Validating Direct Mass Spectrometry Screening for Grease-Proofers Containing 6:2 Fluorotelomer Alcohol in Fiber-Based Food Packaging

Recently, polymeric PFAS-containing grease-proofers were removed from the U.S. food contact market. Validated methods are needed to monitor the removal of polymeric grease-proofers containing 6:2-fluorotelomer alcohol (6:2-FTOH) from fiber-based food packaging. Small-molecule extraction methods are neither specific nor rapid enough to screen for the intentional use of polymers. Direct analysis in real time mass spectrometry (DART-MS) approaches have shown promise for screening polymeric grease-proofers containing 6:2-FTOH but require method validation for regulatory implementation. A hydrolysis isotope dilution DART-MS (ID-DART-MS) method was refined to meet the FDA compound identification and validation guidelines. Method validation experiments demonstrated that hydrolyzable 6:2-FTOH from grease-proofers was identified across all fiber-based food packaging types with less than 5% false positive or negative rates (95% confidence) and a linear response across 4 μg/kg-130 mg/kg hydrolyzed 6:2-FTOH. The method reliably identified six different fluorotelomer-containing grease-proofers with 14 min/sample of effort, making it fit to assess incidence and removal of these PFAS-based grease-proofers.