Simplifying Nontargeted Analysis of PFAS in Complex Food Matrixes.

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Mass Spectrometry

Background:

• Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants with diverse structures.
• Limited availability of PFAS reference standards hinders accurate analysis.

Purpose of the Study:

• To develop a novel nontargeted analytical method for PFAS detection.
• To overcome limitations of current complex, multi-step analytical approaches.

Main Methods:

• Utilized high-resolution mass spectrometry (HRMS) to analyze fish liver extracts.
• Estimated carbon number based on ion abundance between monoisotopic and first isotopic peaks.
• Calculated mass over carbon (m/C) and mass defect over carbon (md/C) ratios.

Main Results:

• PFAS peaks were effectively discriminated from matrix interference using m/C vs. md/C plots.
• Enabled nontargeted detection of PFAS at low µg/kg levels in complex matrices.
• Identified a previously unknown PFAS and unexpected adducts.

Conclusions:

• The m/C vs. md/C concept offers high selectivity for PFAS identification.
• This approach facilitates MS/MS confirmation of detected PFAS features.
• The method is suitable for detecting low-abundance PFAS in complex samples, regardless of ionization mode.