Ambient mass spectrometric analysis of perfluorosulfonic acids with a covalently immobilized irreversible trifluoromethyl-functionalized COF solid-phase microextraction probe

As an emerging potential pollutant, perfluorosulfonic acids (PFSAs) pose a challenge in developing efficient analytical methods to meet diverse practical requirements. Herein, an irreversible trifluoromethyl-functionalized covalent organic framework (TFPPA-CF 3 ) is prepared via condensation of 1,3,5-trimethylphloroglucinol and 2,5-diaminobenzo-trifluoride, and then covalently immobilized on stainless steel fiber for solid-phase microextraction (SPME) of PFSAs. The irreversibility of TFPPA-CF 3 and its covalent bonding way ensure outstanding probe stability, while multiple interactions (F–F interaction, hydrophobic interaction, and electrostatic interaction) confer high affinity for PFSAs extraction. Finally, an ambient mass spectrometric analytical method using TFPPA-CF 3 -based SPME is developed for direct and chromatography-free detection of trace PFSAs, achieving detection limits of 0.71–1.11 ng L −1 and linear ranges of 10–10000 ng L −1 . The TFPPA-CF 3 probe exhibits good stability, preserving over 90 % of extraction efficiency after 100 recycles. The spiked recoveries of the developed method range from 91.6 % to 111.8 % in real-world samples, confirming its practical applicability.