Analysis of PFAS in Water Using Weak-Anion Exchange/Graphitized Carbon Black SPE and LC-MS/MS Analysis According to EPA Method 1633 4th Draft

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

Prepared by A. Cocozza
United Chemical Technologies, Inc, 2731 Bartram Rd, Bristol, PA, 19007, United States


Contact Information: [email protected]; 215-781-9255

ABSTRACT

PFAS, a diverse group of synthetic organofluorine compounds widely used in industrial and consumer products, are persistent and known to bioaccumulate. Before 2021, the EPA only had standardized methods for measuring PFAS in drinking water. EPA Draft 1633 now allows the analysis of 40 target PFAS analytes in various matrices. The fourth draft of method 1633, posted on the EPA website in July 2023, includes a requirement to separate the retention time of the bile salt Taurodeoxycholic Acid (TDCA) from PFOS by a minimum of 1 minute, as well as allows for carbon cleanup in cartridge form rather than loose carbon during extraction, providing required recovery limits are met.
This poster explores the analysis of PFAS according to EPA 1633 4th draft method by LC-MS/MS using UCT’s SelectraCore® C18 HPLC analytical, guard, and delay column, as well as the use of a stacked solid phase extraction (SPE) cartridge containing UCT’s WAX and GCB material. Coreshell columns are beneficial because they reduce backpressure on the LC system while reducing band broadening of the chromatography due to the chemistry of the column. The use of stacked WAX/GCB cartridges will optimize throughput for laboratories by eliminating the need for a dSPE carbon cleanup step. The challenges throughout the development process include optimizing a practical LC method to separate TDCA from PFOS and demonstrating the efficiency of a dual-phase SPE cartridge by achieving recovery limits newly defined in this draft method.