Micro-solvent Cluster Extraction Using Aqueous Mixed Solvents of Ionic Liquid

Abstract

Organic compounds (2-naphthol, phenol, 4-chlorophenol, 4-nitrophenol, and 1,3,5-naphthalenetrisulfonic acid) were sufficiently separated from mixtures during flow in a fused silica capillary tube (50 mm in i.d. and 45 cm in length) with an aqueous mixed solvent of an ionic liquid, 1-butyl-3-methylimidazolium chloride (BMIM + Cl -), without a specific separation column. The method is based on micro-solvent cluster formation in aqueous mixed solvents of ionic liquid and preferential solvation of solvent clusters to analytes. The measurement of large angle X-ray scattering (LAXS) of aqueous mixed solvents with an ionic liquid of tetrafluoroborate (BMIM . The separation mechanism is discussed from the viewpoint of the partition of analytes between micro-solvent clusters of water and organic solvent molecules.

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

“…Recently, capillary chromatography using open fused-silica capillary tubes that were not specially coated or modified were reported. [24][25][26][27][28] In one example, Tabata et al developed an open tubular capillary chromatography method based on the microphase separation of mixed solvents, even though they used narrow-bored tubes of 10 μm i.d. ; 27 when an acetonitrile-water mixture with a suitable salt concentration was pumped into a fused-silica capillary tube in which the inner wall was negatively charged due to the dissociation of its silanol groups, microphase separation occurred near the capillary wall, resulting in a water-enriched aqueous phase attached to the capillary inner wall.…”

“…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.…”

Capillary Chromatography Based on Tube Radial Distribution of Aqueous-Organic Mixture Carrier Solvents: Introduction of Double Tubes Having Different Inner Diameters to the System

“…Capillary chromatography using open fused-silica capillary tubes has also been investigated and the results indicated interesting and unique characteristics. [5][6][7][8] Most capillary chromatography systems feature rapid measurements, easy procedures, inexpensive and small apparatus, small sample volumes, and low costs.…”

Influences of Analyte Injection Volumes and Concentrations on Capillary Chromatography Based on Tube Radial Distribution of Carrier Solvents under Laminar Flow Conditions

“…Well-known methods include capillary electrophoresis, capillary electrochromatography, micellar electrokinetic capillary chromatography, and highperformance liquid capillary chromatography using packed and monolithic columns. However, only a few new concepts concerning capillary chromatography have been reported in the last decade [4,5]. Related research has been discussed in detail in our previous papers [6,7].…”