Fused-silica capillaries with photopolymer components

Abstract

A separation column is provided with a photopolymer component which, when irradiated, causes controlled porosity polymerization. A particularly preferred embodiment is wherein the separation medium is retained by a photopolymer frit, which can be reliably and reproducibly generated with controlled porosity.

It is claimed:  
     
         1 . A separation column comprising: 
 a separation channel extending between an inlet and an outlet and having a channel wall; and,    a separation medium in the channel, said channel having at least one photopolymer frit adapted to retain the separation medium in the channel, the at least one frit having a controlled porosity.    
     
     
         2 . The separation column as in  claim 1  wherein the photopolymer frit is bound to an inner surface of the channel wall.  
     
     
         3 . The column as in  claim 1  wherein the photopolymer frit is adjacent to the inlet, the outlet, or both.  
     
     
         4 . The column as in  claim 1  wherein the controlled porosity of the photopolymer frit is a mean pore size of between about 1.0 μm and 5.0 μm.  
     
     
         5 . The column as in  claim 1  wherein the separation channel is a fused-silica capillary having an internal dimension in the range of between about 5 and 300 μm, and the photopolymer frit is of a structure sufficient to withstand high pressure during packing of the separation medium in the channel.  
     
     
         6 . The separation column as in  claim 5  wherein the photopolymer frit is derived from a methacrylate monomer or a methacrylate-substituted silicate.  
     
     
         7 . The separation column as in  claim 6  wherein the photopolymer frit is derived from a methacrylate monomer polymerized via photoinitiation.  
     
     
         8 . The column as in  claim 6  wherein the photopolymer frit is derived from a photocurable methacrylate-substituted silicate.  
     
     
         9 . The column of  claim 1 , said column having a first portion that is filled with said separation medium and a second portion adjacent to said first portion that transmits radiation.  
     
     
         10 . The column of  claim 9  wherein said second portion does not contain said separation medium.  
     
     
         11 . A separation column comprising: 
 a separation channel extending between an inlet and an outlet and having a channel wall; and,    a separation medium in the channel, said medium including a porous matrix and chromatographic particles dispersed in the matrix, said separation medium being formed of a photopolymer.    
     
     
         12 . The separation column as in  claim 1  wherein the channel wall has an exterior surface, and the exterior surface is substantially covered by a protective coating.  
     
     
         13 . The column as in  claim 12  where the protective coating includes polyimide.