PFAS are Everywhere and Now We Have a Validated Multi-matrix Method 1633 to Find Them

Per- and Polyfluoroalkyl Substances (PFAS) in the Environment
Oral Presentation

Prepared by A. Hanley1, H. McCarty2, J. Willey3, M. Alzipar1
1 - USEPA OST, 1200 Pennsylvania Avenue NW, Washington, DC, 20004, United States
2 - General Dynamics Information Technology, 3170 Fairview Park Drive, Falls Church, VA, 23310, United States
3 - US Navy, , , United States


Contact Information: [email protected]; 202-564-1564

ABSTRACT

On January 31, 2024, the EPA Office of Water, in partnership with the DoD Strategic Environmental Research and Development Program, published Method 1633, which detects 40 PFAS compounds in wastewater, surface water, groundwater, soil, biosolids, sediment, landfill leachate, and fish tissue. This LC/MS/MS method employs isotope dilution and extracted internal standard quantitation and is the culmination of a multi-year effort in support of EPA’s PFAS Strategic Roadmap to address this class of “forever chemicals.” EPA released four draft methods between August 2021 and July 2023 that reflected improvements and clarifications to the extensive extraction, cleanup, and analysis procedures, many based on feedback from laboratories and other interested parties. DoD led the multi-laboratory validation study in collaboration with the Office of Water and the Office of Land and Emergency Management. The study involved 10 commercial or state laboratories, six real-world wastewater samples, and three samples each of surface waters, groundwaters, soils, sediments, biosolids, landfill leachates, and fish or shellfish, making it the largest EPA method validation study in recent memory. All results were subjected to extensive data review procedures and the valid data were compiled and used by EPA and DoD to demonstrate the overall performance of the method for all 40 target analytes. EPA also used the results to develop formal QC acceptance criteria for the final method that cover calibrations and calibration verifications, method blanks, initial precision and recovery, ongoing precision and recovery analyses at two concentrations, and extracted internal standard recoveries. MDLs generated during the study demonstrate that laboratories can reliably detect the target analytes at 0.3 to 10 ng/L in aqueous samples, 0.05 to 0.5 ng/g in solid samples, and 0.1 to 2 ng/g in tissue samples. The method is being widely adopted and replaces many laboratory-specific modifications of other procedures.