ABSTRACT
This chapter provides an overview of important topics pertaining to PFAS isomer research. It focuses on some areas: isomer characterization and profiling, isomer-specific analysis in environmental PFAS source tracking, isomer-specific biotransformation and bioaccumulation, variety of isomer profiles in humans, and isomer-specific toxicity and interaction with biomolecules. The most commonly used analytical instrumentation for the analysis of PFAS is high-performance liquid chromatography with tandem mass spectrometry. A major application of PFAS isomer-specific analysis is to quantitatively assess the contributions from electrochemical fluorination and telomerization manufacturing processes. J. P. Benskin performed isomer profiling of perfluorooctanoic acid in water samples from North America, Asia, and Europe. Bioaccumulation studies generally show enriched linear isomer in fish and wildlife, suggesting that branched isomers are either selectively degraded, metabolized, or less accumulated in animal tissues, while linear PFAS are selectively enriched via preferential bioconcentration, uptake, and accumulation in their respective food webs.
