JP2001255316A - Liquid chromatograph and flow channel changeover valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automate the filling or replacement of a mobile phase and the cleaning operation of a metering pump without increasing cost. SOLUTION: A high pressure valve 26 is changed over to connect the flow channel from a pump part 2 to a sampling needle 36 through a sampling loop 24 and the sampling needle 36 is moved to a drain port 38. A pump 10 is driven at a high speed to fill or replace the flow channel from the interior of the pump 10 to the sampling needle 36 with a desired mobile phase at a high speed. During the filling or replacement of the mobile phase, a low pressure valve 28 is changed over to connect the metering pump 30 to a washing liquid container 44 through a valve 26, a washing liquid flow channel 42 and a valve 28 and a rinse liquid is sucked by the metering pump 30 and, thereafter, the pump 28 is changed over to connect the metering pump 30 to the drain port 38 through the valve 28 and the rinse liquid is discharged from the metering pump 30 to perform the cleaning operation of the metering pump 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid chromatograph for separating and analyzing various compounds in a sample, such as a high performance liquid chromatograph (hereinafter referred to as HPLC), and a flow channel switching by a liquid chromatograph and other devices. The present invention relates to a flow path switching valve to be used.

[0002]

2. Description of the Related Art FIG. 1 is a schematic flow path diagram showing a conventional HPLC. The column 5 for separating the sample, the pump unit 1 for sending the mobile phase to the column 5, and the sample are collected from the sampling needle 39 to the sampling loop 27, and the collected sample is switched to the column 5 by switching the flow path switching valve 29. Auto-injector 3 introduced into the mobile phase flow path upstream of
A detection unit 7 for detecting a sample separated by the column 5;
The control unit 41 is configured to control operations of the pump unit 1 and the auto injector 3.

The pump section 1 is provided with a double plunger reciprocating liquid feed pump 9. The suction side of the primary pump head 11 of the pump 9 is connected to a mobile phase container 15 in which a mobile phase is stored via a check valve 13a, and the discharge side is suction of a secondary pump head 17 via a check valve 13b. Connected to the side. Secondary pump head 1
The discharge side of 7 is connected to the auto injector 3 via a drain valve 19 and a line filter 21.
A pressure sensor 23 is provided in a flow path between the secondary pump head 17 and the drain valve 19. By manually switching the lever 25, the drain valve 19
The discharge side of the secondary pump head 17 can be switched to the auto injector 3 or the drain for connection.

The auto-injector 3 is provided with a 2-position 6-port valve 29 for switching the flow path from the pump section 1 to the sampling loop 27 or the column 5 for connection. The sampling loop 27 is connected to a sampling needle 39 that moves between the injection port 35 and the sample container 37, sucks a sample from the sample container 37, and discharges the sample to the injection port 35. The injection port 35 is connected to the column 5 by switching the valve 29. A measuring syringe 33 is connected to one port of the valve 29 via a three-way valve 31, and is connected to the sampling loop 27 by switching the valve 29. Downstream of the column 5, a detection unit 7 for detecting the sample separated in the column 5 is connected. A thin tube is used for the flow path between the injection port 35 and the valve 29, the flow path between the valve 29 and the column 5, and the flow path between the column 5 and the detection unit 7 to prevent dilution of the sample.

In this conventional example, when the whole flow path is filled with the mobile phase or the mobile phase is replaced when the apparatus is started, the inside of the pump 9 has a relatively large volume, so that the pump 9 operates at a low speed as usual. When the mobile phase flows, it takes a considerable time to replace the mobile phase inside the pump. However, when the mobile phase flows at a high speed, the pressure after the injection port 35 including the column 5 increases because the piping is thin. Therefore, the mobile phase cannot flow at a high speed in the flow path after the injection port 35. Therefore, the pump 9 switches the drain valve 19 to the drain side and then drives the pump 9 at high speed to introduce the mobile phase into the pump 9.

