The rôle of the stationary phase in micellar liquid chromatography : Adsorption and efficiency

✍ Scribed by Alain Berthod; Agnes Roussel

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 849 KB
• Volume: 449
• Category: Article
• ISSN: 1873-3778
• DOI: 10.1016/s0021-9673(00)94400-5

✦ Synopsis

In micellar liquid chromatography a surfactant solution containing micelles is used as a mobile phase. Ionic surfactants strongly adsorb on chromatographic stationary phases. This adsorption can be modified by adding various organic solvents in the micellar mobile phase: the organic modifier, e.g., rz-pentanol can also adsorb on the stationary phase and replace a part of the adsorbed surfactant.

Efficiency in micellar liquid chromatography seems to be linked with the rigidity of the organic layer (bonded moiety + adsorbed molecules) coating the silica surface. Organic modifiers can decrease this rigidity and increase the solute diffusion coefficients in the stationary phase layer. This increase of mass-transfer rate improved the efficiency, n-Propanol and tetrahydrofuran were the most effective organic solvents to improve micellar chromatographic efficicncics. Micellar efficiency was shown to be solute-dependent. Quaternary ammonium salts exhibited low efficiency, even with lz-propanol in the micellar phase, when other solutes (caffeine, toluene) were separated in the same experiment with good efficiency.