Pushing PFAS Possibilities: The Hunt for Ultra Sensitivity to Reach ppq EPA Health Advisory Levels

Drinking Water
Oral Presentation

Prepared by K. Organtini, H. Foddy, N. Dreolin, S. Adams, K. Rosnack, P. Hancock
Waters Corporation, 34 Maple St, Milford, MA, 01757, United States


Contact Information: [email protected]; 508-482-3242

ABSTRACT

PFAS are well known chemicals with a variety of commercial and consumer uses, characterized by their extreme stability and structural diversity. PFAS are highly persistent and toxic contaminants that accumulate in humans, animals, and the environment. Detection requirements for PFAS have been getting more challenging as advisory and regulatory limits continue to be created and updated. In June 2022, the US EPA tightened its health advisory levels (HALs) in drinking water from 70 ng/L to 0.004 ng/L for PFOA and 0.02 ng/L for PFOS. Additionally, final HALs were set for PFBS at 2000 ng/L and HFPO-DA (commonly referred to as GenX) at 10 ng/L. The near zero PFOA and PFOS levels pose analytical challenges regarding instrument sensitivity and sample preparation conditions to limit contamination. This goal of this work was to show with proper care during sample preparation and analysis using a highly sensitive mass spectrometer, these near zero limits are possible to detect.
All samples were prepared in a typical shared laboratory environment, taking extreme care to screen all consumables and reagents for PFAS contamination before use. 250 mL water samples were extracted using Oasis™ WAX SPE Cartridges, followed by analysis using a highly sensitive mass spectrometer.
This presentation will discuss best practices for sample preparation to reduce contamination as well as the minimum level of contamination achieved during these experiments. Additionally, information on the Limit of Quantitation (LOQ) for each compound and method recovery values will be shared.