FluoroMatch: A Comprehensive Software for Non-Targeted PFAS Analysis

BACKGROUND AND AIM: Per- and polyfluoroalkyl substances (PFAS) are distributed globally in products such as food wrappers, firefighting foam, carpets, and much more. PFAS last in the body for a long time, and some are highly toxic. There are potentially still thousands of undiscovered PFAS. Although the structures can vary dramatically, the vast majority of PFAS have some kind of carbon-fluorine chain (e.g., CF2) which allows for an automated non-targeted approach. In fact, FluoroMatch is the first software to process non-targeted mass spectrometry data for PFAS. METHODS: FluoroMatch provides six types of evidence that help build annotation confidence, scoring each identification from A+ to E. Identifications based on class-based MS/MS fragmentation rules from standards score in the A-range (confident), while any other annotations with MS/MS evidence score in the B-range (tentative). FluoroMatch also pulls out hits that fall within a homologous series based on Kendrick mass defect. Thus, any identification that falls in a series of CF2 units (or other common PFAS series) with a confident or tentative annotation scores in the C-range, and any otherwise unidentified annotations that lie in series score in the D-range. These B, C and D-range annotations are by no means confident, but they illuminate the sheer volume of possible PFAS and provide starting points for the discovery of new compounds. RESULTS:In leachate data, there were ~25 confident and ~50 tentative identifications, but there were ~170 hits in series with those identifications and a staggering 5000+ other hits in series. CONCLUSIONS:It is essential to determine what compounds are out there in order to identify and regulate the most concerning ones and to better educate on PFAS health effects. FluoroMatch is a software which automates non-targeted PFAS data-processing and assists researchers in working towards this goal. KEYWORDS: PFAS, Non-targeted, Mass spectrometry