The operation will be described. First, the discharge side of the secondary pump head 17 is connected to the drain by manually moving the lever 25 of the drain valve 19. Next, the pump 9 is driven at a high speed to discharge the mobile phase from the drain via the drain valve 19. After the interiors of the primary pump head 11 and the secondary pump head 17 are filled with the new mobile phase, the pump 9 is returned to a normal speed, and the lever 25 of the drain valve 19 is manually switched to switch the secondary pump head. The discharge side of 17 is connected to the auto injector 3, and a new mobile phase flows through the entire flow path.

[0007]

Manually opening and closing the drain valve to fill or replace the mobile phase involves:
Since it is a complicated operation for the operator, automation is desired. However, when attempting to automate the opening and closing of the drain valve, a high pressure is applied to the drain valve, so that a high-torque motor is required, which increases the cost of the apparatus. Further, a sample suction / discharge member such as a measuring syringe 33 for sucking and discharging a sample must be washed every time the sample is changed. This washing operation can be performed simultaneously with the operation of filling or replacing the mobile phase. It is desired to do so. Therefore, a first object of the present invention is to provide a liquid chromatograph capable of simultaneously filling or replacing a mobile phase and cleaning a suction / discharge member of a sample introduction section without increasing costs, and performing these operations. Is to automate it. A second object of the present invention is to provide a flow path switching valve which is useful for achieving the first object, can be used for other purposes, and enables various flow path switching.

[0008]

The liquid chromatograph of the present invention comprises a column for separating a sample, a liquid sending section for sending a mobile phase to the column, and a suction / discharge member. A sample introduction unit that switches the flow path switching valve to introduce the collected sample into the mobile phase flow path upstream of the column, a detection unit that detects the sample separated by the column, a liquid sending unit, and a sample. A liquid chromatograph including a control unit that controls an operation of an introduction unit, wherein a drain port that discharges a liquid discharged from a sampling needle to the outside, and a flow path switching valve are first,
The control section is provided with a second flow path switching valve, and in addition to controlling the analysis operation by each section, the control section switches the first flow path switching valve to connect the liquid sending section to the sampling needle via a sampling loop, and performs suction and discharge. The member is connected to the cleaning liquid flow path connected to one port of the second flow path switching valve, the sampling needle is positioned at the drain port, and the operation of switching the driving of the liquid feeding section to high-speed driving is also controlled. An operation of switching the second flow path switching valve to connect the suction / discharge member to the cleaning liquid container while keeping the first flow path connection valve in the above-mentioned connected state, and sucking the cleaning liquid into the suction / discharge member; The suction valve is connected to the drain port by switching the passage switching valve, and control is performed to discharge the cleaning liquid sucked into the suction and discharge member to the drain port. Than it is.

When a signal for filling the flow path with the mobile phase or a signal for exchanging the mobile phase is sent from the outside to the control section, the control section controls the liquid sending section and the sample introduction section to control the first flow path. The liquid supply section is connected to the sampling needle side by switching the switching valve, the suction / discharge member is connected to the cleaning liquid flow path side, and the sampling needle is moved from the injection port to the drain port to increase the flow rate of the liquid supply section. The mobile phase is discharged to the outside of the apparatus at high speed from the liquid sending section via the first flow path switching valve, the sampling loop, the sampling needle and the drain port, and the flow path is filled or replaced with a desired mobile phase. Is done. The control unit further switches the second flow path switching valve to connect the cleaning liquid flow path to the cleaning liquid container side while keeping the first flow path switching valve in the above-described connected state, and causes the suction / discharge member to perform a suction operation. The cleaning liquid is sucked into the suction / discharge member via the second flow path switching valve, the cleaning liquid flow path, and the first flow path switching valve, and then the second flow path switching valve is switched to connect the suction / discharge member to the drain port side. The cleaning / discharging member is operated to perform a discharging operation to discharge the cleaning liquid from the suction / discharge member, thereby performing a purifying operation of the suction / discharge member.

