Investigation of structure and enantio selectivity of BSA-encapsulated sol-gel columns prepared for capillary electrochromatography

We have developed a protein-encapsulation technique using sol-gels for the preparation of monolithic capillary columns for capillary electrochromatography. Due to the silica-based matrix used, this hydrogel generates the appropriate clectroosmotic flow. Electroosmotic mobility varied according to the gels fabricated under the different gelation conditions and using different starting materials. Using attenuated total reflectance (ATR)-FT-IR, the residual silanol groups in each hydrogels could be measured without drying procedures and it was found that electroosmotic mobility decreased with a reduction in the residual silanol groups. Enantiomeric separation of D,L-Trp was evaluated using bovine serum albumin (BSA)-encapsulated column. Preparatory conditions for BSA-encapsulated columns also influenced the retention time and enantioselectiVity Of D,L-Trp. The gels composed of clusters with the diameter of around 1 mum. According to ATR-FT-IR study, BSA maintained its structure after encapsulation in the gel. (C) 2002 Elsevier Science B.V. All rights reserved.