JPH09243624A - Sample introducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sample introducing apparatus simple in constitution and capable of corresponding to a sample ranging from a very small amt. to a large quantity without lowering weighing accuracy. SOLUTION: A sampling passage 26 having a sample loop 25 having a sample injection needle 24 connected to one end thereof is connected to a pump passage 33 having a plunger pump 32. Two positions of the first state connecting a moving phase passage 20 having a liquid sending pump 21 and sending a moving phase from a moving phase tank 22 to an analyzing passage 31 having a column 29 and a second state connecting the samapllng passage 26 to the moving phase passage 20 and having an injection port 27 into which the sample injection needle 24 of the sampling passage 26 is inserted are changed over by one valve unit 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample introduction device which is suitable for use in an analytical device such as a liquid chromatograph and which can accurately measure and introduce a small amount of sample to a large amount of sample.

[0002]

2. Description of the Related Art In analyzers such as liquid chromatographs,
In particular, when performing an automatic analysis using an autosampler, a sample introduction device is used to introduce the sample into the analysis device. In the conventional sample introduction device, for example, as shown in FIG. At the time of introduction, with the 6-port valve 1 in the state shown in the figure, the sample injection needle 2 is moved to the position of the sample bottle 3 and lowered, and the syringe 4
A sample of a fixed amount is sucked from the sample bottle 3, and is introduced into the sample loop 5 and weighed. Thereafter, the 6-port valve 1 is rotated to the state shown in FIG. 2, the sample injection needle 2 is moved to the sample introduction port 6, and the sample loop 5 is moved by the mobile phase sent from the mobile phase tank 8 by the liquid delivery pump 7. The sample inside is extruded and introduced into the column 9 together with the mobile phase from the sample introduction port 6. 10 is a detector.

When the sample introduction is completed, the 6-port valve 1 is returned to the state shown in FIG. 1 again, the 3-port valve 11 is switched, the cleaning liquid is sucked from the cleaning liquid tank 12 by the syringe 4, and then the 3-port valve is again used. 11 is switched to wash the washing liquid by the syringe 4 to the sample loop 5 and the sample injection needle 2. At this time, the sample injection needle 2 is moved to the position of the cleaning port 13.

[0004]

In such a conventional sample introducing device, the sample amount is measured by the syringe 4, but when the range of the sample amount to be injected into the analyzing device is wide, There is a problem in that sufficient measurement accuracy cannot be obtained unless the syringe 4 is changed to a suitable one according to the scale of the sample amount to be measured, and the measurement with one syringe 4 inevitably decreases the accuracy. Further, since the sample to be introduced is measured by the syringe 4 via the 6-port valve 1 and the 3-port valve 11, the measuring system may be complicated, resulting in an increase in cost and a decrease in reliability.

An object of the present invention is to provide a sample introduction device having a simple structure and capable of handling a small amount of sample to a large amount of sample without deteriorating the measurement accuracy.

[0006]

In order to achieve the above object, in the sample introducing device of the present invention, a plunger pump is used as a metering pump, and one valve unit (1) has a sample injection needle at one end. While connecting the sampling flow path having the sample loop connected to the suction flow path of the pump flow path having the plunger pump,
A first state in which a mobile phase flow path having a liquid feed pump for sending a mobile phase from a mobile phase tank is connected to an analysis flow path having a column, and (2) a sampling flow path and a mobile phase flow path are connected. At the same time, the two positions of the sample introduction flow path having the injection port into which the sample injection needle of the sampling flow path is inserted and the second state in which the analysis flow path is connected are switched.

In addition to the first and second states,
(3) The suction side flow path of the pump flow path and the flow path communicating with the cleaning liquid tank are connected, the discharge side flow path of the pump flow path is connected to the sampling flow path, and the mobile phase flow path and the analysis flow path are connected. Provide a third state to connect and set these three positions to 1
It is designed to be switched by one valve unit.

As the above-mentioned one valve unit, a 7-way valve (7-port 3-position valve) can be applied, which is preferable.

The plunger pump is of a type in which the plunger is reciprocated in the cylinder by an external drive mechanism.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment in which the sample introduction device of the present invention is applied to a liquid chromatograph will be described with reference to the drawings. Before starting analysis, the state is as shown in FIG. That is, through the 7-port 3-position valve 23, a sample loop 25 having a liquid feed pump 21 for feeding a mobile phase from a mobile phase tank 22 and a sample loop 25 having a sample injection needle 24 connected to one end thereof is provided. An analysis flow path 3 including a sampling flow path 26, a sample introduction flow path 28 having an injection port 27 into which the sample injection needle 24 of the sampling flow path 26 is inserted, and a column 29.
1 is connected to each, and the mobile phase from the liquid feed pump 21 is 7
Port 3 position valve 23 → Sample loop 25 →
Sample injection needle 24 → injection port 27
→ 7 port 3 position valve 23 → column 29 is sent in this order. Note that this is the second state described in the problem solving means.

From this state, the 7-port 3-position valve 23 is switched to the state shown in FIG. 4, and the sample is sampled. That is, through the 7-port 3-position valve 23, the sampling flow path 26 and the plunger pump 32 are
The suction side flow path of the pump flow path 33 having a flow path, the mobile phase flow path 20 for sending the mobile phase and the analysis flow path 31 are respectively connected, and the mobile phase is sent in the order of 7-port 3-position valve 23 → column 29. . Note that this is the first state described in the problem solving means.

