Recent advances in preparation and application of hybrid organic‐silica monolithic capillary columns

Abstract

Hybrid organic-silica monolithic columns, regarded as a second generation of silica-based monoliths, have received much interest due to their unique properties over the pure silicabased monoliths. This review mainly focuses on development in the fields of preparation of hybrid monolithic columns in a capillary and their application for CEC and capillary liquid chromatography separation, as well as for sample pretreatment of solid-phase microextraction and immobilized enzyme reactor since July 2010. The preparation approaches are comprehensively summarized with three routes: (i) general sol-gel process using trialkoxysilanes and tetraalkoxysilanes as coprecursors; (ii) "one-pot" process of alkoxysilanes and organic monomers concomitantly proceeding sol-gel chemistry and free radical polymerization; and (iii) other polymerization approaches of organic monomers containing silanes. The modification of hybrid monoliths containing reactive groups to acquire the desired surface functionality is also described.

Improving the On-Line Extraction of Polar Compounds by IT-SPME with Silica Nanoparticles Modified Phases

“…When using the synthesized TEOS-MTEOS coating, slightly higher efficiencies were observed with respect the PDMS-based coatings for all analytes, suggesting that hydrophobic interactions are also predominant [22]. This is consistent with the fact that the highest ERs values were obtained for the analytes with highly hydrophobic t-butyl moiety, metribuzin and irgarol.…”

Preparation of high efficiency and low carry-over immobilized enzymatic reactor with methacrylic acid–silica hybrid monolith as matrix for on-line protein digestion

“…By a typical one-pot strategy, the hybrid silica monolith is prepared through the sol-gel process with TMOS and VTMS as the precursors at low temperature, and subsequently organic monomers were incorporated into hybrid silica matrix through free-radical polymerization at a relatively high temperature [32][33][34]. However, such a two-step thermal reaction might result in poor reproducibility of batch-to-batch preparation [35].…”

Preparation of well-controlled three-dimensional skeletal hybrid monoliths via thiol–epoxy click polymerization for highly efficient separation of small molecules in capillary liquid chromatography

“…As an attractive alternative to organic and silica monoliths, organic-silica hybrid monolith, which combines the merits of organic and silica monoliths and overcomes their inherent drawbacks to some extent [1,2], was considered as a novel stationary phase and widely applied in the field of analytical chemistry from sample pretreatment to micro/nanoscale chromatographic separation [3][4][5]. Currently, the hybrid monoliths were mainly prepared via tedious sol-gel chemistry, and often resulted in unsatisfactory reproducibility.…”