JPH0469569A - Method and device for dispensing sample for liquid chromatography - Google Patents

Abstract

PURPOSE:To warm a column up to its central part by allowing a free change- over to a circuit which successively connects a pump and a preheater, injector and column and a circuit which connects the pump and the column. CONSTITUTION:A selector valve 3, a preheating tube 4, the injector 5, and the column 6 are housed in an air oven 8. An eluate 9 flows through connecting ports 31 and 32 into the preheating tube 4 and is warmed up by the heater. The column 6 is warmed up by the passage of the warmed eluate 9. Of course, the injector 5, the column 6, etc., are kept warmed by the air oven 8, the column 6 is not warmed up to its center by the oven and, therefore, the warmed eluate 9 is successively passed therein, by which the column is warmed until the difference in the temp. between the inside and the outside is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a sample collection method and apparatus for liquid chromatography.

BACKGROUND OF THE INVENTION In liquid chromatography, in order to improve the reproducibility of analysis, there is a method in which the column is placed in an air-open environment and the temperature is kept constant.

Furthermore, recently this method has been applied to preparative liquid chromatography.

As shown in Figure 7, a conventional liquid chromatography sample separation device, especially a recycling separation device, connects a pump and a detector to a recycle valve, and connects a preheater and an injector column to the pump in sequence. A device is used in which the preheater, injector, and column are housed in an air vent, and the air vent is connected to a detector.

C. Problems to be solved Because the columns used in the preparative liquid chromatography mentioned above have a large inner diameter, it is not possible to heat the center of the column with air opening, and there is a gap between the periphery and the center within the column. This creates a temperature gradient. Therefore, the elution peak may become broad or peak cracking may occur. For this reason, when controlling the temperature of a preparative column with air open, it is necessary to preheat the eluent to the same temperature as the column (preheat) before introducing it into the column.

On the other hand, in order to perform efficient preparative separation in recycling, it is necessary to
...) It is necessary to minimize the dead volume of the equipment and piping to minimize diffusion outside the column.

Therefore, when attempting to use air open for recycling separation, the preheating portion becomes a large dead volume, resulting in poor recycling efficiency.

5. Means to Solve Problems Therefore, in the present invention, the temperature of the preparative column is controlled with air open, and the eluent is preheated to the same temperature as the column and introduced into the column, thereby narrowing the elution peak and suppressing the peak. This paper proposes a method and apparatus for solving the contradictory objectives of sharpening the column, while at the same time isolating the upper part of the column from the recycling system and achieving extremely high recycling efficiency. In the method of introducing the eluent by controlling the temperature in an air open and preheating the eluent, there is a process in which the sample is injected into the recycling system and the eluent is flowed through a preheater and an injector, and a preheating process is performed at the stage when the target component begins to elute. A liquid chromatography sample separation method comprising a step of removing a heater and an injector from a recycling system and flowing a sample eluent, and connecting a pump and a detector via a recycle valve, and a preheater and a preheater between the pump and the detector. In a sample separation device in which an injector and a column are connected and housed in an air opening, a switching valve is provided that connects the pump at one end and the preheater, injector, and column at the other end, and connects the pump, preheater, and injector. The present invention proposes a sample separation device for liquid chromatography, which is characterized in that it can be freely switched between a circuit that connects columns sequentially and a circuit that connects a pump and a column.

E, Example The present invention will be explained in detail below with reference to an embodiment shown in the drawings.

The upper part is a recycle valve, which has an inlet 1g for the eluent 9, a communication hole 12 with the pump 2, a communication hole 17 with the detector 7, and a discharge hole 1□. The pump 2 has two protruding ports and a connecting port 3 of the switching valve 3. It is connected to. One end of a preheat tube 4 as a preheater is communicated with the connection port 3□ of the switching valve 3, and the other end is connected to the switching port 5 of the injector 5. It is connected to. A loop 52 is connected to the injector 5 so that it can be switched freely, and one end of the loop 52 is connected to the connection port 3. of the switching valve 3 via the switching port 5□. It is connected to. A column 6 has one end connected to the connection port 34 of the switching valve 3, the other end connected to the detector 7, and the detection fM7 has one end connected to the communication hole 17 of the recycle valve 1.

The above-described switching valve 3, preheat tube 4, injector 5, and column 6 are housed in the air opening 8. Further, although a four-way switching valve is used as the switching valve 3 in the drawings, it is of course possible to use a six-way switching valve or any other suitable valve.

The use and operation thereof will be explained below. A sample is injected into the injector 5 in a conventional manner by injecting an arbitrary amount with a syringe through a needle port or by injecting a loop volume into a loop.

The eluent is circulated through the preheater and injector until the target component for recycling is eluted. That is,
The eluent 9 and the suction port 1g are communicated, and the eluent 9 is sucked through the communication hole 12 by the suction operation of the pump 2, and the eluent 9 is drawn into the eluent 2□.
Then feed it into the connection port 31 of the switching valve 3. At this time,
In the switching valve 3, the connection port 31 and the connection port 3□ communicate with each other, and the eluent 9 flows into the preheat tube 4 through the connection ports 31 and 32 and is heated by the heater. Then, it is sent to the injector 5. Next, the sample is sent through the switching port 53 through the loop 5□, through the switching port 51, through the connection port 31 of the switching valve 3, and into the column 6 through the connection port 34. The column 6 is warmed by the passage of the warmed eluent 9. Of course, injector 5,
Although the column 6 and the like are heated by the air open 8, the column 6 cannot be heated to the center by the oven, so by sequentially flowing the heated eluent 9, it can be heated until the difference between the inside and outside is eliminated. The eluent 9 discharged from the column 6 passes through the detector 7, returns to the recycle valve 1, and is discharged from the discharge hole 1.

