Ion chromatography system with eluent recycle

Patent metadata

Field	Value
Publication number	US-9322815-B2
Application number	US-3654408-A
Country	US
Kind code	B2
Filing date	Feb 25, 2008
Priority date	Feb 25, 2008
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

Ion chromatography apparatus including (a) a chromatographic column, (b) a source of an aqueous eluent liquid stream, (c) a detector, (d) a recycle line between the detector and the chromatographic column, and (e) a purifying device disposed along the recycle line including ion exchange removal medium. Also, such apparatus with an electrolytic purifying device disposed along the recycle line. Also, methods of using such apparatus.

First claim

What is claimed is:

1. An ion chromatography apparatus comprising,
(a) a chromatographic column, having an inlet and an outlet, including ion exchange separation medium having exchangeable ions of one charge, positive or negative, for separating analyte ions of the same charge as said exchangeable ions, said chromatographic column not being associated with electrodes for passing an electric current through said separation medium,
(b) a source of an aqueous eluent liquid stream in fluid communication with said chromatographic column inlet,
(c) a detector, including an inlet and an outlet, for detecting analyte ions in a sample downstream from said chromatographic column outlet, said detector inlet being in fluid communication with said chromatographic column outlet,
(d) a recycle line providing fluid communication between said detector and said chromatographic column inlet,
(e) an electrolytic purifying device comprising a regenerant channel separated from a sample stream flow channel by an ion exchange removal membrane, said purifying device being capable of continuous regeneration by applying an electric field across said ion exchange removal membrane disposed along said recycle line, said ion exchange removal membrane including exchangeable ions of the same charge as said separation medium exchangeable ions, said sample stream flow channel being in fluid communication with said detector outlet, said apparatus not including a suppressor disposed between said chromatographic column outlet and said detector, and
(f) an external water source being in fluid communication with said regenerant channel but not in fluid communication with said recycle line.

2. The apparatus of claim 1 in which said detector is a conductivity detector.

3. The apparatus of claim 1 further comprising a pair of electrodes disposed to pass electric current through said ion exchange removal membrane.

4. The ion chromatography apparatus of claim 1 in which said purifying device is for removal of sample analyte ions in said eluent liquid stream, said purifying device further comprising eluent liquid from said eluent liquid stream in contact with said ion exchange removal membrane.

Assignees

• Srinivasan Kannan
• Lin Rong
• Bhardwaj Sheetal
• Pohl Christopher A
• Dionex Corp

Inventors

• Srinivasan Kannan
• Lin Rong
• Bhardwaj Sheetal
• Pohl Christopher A

Classifications

• G01N30/96 Primary

  using ion-exchange (G01N30/02, G01N30/90 take precedence) · CPC title