EPA Draft Method 1633 for PFAS Analysis: Evaluation of SPE Extraction Options

Polyfluoroalkyl Substances (PFAS) in the Environment (Session 2)
Oral Presentation

Prepared by H. Lord
Bureau Veritas, 6740 Campobello Road, Mississauga, ON, L5N 2L8, Canada


Contact Information: [email protected]; 905-301-1757

ABSTRACT

Draft Method EPA 1633 was released in August 2021. Despite its Draft status there is interest to have the method accredited by laboratories as is, ahead of being fully promulgated. A memorandum issued Dec. 7, 2021 by the US Department of Defense directed that that all new projects after 2021 use the method with a laboratory accredited by the DoD Environmental Laboratory Accreditation program. Table B-24 was added to the DoD Quality Systems Manual (v.5.4) to provide data quality acceptance criteria as these are absent in the draft method.

Table B-24 emphasizes that all of the requirements contained in EPA Draft Method 1633 must be met. The method itself is however ‘performance-based’ and guidance is provided by which laboratories are able to establish equivalency of modified procedures, apparatus and materials. Of note, the specific requirements of the method suggest a need to establish equivalency for alternatives to the specified solid phase extraction (SPE) procedures.

The method requires SPE clean-up of all matrix extracts. One particular SPE cartridge from a single vendor is specified, along with an ‘or equivalent’ provision. While such narrow specifications contribute to method consistency they also carry risks. First, the supply chain challenges being experienced by the industry are requiring a broadening of supplier options for lab supplies and second, the method as written suggests the step may be a limitation to productivity.

To address these risks we have evaluated different options for the solid-phase extraction step, using cartridges from different vendors and in different configurations. Comparisons were made relative to validated procedures conducted according to the requirements of the method and Table B-24, and evaluated following the requirements for establishing equivalency outlined in Section 1.5. This presentation will describe the results of these trials.