title: Preparation and characterization of monolithic porous capillary columns loaded with chromatographic particles.
abstract: Using sol-gel technology, a porous glass matrix (xerogel) is formed in a capillary column and acts as a support for a stationary phase of chromatographic particles used in capillary electrochromatography. Preparation of the sol-gel matrix and immobilization of the octadecylsilica (ODS) stationary phase occur in a single step. The presence of the particles in the column greatly reduces matrix cracking caused by internal pressure differentials within the pores of the sol-gel matrix. Good electroosmotic flow is achieved in part because of the inherent negative charge of both the particles and the sol-gel matrix. The performance of these sol-gel/ODS capillary columns was evaluated with a mixture of aromatic and nonaromatic organic compounds. Efficiencies of up to 80 000 plates/m were observed in columns with immobilized 3-μm ODS particles. The efficiency and resolution are enhanced when 3-μm ODS particles are used in place of the 5-μm particles.
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305-5080.
authors.forename: M T
authors.initials: MT
authors.lastname: Dulay
authors.forename: R P
authors.initials: RP
authors.lastname: Kulkarni
authors.forename: R N
authors.initials: RN
authors.lastname: Zare