Capillary chromatography based on tube radial distribution of aqueous-organic mixture carrier solvents: introduction of double tubes having different inner diameters to the system.

A tube radial distribution chromatography (TRDC) system was previously developed using an open capillary tube and an aqueous-organic solvent (water-acetonitrile-ethyl acetate) mixture as a carrier solution. In this study, we introduced double capillary tubes having different inner diameters to the system. The tubes were fused-silica capillary tubes with 100 and 250 microm i.