Continuously regenerated and integrated suppressor and detector for suppressed ion chromatography and method

Abstract

An integrated suppressor and detector for suppressed ion chromatography includes a stationary phase, a fluid flow path, at least first and second regeneration electrodes, and at least first and second sensor electrodes. Methods of suppressed ion chromatography using the integrated suppressor and detector are also described.

We claim:  
     
         1 . An integrated suppressor and detector for detecting analyte ions in a sample comprising: 
 (a) a suppressor; and    (b) at least a first sensor electrode and a second sensor electrode positioned in the suppressor for detecting the analyte ions.    
     
     
         2 . The integrated suppressor and detector of    claim 1    further comprising ion exchange resin.  
     
     
         3 . The integrated suppressor and detector of    claim 2    wherein at least a portion of the ion exchange resin is positioned between the first and second sensor electrodes.  
     
     
         4 . The integrated suppressor and detector of    claim 3    further comprising a fluid flow path wherein the first and second sensor electrodes are positioned in the fluid flow path.  
     
     
         5 . A method of conducting suppression ion chromatography wherein a suppressor is continuously regenerated comprising: 
 (a) providing a stationary phase comprising suppressor ions;    (b) providing an aqueous mobile phase comprising analyte ions to be detected;    (c) performing electrolysis on the mobile phase; and    (d) flowing regenerating ions through the stationary phase.    
     
     
         6 . The method of    claim 5    wherein the regenerating ions are selected from the group consisting of hydronium ions and hydroxide ions.  
     
     
         7 . The method of    claim 6    wherein the suppressor ions comprise cation exchange resin with exchangeable hydronium ions, and the analyte ions comprise anions.  
     
     
         8 . The method of    claim 6    wherein the suppressor ions comprise anion exchange resin with exchangeable hydroxide ions, and the analyte ions comprise cations.  
     
     
         9 . An integrated suppressor and detector for use in conducting suppression ion chromatography comprising: 
 (a) at least a first regeneration electrode and a second regeneration electrode, and a fluid flow path extending between the first and second regeneration electrodes;    (b) a stationary phase comprising suppressor ions positioned in the fluid flow path;    (c) at least first and second sensor electrodes positioned in the fluid flow path; and    (d) a measuring device in electrical communication with the first and second sensor electrodes.    
     
     
         10 . The integrated suppressor and detector of    claim 9    wherein the suppressor ions are selected from the group consisting of hydronium ions and hydroxide ions; the first and second sensor electrodes are positioned in the fluid flow path; and at least a portion of the stationary phase is positioned between the first and second sensor electrodes.  
     
     
         11 . The integrated suppressor and detector of    claim 10    wherein the first and second sensor electrodes comprise platinum.  
     
     
         12 . The integrated suppressor and detector of    claim 9    wherein the first regeneration electrode and the second regeneration electrode are also simultaneously the first and second sensor electrodes, respectively.  
     
     
         13 . The integrated suppressor and detector of    claim 9    wherein one of the first or second regeneration electrodes is also simultaneously one of the first or second sensor electrodes.  
     
     
         14 . The integrated suppressor and detector of    claim 9    wherein the stationary phase comprises an ion exchange membrane.  
     
     
         15 . The integrated suppressor and detector of    claim 9    wherein the stationary phase comprises ion exchange resin.  
     
     
         16 . A method of detecting analyte ions using suppression ion chromatography comprising: 
 (a) providing first and second regeneration electrodes;    (b) providing a fluid flow path with a stationary phase comprising suppressor ions selected from the group consisting of hydronium ions and hydroxide ions, wherein the fluid flow path extends between the first and second regeneration electrodes;    (c) providing a first sensor electrode and a second sensor electrode positioned in the fluid flow path;    (d) converting the analyte ions in the fluid flow path to either their acid or base; and    (e) detecting the converted analyte ions in the fluid flow path with the sensor electrodes.    
     
     
         17 . The method of    claim 16    wherein the analyte ions comprise cations and the cations are converted to their base by ion exchange of analyte counterions with suppressor ions comprising hydroxide ions.  
     
     
         18 . The method of    claim 16    wherein the analyte ions comprise anions and the anions are converted to their acid by ion exchange of analyte counterions with suppressor ions comprising hydronium ions.  
     
     
         19 . A method of conducting suppression ion chromatography comprising: 
 (a) providing a stationary phase comprising suppressor ions selected from the group consisting of hydronium ions and hydroxide ions, wherein at least a portion of the stationary phase is positioned in a fluid flow path positioned between a first regeneration electrode and a second regeneration electrode;    (b) providing an aqueous mobile phase comprising analyte ions to be detected, analyte counterions and electrolyte;    (c) flowing the mobile phase through the stationary phase;    (d) suppressing the mobile phase by ion exchange of the electrolyte with the suppressor ions of the stationary phase;    (e) converting the analyte ions in the fluid flow path to their acid or base by ion exchange of the analyte counterions ions with the suppressor ions of the stationary phase;    (f) detecting the acid or base of the analyte ions located in the fluid flow path; and    (g) regenerating the stationary phase during step (c) by performing electrolysis on the mobile phase.    
     
     
         20 . The method of    claim 19    wherein the analyte ions comprise anions, and the anions are converted to their acid.  
     
     
         21 . The method of    claim 19    wherein the analyte ions comprise cations, and the cations are converted to their base.  
     
     
         22 . The method of    claim 19    where the step of regenerating the stationary phase comprises: 
 conducting electrolysis of water; and  
 flowing regenerating ions selected from the group consisting of hydronium ions and hydroxide ions through the stationary phase.  
 
     
     
         23 . A method of conducting suppression ion chromatography wherein a mobile phase is regenerated comprising: 
 (a) flowing a mobile phase comprising electrolyte to a suppressor;    (b) suppressing the mobile phase by ion exchange of the electrolyte with suppressor ions selected from the group consisting of hydronium ions and hydroxide ions; and    (c) combining the electrolyte with regeneration ions selected from the group consisting of hydroxide ions and hydronium ions.    
     
     
         24 . The method of    claim 23    wherein the regeneration ions are produced by electrolysis of water in the mobile phase.