Acylation-based post-modification synthesis of an efficient fluorophilic magnetic microporous organic network for improved extraction of fluorine-containing drugs.

A novel pentafluorophenyl-functionalized fluorophilic magnetic microporous organic network (MMON-PFB) was synthesized via an acylation-based post-modification strategy for highly improved magnetic solid-phase extraction (MSPE) of trace fluorine-containing drugs (FCDs) in animal-derived foods and water samples. After modifying MMON-OH with PFB, MMON-PFB simultaneously possesses F-F, hydrogen bonding, π-π staking, and hydrophobic interaction sites, and the MSPE recovery largely increased from 45.2% to 99.4%, enabling efficient and selective enrichment of FCDs. A sensitive MMON-PFB-MSPE-HPLC-UV method for FCDs detection was established under optimized conditions, featuring wide linear ranges (0.2-1000 μg L-1), low detection limits (0.07-0.2 μg L-1), and good precisions. Mechanism studies show that post-modification of PFB provides additional F-F and π-π interaction sites for FCDs. This work not only provides a reliable and sensitive method for the determination of trace FCDs in complex matrices but also offers a new approach for the design and preparation of fluorophilic adsorbent in sample pretreatment.