Photopolymerized sol-gel monoliths for capillary electrochromatography

A solution of methactyloxypropylbrimethoxysilane in the presence of an acid catalyst, water, toluene, and a photoinitiator was irradiated at 365 nm fo r 5 min in a 75-mum i.d. capillary to prepare a porous monolithic sol-gel c olumn by a one-step, in situ, process. The photopolymerized sol-gel (PSG) c olumn shows reversed-phase behavior. Using this column, a variety of low-mo lecular-weight neutral compounds, including polycyclic aromatic hydrocarbon s, alkyl benzenes, alkyl phenyl ketones, and steroids are separated from mi xtures. Various different operational parameters, such as buffer compositio n, field strength, and column temperature, were varied to assess their infl uence on column performance. Use of PSG as a stationary phase for a pressur e-driven separation is also demonstrated.