| Abstract
| - The first member of the single-isomer, sulfated γ-cyclodextrin family, the sodium salt of octakis(2,3-diacetyl-6-sulfato)-γ-cyclodextrin (ODAS-γCD) has been synthesized,analytically characterized, and used to separate, by capillary electrophoresis, a variety of neutral, acidic, basic, andamphoteric enantiomers in low pH background electrolytes. The anionic effective mobilities of the neutral andanionic analytes were found to increase with the concentration of ODAS-γCD. For weakly binding cationic analytes, the effective mobilities went from cationic highvalues, through zero, to increasingly larger anionic valuesas the concentration of ODAS-γCD was increased. For thestrongly complexing cationic analytes, the effective mobilities became anionic even at very low ODAS-γCD concentrations and became smaller as the ionic strength of thebackground electrolyte increased with the increasingODAS-γCD concentration. Separation selectivity followedthe predictions of the charged resolving agent migrationmodel: for neutral analytes it decreased as the concentration of ODAS-γCD was increased. For cationic analytes,selectivities were found to increase as the cationic effectivemobilities approached zero, then decreased as the concentration of ODAS-γCD was increased further. The extentof peak resolution that could be realized with ODAS-γCDstrongly depended on the magnitude of separation selectivity and the normalized electroosmotic flow mobility.ODAS-γCD proved to be a broadly applicable chiralresolving agent.
|
