Optimization of lambda-carrageenan as a chiral selector in capillary electrophoresis separations

Lambda-carrageenan, a linear high molecular weight sulfated polysaccharide, was employed as a chiral selector in capillary electrophoresis for the separation of enantiomers of weakly basic pharmaceutical compounds. In order to improve the utility of the chiral selector, the purity and concentration of the lambda-carrageenan and other important capillary electrophoresis method parameters were investigated. The results indicated that the purity and concentration of the lambda-carrageenan, ionic strength of the buffer, and temperature were critical to successful enantioseparation. These new method conditions were then applied to previously investigated beta-blockers (such as propranolol HCl and pindolol) and racemic tryptophan derivatives. These studies were successful in identifying important method conditions for the improved enantioselectivity with lambda-carrageenan.