Influence of Adding Surfactants to an Analyte Solution on Separation Performance in Open-tubular Capillary Chromatography Based on the Tube Radial Distribution of Ternary Mixed Carrier Solvents

Abstract

An open-tubular capillary chromatography system has been developed using a ternary mixed solvent mixture, i.e., water–hydrophilic/hydrophobic organic solvent mixture as a carrier solution. In this study, the influence of adding surfactants to an analyte solution on separation performance was examined in a chromatographic system using a fused-silica capillary tube (75 µm inner diameter and 100 cm effective length) and a ternary mixture of water–acetonitrile–ethyl acetate (3:8:4 volume ratio) carrier solution. Sodium dodecyl sulfate (anionic), ethylhexadecyldimethylammonium bromide (cationic), and Triton X-100 (nonionic) were used as surfactants. Model analytes, 1-naphthol and 2,6-naphthalenedisulfonic acid, were separated in this order by adding the anionic and nonionic surfactants. These surfactants in the analyte solution greatly improved the separation performance (theoretical plate numbers for 2,6-naphthalenedisulfonic acid; >10000) compared with the same separation performed in the absence of surfactants. On the other hand, the analytes were not separated at all using a cationic surfactant.

Fundamental Research and Application of the Specific Fluidic Behavior of Mixed Solvents in a Microspace

“…To improve the resolution of the peaks, and hence to improve the separation efficiency, the addition of surfactants to the analyte solution was examined. 55 The separation performance of the TRDC system was compared with that of conventional capillary separation systems, such as capillary zone electrophoresis (CZE). 56 The elution behavior of five model analytes was examined.…”