JP2510199Y2 - Liquid sending device for supercritical fluid chromatography - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a liquid delivery device, particularly a liquid delivery device for a supercritical fluid chromatograph for delivering a mobile phase fluid and a modifier to a supercritical fluid chromatograph device. Regarding the device.

[Conventional technology]

Supercritical fluid chromatography is a chromatography in which a fluid heated and compressed at a critical temperature or higher and a critical pressure or higher is used as a mobile phase. The supercritical fluid has physical properties intermediate between those of gas and liquid, and polymer materials can be analyzed at low temperature. In addition, it is easy to use a capillary column that is difficult to use in ordinary liquid chromatography, and the linear velocity can be increased and the analysis time can be shortened. That is, since the supercritical fluid has a larger diffusion coefficient than liquid, the mass transfer rate and equilibrium rate are faster, and the linear velocity that gives the optimum theoretical plate height is higher than that of liquid chromatography, and even at high linear velocity. Column efficiency is obtained. The fluid used for supercritical fluid chromatography is usually carbon dioxide (CO
₂ ), and N ₂ O, NH _{3 and the} like can also be used. Furthermore, polar substances such as methanol, formic acid, and water are used as modifiers as needed.

As a conventional configuration for adding a modifier, (a) a liquid as a modifier is pressurized and sent to and mixed with a flow of a mobile phase fluid pressurized by a pump.

(B) A mobile phase fluid and a modifier liquid are put in a pressure-resistant container in a pressurized state and mixed, and this mixed liquid is guided to a pump and pressure-fed.

Two types of configurations are known.

[Problems to be solved by the device]

In the conventional configuration of the above (a), a pump for liquid transfer is required for each of the mobile phase fluid and the modifier liquid. Also, the required pump must be of the flow control type.

In the conventional configuration of the above (b), since it is necessary to mix the mobile phase fluid and the modifier liquid in advance,
The modifier concentration cannot be changed during the analysis. Further, during the analysis, it is necessary to constantly uniformly mix the mobile phase fluid and the modifier in the pressure vessel.

It is an object of the present invention to provide a liquid delivery device for a supercritical fluid chromatograph, which has a simple pump configuration and can easily change the modifier concentration during measurement.

[Means for solving the problem]

The liquid delivery device according to the present invention is a liquid delivery device for a supercritical fluid chromatograph for delivering a mobile phase fluid and a modifier to the supercritical fluid chromatograph device. This device
Either of a liquid feed pump for sending fluid to the supercritical fluid chromatograph, a container for mobile phase fluid, a container for modifier, a pressure matching means for matching the pressure between both containers, or both containers And a switching means for connecting one to the liquid feed pump.

[Action]

In the liquid delivery device for a supercritical fluid chromatograph according to the present invention, the mobile phase fluid is stored in the mobile phase fluid container, and the modifier is stored in the modifier container.

The mobile phase fluid and the modifier in both containers are sent to the supercritical fluid chromatograph by a liquid sending pump. At this time, the switching means connects one of the two containers to the liquid feed pump. As a result, the mobile phase fluid and the modifier are alternately sent to the supercritical fluid chromatograph by the liquid sending pump. During this liquid feeding operation, the pressure matching means matches the pressure between the mobile phase fluid container and the modifier container. Accordingly, the fluid does not flow backward when the liquid transfer path is switched by the switching means.

Here, since the mobile phase fluid and the modifier can be transferred by the common liquid sending pump, the pump structure is simplified. Further, by changing the switching operation by the switching means, the modifier concentration can be easily changed even during the analysis.

〔Example〕

FIG. 1 shows a supercritical fluid chromatographic analysis device equipped with a liquid delivery device according to an embodiment of the present invention.

In FIG. 1, a supercritical fluid chromatograph analyzer includes a chromatograph device 1, a liquid delivery device 2 connected to the chromatograph device 1, and a control device 3 for controlling the operations and data processing. It has and.

The chromatographic apparatus 1 mainly has a sampling valve 4, a column 5 having an inlet connected to the sampling valve 4, and a detector 6 arranged at the outlet of the column 5. The sampling valve 4 is composed of a high-pressure switching valve, and the sample introduced into the fixed loop (not shown) is transferred to the column 5 by the automatic switching of the valve 4.
To be sent to. The column 5 can be heated by a heating device (not shown) and is of a forced circulation type. As the column 5, for example, a micropacked column or a capillary column is used. The detector 6 is, for example, a flame ionization detector (FID).

