Abstract
Per- and polyfluoroalkyl substances (PFASs) are often present in complex mixtures at trace levels in environmental samples, posing difficulties for analytical chemists. Ion mobility offers highly replicable identifiers, enabling the use of community-based libraries for PFAS annotation in nontargeted analysis. Currently, limited software exists to leverage the capabilities of liquid chromatography ion mobility high-resolution mass spectrometry (LC-IM-HRMS) for nontargeted analysis. FluoroMatch IM is a free vendor-neutral open-source tool for rapid annotation of PFASs in LC-IM-HRMS datasets. Annotation algorithms include collision cross-section (CCS) matching, formula prediction, homologous series detection, mass defect filtering, and accurate mass matching with a database of 194 PFAS ions that can be continuously expanded by the community. Results from FluoroMatch IM were compared to a targeted approach with a laboratory-prepared mixture of 63 PFASs and real wastewater samples. A nontarget workflow incorporating FluoroMatch IM revealed additional likely PFASs (n = 16) while confirming most targeted annotations (11/12) in wastewater samples. Validation of the standard mix showed a low false negative rate of 5% and a 5% false positive rate for features included in the CCS library, with a 0% false positive rate for features assigned confident scores. This study demonstrates the promise of FluoroMatch IM for streamlining PFAS analysis workflows.