Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Drinking Water in Accordance with EPA 533

Significance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants linked to adverse human health effects. Regulatory agencies such as the U.S. EPA and ECHA have established stringent maximum contaminant levels in drinking water, necessitating highly sensitive and reliable analytical methods.

Study Objectives and Overview

This study evaluates Shimadzu’s LCMS-8060RX combined with a preconfigured LC/MS/MS method package compliant with EPA Method 533. The aim is to measure 25 target PFAS compounds in drinking water at concentrations below EPA’s final MCLs, assessing method sensitivity, accuracy, and reproducibility.

Methodology and Instrumentation

• Instrumentation
  • UHPLC: Nexera X3 system with Shim-pack GIST HP C18 analytical column and a delay column to minimize system contamination.
  • Mass Spectrometry: LCMS-8060RX triple-quadrupole with UF technology and CoreSpray ion source, operating in ESI negative mode with MRM detection.
• Sample Preparation
  • Add 20 µL isotope dilution analogues, perform anion-exchange SPE.
  • Evaporate eluate under nitrogen, reconstitute in 80% methanol.
  • Spike with performance standards before injection (2 µL).
• Analytical Conditions
  • Mobile Phases: 5 mM ammonium acetate in water (A) and methanol (B).
  • Gradient: B from 5% to 40% in 1 min, ramp to 95% by 8 min, hold to 10 min, return to 5% by 10.1 min, re-equilibrate to 15 min.
  • Flow Rate: 0.25 mL/min, Column Temperature: 45 °C.

Main Results and Discussion

• Calibration: Nine-point curves (0.2–100 ng/L) achieved correlation coefficients >0.997 and accuracy between 85–130%.
• Chromatography: Clear MRM peaks at 0.4 ng/L, demonstrating sensitivity at one-tenth of EPA MCL levels.
• Ultrapure Water Spike Recovery: Recoveries of 89–125% at 1 and 4 ng/L with repeatability (%RSD) <20%.
• Isotope Dilution and Performance Standards: Dilution analogues recovered at 80–115%, performance standards at 95–110%.
• Drinking Water Spike Recovery: Laboratory fortified sample and duplicate at 4 ng/L met recovery criteria (85–115%) with RPD <11%.

Benefits and Practical Applications

• Pre-optimized method files drastically reduce method development time.
• Enables accurate quantification of multiple PFAS at trace levels in drinking water.
• Supports compliance monitoring and quality assurance in environmental laboratories.

Future Trends and Potential Applications

As regulations expand and new PFAS variants emerge, demand will grow for higher-throughput, automated workflows and non-targeted screening via high-resolution MS. Miniaturization of sample preparation and on-site monitoring technologies are expected to advance field analysis capabilities.

Conclusion

Shimadzu’s LCMS-8060RX paired with the EPA Method 533 package delivers robust, sensitive, and reproducible analysis of 25 PFAS in drinking water below regulatory limits, streamlining laboratory workflows and ensuring regulatory compliance.

Instrument Used

Shimadzu Nexera X3 UHPLC; Shim-pack GIST HP C18 columns; Shimadzu LCMS-8060RX triple-quadrupole MS with CoreSpray and UF technologies.

References

• EPA. Final PFAS National Primary Drinking Water Regulation, 2024.
• EPA. Method 533: Determination of PFAS in Drinking Water by Isotope Dilution SPE and LC-MS/MS.