Enhanced stability self-assembled coatings for protein separations by capillary zone electrophoresis through the use of long-chained surfactants.

Abstract

Semipermanent coatings were generated within fused-silica capillaries by flushing the capillary with a 0.1 mM solution of the double-chained cationic surfactants didodecyldimethylammonium bromide, dimethylditetradecylammonium bromide (2C(14)DAB), dihexadecyldimethylammonium bromide, and dimethyldioctadecylammonium bromide (2C(18)DAB) and the triple-chained surfactant tridodecylmethylammonium iodide. All of these coatings were semipermanent, whereby the coating remained intact after the unadsorbed surfactant was removed from the capillary. The separation efficiencies for four model cationic proteins ranged from 1.2 to 1.4 million plates/m for the 2C(14)DAB coating to 0.3-0.4 million plates/m for the 2C(18)DAB coatings. The stability of the coating increased with increasing hydrophobicity of the surfactant (i.e., increasing chain length and decreasing cmc). Over 60 successive separations were performed on a 2C(18)DAB-coated capillary over 12 days, without any regeneration of the coating. The migration times varied by less than 2.3% over this period with no loss in efficiency.

• Authors: Mahmoud M Yassine, Charles A Lucy
• Journal: Analytical chemistry (Anal Chem) Vol. 77 Issue 2 Pg. 620-5 (Jan 15 2005) ISSN: 0003-2700 [Print] United States
• PMID: 15649062 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Lipid Bilayers
• Proteins
• Quaternary Ammonium Compounds
• Surface-Active Agents
• didodecyldimethylammonium

Topics

• Electroosmosis
• Electrophoresis, Capillary (instrumentation, methods)
• Lipid Bilayers (chemistry)
• Proteins (isolation & purification)
• Quaternary Ammonium Compounds (chemistry)
• Reproducibility of Results
• Surface Properties
• Surface-Active Agents (chemistry)