High efficiency sol-gel gas chromatography column

Abstract

A capillary column ( 10 ) includes a tube structure having inner walls ( 14 ) and a sol-gel substrate ( 16 ) coated on a portion of inner walls ( 14 ) to form a stationary phase coating ( 18 ) on inner walls ( 14 ). The sol solution used to prepare the sol-gel substrate ( 16 ) has at least one baseline stabilizing reagent and at least one surface deactivation reagent resulting in the sol-gel substrate ( 16 ) having at least one baseline stabilizing reagent residual and at least one surface deactivating reagent residual. A method of making the sol-gel solution is by mixing suitable sol-gel precursors to form the solution, stablizing the solution by adding at least one baseline stabilization reagent, deactivating the solution by adding at least one surface deactivation reagent to the solution, and reacting the solution in the presence of at least one catalyst.

What is claimed is:  
     
         1 . A capillary column comprising: 
 a tube structure including inner walls; and    a sol-gel substrate coated on a portion of said inner walls of said tube structure to form a stationary phase coating on said inner walls, said sol-gel substrate including at least one baseline stabilizing reagent residual and at least one surface deactivation reagent residual.    
     
     
         2 . The capillary column according to  claim 1 , wherein said at least one baseline stabilizing reagent residual is selected from the group consisting of residuals from bis(trimethoxysilylethyl)-benzene, sol-gel active reagents with phenyl-containing groups, and cyclohexane-containing groups.  
     
     
         3 . The capillary column according to  claim 1 , wherein said at least one surface deactivation reagent residual is selected from the group consisting of 1,1,1,3,3,3-hexamethyldisilazane, hydrosiloxane, and hydrosilane.  
     
     
         4 . The capillary column according to  claim 1 , wherein said sol-gel substrate is made from sol-gel precursors having the general structure:  
       
         
           
           
               
               
           
         
         wherein,  
         Z=a precursor-forming element selected from the group consisting of silicon, aluminum, titanium, zirconium, vanadium, and germanium, alkyl moieties and their derivatives, alkenyl moieties and their derivatives, aryl moieties and their derivatives, arylene moieties and their derivatives, cyanoalkyl moieties and their derivatives, fluoroalkyl moieties and their derivatives, phenyl moieties and their derivatives, cyanophenyl moieties and their derivatives, biphenyl moiety and its derivatives, cyanobiphenyl moieties and their derivatives, dicyanobiphenyl moieties and their derivatives, cyclodextrin moieties and their derivatives, crown ether moieties and their derivatives, cryptand moieties and their derivatives, calixarene moieties and their derivatives, liquid crystal moieties and their derivatives, dendrimer moieties and their derivatives, cyclophane moieties and their derivatives, chiral moieties, and polymeric moieties; and  
         R 1 , R 2 , R 3 , and R 4 =R-groups that are moieties selected from the group consisting of sol-gel-active moieties, alkoxy moieties, hydroxy moieties, non-sol-gel-active moieties, methyl, octadecyl, and phenyl.  
       
     
     
         5 . The capillary column according to  claim 4 , wherein said alkoxy groups are selected from the group consisting of a methoxy group, ethoxy group, n-Propoxy group, iso-Propoxy group, n-butoxy group, iso-butoxy group, and tert-butoxy group.  
     
     
         6 . The capillary column according to  claim 4 , wherein said R-groups are at least two moieties selected from the group consisting of sol-gel active moieties, alkoxy moieties, and hydroxy moieties.  
     
     
         7 . The capillary column according to  claim 6 , wherein remaining said R-groups are moieties selected from the group consisting of methyl, octadecyl, phenyl, and hydrogen.  
     
     
         8 . The capillary column according to  claim 1 , wherein said sol-gel substrate further includes a residual deactivation reagent selected from the group consisting of polymethylhydrosiloxane and hexamethyldisilazane.  
     
     
         9 . The capillary column according to  claim 1 , wherein said tube structure is made of materials selected from the group consisting of glass, fused silica, alumina, titania, and zirconia.  
     
     
         10 . A method of making a sol-gel capillary solution for placement into a capillary column by: 
 mixing suitable sol-gel precursors to form a sol-gel solution;    stabilizing the sol-gel coating by adding at least one baseline stabilization reagent to the sol-gel solution;    deactivating the sol-gel coating by adding at least one surface deactivation reagent to the sol-gel solution; and    reacting the solution in the presence of at least one catalyst.    
     
     
         11 . The method according to  claim 10 , wherein said reacting step further includes adding trifluoroacetic acid as the catalyst and the additional catalyst is selected from the group consisting of acids, bases or fluorides.  
     
     
         12 . The method according to  claim 10 , including the step of adding ammonium fluoride as an additional catalyst.  
     
     
         13 . The method according to  claim 10 , including the step of hydrothermally pre-treating the capillary column.