On the other hand, the sample injection needle 24 of the sampling flow path 26 moves away from the injection port 27, moves to the position of the sample bottle 34, and descends into the sample bottle 34. Is sucked and introduced into the sample loop 25. Then, the sample injection needle 24 moves to the position of the injection port 27 again.

When the sampling of the sample is completed in this way, the 7-port 3-position valve 23 is again switched to the state shown in FIG. 3, the sample is introduced into the analysis channel 31, and the analysis is started. That is, the mobile phase sent from the liquid delivery pump 21 is a 7-port 3-position valve 23 →
Sample loop 25 → Sample injection needle 24 → Injection port 27 → 7 port 3 position valve 2
The sample that has been sucked into the sample loop 25 and the sample injection needle 24 is sent to the column 29 together with the sample loop 25 and the sample injection needle 24, and is separated by the column 29. The result is detected by the detector 30. To be done.

During analysis, the suction side flow path of the pump flow path 33 and the flow path 37 communicating with the cleaning liquid tank 35 are connected via the 7-port 3-position valve 23, and the plunger pump 32 is driven to drive the cleaning liquid. By sucking the cleaning liquid from the tank 35 and discharging it from the cleaning port 36, the plunger pump 32 and the pump flow path 33 can be cleaned respectively.

Further, as another embodiment of the present invention, it is possible to configure as shown in FIG. That is, in the state of FIG. 4, the suction side flow path of the pump flow path 33 and the cleaning liquid flow path 37 are connected via the 7-port 3-position valve 23, and the discharge side flow path of the pump flow path 33 and the cleaning port 36 are connected. A three-way electromagnetic valve 38 is provided in between, and the remaining port (the discharge side flow path of the pump flow path 33) is connected to the sampling flow path 26. It should be noted that this is the third problem described in the problem solving means.
It is a state of.

In this state, the sample injection needle 2
When 4 is moved to the position of the cleaning port 36 and the plunger pump 32 is driven, the cleaning liquid becomes 7 port 3 position valve 23 → plunger pump 32 → pump flow path 33.
→ 3 way solenoid valve 38 → 7 port 3 position valve 2
It is possible to wash the sample loop 25 and the sample injection needle 24, respectively, in the order of 3 → sampling flow path 26 → sample loop 25 → sample injection needle 24 → wash port 36.

At this time, the three-way electromagnetic valve 38 connects the discharge side flow path of the pump flow path 33 and the sampling flow path 26 via the 7-port three-position valve 23, that is, the discharge side flow of the pump flow path 33. The connection between the passage and the cleaning port 36 is cut off.

[0018]

Since the present invention is configured as described above, it is possible to accurately measure a small amount of sample to a large amount of sample when aspirating and introducing the sample. Moreover, since the flow path is switched by one valve unit,
It is possible to simplify the flow path configuration, reduce costs, and improve reliability. Furthermore, it is possible to support automatic cleaning of the sample loop and the sample injection needle.

[Brief description of drawings]

FIG. 1 is a diagram showing a flow channel configuration (state during sampling) of a conventional sample introduction device.

FIG. 2 is a diagram showing a flow channel configuration (state during sample introduction) of a conventional sample introduction device.

FIG. 3 is a diagram showing a flow channel configuration of the sample introduction device of the present invention (state before starting analysis and during sample introduction / analysis).

FIG. 4 is a view showing a flow channel configuration (state at the time of sampling) of the sample introduction device of the present invention.

FIG. 5 is a diagram showing a flow path configuration (state during cleaning of a sample loop and a sample injection needle) of a sample introduction device which is another embodiment of the present invention.

[Explanation of symbols]

20 ... Mobile phase flow path 21 ... Liquid feed pump 22 ... Mobile phase tank 23 ... 7 port 3
Position valve 24 ... Sample injection needle 25 ... Sampling loop 26 ... Sampling flow path 27 ... Injection port 28 ... Sample introduction flow path 29 ... Column 31 ... Analysis flow path 32 ... Plunger pump 33 ... Pump flow path 34 ... Sample bottle 35 ... Cleaning liquid tank 36 ... Cleaning port 37 ... Cleaning liquid flow path 38 ... 3-way solenoid valve

Claims (2)

[Claims] (1) A sampling flow path having a sample loop having a sample injection needle connected to one end is connected to a suction flow path of a pump flow path having a plunger pump, and a liquid transfer pump is provided for movement. A state in which a mobile phase flow path for feeding a mobile phase from a phase tank and an analysis flow path having a column are connected, and (2) a sampling flow path and a mobile phase flow path are connected, and a sample injection needle of the sampling flow path 2. A sample introduction device characterized in that two positions, that is, a state in which a sample introduction flow path having an injection port into which is inserted and an analysis flow path are connected, are performed by switching one valve. 2. (1) A sampling flow path having a sample loop having a sample injection needle connected to one end is connected to a suction flow path of a pump flow path having a plunger pump, and a liquid transfer pump is provided for movement. A state in which a mobile phase flow path for feeding a mobile phase from a phase tank and an analysis flow path having a column are connected, and (2) a sampling flow path and a mobile phase flow path are connected, and a sample injection needle of the sampling flow path And a state in which the sample introduction flow path having an injection port into which is inserted is connected to the analysis flow path, and (3) the suction side flow path of the pump flow path and the flow path communicating with the washing liquid tank are connected to each other, and The discharge side flow path and the sampling flow path are connected, and the mobile phase flow path and the analysis flow path are connected. Sample introduction device that.