Capillary chromatography based on tube radial distribution of aqueous–organic mixture carrier solvents

Microfluidic Analytical System with On-Line Luminol Chemiluminescence Detection Based on Annular Flow of Phase Separation Multiphase Flow

“…We have recently developed a method of generating a multiphase flow using two-phase separation mixed solvent solutions [10] [11] [12] [13]. When mixed solvent solutions, such as a water-hydrophilic/hydrophobic organic solvent solution, are delivered into a microspace, such as a capillary tube and a microchannel on a microchip, phase transformation of the mixed solvent solution occurs in the microspace with changes in temperature and/or pressure, leading to a kinetic liquid-liquid interface.…”

Analytical Conditions and Separation Performance of Capillary Chromatography Based on the Tube Radial Distribution of Aqueous-Organic Mixture Carrier Solvents under Laminar-Flow Conditions

“…was carried out together with an ionic liquid and a gel. 28 We developed a capillary chromatography method using an open capillary tube and a water-hydrophilic-hydrophobic organic solvent mixture (homogeneous solution) as a carrier solution; [29][30][31][32][33] the system worked under laminar-flow conditions. We called this a tube radial distribution chromatography (TRDC) system.…”

“…We have demonstrated the separation of a mixture of hydrophilic and hydrophobic molecules by capillary chromatography using open capillary tubes made of fused-silica, polyethylene, or poly(tetrafluoroethylene) (PTFE) (50, 200, or 100 μm i.d., respectively), and a water-acetonitrile-ethyl acetate mixture carrier solution (homogeneous solution). 29,30 The elution times of the analytes in the system can be easily reversed by changing the component ratio of the carrier solvents (or by using an organic solvent-rich carrier solution and a water-rich carrier solution) in all types of the capillary tubes. The first peaks nearly appeared with the average linear velocities, and the second peaks were eluted with smaller velocities than the average linear velocities under laminar-flow conditions with both of the organic solvent-rich and the water-rich carrier solution.…”

Capillary Chromatography Based on the tube Radial Distribution of aqueous-organic mixture Carrier solvents: Effects of the inner-Wall Characteristics of the Fused-silica tube on separation Performance

“…1,2 In contrast to conventional capillary electrochromatography, 3,4 capillary electrophoresis 5,6 and capillary liquid chromatography, 7,8 separation in this system was performed without the use of any specific materials, such as packed capillary tubes, additives, such as gels, surfactants, host molecules or salts, or high-voltage supply devices.…”

“…We call this a tube radial distribution chromatography (TRDC) system. 2 The separation performance in the TRDC system was explained as follows: 2 1) Water and organic solvents in the carrier solution are not dispersed uniformly in the capillary tube, based on the tube radial distribution of the solvents under laminar flow conditions. A major solvent phase (water-rich or organic solvent-rich) forms around the middle of the tube far from the inner-wall, while a minor solvent phase (organic solvent-rich or water-rich) is generated near the inner-wall of the capillary tube (pseudo-stationary phase).…”