Ion chromatograph

Patent metadata

Field	Value
Publication number	US-12306153-B2
Application number	US-201917441936-A
Country	US
Kind code	B2
Filing date	Mar 27, 2019
Priority date	Mar 27, 2019
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

In an ion chromatograph, a sample that is included in an eluent and is to be measured is separated into ion species components by a separation column. An electrode liquid to be introduced into an input port is branched by a three-way valve and is discharged from each of a first output port and a second output port. An eluent from the separation column passes through an eluent flow path of an ion suppressor. An electrode liquid from the first and second output ports passes through each of an anode-side flow path and a cathode-side flow path of the ion suppressor. Ion exchange is performed by electrolysis between an eluent that passes through the eluent flow path and an electrode liquid that passes through the anode-side flow path and the cathode-side flow path, and a sample that passes through the eluent flow path and is separated by the separation column is detected by a detector. A backward flow of an electrode liquid in the cathode-side flow path is suppressed by a backward flow suppression mechanism.

First claim

The invention claimed is:

1. An ion chromatograph comprising:
a separation column that separates a sample that is included in an eluent. wherein the sample to be measured into ion species components;
a three-way valve that has an input port, a first output port and a second output port, wherein in the three-way valve branches an electrode liquid to be introduced into the input port to discharge a first output port electrode liquid, and a second output port electrode liquid from the respective of the first output port and the second output port;
an ion suppressor that includes an eluent flow path through which the eluent from the separation column passes, an anode-side flow path through which the first output port electrode liquid from the first output port passes and a cathode-side flow path through which the second output port electrode liquid from the second output port passes;
wherein the ion suppressor performs ion exchange by electrolysis between an-the eluent that passes through the eluent flow path, the first output port electrode liquid that passes through the anode-side flow path, and the second output port electrode liquid that passes through the cathode-side flow path;
a detector that detects the sample that passes through the eluent flow path and is separated by the separation column; and
a backward flow of the second output port electrode liquid in the cathode-side flow path, wherein:
the backward flow suppression mechanism includes:
a first pipe that has a flow path resistance and that connects the first output port to an upstream portion of the anode-side flow path, and

the flow path resistance of the second pipe is smaller than the flow path resistance of the first pipe to prevent the backward flow to the three-way valve of the second output port electrode liquid from the cathode-side flow path.

2. The ion chromatograph according to claim 1 , wherein
an inner diameter of the second pipe is larger than an inner diameter of the first pipe.

3. The ion chromatograph according to claim 2 , wherein
the inner diameter of the second pipe is not less than 1.2 times and not more than 6 times as large as the inner diameter of the first pipe.

4. The ion chromatograph according to claim 1 , wherein
the first pipe is longer than the second pipe.

5. The ion chromatograph according to claim 4 , wherein
a length of the first pipe is not less than twice and not more than 1000 times as large as a length of the second pipe.

6. The ion chromatograph according to claim 1 , wherein
the backward flow suppression mechanism includes:
a check valve provided in the second pipe.

7. The ion chromatograph according to claim 1 , wherein
an amount of bubbles generated in the cathode-side flow path is larger than an amount of bubbles generated in the anode-side flow path, and
the flow path resistance of the second pipe being smaller than the flow path resistance of the first pipe suppresses a backward flow of bubbles and the second output port electrode liquid in the cathode-side flow path, and causes a flow rate of the second output port electrode liquid to be supplied to the second pipe and a flow rate of the first output port electrode liquid to be supplied to the first pipe to be closer to being equal to each other as compared to a case where the flow path resistance of the second pipe is equal to the flow path resistance of the first pipe.

Assignees

• Shimadzu Corp

Inventors

• Fujiwara Masanori
• Sakamoto Katsumasa

Classifications

• G01N2030/965

  suppressor columns · CPC title

• G01N30/02

  Column chromatography · CPC title

• G01N27/62

  by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode · CPC title

• G01N30/96 Primary

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