Enantioseparation by simultaneous biphasic recognition using mobile phase additive and chiral stationary phase in capillary electrochromatography

Biphasic chiral recognition was first applied for the enantioseparation acidic drugs in capillary electrochromatography. The biphasic recognition system was composed of mobile phase additive (β-cyclodextrin) and monolithic chiral stationary phase (proteins). The pretreated silica-fused capillary was treated with 3-trimethoxysilyl propyl methacrylate to attach double bond ligand onto the surface. The mixed monolithic chiral stationary phase was constructed with bovine serum albumin and pepsin using one-pot polymerization by chemical covalent coupling, while dimethyl sulfoxide and methanol were used as the progenic solvents. The effects of the type and concentration of β-cyclodextrin additive as well as pH value of the mobile phase on the separation efficiency were optimized. The performance of the biphasic recognition system was validated by separating acidic drugs (such as ketoprofen, ibuprofen, loxoprofen, flurbiprofen and carprofen) in capillary electrochromatography, achieving outstanding separation efficiency. In terms of migration time and resolution, the run-to-run, intra-day, and inter-day repeatability through relative standards deviation were within 5.0%, exhibiting excellent stability of the biphasic recognition system. Conceivably, the experimental result reveals that biphasic chiral recognition capillary electrochromatography offers a promising prospect for enantioseparation of chiral compounds in a highly efficient manner.