Application of cyclodextrin-modified gold nanoparticles in enantioselective monolith capillary electrochromatography.

β-cyclodextrin modified gold nanoparticles (CD-GNP) were employed as the stationary phase in monolith capillary electrochromatography (CEC) to facilitate enantioseparation. CD-GNP were covalently bound to the surface of the thiolated porous polymer monolithic column. The fabricated enantioselective monolithic column was characterized by a variety of spectroscopic methods. The column exhibited steady EOF mobility over pH values ranging from 4.6 to 9.7. Additionally, the column was stable under CEC separation conditions over 180 min. Moreover, the column exhibited good column-to-column reproducibility. The CD-GNP-modified monolithic column was employed in the efficient CEC separation of three pairs of drug enantiomers (chlorpheniramine, zopiclone and tropicamide). The results exhibit reproducible run-to-run enantioseparations and the monolith column can maintain its enantioselectivity for more than 1 month if the column is stored in a CD-GNP solution at 4°C.