Filling the Gaps in PFAS Detection: Integrating GC-MS Non-Targeted Analysis for Comprehensive Environmental Monitoring and Exposure Assessment

Per- and polyfluoroalkyl substances (PFAS) have garnered increasing attention in recent years and non-targeted analysis (NTA) has become essential for elucidating novel PFAS structures. NTA and PFAS research have been dominated by liquid chromatography - mass spectrometry (LC-MS) with gas chromatography - mass spectrometry (GC-MS) used less often as evidenced by bibliometrics. However, the performance of GC-MS in NTA studies (GC-NTA) rivals that of LC-ESI-MS and GC-MS is shown to cover a complimentary chemical space. An LC-ESI-MS amenability model applied to a list of approximately 12,000 PFAS revealed that less than 10% of known PFAS chemistry is predicted to be amenable to typical LC-MS analysis. Therefore, there is strong potential for applying GC-MS methods to more fully assess the PFAS environmental contamination landscape, uniquely shedding light on both known and novel PFAS, especially within the chemical space realm of volatile and semi-volatile PFAS. Waste streams from fluorochemical manufacturing facilities have been heavily studied using LC-MS and targeted GC-MS; however, GC-NTA is needed to discover novel PFAS that are not amenable to LC-MS emitted from facilities. Studies on the incineration of PFAS-containing materials, such as aqueous film forming foam, have focused on the destruction of parent compounds and little is known about the transformation products formed during such processes. GC-NTA holds the potential to elucidate transformation products formed when PFAS are incinerated. Wastewater treatment plants and landfills are known sources of PFAS to the environment, yet GC-NTA is needed to understand air emissions of PFAS and PFAS transformation products from these sources. Consumer products are known to lead to indoor exposures to PFAS via emissions to air and dust but research in this area has either used LC-MS or targeted GC-MS. Despite the challenges with advancing GC-NTA, we call on NTA researchers, grantors, managers, and other stakeholders to recognize the potential and necessity of GC-NTA in PFAS research so that we may face these challenges together.