Method Validation for the California Expanded List for PFAS Compounds

Polyfluoroalkyl Substances (PFAS) in the Environment
Poster Presentation

Prepared by R. Jack1, D. Schiessel2, D. Kennedy1
1 - Phenomenex, 86 Lester ave, San Jose, California, 95125, United States
2 - Babcock Laboratories Inc., 6100 Quail Valley Ct, Riverside, CA, 92507, United States


Contact Information: richardj@phenomenex.com; 408-242-2996

ABSTRACT

Publicly owned treatment works (POTWs) are potentially significant receivers of perand polyfluoroalkyl substances (PFAS) and have the potential to discharge these wastes to the environment. Recently, the State of California issued ORDER WQ 2020-0015-DWQ, which requires wastewater utilities discharging more than 1 mgd to conduct sampling and analysis for an expanded list of 31 PFAS compounds. The list include PFCA’s from C4-C18, PFSA’s from C4-C10, Perfluorooctane Sulfonamide and Derivatives (PFOSA, FOSEs, FOSAs, and FOSAAs), Fluorotelomer sulfonates(FTS) , Fluorotelomer carboxylic acids(FTCA), Perfluoroalkyl ether carboxylic acids (PFECA), Chlorinated Polyfluoroalkyl Ether Sulfonic Acids (Cl-PFESAs) plus four additional compounds Nonafluoro-3,6-dioxaheptanoic acid (NFDHA), Perfluoro(2-ethoxyethane) sulfonic acid (PFEESA), Perfluoro-3-methoxypropanoic acid (PFMPA), Perfluoro-4-methoxybutanoic acid (PFMBA). In August 2019, the State Water Board lowered the drinking water notification levels for PFOS and PFOA to 6.5 ppt and 5.1 ppt, respectively. In February 2020, the State Water Board lowered the response levels for PFOA and PFOS from 70 ppt combined to 10 ppt for PFOA and 40 ppt for PFOS based on a running four quarter average.
Sampling and analysis are required for one year. Here we report the use of a modified EPA 537.1 validation protocol for this expanded list of PFAS compounds. This poster will describe such an optimized Method 537.1 production scheme and will provide accuracy and precision results developed by a commercial laboratory for the analysis of the PFAS matrix spike recoveries in reagent and wastewater samples. We will also show detection limits, fast run times and optimized performance using a pH gradient chromatographic separation.