Preparation of phenyl-silica hybrid monolithic column with "one-pot" process for capillary liquid chromatography

A phenyl-silica hybrid monolithic column for capillary liquid chromatography (cLC) was prepared through "one-pot" process by con-currently using benzyl methacrylate and alkoxysilanes. The effects of the molar ratio of tetramethoxysilane/vinyltrimethoxysilane (TMOS/VTMS), polycondensation temperature, content of supramolecule template (cetyltrimethylammonium bromide, CTAB), ratio of N,N'-dimethylformamide/methanol (v/v), the volume of benzyl methacrylate on the morphologies of the prepared phenyl-silica hybrid monolithic columns were investigated in detail. The permeability of the hybrid monolithic column was calculated as 3.23 × 10⁻¹³ m², and the minimum plate height was determined as 8.38 μm which corresponding to 119,000 theoretical plates per meter. Separation of various neutral, polar and basic analytes as well as small peptides on the hybrid monolithic column was achieved by cLC and showed high efficiency and satisfactory reproducibility. Moreover, the prepared hybrid monolithic column was also applied for the analysis of tryptic digests of bovine serum albumin (BSA), ovalbumin, α-casein, cytochrome C and myoglobin by cLC tandem mass spectrometry (cLC-MS/MS), and the results showed that the separation performance was close to that of the octadecylsilane (C18) packed capillary column which demonstrating its potential in proteome analysis. Moreover, since the prepolymerization system was mainly consisted of organic solvents (methanol and N,N'-dimethylformamide), various hydrophobic monomers could be potentially used to prepare organic-silica hybrid monolithic columns through "one-pot" approach.