The flow path switching valve of the present invention comprises a stator provided with six ports arranged at equal intervals on a circumference, a flow path groove A for switching the port to a port or a port, and a port groove. A flow channel switching valve comprising: a flow channel groove B for switching and connecting to a port or a port; and a rotor having a flow channel groove C for switching and connecting a port to a port or a port. Has a channel groove longer than the distance from the port or from the port, and the channel groove B has a channel groove longer than the distance from the port or from the port.

Part of the flow grooves A and B are formed so that the flow grooves extend beyond the distance between the ports. As a result, in addition to the two positions where the flow grooves A, B, and C connect the ports, the flow groove A connects the port to the port, and the flow groove B connects the port to the port.
Alternatively, a state in which the port is connected to the port by the channel groove A and the port is connected to the port by the channel groove B, and the channel groove C does not connect the ports can be obtained. This flow path switching valve is not only the liquid chromatograph of the present invention,
The present invention can be applied to other analysis devices and other devices that require various flow path switching.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first flow path switching valve has at least a first position in which a liquid sending section is connected to a column via a sampling loop and a liquid sending section directly connected to a column. To connect to the sampling loop
And a third position in which the liquid sending section is connected to the sampling loop, the upstream of the column is closed, and the suction / discharge member is connected to the washing liquid flow path connected to one port of the second flow path switching valve. The second flow path switching valve has at least a first position in which the suction and discharge member is connected to the drain port and a cleaning flow path is not connected to the cleaning liquid container, and a suction and discharge member. It is preferable that the connection can be made between a second position in which the cleaning liquid flow path is connected to the cleaning liquid container without being connected to the drain port. In order to facilitate replacement of the mobile phase, a plurality of mobile phase containers containing different mobile phases are connected to the suction side of the liquid sending unit via respective solenoid valves or liquid sending pumps. It is preferable that the mobile phase can be selected by opening / closing a valve or driving a liquid feed pump.

[0013]

FIG. 2 is a schematic flow diagram showing an embodiment of the present invention. A pump section (liquid sending section) 2 for sending a mobile phase, an auto injector (sample introducing section) 4 for introducing a sample into a flow path, a column 6 for separating a sample, and a detecting section 8 for sequentially detecting the separated sample. It is configured. The pump section 2 is provided with a double plunger reciprocating liquid feed pump 10 as an example. The suction side of the primary side pump head 12 of the pump 10 is connected to a mobile phase container 16 in which the mobile phase is stored via a check valve 14a, and the discharge side is connected to a secondary side pump head 18 via a check valve 14b. Is connected to the suction side. The discharge side of the secondary pump head 18 is
It is connected to the auto injector 4 via a line filter 20 for removing foreign matter mixed in the mobile phase. A pressure sensor 22 is provided in a flow path between the secondary pump head 18 and the line filter 20.

FIG. 3 is a schematic flow diagram showing the auto injector 4 in more detail. Auto injector 4
Is provided with a high-pressure valve (first flow path switching valve) 26 and a low pressure valve (second flow path switching valve) 28 to switch the flow path. The high-pressure valve 26 has six ports on the stator, and the rotor has three flow grooves A, B, and C to switch the connection between the ports.
It has. From the port, on the circumference of the stator,
The rotors are arranged at equal intervals for 60 ° rotation of the rotor. The flow channel A is a flow channel for switching the port to the port or the port for connection, the flow channel B is a flow channel for switching the port to the port or the connection, and the flow channel C is the port. Is a channel groove for switching and connecting to a port or a port.

The flow channel A has a flow channel that is longer than the distance from the port or from the port.
Has a channel groove that is longer than the distance from the port or from the port. That is, the flow grooves A and B
Is formed so that the flow channel extends beyond the rotation of 60 °, and the length of the flow channels A and B is, for example, 90 ° of rotation. As a result, in addition to the two positions where the flow grooves A, B, and C respectively connect the ports, as shown in the auto drain position in FIG. While the port is connected to the port by the flow channel B, the flow channel C can be in a state where the ports are not connected to each other, and the high-pressure valve 26 is a three-position valve.

