Comparative effects of sodium dodecyl sulfate and sulfobutyl ether-beta-cyclodextrin as pseudostationary phases in the electrokinetic chromatographicseparation of hydrophobic compounds

An alternative approach to the separation of hydmphobic compounds by electr okinetic chromatography using a negatively charged cyclodextrin, sulfobutyl ether-beta-cyclodextrin (SBE-beta-CD), as a pseudostationary phase is desc ribed. While the separation power of SBE-beta-CD is comparable with sodium dodecyl sulfate for compounds with relatively low retention factors, a cons iderable improvement in resolution and small differences in selectivity wer e observed with this pseudostationary phase for highly hydrophobic compound s exemplified by C-5-C-11 phenones. Moreover this approach allows electroki netic chromatography to be performed in reversed flow mode where the pseudo stationary phase elutes in the opposite direction to the electroosmotic flo w, even at neutral pH and without the need for treated capillaries or addit ion of organic modifiers, thereby expanding the elution range. (C) 1999 Els evier Science B.V. All rights reserved.