EFFECT OF CYCLODEXTRINS ON THE STABILITY OF BILAYER: A NOVEL ELECTROPHORETIC APPROACH

Abstract

In capillary electrophoresis, a common approach to prevent adsorption of an analyte onto a capillary's inner surface is to use surfactants as coating materials. These coating materials form a bilayer structure that resembles the arrangement of phospholipids (natural surfactants) in cell membranes. In this study, a bilayer coating was produced on the surface of a capillary using either a double-chained cationic surfactant, dimethyldioctadecylammonium bromide (2C₁₈DAB), or a triple-chained cationic surfactant, tridodecylmethylammonium iodide (3C₁₂MAI). The resulting bilayer coatings were investigated in the presence of various neutral cyclodextrins using hydrodynamic rinsing and performing successive runs. All types of cyclodextrins that were investigated had the effect of partially destabilizing the bilayer. However, cyclodextrin, as well as type of surfactant has a remarkable effect on the extent of a bilayer's stability. The most stable bilayer was obtained on capillaries coated with 2C₁₈DAB using HP-βCD as the running buffer. Under such conditions, reversed EOF (electroosmotic flow) decreased only by 1.5% in over 100 min of electrophoretic separation.

Keywords:

• bilayer
• capillary electrophoresis
• cell membrane
• coating
• cyclodextrin
• surfactant

ACKNOWLEDGMENT

We wish to thank Minoo Company for kind gift of Rac-AML and Cipla Company for S-AML.

Notes

Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/ljlc.