Cage-like silica nanoparticles-functionalized silica hybrid monolith for high performance capillary electrochromatography via “one-pot” process

A cage-like silica nanoparticles-functionalized silica hybrid monolith for high performance capillary electrochromatography (CEC) has been prepared via “one-pot” process. In this process, the polycondensation of hydrolyzed alkoxysilanes and in situ reaction of mercaptopropyltrimethoxysilane (MPTS) with sodium 3-mercapto-1-propanesulfonate modified octavinyloctasilasesquioxane (MPS-OVS) simultaneously occurred in a pretreated capillary. The characterization and evaluation results indicated that the obtained MPS-OVS hybrid monolithic capillary column has homogeneous macroporous morphology with a permeability of 5.37 × 10−13 m2 and strong electro osmotic flow (EOF) over a wide pH range from 2.7 to 11.2. The EOF on the MPS-OVS hybrid monolithic column reached its maximum of 0.327 cm2 kV−1 s−1 at pH 9.7. The best theoretical efficiency of ∼470,000 plates/m was obtained for 2-aminophenol in CEC. Anilines and phenols were well separated on the MPS-OVS hybrid monolithic column by CEC, indicating typical reversed-phase and cation-exchange chromatographic retention mechanisms of the column. The monolith was further applied to the separation of bovine serum albumin (BSA) tryptic digests, and the result indicated its potential in the analysis of some complex samples.