Specific capture of phosphopeptides by Zr4+-modified monolithic capillary column

A method to prepare zirconium phosphate (ZrP)-modified monolithic capillary column for highly specific capture of phosphopeptides is presented. In this method, the phosphate monolithic capillary column was prepared by direct copolymerization of the functional monomer containing phosphate group (ethylene glycol methacrylate phosphate) and cross-linker (bis-acrylamide) in a ternary porogenic solvent. Copolymerization of cross-linker and functional monomer simplifies the procedure for the preparation of phosphate chromatographic media. After Zr4+ was immobilized, the ZrP-modified monolithic capillary column was evaluated by the analysis of standard phosphoproteins and the excellent selectivity of this approach was demonstrated by analyzing phosphopeptides in the digest mixture of beta-casein and BSA with molar ratio of 1:200.