Hybrid monolithic columns coated with cellulose tris(3,5-dimethylphenyl-carbamate) for enantioseparations in capillary electrochromatography and capillary liquid chromatography

Abstract

A hybrid monolithic capillary column synthesized with (3-chloropropyl)-trimethoxysilane (CPTMS) and tetramethoxysilane (TMOS) via sol–gel chemistry was in situ coated with cellulose tris(3,5-dimethylphenyl-carbamate) (CDMPC) for enantioseparations in capillary electrochromatography (CEC) and capillary liquid chromatography (CLC). Prior to coating, the prepared CP-silica hybrid monolith was straightforwardly modified with diethylenetriamine (DETA) to introduce NH2 functionalities via the nucleophilic substitution reaction, which generate the stronger EOF for CEC. The coating condition was optimized to obtain a stable and reproducible chiral stationary phase for enantioseparation. The results indicated that racemic benzoin was baseline separated on the resulting hybrid monolith coated with 30mg/mL CDMPC in CEC, while several racemates were successfully enantioseparated on the resulting CP-silica hybrid monolithic column coated with 60mg/mL CDMPC in CLC with RP and NP modes.