Chromatographic material having improved ph stability, method for preparation thereof and uses thereof

Abstract

A chromatographic material including a substrate having a surface and having a polymeric layer covalently bound to the surface; the polymeric layer comprising polymer molecules covalently attached to the surface of the substrate, each polymer molecule being attached to the surface via multiple siloxane bonds and each polymer molecule being connected to one or more functionalizing compounds that each comprise a functional group, wherein the polymeric layer is formed by covalently attaching polymer molecules to the surface of the substrate via multiple siloxane bonds, each polymer molecule containing multiple first reactive groups, and reacting the first reactive groups of the attached polymer molecules with at least one functionalizing compound that comprises a second reactive group that is reactive with the first reactive groups and that further comprises a functional group. Preferred conditions of reacting the polymer with the substrate include elevated temperature and reduced pressure.

1 . A chromatographic material comprising:
 a substrate having a surface and the substrate having a polymeric layer covalently bound to the surface;   the polymeric layer comprising polymer molecules covalently attached to the surface of the substrate, each polymer molecule being attached to the surface via multiple siloxane bonds and each polymer molecule being connected to one or more functionalizing compounds that each comprise a functional group.   
     
     
         2 . The chromatographic material according to  claim 1 , wherein the polymeric layer is formed by covalently attaching polymer molecules to the surface of the substrate via multiple siloxane bonds, each polymer molecule containing multiple first reactive groups, and reacting the first reactive groups of the attached polymer molecules with at least one functionalizing compound that comprises a second reactive group that is reactive with the first reactive groups and that further comprises a functional group. 
     
     
         3 . The chromatographic material according to  claim 1 , wherein the functional group has chromatographic functionality and is selected from the group consisting of alkyl and aryl. 
     
     
         4 . The chromatographic material according to  claim 2 , wherein the first reactive groups comprise olefinic groups. 
     
     
         5 . The chromatographic material according to  claim 4 , wherein the first reactive groups comprise a member selected from the group consisting of vinyl groups and allyl groups. 
     
     
         6 . The chromatographic material according to  claim 5 , wherein all of the first reactive groups are vinyl groups. 
     
     
         7 . The chromatographic material according to  claim 2 , wherein there is a substantially uniform distance between adjacent first reactive groups of the polymer. 
     
     
         8 . The chromatographic material according to  claim 2 , wherein the second reactive group comprises a member selected from the group consisting of an olefinic group and a thiol group. 
     
     
         9 . The chromatographic material according to  claim 2 , wherein the second reactive group comprises a member selected from the group consisting of a vinyl group and an allyl group. 
     
     
         10 . The chromatographic material according to  claim 2 , wherein the polymer molecule is based on a vinylsiloxane. 
     
     
         11 . The chromatographic material according to  claim 10 , wherein the vinylsiloxane polymer has a formula I: 
       
         
           
           
               
               
           
         
         wherein n is an integer from 3 to 100, R 1  and R 2  are independently selected from the group consisting of: alkoxy, hydroxyl and halo. 
       
     
     
         12 . The chromatographic material according to  claim 11 , wherein R 1  and R 2  are independently selected from the group consisting of: methoxy, ethoxy and hydroxyl. 
     
     
         13 . The chromatographic material according to  claim 10 , wherein the vinylsiloxane polymer is a co-polymer. 
     
     
         14 . The chromatographic material according to  claim 10 , wherein the vinylsiloxane co-polymer has a formula III: 
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are independently selected from the group consisting of: alkoxy, hydroxyl and halo; and wherein n is an integer from 3 to 100, and m is an integer from 1 to 70. 
       
     
     
         15 . The chromatographic material according to  claim 2 , wherein the polymer molecule is a silyl modified polybutadiene. 
     
     
         16 . The chromatographic material according to  claim 15 , wherein the silyl modified polybutadiene is an alkoxysilyl modified polybutadiene having a repeat unit of formula VI: 
       
         
           
           
               
               
           
         
         wherein each R 1  is independently selected from the group consisting of: methoxy and ethoxy. 
       
