FluoroMatch IM: An Interactive Software for PFAS Analysis by Ion Mobility Spectrometry

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.