Synthesis of Davankov-type hypercrosslinked resins using different isomer compositions of vinylbenzyl chloride monomer, and application in the solid-phase extraction of polar compounds

Two different gel-type resins have been prepared by suspension polymerization using 2 wt % divinylbenzene (DVB) with either p-vinylbenzyl chloride (pVBC) or a mixture of VBC isomers (similar to 70% m-; similar to 30% p-). Significant difference in the chlorine content was observed, which was attributed to a more favored hydrolysis process when p-VBC was used. The presence of hydroxyl groups has been confirmed by elemental microanalytical data and solid-state C-13 cross-polarization/magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR) spectra. Hypercrosslinked resins were prepared from both gel-type precursors by treatment with FeCl3, in 1,2-dichloroethane (DCE) at 80 degrees C. The resultant resins showed differences in specific surface area and degree of hydrophilicity. The performance of the hypercrosslinked resins was evaluated in solid-phase extraction (SPE) of polar compounds, and better results were obtained for the hypercrosslinked resin prepared from p-VBC that combines a relatively high specific surface area (908 m(2) g(-1)) and somewhat higher oxygen content (3.96 wt % O).