Carbamate chiral surfactants for capillary electrophoresis

Chiral resolution in capillary electrophoresis (CE) was studied with several novel synthetic surfactants, which are synthesized from an amino acid (L-leucine, L-valine, L-isoleucine, or L-serine) and an alkyl chloroformate with a chain length of C-4 to C-12. Several chiral drugs, including atenolol, benzoin, laudanosine, propranolol, ketamine, hydrobenzoin and nefopam were used as test compounds. It was found that resolution can be readily manipulated by varying the chain length, the amino acid and the surfactant concentration. Sulfonated beta-cyclodextrin (beta-CD) was also studied and compared with these novel surfactants. A different selectivity was found for sulfonated beta-CD due to its distinct structure. Neither the new surfactants nor beta-CD gave a satisfactory chiral resolution for all the seven drugs. However, a mixture of a surfactant and sulfated beta-CD was suitable for chiral resolution of all seven drugs. These mixed reagents were also effective for CE resolution of eight dansyl amino acids. (C) 1999 Elsevier Science B.V. All rights reserved.