Method and apparatus for generating a high purity eluant

Abstract

An apparatus and method for electrochemically modifying the retention of a species on a chromatography material is disclosed. The apparatus comprises a housing having an effluent flow channel adapted to permit fluid flow therethrough. The effluent flow channel comprises chromatography material. The apparatus further comprises first and second electrodes positioned such that at least a portion of the chromatography material is disposed between the first and second electrodes, and fluid flow through the apparatus is between, and in contact with, the first and second electrodes.

1 . An apparatus for electrochemically modifying the retention of a species on chromatography material comprising:
 a) a housing, the housing comprising an effluent flow channel, the effluent flow channel comprising chromatography material and the effluent flow channel adapted to permit fluid flow therethrough;   b) a first electrode and a second electrode positioned such that at least a portion of the chromatography material is disposed between the first and second electrodes, and the fluid flow through the effluent flow channel is between, and in contact with, the first and second electrodes.   c) a power source connected to the first and second electrodes.   
   
   
       2 . The apparatus of  claim 1  wherein the first and second electrodes are positioned in the housing. 
   
   
       3 . The apparatus of  claim 1  wherein the chromatography material is selected from the group consisting of affinity stationary phase chromatography material, reversed phase chromatography material, ion-exchange chromatography material; chelation chromatography material, hydrophobic chromatography material, normal phase chromatography material, and size exclusion chromatography material. 
   
   
       4 . The apparatus of  claim 3  wherein the chromatography material comprises chromatography packing material. 
   
   
       5 . The apparatus of  claim 3  wherein the effluent flow channel further comprises a cavity in which fluid flows through the effluent flow channel, the cavity defined by at least one wall wherein at least a portion of the wall comprises chromatography material. 
   
   
       6 . The apparatus of  claim 1  further comprising a detector in fluid connection with the effluent flow channel. 
   
   
       7 . The apparatus of  claim 6  further comprising an ion exchange bed in fluid connection with the detector. 
   
   
       8 . The apparatus of  claim 7  further comprising a back-pressure regulator in fluid connection with, and positioned between, the detector and the ion exchange bed. 
   
   
       9 . The apparatus of  claim 1  further comprising an eluant source. 
   
   
       10 . The apparatus of  claim 9  wherein the eluant source comprises water. 
   
   
       11 . The apparatus of  claim 9  wherein the eluant source comprises a non-aqueous species. 
   
   
       12 . The apparatus of  claim 5  wherein the wall comprises hollow tubing comprising a chromatography stationary phase. 
   
   
       13 . The apparatus of  claim 5  wherein the chromatography material is coated on the wall. 
   
   
       14 . A method of electrochemically modifying the retention of a species on a chromatography material comprising:
 a) providing a stationary phase comprising chromatography material with the species retained thereon;   b) providing a first electrode and a second electrode positioned such that at least a portion of the chromatography material is disposed between the first and second electrodes;   c) providing a mobile phase comprising eluant;   d) electrochemically modifying the eluant by flowing the eluant between, and in contact with, the first and second electrodes; and   e) flowing the modified eluant to the chromatography material thereby modifying the retention of the species on the chromatography material.   
   
   
       15 . The method of  claim 14  wherein the eluant comprises water. 
   
   
       16 . The method of  claim 14  wherein the eluant comprises nonaqueous species. 
   
   
       17 . The method of  claim 14  wherein the chromatography material is selected from the group consisting of affinity stationary phase chromatography material, reversed phase chromatography material, ion-exchange chromatography material, chelation chromatography material, hydrophobic chromatography material, normal phase chromatography material, and size exclusion chromatography material. 
   
   
       18 . The method of  claim 17  wherein the chromatography material comprises chromatography packing material. 
   
   
       19 . A system for generating a high purity eluant that can be used in detecting sample ions comprising:
 a water source;   an eluant generator comprising a path of water flow in communication with an internal reservoir of eluant ions having opposite charge as the sample ions; the eluant generator having no external source of eluant ions;   a first electrode and a second electrode;   a power source in electrical communication with the first and second electrodes;   an analytical column comprising ion exchange resin, the analytical column located downstream in a path of fluid flow from the eluant generator;   a suppressor comprising a suppressor stationary phase having exchangeable ions selected from the group consisting of hydronium ions and hydroxide ions, the suppressor being positioned downstream in the path of fluid flow from the analytical column, wherein at least a portion of the suppressor stationary phase is positioned between a first suppressor electrode and a second suppressor electrode, the suppressor electrodes being in electrical communication with a power source; and   a detector positioned downstream in the path of fluid flow from the suppressor.   
   
   
       20 . The system of  claim 19  wherein the internal reservoir comprises ion exchange resin. 
   
   
       21 . A method of generating a high purity eluant for detecting sample ions comprising:
 providing a water source;   providing an eluant generator comprising an internal reservoir of eluant ions having the opposite charge as the sample ions; the eluant generator having no external source of eluant ions;   flowing water through the eluant generator and performing electrolysis of the water in the eluant generator to generate electrolysis ions having the opposite charge as the eluant ions wherein the electrolysis ions are selected from the group consisting of hydronium ions and hydroxide ions;   combining the electrolysis ions with the eluant ions to form a high purity eluant;   flowing the sample ions and the high purity eluant through an analytical column to separate the sample ions; and   flowing the separated sample ions to a detector where the sample ions are detected.   
   
   
       22 . The method of  claim 21  wherein the sample ions comprise anions, the eluant ions comprise cations and the electrolysis ions comprise hydroxide ions. 
   
   
       23 . The method of  claim 22  wherein the eluant ions comprise sodium. 
   
   
       24 . The method of  claim 21  wherein the sample ions comprise cations, the eluant ions comprise anions and the electrolysis ions comprise hydronium ions. 
   
   
       25 . The method of  claim 24  wherein the eluant ions comprise chloride. 
   
   
       26 . The method of  claim 21  wherein an electrode is in liquid communication with the water flowing through the eluant generator. 
   
   
       27 . The method of  claim 21  wherein the sample ions and high purity eluant are flowed through a suppressor, wherein the suppressor is positioned downstream from the analytical column and upstream of the detector in the path of fluid flow.