Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Drinking Water in Accordance with EPA Method 537.1

Significance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are widely used for their chemical stability and resistance properties but persist in the environment and pose health risks. Regulatory agencies such as the US EPA have established strict maximum contaminant limits (MCLs) for PFAS in drinking water, driving the need for highly sensitive and reliable analytical protocols.

Study Objectives and Overview

This study evaluates the performance of the Shimadzu LCMS-8060RX coupled with a dedicated LC/MS/MS Method Package for PFAS in Drinking Water to quantify 18 PFAS compounds in accordance with EPA Method 537.1, targeting detection limits well below current regulatory MCLs.

Methodology and Instrumentation

• Sample Preparation: Drinking water (250 mL) spiked with surrogate standards and Trizma buffer undergoes solid-phase extraction on styrenedivinylbenzene (SDVB) cartridges, followed by elution, concentration, and reconstitution in 96% methanol with internal standards.
• Liquid Chromatography: Nexera-X3 UHPLC with Shim-pack Velox SP-C18 column (50 × 2.1 mm, 2.7 µm) using a gradient of 5 mM ammonium acetate (aqueous) and methanol over an 18 min run at 0.25 mL/min and 45 °C.
• Mass Spectrometry: LCMS-8060RX operating in negative ESI mode with MRM acquisition. Optimized nebulizing (3 L/min), drying (5 L/min), and heating (15 L/min) gas flows, DL at 150 °C, block heater at 250 °C, and interface at 100 °C.

Main Results and Discussion

• Calibration Performance: Standards from 0.05 to 25 µg/L yielded correlation coefficients (R) ≥ 0.997 for all 18 PFAS and area repeatability < 11% RSD at the lowest level (0.05 µg/L).
• Spike Recovery in Ultrapure Water: At 1 ng/L and 4 ng/L spikes, recoveries ranged 93–109% with concentration RSD < 10%, confirming method robustness.
• Spike Recovery in Drinking Water: Laboratory fortified samples at 4 ng/L achieved 84–101% recoveries and RPD < 6%, meeting EPA Method 537.1 acceptance criteria.
• Method Sensitivity: Limits of quantitation correspond to one-tenth of EPA Final MCLs (e.g., 0.4 ng/L for PFOA), ensuring compliance monitoring capability.

Benefits and Practical Applications

• Simultaneous trace-level analysis of 18 regulated PFAS compounds in drinking water aligned with EPA regulations.
• Preconfigured method package streamlines instrument setup, reduces validation workload, and accelerates time-to-data.
• Applicable in environmental monitoring, QA/QC laboratories, and compliance testing workflows.

Future Trends and Opportunities

Emerging directions include expanding target analyte lists to novel PFAS, integrating high-resolution MS for non-target screening, adopting automated high-throughput sample preparation, and miniaturizing SPE protocols for field-deployable testing.

Conclusion

The Shimadzu LCMS-8060RX with its PFAS Method Package offers robust, sensitive, and precise quantification of 18 PFAS in drinking water at regulatory limits. Excellent linearity, precision, and recovery demonstrated full compliance with EPA Method 537.1 and support routine environmental surveillance.

Used Instrumentation

• Shimadzu Nexera-X3 UHPLC system
• Shim-pack Velox SP-C18 column (50 × 2.1 mm, 2.7 µm)
• Shimadzu LCMS-8060RX triple quadrupole mass spectrometer
• SDVB polymeric SPE cartridges (InertSep PLS-2, 500 mg)

References

• US EPA. Final PFAS National Primary Drinking Water Regulation. 2024.
• US EPA. Method 537.1: Determination of Selected Per- and Polyfluoroalkyl Substances in Drinking Water by Solid Phase Extraction and LC/MS/MS, Version 2.0, March 2020.