JPS62856A - liquid chromatograph - Google Patents

Abstract

PURPOSE:To execute easy air venting by providing a six-way flow passage selector valve between a pump for feeding eluates and mixer so that the flow direction of the eluates in the mixer is changed over in the ordinary analyzing stage and in the exchanging stage of the eluates. CONSTITUTION:The eluates 11, 12, 13 fed by the pump 1 flow through the mixer 3 from above to below via the six-way flow passage selector valve 2A, flow through a column 5 again via the valve 2A and a sampler 4, are detected by a detector 6 and are discharged as a drain 9B in the analyzing stage. The valve 2A is changed over so that the eluates 11, 12, 13 fed by the pump 1 are passed through the valve 2A and through the mixer 3 from below to above in the exchanging stage of the eluates and the air venting stage. The easy air venting is thus executed.

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a liquid chromatograph, and particularly to a gradient apparatus having a mixer with a stirrer, in which the direction of flow of an eluent in the mixer can be easily changed up or down. It concerns liquid chromatographs, which are rivals.

[Background of the invention]

When performing a gradient elution method with a liquid chromatograph, one type of mixer that mixes the eluent uniformly is one that has one or more internal partitions that narrow the flow path, or one that has a high stirring capacity. Some systems are equipped with star sea in order to increase the stability, and in this case, the eluent can be mixed more uniformly if it flows from top to bottom. However, if you insert air into the tube to prevent backflow when exchanging the eluent, etc.

A problem arises in that air accumulates inside the mixer and becomes difficult to escape.

For this reason, in the invention previously given by the present inventor, the flow direction of the eluent in the mixer 3 is fixed from bottom to top, as shown in the flow path diagram of a liquid chromatograph shown in FIG. was. In FIG. 5, 1 is a pump, 4 is a sampler 5 is a column, 6 is a detector, 7 is a drain valve, and 9B.

9C is a drain, and 11, 12.13 are eluents.

The relationship between the configuration of the mixer and the gradient curve and baseline in each case is shown in Figure 6.
In the figure, a is a gradient curve, and 6 is a baseline.

FIG. 6(A) shows when there is nothing inside the mixer 3,
This is a case where the eluent flows from the bottom to the top. In this case, the put volume in the mixer 3 is large, and mixing is incomplete, resulting in poor efficiency. Figure 6 (B) shows a case where the mixer 3 is filled with glass beads and sintered metal 21 and the eluent is flowed upward from the bottom. Although the volume decreases, the mixing effect is not constant. Figure 6 (C) shows the case where the eluent is flowed from top to bottom in the mixer 3 equipped with a starter 22. In this case, the mixing effect is good, but the mixing effect is not constant. 22
A drive unit is required for this purpose, and a measure is required to remove air bubbles from the top during liquid exchange. FIG. 6(D) shows a case where a partition part 23 having one or more pores is provided in the mixer 3 and the eluent flows from above to below. In this case, the mixing effect can be improved. Furthermore, by flowing the eluent from top to bottom, the same effect as in the case of FIG. 6(C) can be obtained even when no stark is provided inside the mixer 3. Therefore, when air enters the system due to exchanging the eluent, it is most efficient if the air can be removed smoothly.

Therefore, when using the methods shown in Figure 6 (C) and (D),
It would be extremely effective if the air could be removed easily.

[Purpose of the invention]

The present invention has been made in view of the above, and its purpose is to be able to easily switch the flow direction of the eluent in the mixer between normal analysis and eluent exchange with a simple operation. The purpose of the present invention is to provide a liquid chromatograph that can vent air.

[Summary of the invention]

A feature of the present invention is that a flow path switching valve is provided between a pump for feeding the eluent and the mixer, which can reverse the flow direction of the eluent in the mixer. The point lies in the structure.

[Embodiments of the invention]

The present invention will be explained in detail below using the embodiments shown in FIGS. 1 to 4.

