Reversed-phase liquid chromatography on a microchip with sample injector and monolithic silica column

In micro total analysis systems, liquid chromatography (LC) works under pressure-driven flow is the essential analysis component. There were not, however, much works on microchip LC. Here we developed a microchip for reversed-phase LC using porous monolithic silica. The chip consisted of a double T-shaped injector and a ∼ 40-cm serpentine separation channel. The octadecyl-modified monolithic silica was prepared in the specified part of the channel on the microchip using sol–gel process. Furthermore, the effect of geometry of turn sections on band dispersion at turns was examined under pressure-driven flow. High separation efficiencies of 15,000–18,000 plates/m for catechins were obtained using the LC chip.