The liquid sending device 2 mainly includes a liquid sending pump 7 for sending a fluid to the chromatograph device 1, a mobile phase fluid container 8 composed of a large pressure resistant container, and a modifier container 9 composed of a small pressure resistant container. Have

The liquid feed pump 7 is a pump that feeds liquid by driving a microplunger at high speed. The liquid feed pump 7 includes a microplunger and a mixer (both not shown) arranged on the downstream side thereof.

A pipe 10 is connected to the suction side of the liquid feed pump 7. The pipe 10 branches off at its upstream end, and both vessels
It communicates with 8, 9. A three-way switching valve 11 is arranged at the branch of the pipe 10. The three-way switching valve 11 operates so that either one of the two containers 8 and 9 is communicated with the liquid feed pump 7 side.

As shown in FIG. 2, the container 8 contains liquid dicarbooxygen 8a as a moving bed fluid. Meanwhile, container 9
Inside, water 9a (example) as a modifier is stored. Between the upper parts of both containers 8 and 9, a cylindrical connecting part 12
Is provided. One end of the connecting portion 12 is opened to the container 8 and the other end is opened to the container 9. Inside the connecting portion 12, a partition wall 13 that is movable in the direction of the center line (left and right direction in FIG. 2) is provided. Further, on the container 8 side with respect to the partition wall 13,
A seal ring 14 is provided in the connecting portion 12. A generally cylindrical bellows 15 is provided between the seal ring 14 and the partition wall 13.
Has been fixed. As a result, the partition wall 13 can be moved in the left-right direction in FIG. 2, but the partition wall 13, the seal ring 14, and the bellows 15 separate the spaces inside the containers 8 and 9. In this embodiment, the connecting portion 12 serves as pressure equalizing means.

Further, the liquid feed pump 7 of the liquid feed device 2 is provided with a control unit 16 shown in FIG. The control unit 16 includes a microcomputer including a CPU, ROM, RAM and the like. The control unit 16 is connected to a pump 17 including a micro-plunger, the above-described three-way switching valve 11, the control device 3, and other input / output units.

The controller 3 (FIG. 1) has a controller 18 including a CPU, ROM and RAM. The controller 18 is connected with a keyboard 19 having keys and a display for inputting commands by an operator, an electrometer 20 for data processing, and a printer 21. Further, the controller 18 is also connected to the chromatograph device 1 and the liquid delivery device 2.

Next, the operation of the above-described supercritical fluid chromatographic analysis device will be described.

When this analyzer is started, initial settings such as heating the chromatographic apparatus 1 to a predetermined temperature are performed. In the initial setting stage, various designations including designation of the modifier concentration in the moving bed fluid (designation via the keyboard 19) are also performed.

When the initial setting is completed, the supply of the moving bed fluid containing the modifier from the liquid sending device 2 to the chromatographic device 1 is started. The control unit 16 of the liquid delivery device 2 performs control according to the flowchart shown in FIG.

In FIG. 4, in step S1, initial settings such as setting the pump 17 to the initial position and setting the three-way switching valve 11 to the initial position are performed. When the initial setting is completed, it is determined in step S2 whether or not there is a pump start command from the control device 3. Similarly, in step S3, it is determined whether or not there is a pump stop command. In step S4,
It is determined whether or not there is a switching command for the three-way switching valve 11. In step S5, other processing such as processing based on information from a sensor (not shown) is performed. When the process in step S5 is completed, the process returns to step S2. That is, in steps S2 to S4, the control device 3 waits for a pump start / stop command and a valve switching command.

If there is a pump start command from the controller 3, the program proceeds from step S2 to step S6 to start the pump 17. Thereby, for example, first, the mobile phase fluid is supplied from the container 8 to the liquid feed pump 7 side. When the predetermined time corresponding to the specified modifier concentration elapses, the control device 3 issues a valve switching command to the liquid delivery pump 7, and the program proceeds from step S4 to step S7. In step S7, the three-way switching valve 11 is switched,
The modifier is supplied from the container 9 to the liquid delivery pump 7 side. When the time corresponding to the designated concentration has elapsed, the valve switching designation is again made from the control device 3, so the program shifts from step S4 to step S5 again and performs the valve switching operation. As a result, the mobile phase fluid is supplied to the liquid feed pump 7 again. In this way, the switching operation of the three-way switching valve 11 supplies the mobile phase fluid and the modifier to the liquid delivery pump 7 one after another so that the specified modifier concentration is achieved. In the liquid feed pump 7, both liquids are mixed in a mixer (not shown) and then supplied to the chromatograph device 1.

