Extractable Perfluoroalkyl Carboxylic Acids and Sulfonates in Food Contact Materials: Development of a Simple Analytical Method with Ultrasonic Extraction, Dispersive Sorbent Clean-Up, and LC-MS/MS Quantification

Poly- and perfluoroalkyl substances (PFASs) have attracted great scientific attention because of their environmental persistence, bioaccumulation potentials, and toxicity. This study validated a simple and efficient sample preparation method for determining extractable PFASs, including 12 perfluoroalkyl carboxylic acids and 4 perfluoroalkyl sulfonates. The samples underwent ultrasonic extraction, and the extracts were cleaned up by dispersive solid-phase extraction technique with graphitized carbon if necessary. PFAS quantification was performed by a liquid chromatography-tandem mass spectrometry system. The instrument provided analytical signals for all target compounds with good repeatability (RSD < 15%), reproducibility (RSD < 20%), linearity (R-2 > 0.99), and low detection limits (0.10-1.0 ng/mL). The validated method exhibited adequate recovery (70-115%), precision (RSD < 15%), and method detection limits (0.020-0.70 ng/g). This validated method was applied to analyze PFASs in several food packaging samples collected in Vietnam, showing very low levels (range 0.090-2.9 ng/g; median 0.72 ng/g) derived from unintentional sources.