Kkc. Yeung et Ca. Lucy, SUPPRESSION OF ELECTROOSMOTIC FLOW AND PREVENTION OF WALL ADSORPTION IN CAPILLARY ZONE ELECTROPHORESIS USING ZWITTERIONIC SURFACTANTS, Analytical chemistry, 69(17), 1997, pp. 3435-3441
Addition of zwitterionic surfactants such as dodecyldimethyl(3-sulfopr
opyl)ammonium hydroxide, hexadecyldimethyl(3-sulfopropyl)ammonium hydr
oxide, and coco (amidopropyl)hydroxyldimethylsulfobetaine (Rewoteric A
M CAS U) to an electrophoretic buffer suppress the electroosmotic flow
by 50-90%. Onset of suppression occurs at approximately the critical
micelle concentration of the surfactant. CAS U effectively suppresses
the electroosmotic now over the pH range 3-12. Addition of 2 mM CAS U
to the electrophoretic buffer prevents adsorption of cationic proteins
lysozyme, alpha-chymotrypsinogen A, cytochrome c, and ribonuclease A.
Migration time reproducibility for these proteins is similar to 1% RS
D within 1 day and 2-5% from day to day. Efficiencies in excess of 750
000 plates/m and recoveries of >80% were observed for protein injectio
ns from distilled water. Alternatively if 2 mM CAS U is added to sampl
es, recoveries were quantitative, although efficiencies decreased to 3
25000-600000 plates/m. The natural electroosmotic now of the capillari
es is regenerated simply by rinsing with sodium hydroxide.