conclusion

A unified SPE–LC/TQ method has been developed for sensitive, precise quantitation of a broad suite of PFAS in drinking and surface waters. Its robustness, low detection limits, and broad applicability support regulatory compliance and environmental monitoring initiatives.

References

• Coggan LC et al 2019 A Single Analytical Method for the Determination of 53 Legacy and Emerging PFAS in Aqueous Matrices Anal Bioanal Chem 411 3507-3520
• Fenton SE et al 2021 Per- and Polyfluoroalkyl Substance Toxicity and Human Health Review Environ Toxicol Chem 40(3) 606-630
• US EPA 2016 Definition and Procedure for the Determination of the Method Detection Limit Revision 2 EPA 821-R-16-006
• Rosenblum L Wendelken SC 2019 EPA Method 533 Determination of Per- and Polyfluoroalkyl Substances in Drinking Water by Isotope Dilution Anion Exchange SPE and LC-MS/MS EPA 815-B-19-020
• European Environment Agency 2019 Emerging chemical risks in Europe PFAS