The micro-flow reaction system featured the liquid-liquid interface created with ternary mixed carrier solvents in a capillary tube.

A micro-flow reaction system was developed in which liquid-liquid interface was created based on the tube radial distribution of ternary mixed carrier solvents. The system was constructed from double capillary tubes having different inner diameters (100 and 250 µm i.d.). The smaller tube was inserted into the larger one through a T-type joint. The reaction of a protein with a fluorescence derivatizing reagent was adopted as a model. A water-acetonitrile mixture (3:1 volume ratio) including bovine serum albumin (hydrophilic) was delivered into the large tube from the inside through the small tube and an acetonitrile-ethyl acetate mixture (7:4 volume ratio) containing fluorescamine (hydrophobic) as a derivatizing reagent was delivered from the outside through the joint. Solutions were mixed through the double capillary tubes to promote ternary mixed carrier solvents (water-acetonitrile-ethyl acetate; 1:2:1 volume ratio). The liquid-liquid interface was created based on the tube radial distribution of ternary solvents in the larger tube. The derivatization reaction was performed in the larger, or reaction, tube in the micro-flow system. The fluorescence intensity of the fluorescamine-derivatized bovine serum albumin obtained by the system, which specifically included the kinetic liquid-liquid interface in the tube, was greater than that obtained through a batch reaction using a homogeneous solution of water-acetonitrile (1:2 volume ratio).

Consideration of the tube radial distribution of the carrier solvents in a capillary tube under laminar flow conditions and computer simulation.

When the ternary mixed solvents of a water-hydrophilic/hydrophobic organic solvent mixture are delivered under microspace under laminar flow conditions, the solvent molecules are radially distributed in the microspace, and generate a major inner phase and a minor outer phase. We call this fluidic phenomenon as the tube radial distribution phenomenon (TRDP). In this paper, phase formation in the TRDP was collectively considered based on experimental data, such as the inner and outer phase formation in a microchannel under laminar flow conditions, the phase diagram for the ternary mixed solvents, the solvent-component ratios required for the TRDP, and the phase transformation in a batch vessel above atmospheric pressure, which were mainly reported in our previous papers. Furthermore, the formation of inner and outer phases in a capillary tube was simulated with the two-component solvents mixture model of water and ethyl acetate. Phase formations in capillary tubes were expressed through computer simulations.

Biomolecule analyses in an open-tubular capillary chromatography using ternary mixed carrier solvents with chemiluminescence detection.

We examined the elution behavior of isoluminol isothiocyanate (ILITC)-labeled biomolecules (α-amino acids, peptides, and proteins) in an open-tubular capillary chromatography system using an untreated fused-silica capillary tube and a water-acetonitrile-ethyl acetate mixture carrier solution. Such an open-tubular capillary chromatography is called "tube radial distribution chromatography (TRDC)" for convenience. A mixture of ILITC and ILITC-labeled biomolecules was analyzed using TRDC with chemiluminescence detection that provided simple instrument without a light source and complex optical devises. The ILITC and the labeled twenty α-amino acids were separated, in this order or the reverse order, or not separated with an organic solvent-rich and water-rich carrier solution. Their elution behavior was considered to be of hydrophilic or hydrophobic nature of ILITC and the labeled α-amino acids. The ILITC and the labeled protein, alcohol dehydrogenase and bovine serum albumin, were separated in this order with an organic solvent-rich carrier solution, while they were eluted in the reverse order with a water-rich carrier solution, based on the TRDC separation performance. The TRDC system worked with the untreated open-tubular capillary tube not using any specific capillary tubes, such as coated, packed, or monolithic.