ABSTRACT
Enantiomers and diastereomers of chrysanthemic, permethrinic, and deltamethrinic pyrethroic acids were separated from each other, using positively ionizable permethyl monoamino beta-cyclodextrin (PMMAbetaCD). The highest chiral resolution value was 20.0. The optimum conditions of separation were found to be 16 mM PMMAbetaCD concentration and pH 6.5, where analytes and selector were in oppositely ionized states. Selectivity of PMMAbetaCD proved to be the best among the cyclodextrin derivatives studied.
Subject(s)
Cyclodextrins , Electrophoresis, Capillary/methods , Insecticides/isolation & purification , Pyrethrins/isolation & purification , beta-Cyclodextrins , Cyclodextrins/chemistry , Hydrogen-Ion Concentration , Nitriles , Permethrin/isolation & purification , StereoisomerismABSTRACT
Enantiomers of disopyramide display different biological actions, and therefore chiral selective analysis is necessary. Fifteen different cyclodextrins (CDs) and CD derivatives were tested as capillary electrophoresis (CE) additives for the chiral separation of disopyramide. Eleven types of CDs showed chiral recognition features and four types had a baseline or close to baseline separation. The best resolution (Rs = 3.0) was with 15 mM carboxymethylated beta-CD (pH 4.9). A sharp decrease in the selectivity of gamma-phosphate (gamma-PhoCD) was observed in the pH range of 2-3, indicating a structural change of gamma-PhoCD. The enantiomers of disopyramide were separated in its ionized as well as neutral forms using acidic substituted CDs. The results show that the size of the CD cavity can not be used as a guide to estimate chiral separations, suggesting a more complex separation mechanism of these CDs towards disopyramide.
Subject(s)
Cyclodextrins/chemistry , Disopyramide/isolation & purification , Electrophoresis, Capillary/methods , alpha-Cyclodextrins , beta-Cyclodextrins , gamma-Cyclodextrins , Disopyramide/chemistry , Molecular StructureABSTRACT
The cis (Z) and trans (E) isomers of clomiphene were separated using capillary electrophoresis. Various derivatives of cyclodextrins (CDs) were applied as buffer additives, achieving a resolution of greater than 18. The effect of various parameters, type and concentration of CDs, type and concentration of background electrolytes (BGEs), pH, and organic modifiers has been studied systematically. Migration reversal was observed in several cases. The load ability of the various buffer systems was also taken into account.
