Preparation of a polyhedral oligomeric silsesquioxane-based perfluorinated monolithic column

A monolithic column with high affinity to fluorous compounds was prepared using a polyhedral oligomeric silsesquioxane (POSS) reagent as the cross-linker and pentadecafluorooctyl methacrylate (PDFOMA) as the functionality monomer. The pore properties and permeability could be tuned by the composition of the polymerization mixture. The characterization and evaluation results revealed that the obtained POSS-PDFOMA hybrid monolith owned the merits of POSS and PDFOMA with good mechanical stability, no residual silanol and high affinity to fluorous compounds. A series of perfluoroalkyl methacrylates were baseline resolved on the optimized monolithic column under isocratic elution of 70% acetonitrile aqueous solution. Such a resolution could not be achieved on a silica-based C18 monolithic column. A column efficiency of 30000N/m was observed. In addition, several perfluoroalkyl sulfonates were also baseline separated on the fluorous monolith applying 0.1% (v/v) acetic acid aqueous solution containing 75% acetonitrile as mobile phase without the addition of ammonium.