Methodology for studying biotransformation of polyfluoroalkyl precursors in the environment

•Extraction strategies are vital for recovering both neutral and ionic analytes.•Concentration and derivatization assist analysis of transient intermediates.•Coupled instrumentation decreases challenges from complex environmental matrices.•Mass spectrometry elucidation and QSAR prediction identify novel metabolites.•Challenges on studying alternative polyfluoroalkyl substances.

Biotransformation of polyfluoroalkyl precursors contributes in part to the perfluoroalkyl carboxylates and sulfonates detected in the global environment and biota. Robust sample preparation and sensitive analytical techniques for maximum analyte recovery are essential to identify and to quantify biotransformation products often present at low levels in environmental matrices and experimental systems. This critical review covers current sample-preparation and analytical methods, including extraction, concentration, clean-up and derivatization, mass spectrometry coupled to gas or liquid chromatography, and radioisotope labeling and tracking techniques. We also critically review methodologies for molecular structural elucidation and in-silico prediction of potential transformation products. We describe current knowledge gaps and challenges in studying novel alternative polyfluoroalkyl substances. We discuss future trends on utilizing advanced analytical techniques.