When the target component of the sample flowing together with the eluent 9 begins to elute through the above operations, the recycle valve is switched to connect the communication hole 1□ and the communication hole I7 to form a circulation system. At the same time, switch the switching valve 3 and connect the connection port 31.
and connection port 34, and connect connection port 31, connection port 3□, and connection port 3. and the connection port 34 are cut off.

As a result, a recycle system including the recycle valve 1, the pump 2, the switching valve 3, the column 6, the detector 7, and the recycle valve 1 is formed.

In addition, as another route, as shown in Figures 3 and 4, the preheat tube 4 is connected to the connection port 3□, 33 of the switching valve 3.
The connection port 34 is connected to the switching port 5 of the injector 5.
Connect to □. Other switching ports of injector 5 5.
is connected to column 6. or.

The injector 5 has a switching port 5□ and a loop 5□ between the switching port 5□ and the switching port 51 so as to be freely switchable. When the switching valve 3 is switched, the connection port 3□ and the connection port 34 are communicated with each other, and the connection port 3□ of the switching valve 3 and the connection port 33 are cut off.

Furthermore, injector 5 is also disconnected from loop 5□.

In this case as well, a recycling system similar to the above is formed.

Example column: Inertsil PREP-ODS250
20+nm1. D.

Eluent Acetonitrile/Water = 674 Flow rate 10m Q/ll1in detection
UV254nm Temperature 40℃ Injection sample 1, m-Methyl acetophenone
2. o-Methyl acetophenone
FIG. 5 shows the chromatogram obtained as a result of carrying out the experiment according to FIG. 1 above.

In addition, the chromatogram of the results obtained in accordance with FIG. 7 is shown in FIG.

As a result, in the former case, the separation of the two components is still incomplete even after 11 times of recycling, whereas in the latter case, the separation of the two components is completed after 7 times of recycling.

Effects of the Invention According to the present invention as described above, in the method of controlling the temperature of the column in an air-open environment and preheating the eluent before introducing it, the sample is injected into the recycling system and passed through the preheater and injector. The process consists of the step of flowing the eluent, and the step of removing the preheater and injector from the recycling system and flowing the sample eluent at the stage when the target component begins to elute.Then, the pump and detector are connected via the recycle valve, and the pump A preheater, an injector, and a column are connected between the sensor and the detector, and in a sample separation device housed in an air open, a switching valve is installed, with one end connected to the pump and the other end connected to the preheater and the injector column, respectively. The circuit can be switched between a circuit that connects the pump, preheater, injector, and column in sequence, and a circuit that connects the pump and column, so the column is preheated by the eluent and heated to the same temperature as the eluent, allowing the target components to be absorbed. By forming a circulation system excluding the preheater and injector at the stage of elution, it is possible to prevent elution peaks from becoming broad or peak cracking due to temperature differences, and to produce clear peaks, while blocking dead volume. The recycling effect can be improved. Moreover, the structure is extremely simple and inexpensive, and the practical effects are great.

[Brief explanation of the drawing]

Figures 1 and 2 are illustrations of an embodiment of the present invention, Figures 3 and 4 are illustrations of an embodiment of the invention, Figure 5 is a chromatogram obtained by the conventional example, and Figure 6 is an illustration of the invention. The chromatogram obtained in the example, Figure 7, shows uI! It is an explanatory diagram of the next example. ,・1... Recycle valve, 2... Pump, 3.
...Switching valve, 6...Column, 7...Detector 1゜Indication of incident 1990 Patent Application No. 180565 2゜Name of invention Liquid chromatography sample separation method and device 3, correction Patent applicant address 2-4-10 Kabukicho, Shinjuku-ku, Tokyo Name Gascro Kogyo Co., Ltd. Representative Kenji Mori 4, agent 160 Address Nishi-Shinjuku, Shinjuku-ku, Tokyo 7-3-10 5゜

Claims (2)

[Claims] (1) In a method in which the temperature of the column is controlled in an air-open environment and the eluent is preheated and introduced, the sample is injected into the recycling system and the eluent is flowed through the preheater and injector, and the target component is eluted. A sample separation method for liquid chromatography that consists of the step of removing the preheater and injector from the recycling system and flowing the sample eluent at the beginning. (2) In a sample separation device in which a pump and a detector are connected via a recycle valve, a preheater, an injector, and a column are connected between the pump and the detector, and the sample separation device is housed in an air opening, one end is It is characterized by a switching valve that connects the pump and others to the preheater, injector, and column, respectively, so that it can be freely switched between a system that sequentially connects the pump, preheater, injector, and column, and a system that connects the pump and column. Liquid chromatography sample separation device.