Per- and polyfluoroalkyl substances (PFAS) are an emerging chemical class of concern. Recently in the United States, Health Advisory Limits for two PFAS in drinking water were established for perfluorooctane sulfonate and perfluorooctanoate in drinking water (set to 70 ng/L combine concentration) by the EPA. Because of PFAS mobility, persistence, and occurrence in drinking water throughout the country, it is import to understand potential sources of PFAS. In the first study, PFAS sample collection and storage and materials used in the field were examined. Sampling parameters including sampling materials, sample collection, and sample storage for the analytes represented by the new analytical method were examined. The optimal sample storage and analysis conditions were determined. Additionally, a characterization of 66 sampling materials was performed and a list of PFAS containing materials was compiled, as well as a list of materials that contain no PFAS. This study represents a comprehensive approach to over 35 PFAS actually present at an environmentally relevant site, sampling and storage, and materials that may impact analysis and cause false positives. In the second study, a subset of seventeen papers and textiles were analyzed using four techniques: liquid chromatography tandem mass spectrometry (LC-MS/MS) for 73 individual PFAS, gas chromatography mass spectrometry (GC-MS) for 7 individual PFAS, total oxidizable precursor (TOP) assay, and total fluorine by particle-induced gamma-ray emission (PIGE) spectroscopy. Total PFAS measured by LC-MS/MS, GC-MS, which represent monomeric PFAS with the potential for human exposure, only represent <2.6% of the total polymeric PFAS material bound to the surface of papers and textiles.
Environmental PFAS contaminations is leading to a direct need for remediation. In the third study, PFAS breakthrough curves resulting from a pilot-scale granular activated carbon (GAC) system were modeled to determine the efficacy for removal of individual PFAS present at a military site over 11 months. The relationship between the order of individual PFAS elution by analytical analysis by LC-MS/MS or LC-QTOF was determined to be the same as the order of breakthrough from GAC. Understanding of PFAS mass balance leads to more effective remediation with an understanding of PFAS effluent breakthrough.