Method Performance Uing Dual WAX/GCB and GCB/WAX SPE Formats for Draft EPA Method 1633

Polyfluoroalkyl Substances (PFAS) in the Environment
Oral Presentation

Prepared by R. Jack1, P. Bassignani2, M. Shimizu3, S. Lodge1
1 - Phenomenex, 86 Lester ave, San Jose, CA, 95125, United States
2 - Alpha Analytical Laboratories, , Mansfield, MA, 02048, United States
3 - Sciex, , Framingham, MA, 01701, United States

Contact Information: [email protected]; 408-242-2996


EPA draft method 1633 covers the extraction and analysis of 40 per- and polyfluoroalkyl substances (PFAS) in a variety of environmentally relevant matrices known as “Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous, Solid, Biosolids, and Tissue Samples by LC-MS/MS”.1 The method involves a two-step SPE approach using weak anion exchange (WAX) followed by graphitized carbon black (GCB) clean-up in a powder format, known as dispersive GCB (dGCB). For water samples, dGCB is added after extraction, but added before SPE for soil samples. The purpose of the additional GCB clean-up step is to eliminate matrix that can cause interference and reduce bias. Adding dGCB is very labor intensive and therefore not practical due to the added time needed to add, mix, and centrifuge for each sample, especially in high throughput laboratories. For these reasons, cartridges were developed as a single cartridge stacked with WAX and GCB sorbents that function as a traditional Solid Phase Extraction (SPE) cartridge with a built-in polishing step to meet the method guidelines. The goal of this study was to evaluate the method extraction procedure using the dual step approach using WAX plus Dispersive SPE compared to a single approach using a dual stacked SPE phases for wastewater, groundwater and surface water extracts from EPA 1633 validations studies.