Non-Targeted PFAs Analysis
Per- and Polyfluoroalkyl Substances (PFAS) are a group of chemicals of concern from a human and environmental health standpoint; also called forever chemicals these chemicals have long half lives both in the body and environment and have been linked to various cancers, obesity, metabolic disorders, and other health issues. Studies assessing the health burden of PFAS have focused on a limited number of legacy and alternative chemicals using targeted measurement methods, which only account for a small fraction of these fluorinated compounds. The range of PFAS structures is enormous, due to the constant introduction of new compounds and PFAS chemical and biological transformation in the environment; a non-exhaustive list of over 8,000 unique chemical structures can be found in the EPA PFAS master list.
FluoroMatch Suite is an open-source platform consisting of a number of software covering all steps of the non-targeted mass spectrometry workflow for PFAS. The software covers peak picking, alignment, blank filtering, annotation, scoring, grouping features into series, and visualizing the data for manual review. It currently is the only software designed specifically for this purpose, and most comprehensive software for PFAS annotation. FluoroMatch Suite is comprised four modules: FluoroMatch Flow, FluoroMatch Modular, FluoroMatch Generator, and FluoroMatch Visualizer. Additional information can be found here.
FluoroMatch Visualizer was the more recent addition to FluoroMatch Suite. we present FluoroMatch Visualizer. This module was developed to address the bottlenecks in manual review of data to evaluate confidence in assignment of structure. FluoroMatch Visualizer was developed in Microsoft PowerBI to provide interactive visualizations which include normalized mass defect plots, retention time versus accurate mass plots, MS/MS fragmentation spectra, and tables of annotations and meta-data. All graphs and tables are interactive and have cross-filtering such that when a user selects a feature (e.g., retention time and mass-to-charge pair), all other visuals highlight the feature of interest. Several filtering options have been integrated into this novel data visualization tool, specifically with the capability to filter by PFAS chemical series, fragment(s), assignment confidence, and MS/MS file(s). Using this open source and freely accessible tool and FluoroMatch outputs, annotations can be extensively validated, increasing annotation confidence.
FluoroMatch Visualizer is shown below with an example dataset of PFAS detected in Aqueous Film Forming Foam (AFFF). Additional information about this tool and dataset is available in a manuscript pre-print available here.