A new 3D COF with excellent fluorescence response for water and good adsorption performance for polychlorinated biphenyls

A new three-dimensional(3D) covalent organic framework (COF) was designed and synthesized. It showed excellent fluorescence property and good fluorescence response for water. The fluorescence property decreased with the addition of water, and it showed good linearity in the water concentration range of 0.1-1.5 wt% with R-2 of 0.9988. The detection limit of water in acetonitrile was 0.036 wt%. It also showed good adsorption performance for polychlorinated biphenyls (PCBs), and the extraction performance of PCBs from water samples was evaluated GC-MS/MS. The optimized conditions were pH 7; adsorbent amount, 20 mg; eluent, 1.0 mL hexane; desorption time, 5 min. The obtained recoveries were in the range of 90.9%-101.3%. The limits of detection and limits of quantitation for PCBs were in the range of 0.56-2.81 ng/L and 2.0-8.7 ng/L, respectively. This is the first report of COFs which showed both excellent fluorescence and adsorption performance.