Kw. Whitaker et al., SEPARATIONS OF ALKYL-SUBSTITUTED ANTHRACENES USING CYCLODEXTRIN DISTRIBUTION CAPILLARY ELECTROCHROMATOGRAPHY, The Journal of microcolumn separations, 8(7), 1996, pp. 461-468
Alkyl-substituted anthracenes were separated using a technique dubbed
cyclodextrin distribution capillary electrochromatography (CDCE). Nati
ve beta- or gamma-cyclodextrins (CDs), in conjunction with carboxymeth
yl-beta-cyclodextrin (CM-beta-CD) or sulfated-beta-cyclodextrin (Su-be
ta-CD), were employed in running buffers to create a dual-CD-phase sys
tem. In this system, analytes are separated based upon their different
ial distribution between the neutral CDs (beta-CD or gamma-CD) moving
with the bulk electroosmotic flow and electrophoretically mediated, ch
arged CDs (CM-beta-CD or Su-beta-CD). Comparisons are drawn between CD
CE and CD-modified micellar electrokinetic capillary chromatography. C
DCE is shown to provide unique selectivity and good resolution of meth
yl-ethyl-substituted anthracenes. Control of retention is possible thr
ough varying the concentrations and types of CDs employed. Laser-induc
ed fluorescence provides detection limits in the low-to-subparts per b
illion range. Field strength and total CD concentration exert a substa
ntial influence on the observed plate height. Analysis of CM-beta-CD w
ith capillary electrophoresis reveals information about composition (r
ange of degree of substitution) of the derivatized CD phase. Molecular
modeling is also employed to investigate that position of CM substitu
tion has on the shape of the CD. (C) 1996 John Wiley & Sons, Inc.