of diluted AFFF at ambient conditions. In those studies, the total fluorine concentrations were mostly estimated either using the total oxidizable precursor array (TOPA) analysis or NMR as 0.16-27 mg/L, and the DeF ranged from 50-81% (Table ). Therefore, this study focused on the treatment of FT-derived AFFF, which is responsible for telomer-dominant PFAS contamination in water and soil. The targeted analysis of 30 PFAS in the AFFF identified 6:2 FTS (175.5 mg/L) as the dominant PFAS, along with 8:2 FTS, PFCAs, and perfluorosulfonic acid (PFSAs). The TOF was 9,080 mg/L (Table ). The fluorine on target PFAS (121.7 mg/L) only makes up 1.3% of the TOF, suggesting the existence of massive amounts of unidentified fluorocarbon components. The rich organic matrix contributed to an extremely high total organic carbon (TOC) of 234 g/L.