Figure 1 is a flow path system diagram showing one embodiment of the liquid chromatograph of the present invention, and shows the state during analysis. In FIG. 1, two or more eluents 1 are delivered by a pump 1.
1, 12, and 13 flow from above to below the mixer 3 via the hexagonal flow path switching valve 2A, pass through the sampler 4 through the column 5 via the hexagonal flow path switching valve 2A, and are detected by the detector 6. , is discharged as a drain 9B. 7 is a drain valve, which is closed in this case. 8 is one unused vertex of the hexagonal flow path switching valve 2A.

FIG. 2 is a flow path system diagram when exchanging the eluent and venting air in FIG. 1. In this case, the hexagonal flow path switching valve 2A is switched as shown. In this case, one or more eluents 11, 12, 13 sent by the pump 1 pass through the hexagonal flow path switching valve 2A, flow from below to the top of the mixer 3, and then pass through the hexagonal flow path switching valve 2A again. Through drain 9A
It is discharged as.

In FIGS. 1 and 2, the mixer 3 is provided with a partition 23 having one or more pores inside, but a mixer with a stirrer may also be used.

According to the embodiment shown in FIGS. 1 and 2, the flow direction of the eluent in the mixer 3 can be changed in the vertical direction by operating the hexagonal flow path switching valve 2A during normal analysis and when exchanging the eluent. It has the advantage that it can be switched in the opposite direction and air can be easily vented.

FIG. 3 is a flow path system diagram corresponding to FIG. 1 showing another embodiment of the present invention, and the same parts as in FIG. Note that FIG. 3 shows the state during normal analysis. In FIG. 3, the hexagonal flow path switching valve 2A in FIG. 1 is replaced with a four-way flow path switching valve 2B, and the other features are the same as in FIG. 1. In this case as well, pump 1
Two or more eluents 11, 12, 13 delivered by
flows from the top to the bottom of the mixer 3 via the four-way flow switching valve 2B, passes through the sampler 4 via the four-way flow switching valve 2B, passes through the column 5, and is discharged as drain 9B detected by the detector 6. Ru.

FIG. 4 is a flow path system diagram when exchanging the liquid and releasing air in FIG. 3. When the four-way flow path switching valve 2B is switched as shown in FIG. The eluents 11, 12, and 13 pass through the four-way flow path switching valve 2B, flow from the bottom to the top of the mixer 3, and then pass through the four-way flow path switching valve 2B again, so that air bubbles in the mixer 3 are removed from the column 5.
When the drain valve 7 is opened to avoid air entering the drain 9C, the air passes through the drain valve 7 and drains into the drain 9C.
It is discharged as.

Therefore, the same effects as those in FIGS. 1 and 2 can be obtained also in FIGS. 3 and 4.

〔Effect of the invention〕

As explained above, according to the present invention, the flow direction of the eluent in the mixer can be switched with a simple operation between normal analysis and eluent exchange, and air can be easily vented. effective.

[Brief explanation of the drawing]

1 and 2 are flow path system diagrams showing an embodiment of the liquid chromatograph of the present invention, and FIG. 1 shows the state during analysis,
Figure 2 shows the conditions during eluent exchange and air removal.
3 and 4 are flow path system diagrams showing other embodiments of the present invention, FIG. 3 shows the state during analysis, and FIG. 4 shows the state during eluent exchange and air venting. Fig. 5 is a flow path system diagram of a liquid chromatograph shown in the invention previously filed by the applicant of the present invention, and Fig. 6 shows the relationship between the form of the mixer and the gradient curve and baseline in each case. It is a line diagram. l... Pump, 2A... Hexagonal flow path switching valve, 2B
...Four-way flow path switching valve, 3...Mixer, 4 Sampler, 5...Column, 6...Detector, 7...Drain valve.

Claims (1)

[Claims] 1. A pump that sends a plurality of eluents, a mixer that mixes the eluent that has been sent, a sample introduction device that introduces a sample into the eluate from the mixer, a separation column, and a detector. A liquid chromatograph comprising: a flow path switching valve that can reverse the flow direction of the eluent in the mixer between the pump and the mixer. liquid chromatograph.