Abstract
Open-tubular capillary chromatography was developed based on tube radial distribution of the water–acetonitrile mixture solvents containing sodium chloride under laminar flow conditions. The specific homogeneous carrier solvents were radially distributed in the capillary tubes, generating inner and outer phases. This distribution behavior was observed with fluorescence microscope-CCD camera system and considered with the phase diagram constructed with the solvents composition and sodium chloride concentration. Hydrophilic 1-naphthol and hydrophobic 2,6-naphthalenedisulfonic acid as model analytes were separated in this order with the fused-silica capillary tube (100 µm inner diameter), while, in the reverse order with the PTFE capillary tube (100 µm inner diameter). The outer phase created in the capillary tube functioned as a pseudo-stationary phase in chromatography. The mixture solution including five analytes was examined with the present capillary chromatography. The opposite elution order was observed between the fused-silica and PTFE tubes.
Notes
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