On the basis of the above-mentioned valve switching operation, the moving bed fluid and the modifier are successively sent from the both containers 8 and 9 to the liquid sending pump 7 side. As a result, the internal pressure fluctuates between the containers 8 and 9, and an imbalance in pressure tends to occur between the containers 8 and 9. However, in this embodiment, the partition wall shown in FIG.
The movement of 13 absorbs the internal pressure difference, and both containers 8 and
Match the internal pressure within 9. Therefore, the three-way switching valve 11
The fluid will not flow back into the container 8 or 9 during the switching operation.

Since the operation of the Kramatograph apparatus 1 and the processing operation based on the detection result thereof are normal operations, detailed description thereof will be omitted here.

When the analysis operation is completed, a pump stop command is issued from the control device 3, so in the liquid delivery device 2, the process proceeds from step S3 to step S8, and the pump 17 is stopped.

Here, since the moving bed fluid and the modifier housed in both the containers 8 and 9 having the same internal pressure are alternately sent to the liquid sending pump 7 via the valve 11, the liquid sending pump 7 is connected between the two fluids. It becomes possible to share with, and the pump structure becomes simple.
Moreover, since the modifier concentration can be changed only by changing the switching timing of the switching valve 11, the modifier concentration can be easily changed even during the analysis in the chromatograph.

[Other Examples]

(A) In the above embodiment, the switching timing of the three-way switching valve 11 is determined by the command from the control device 3, but the control unit 16 may be provided with the function of determining the valve switching timing. In this case, data of the modifier concentration is input as a signal from the control device 3 to the liquid feed pump 7, and the liquid feed pump 7 determines the valve switching timing based on the signal.

(B) In addition to or instead of the connecting portion 12, the containers 8 and 9 may be provided with a temperature control device (cooling device, heating device, or both). This also enables the operation of matching the internal pressures of the containers 8 and 9.

(C) By synchronizing the opening / closing timing of the inlet of the three-way switching valve 11 with the fluid suction timing of the liquid feed pump 7, the fluid can be transported more smoothly.

(D) It is also possible to use a plurality of modifiers by providing a plurality of modifier containers and connecting them to the moving-bed fluid container in the same manner as described above.

(E) The modifier may be filled in the connecting portion 12.

(F) As the three-way switching valve 11, individual open / close valves can be used individually. Alternatively, a solenoid valve may be used.

(G) Instead of pressure control by moving the partition wall 13,
The pressure may be controlled by providing a pressure sensor therein and supplying pressurized gas to the container 9 through a valve. Here, the pressure between the two containers 8 and 9 is made to match by appropriately supplying pressurized gas to the container 9 based on the detection result from the pressure sensor.

[Effect of device]

Since the liquid delivery device for a supercritical fluid chromatograph according to the present invention is provided with the pressure matching means and the switching means as described above, the pump configuration is simplified and the modifier concentration can be easily changed during analysis. You can do it.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a supercritical fluid chromatograph analysis apparatus adopting one embodiment of the present invention, FIG. 2 is a vertical sectional view of a container portion of one embodiment of the present invention, and FIG. 3 is the present invention. FIG. 4 is a schematic block diagram of a control unit according to one embodiment of the present invention, and FIG. 1 ... Chromatograph device, 2 ... Liquid sending device, 7 ... Liquid sending pump, 8 ... Mobile phase fluid container, 9 ... Modifier container, 11 ... Three-way switching valve, 13 ... Partition wall, 17 ……
pump.

Claims (1)

(57) [Scope of utility model registration request] 1. A liquid delivery device for a supercritical fluid chromatograph for delivering a mobile phase fluid and a modifier to a supercritical fluid chromatograph device, the delivery device for delivering a fluid to the supercritical fluid chromatograph device. A liquid pump, a mobile phase fluid container, a modifier container, pressure matching means for matching the pressure between the two containers, and one of the two containers for communicating with the liquid delivery pump A liquid feeding device for a supercritical fluid chromatograph, which comprises a switching means.