Enantioseparation of tropa alkaloids by means of anionic cyclodextrin-modified capillary electrophoresis.

Anionic cyclodextrins (CDs), i.e., sulfated CD, sulfobutylether beta-CD (SBE-beta-CD) and heptakis(2,3-di-O-acetyl-6-sulfato)-beta-CD (HDAS-beta-CD), were used to separate the isomers of atropine, homatropine, ipratropium, scopolamine and butylscopolamine. Variations in the pH value and the concentration of the various CDs revealed the sulfated beta-CD to be superior to the other derivatives. In a basic medium at low concentrations of sulfated CD the enantiomers of atropine, homatropine and ipratropium were well resolved in a short migration time, which is appropriate for the routine analysis of the enantiomeric excess. Scopolamine and butylscopolamine compounds could not be separated with either CD.