Simultaneous enrichment of bisphenols and polyfluoroalkyl substances by cyclodextrin-fluorinated covalent organic frameworks membrane in food packaging samples

Efficient separation and preconcentration of trace harmful substances in food samples is a prerequisite for reliable analysis. Most of harmful substances with different properties coexist in the food samples, which is difficult to achieve simultaneously extraction through traditional adsorbents. In this work, a new adsorbent based on cyclodextrin- fluorinated covalent organic frameworks (CD-F-COF) was prepared. The mechanism of the CD-F-COF recognizing polyfluoroalkyl substances (PFASs) and bisphenols (BPs) were validated by molecular simulation. The CD-F-COF showed strong fluorophilic and host-guest interactions for polyfluoroalkyl substances (PFASs) and bisphenols (BPs), respectively. The CD-F-COF coated membranes were immobilized on the syringe filter and coupled with multi-channel syringe pump to achieve high-throughput sample pretreatment. After that, a sensitive analytical method for the simultaneous enrichment and determination of trace BPs and PFASs was established followed by HPLC-MS/MS. The results indicated that the limits of detection for the seven BPs and three PFASs were in the range of 0.006-0.050 ng/g and 0.001-0.008 ng/g. This method has great potential for application in sample preparation as it can fulfill fast and high-throughput for enrichment of trace multiple targets.