Development of Qualitative and Quantitative Analytical Methods for the Analysis of Per-and Polyfluoroalkyl Substances (PFAS) in Environmental Samples by UHPLC-MS/MS

Abstract

Per- and polyfluoroalkyl substances (PFAS) are synthetic compounds widely used in industrial and consumer products. Over the years, these substances have been distributed in environmental media, human populations, and wildlife species. Detecting trace amounts of PFAS in environmental systems can be challenging due to their complex transport and transformation pathways, and limitations in detection techniques. The primary goal of this research is to develop analytical methods for detecting and measuring PFAS in environmental samples. To achieve this, ultra-high performance liquid chromatography paired with triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS) was used to design three analytical methods that can identify 35 types of PFAS. The first method focused on identifying 17 PFAS, including perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkyl sulfonic acids (PFSAs), and perfluoroalkyl ether acids (PFECAs). The second method was developed to identify five perfluoroalkyl sulfonamides (FASAs) in environmental samples. The third method targeted 6 isomers of perfluorooctanoic acid (PFOA) and 7 isomers of perfluorooctyl sulfonate (PFOS). Each method involved sample preparation and UHPLC-MS/MS conditions optimization, validation, and application to environmental water samples. Also, the developed methods were applied further to analyze PFAS in several collaborative research projects at Auburn University. Sample preparation methods were optimized to detect trace-level PFAS in various samples such as water, sediment, fish, oysters, mussels, and algae. Each chapter comprehensively summarizes the study's methodology, application, and results.