Lessons Learned While Evaluating the Complete Analytical Workflow for the Analysis of PFAS Compounds using EPA 533 Methodology

Polyfluoroalkyl Substances (PFAS) in the Environment
Oral Presentation

Prepared by J. Simon
Merck KGaA / MilliporeSigma, Frankfurter Str. 250, Darmstadt, GE, A019 001, Germany


Contact Information: johanna.simon@merckgroup.com; 49 6151 72-20801


ABSTRACT

Per- and polyfluoroalkyl substances (PFAS) are man-made organic fluorine compounds that are found in the environment, in blood or tissue of animals and humans worldwide. PFAS are persistent chemicals, can easily migrate into water, food, air or soil, where they accumulate over time. There is evidence from human and animal studies that the exposure of PFAS can have adverse health impacts such as hormone suppression, high cholesterol, liver damage or cancer. Therefore, the U.S. Environmental Protection Agency (EPA) has started action plans against PFAS and one of them is the determination of PFAS compounds in drinking water using liquid chromatography–mass spectrometry (LC-MS).

A complete workflow for the extraction, screening, analysis and quantification of PFAS compounds in drinking water according the EPA 533 method is presented. The new weak anion exchange cartridge (Supelclean ENVI-WAX SPE) was used for sample preparation and provided a high PFAS recovery, while having a low PFAS background. Up to 12 samples could be extracted in parallel with the Visiprep™ SPE Vacuum Manifold that is completely PTFE free. The new Ascentis® Express PFAS HPLC column, which has a Fused-Core® technology and a particle size of 2.7 µm, provided high-resolution separation with excellent selectivity and peak shape. The level of PFAS detected in UHPLC-MS LiChrosolv® solvents was extremely low (< 4 ppt) and therefore, those solvents were used as the mobile phase to prevent PFAS background contamination. Additionally, a specific delay column (RP-C30 phase) was implemented to retain systemic PFAS compounds. Defined reference standard mixtures containing branched and linear isomer PFAS compounds relevant for EPA 533 were designed. With this a complete solution for the accurate identification and quantification PFAS compounds in drinking water according to EPA 533 is presented along with the best practice lessons learned.