0000000000528386
AUTHOR
P.p.h. Tock
The application of porous silica layers in open tubular columns for liquid chromatography
Two methods to realize a porous retentive silica layer on the inner wall of 10–25 µm fused silica capillaries for OTLC, etching and precipitation of silica from solution, have been investigated. Etching of the fused silica capillaries with 1M KOH, creates an activated surface, but the capacity of the silica layer is too small to serve as retentive layer in OTLC. Better prospects are offered by the precipitation of silica from a solution of polyethoxysiloxane, dynamically coated on the inner wall of the fused silica capillary. It appears to be possible to deposite a porous silica layer up to 0.8 µm thick (in a 25 µm capillary) by this method, which seems to be suitable for liquid-solid an dy…
Performance of porous silica layers in open-tubular columns for liquid chromatography
Abstract Progress has been made in the preparation of porous silica layers in fused-silica capillaries for open-tubular liquid chromatography. The porous silica layer is prepared by (i) static coating of the silica precursor, polyethoxysiloxane (PES), followed by (ii) converting the PES film into a porous silica layer with ammonia solution. The porous silica layer can be easily modified by silane reagents commonly used in packed column high-performance liquid chromatography. The performance of the silica layer with the different phase systems was tested with polyaromatic hydrocarbons and derivatized amino acids as samples.