Analysis of emerging per- and polyfluoroalkyl substances: Progress and current issues

The increasingly stringent restrictions on legacy per- and polyfluoroalkyl substances (PFASs) have led to the compensatory use of new fluorinated replacements. These new compounds, hereafter referred to as emerging PFASs, continue to be discovered and are now showing ubiquity in abiotic and biotic environments. Thus, there is an urgent need for robust, yet sensitive analytical methods to determine their occurrence and understand their behavior, fate, impact, and toxicity. Here, we review the up-to-date sample preparation and analytical methodologies for emerging PFASs based on peer-reviewed literature published in the past three years (2015-2018). The determination of emerging PFASs is similar to that of legacy PFASs, with satisfactory performances for most emerging PFASs achieved using conventional extraction and analytical approaches. However, the determination of certain specific analytes remains challenging due to the unavailability of standards and reference materials, low recoveries and matrix effects, background contamination, and poor sensitivities due to in-source fragmentation. Despite recent progress in identifying ionic semi-volatile PFASs with liquid chromatograph-high-resolution mass spectrometry (LC-HRMS), our knowledge on new types of neutral volatile PFASs remains poor due to limited non-target analysis using gas chromatograph (GC)-HRMS. (C) 2019 Elsevier B.V. All rights reserved.