Preparation of Carboxymethyl-β-Cyclodextrin/SiO₂/TiO₂ Hybrid Open Capillary Column and Its Application to Capillary Electrochromatography

Using tetrabutyloxytitanate and tetraethyloxysilicane as inorganic matters, carboxymethyl-β-cyclodextrin (CM-β-CD) as organic matter, and keeping morg∶minorg as 4∶3, the sol of CM-β-CD/SiO2/TiO2 was prepared by the sol-gel method; and a novel cyclodextrin-based organic-inorganic hybrid open capillary column with the sol material as stationary phase was prepared. The column prepared was characterized by SEM and IRS, showing that the stationary phase was bonded evenly with and bound tightly on the inner surface of the capillary column; that bonding between COO- and Ti-O was formed; and that a new coorrdination complex retaining the cyclodextrin molecule was formed. The open capillary column was applied to chiral separation of enantiomers of amino acid, mixture of amino acids and 2 chiral drugs, satisfactory separation from base lines was attained. Buffer solution of NaH2PO4 (pH 8.0) mixed with acetonitrile with volumic ratio of 7 to 3 was used as mobile phase, separation voltage of 15 kV and detection wavelength of 200 nm were adopted in the experiments. Maximum column efficiency and precision of migration time were tested, giving values of N and RSD (n=10) of 116 478 plates/m and 3.1% respectively.