Sulfonamide based anion exchange resins

Abstract

An ion exchange resin for use as a stationary phase in an ion chromatography column. The ion exchange resin has a negatively charged substrate particle, a positively charged polymer layer bound to the negatively charged substrate particle, a linker, and an ion exchange group. The ion exchange group includes a sulfonamide group and an amine, in which the ion exchange group is coupled to the positively charged polymer layer via the linker. When the sulfonamide is in a neutral form, a positively charged amine group provides retention; while when the sulfonamide is in an anionic form, the sulfonamide anion becomes a counter ion to the positively charged amine group, forming a zwitterion that reduces retention at that site. Accordingly, the retention time is able to be controlled by adjusting the mobile phase pH.

What is claimed is: 
     
         1 . An ion exchange resin comprising:
 a negatively charged substrate particle;   a positively charged polymer layer bound to the negatively charged substrate particle, in which the positively charged polymer layer includes a linker; and   an ion exchange group including a sulfonamide group and an amine, in which the ion exchange group is coupled to the positively charged polymer layer via the linker.   
     
     
         2 . The ion exchange resin of  claim 1 , in which the amine is selected from a group consisting of a secondary amine, a tertiary amine, a quaternary amine, and a combination thereof. 
     
     
         3 . The ion exchange resin of  claim 1 , in which the ion exchange group includes a quaternary amine and the ion exchange group is configured to be zwitterionic when the sulfonamide is in a deprotonated state. 
     
     
         4 . The ion exchange resin of  claim 1 , in which the negatively charged substrate particle is a polymeric particle and the ion exchange resin is configured to retain the ion exchange group when subjected to eluent having a pH ranging from 0 to 14. 
     
     
         5 . The ion exchange resin of  claim 1 , in which the negatively charged substrate particle comprises a sulfonated copolymer of an ethylvinylbenzene and a divinylbenzene. 
     
     
         6 . The ion exchange resin of  claim 2 , in which the negatively charged substrate particle comprises a super macroporous particle. 
     
     
         7 . The ion exchange resin of  claim 6 , in which the super macroporous particle has a diameter of 4-6 μm, a surface area of 20-30 m 2 /g, and pore sizes of 1000 Å-2000 Å. 
     
     
         8 . The ion exchange resin of  claim 1 , in which the positively charged polymer layer comprises quaternary amines. 
     
     
         9 . The ion exchange resin of  claim 8 , in which the positively charged polymer layer further comprises ether groups and hydroxyl groups. 
     
     
         10 . The ion exchange resin of  claim 9 , in which the positively charged polymer layer comprises a structure according to Formula (I): 
       
         
           
           
               
               
           
         
       
       wherein n ranges from about 5 to about 150, and R is an alkyl group. 
     
     
         11 . The ion exchange resin of  claim 9 , in which the positively charged polymer layer comprises a structure according to Formula (III): 
       
         
           
           
               
               
           
         
       
       wherein n ranges from about 5 to about 150, and R is an alkyl group. 
     
     
         12 . The ion exchange resin of  claim 1 , in which the linker includes an aromatic ring. 
     
     
         13 . The ion exchange resin of  claim 1 , in which the ion exchange group comprises a structure according to Formula (II): 
       
         
           
           
               
               
           
         
       
       or a salt thereof, wherein R 1  is selected from unsubstituted alkyl, and substituted alkyl;
 L 1  is selected from substituted alkyl, unsubstituted alkyl, substituted aryl, and unsubstituted aryl; 
 R 2  is selected from the group consisting of H, unsubstituted alkyl, substituted alkyl, a lone pair of electrons, and a support structure, in which the support structure includes the linker, the positively charged polymer layer, and the negatively charged substrate particle; 
 R 3  is selected from the group consisting of H, unsubstituted alkyl, substituted alkyl, a lone pair of electrons, and the support structure, and 
 R 4  is selected from the group consisting of H, unsubstituted alkyl, substituted alkyl, a lone pair of electrons, and the support structure, with the proviso that two or more of R 2 , R 3 , and R 4  cannot be lone pair electrons, and with the proviso that at least one of R 2 , R 3 , and R 4  comprises the support structure. 
 
     
     
         14 . The ion exchange resin of  claim 13 , in which R 1  and R 2  each include an unsubstituted alkyl containing two to three carbons and R 3  includes the support structure. 
     
     
         15 . The ion exchange resin of  claim 13 , in which the salt thereof comprises a quaternary amine and an anion, the anion selected from the group consisting of a hydroxide ion, a carbonate ion, a bicarbonate ion, and a combination thereof. 
     
     
         16 . A method of using an ion exchange resin packed in a chromatography column, the method comprising:
 flowing an eluent through the chromatography column, in which the eluent comprises carbonate and bicarbonate, wherein the ion exchange resin containing a positively charged polymer layer coupled to the ion exchange resin, in which the positively charged polymer layer includes a linker; and   an ion exchange group including a sulfonamide group and a positively charged amine, in which the ion exchange group is coupled to the ion exchange resin via a linker; and   separating a sample that includes a trivalent species.   
     
     
         17 . The method of  claim 16  further comprising:
 adjusting a ratio of a carbonate concentration and a bicarbonate concentration so that a carbonate peak does not overlap with an analyte peak. 
 
     
     
         18 . The method of  claim 16 , in which the
 adjusting a pH value of the eluent so that a first analyte peak does not overlap with a second analyte peak.   
     
     
         19 . The method of  claim 16 , in which the trivalent species includes phosphate or arsenate. 
     
     
         20 . An ion exchange resin comprising:
 a negatively charged substrate particle;   a positively charged polymer layer bound to the negatively charged substrate particle, in which the positively charged polymer layer includes a linker; and   
       a first ion exchange group including a first sulfonamide group and a first quaternary amine, in which the first ion exchange group is coupled to the positively charged polymer layer via the linker; and
 a second ion exchange group including a second sulfonamide group and a second quaternary amine, in which the second ion exchange group is coupled to the positively charged polymer layer via the linker, in which the first ion quaternary amine is different than the second quaternary amine. 
 
     
     
         21 . The ion exchange resin of  claim 20 , in which the first ion exchange group comprises N,N-dimethylaminopropyl methylsulfonamide and the second ion exchange group comprises N,N-diethylaminoethyl methylsulfonamide. 
     
     
         22 . The ion exchange resin of  claim 20 , in which a ratio of the first ion exchange group to the second ion exchange group is 1:1.