PFAS in extracts were analyzed using ultra-high-performance liquid chromatography (UPLC, Thermo Vanquish) coupled to a triple quadrupole mass spectrometer (MS/MS, Thermo Altis) in the Center for Air and Aquatic Reseach Engineering and Science at Clarkson University, a DoD accredited lab for PFAS analysis. A 10 μL sample was injected and then separated on a Thermo analysis were performed with TraceFinder 5.1 (Thermo Scientific). The setup of LC-MS/MS can be found in Text S4. Method detection limits of 30 PFAS were at ng/L levels, as tabulated in Table . Nontargeted analysis of PFAS precursors was conducted through a high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC/QToF-MS, SCIEX) in both ESI positive and negative modes. Details of the nontargeted analysis can be found in Text S5.