Supercritical fluid-liquid chromatograph, and analysis method thereof

Patent metadata

Field	Value
Publication number	US-2016202218-A1
Application number	US-201614988854-A
Country	US
Kind code	A1
Filing date	Jan 6, 2016
Priority date	Jan 14, 2015
Publication date	Jul 14, 2016
Grant date	—

Abstract

A back pressure valve configured to switch between a pressurized state and a released state open to an atmosphere is used as a back pressure valve in a supercritical fluid chromatograph. Switching from a state of supercritical fluid chromatography analysis to liquid chromatography is performed by stopping a pump that supplies a supercritical fluid, continuously operating a pump that supplies a solvent used as a modifier, and bringing the back pressure valve into the released state.

First claim

What is claimed is:

1 . A supercritical fluid-liquid chromatograph comprising:
a first solvent delivery section for delivering a solvent to be a supercritical fluid by a first pump; a second solvent delivery section for delivering an organic solvent having polarity and compatibility with the solvent by a second pump; a separation column arranged on an analysis channel downstream a merging section of the first solvent delivery section and the second solvent delivery section; a sample injection section arranged between the merging section and the separation column in the analysis channel, for injecting a sample into the analysis channel; a back pressure valve arranged downstream the separation column with respect to flow of a mobile phase in the analysis channel, capable of keeping an inside of the analysis channel at a pressurized state to maintain the mobile phase in a supercritical fluid state; a detector arranged between the separation column and the back pressure valve in the analysis channel and/or outside a release port of the back pressure valve to an atmosphere, for detecting a sample component eluted from the separation column; and a control section for controlling operations of the first pump, the second pump, and the back pressure valve, wherein the back pressure valve is configured to switch between the pressurized state and a released state open to the atmosphere, and wherein the control section is configured to perform switching from supercritical fluid chromatography where the first pump and the second pump are brought into an operating state and the back pressure valve is maintained for the pressurized state, to liquid chromatography where the first pump is stopped, the second pump continues to operate, and the back pressure valve is brought into the released state.

2 . The supercritical fluid-liquid chromatograph according to claim 1 ,
wherein the control section includes an analysis program storage section for storing an analysis program of setting operation conditions of the first pump, the second pump, and the back pressure valve with respect to time, and wherein the supercritical fluid-liquid chromatograph executes the switching from the supercritical fluid chromatography to the liquid chromatography, based on the analysis program.

3 . The supercritical fluid-liquid chromatograph according to claim 2 ,
wherein a third solvent delivery section for supplying a third solvent capable of constituting together with the organic solvent the mobile phase for the liquid chromatography by a third pump is connected to the merging section, wherein the analysis program storage section also stores an analysis program for gradient analysis in the liquid chromatography, and wherein the control section is configured to control the second pump and the third pump to perform gradient analysis in the liquid chromatography.

4 . The supercritical fluid-liquid chromatograph according to claim 2 ,
wherein the second solvent delivery section is configured to be capable of supplying, in addition to the organic solvent, the third solvent capable of constituting together with the organic solvent the mobile phase for the liquid chromatography by the second pump, wherein the analysis program storage section also stores the analysis program for the gradient analysis in the liquid chromatography, and wherein the control section is configured to control an operation of the second solvent delivery section to supply, in the supercritical fluid chromatography, only the organic solvent from the second solvent delivery section, and to supply, in the liquid chromatography, the organic solvent and the third solvent from the second solvent delivery section and perform gradient analysis.

5 . An analysis method that uses an analysis device including an analysis channel provided with a separation column, a mobile phase delivery section for supplying a mobile phase to the analysis channel, a sample injection section for injecting a sample between the separation column and the mobile phase delivery section in the analysis channel, a back pressure valve arranged downstream the separation column with respect to flow of a mobile phase in the analysis channel, capable of keeping an inside of the analysis channel at a pressurized state to maintain the mobile phase in a supercritical fluid state, and a detector arranged between the separation column and the back pressure valve in the analysis channel and/or outside a release port of the back pressure valve to an atmosphere, for detecting a sample component eluted from the separation column, the method comprising:
(A) supplying a mobile phase to be in a supercritical fluid state as the mobile phase from the mobile phase delivery section, injecting a sample from the sample injection section while maintaining the mobile phase in the analysis channel in the supercritical fluid state by the back pressure valve, and starting supercritical fluid chromatography analysis; (B) after the supercritical fluid chromatography analysis where the mobile phase is a mixed solution of a solvent to be a supercritical fluid and an organic solvent having polarity and compatibility with the solvent, switch from a state of supercritical fluid chromatography to a state of liquid chromatography by switching the mobile phase supplied from the mobile phase delivery section so as to contain only the organic solvent and releasing the back pressure valve to an atmospheric pressure, and (C) subsequently performing liquid chromatography analysis using the mobile phase containing the organic solvent.

6 . The analysis method according to claim 5 , wherein the step (C) is gradient analysis where another solvent is mixed with the organic solvent as the mobile phase.

Assignees

• Shimadzu Corp

Inventors

• Owa Michiaki

Classifications

• C07K1/16

  by chromatography · CPC title

• B01D15/40

  using supercritical fluid as mobile phase or eluent · CPC title

• G01N30/34 Primary

  of fluid composition, e.g. gradient (G01N30/36 takes precedence) · CPC title

• G01N30/74

  Optical detectors {(measurement of intensity, velocity, spectral content, polarisation, or phase of infrared, visible or ultraviolet light G01J)} · CPC title

• G01N30/16

  Injection (G01N30/24 takes precedence) · CPC title