     
     
         17 . The chromatographic material according to  claim 15 , wherein the silyl modified polybutadiene is an alkylalkoxysilyl modified polybutadiene. 
     
     
         18 . A method of forming functionalized silica for chromatographic use, the method comprising:
 in a first stage, reacting silica with at least one first functionalizing compound under conditions of at least about 100° C. and of less than 500 mbar, the first functionalizing compound or compounds comprising:
 one or more silyl groups for reacting with the surface of the silica; and one or more first reactive groups, 
 thereby covalently attaching the first functionalizing compound or compounds to the surface of the silica and leaving the first reactive groups unreacted; and 
   in a second stage, reacting the one or more first reactive groups of the surface bound first functionalizing compound or compounds with at least one second functionalizing compound, the second functionalizing compound comprises:
 one or more second reactive groups reactive with the one or more first reactive groups; and 
 a functional group. 
   
     
     
         19 . The method according to  claim 18 , wherein the first functionalizing compound is a polymer. 
     
     
         20 . The method according to  claim 19 , wherein the polymer is selected from the group consisting of: siloxane polymer; vinylsiloxane polymer; vinylalkoxysiloxane; silyl modified polybutadiene; and alkoxysilyl modified polybutadiene. 
     
     
         21 . The method according to  claim 19 , wherein the first reactive groups are selected from the group consisting of vinyl and allyl groups. 
     
     
         22 . The method according to  claim 19 , wherein the second functionalizing compound comprises a C4-C30 alkene. 
     
     
         23 . The method according to  claim 19 , wherein the one or more second reactive groups are selected from the group consisting of olefinic groups and thiol groups. 
     
     
         24 . The method according to  claim 23 , wherein the temperature in the first stage when reacting silica with at least one first functionalizing compound is at least about 200° C. 
     
     
         25 . The method according to  claim 24 , wherein the temperature in the first stage when reacting silica with at least one first functionalizing compound is in the range about 200 to about 300° C. 
     
     
         26 . The method according to  claim 18 , wherein the pressure in the first stage when reacting silica with at least one first functionalizing compound is less than 100 mbar. 
     
     
         27 . The method according to  claim 18 , wherein the pressure in the first stage when reacting silica with at least one first functionalizing compound is from about 0.1 mbar to about 100 mbar. 
     
     
         28 . The method according to  claim 18 , wherein reacting silica with at least one first functionalizing compound in the first stage is performed in the absence of a solvent. 
     
     
         29 . The method according to  claim 18 , wherein reacting silica with at least one first functionalizing compound in the first stage is performed in the presence of a catalyst. 
     
     
         30 . The method according to  claim 18 , wherein the temperature in the second stage when reacting the one or more first reactive groups with the second functionalizing compound is at least about 100° C. 
     
     
         31 . The method according to  claim 30 , wherein the temperature in the second stage when reacting the one or more first reactive groups with the second functionalizing compound is in the range from about 100 to about 200° C. 
     
     
         32 . The method according to  claim 30 , wherein the pressure in the second stage when reacting the one or more first reactive groups with the second functionalizing compound is at least atmospheric pressure. 
     
     
         33 . The method according to  claim 32 , wherein the pressure in the second stage when reacting the one or more first reactive groups with the second functionalizing compound is less than 500 mbar. 
     
     
         34 . (canceled) 
     
     
         35 . A method of separating aminoglycoside antibiotics comprising flowing a mobile phase containing a sample comprising one or more aminoglycoside antibiotics through a column to chromatographically separate the one or more aminoglycoside antibiotics from each other, wherein the column is packed with a chromatographic material, the chromatographic material comprising:
 a substrate having a surface and the substrate having a polymeric layer covalently bound to the surface;   the polymeric layer comprising polymer molecules covalently attached to the surface of the substrate, each polymer molecule being attached to the surface via multiple siloxane bonds and each polymer molecule being connected to one or more functionalizing compounds that each comprise a functional group.   
     
     
         36 . The method according to  claim 35 , wherein the pH of the mobile phase is 1.0 or less or 13.0 or higher. 
     
     
         37 - 48 . (canceled)