The stator of the low-pressure valve 28 has four ports a to d, and its rotor has a position connecting the ports b and c, and ports d and a as shown in FIGS. 6 and 9 described later. And a flow path groove that can take three positions, that is, a position where no port is connected, as shown in FIG. 8 described later. Therefore, the low pressure valve 28 is also 3
It is a position valve.

The port of the high pressure valve 26 is connected to the pump 2
Is connected to the flow path of the mobile phase container 16 to which the mobile phase is supplied. A sampling loop 24 is provided in the flow path connected to the port, and a sampling needle 36 is provided at the tip of the flow path. The sampling needle 36 can move between the injection port 32, the sample container 34, and the drain port 38 (see FIG. 2). The flow path connected to the port is connected to the port b of the low-pressure valve 28 via a measuring pump (suction / discharge member) 30. The port is connected to a port a of the low-pressure valve 28 by a cleaning liquid flow path 42. An injection port 32 is connected to the port. The port is connected to an analysis flow path connected to the detection unit 8 via the column 6.

A drain port 38 is connected to the other port c of the low-pressure valve 28, and a rinse liquid (cleaning liquid) for cleaning the sampling needle 36 is connected to the drain port 38.
Is supplied, and the mobile phase can be discharged from the sampling needle 36. The rinsing liquid and mobile phase
It overflows from the drain port 38 and is discharged to the drain. The flow path connected to another port d is led to a cleaning liquid container 44 storing a rinsing liquid.

Injection port 32-valve 26
The flow path between the valve 26 and the flow path between the column 6 and the column 6
A thin tube is used in the flow path between the detection units 8 to prevent dilution of the sample. A control unit 40 is provided for controlling operations of the pump unit 2 and the auto injector 4.

In this embodiment, the operation at the time of analysis will be described. 3 to 7 show the sampling operation in order of position. FIG. 3 shows the (A) Ready (analyzing) position.
And the mobile phase sent out by the pump unit 2 passes through the sampling loop 24 and passes through the sampling needle 36 and the injection port 32.
Flows from the column 6 through the flow path passing through the detection unit 8 via the connection point of The low pressure valve 28 is connected between the ports b and c, and the metering pump 30 is opened to the atmosphere via the drain port 38.

FIG. 4 shows a (B) De-press (depressurizing step) position, in which the high-pressure valve 26 is switched from the state shown in FIG.
The flow path including the sample loop 24 is opened from the metering pump 30 to the atmosphere via the drain port 38, and the metering pump 30 is discharged in preparation for the next sample suction step.
In addition, by being connected to the port of the high-pressure valve 26, the mobile phase continues to flow through the flow path passing through the column 6 and passing through the detection unit 8.

FIG. 5 shows the (C) Load (sample suction) position. The low pressure valve 28 is switched from the state shown in FIG. 4 and the port b connected to the metering pump 30 is closed. Then, the sampling needle 36 is immersed in the sample container 34 containing the sample, the metering pump 30 is operated to suction, and the sample is sucked into the sampling loop 24 and collected.

FIG. 6 shows a (D) INJ / Purge in (sample injection / metering pump purge suction) position. The sampling needle 36 is returned to the injection port 32 from the state of FIG. 5, and the high-pressure valve 26 is switched.
The connection with the port and the connection with the port are made. As a result, the mobile phase passes through the sampling loop 24, flows through the flow path from the column 6 through the connection point between the sampling needle 36 and the injection port 32, and passes through the detection unit 8, and the sample collected by the sampling loop 24 flows into the column 6. The sample is then separated in column 6.

The high pressure valve 26 is also connected to a port in the state shown in FIG. Then, the low pressure valve 28 is switched from the state of FIG. 5 to a state in which the port b and the port c are connected while the port a is closed. Then, the measuring pump 30 is caused to perform a discharging operation, and the rinsing liquid and the sample in the measuring pump 30 are discharged to the drain port 38. Thereafter, the low-pressure valve 28 is switched again to connect between the ports a and d as shown in FIG. 6, and after the port b is closed, the metering pump 30 is operated to suction and the cleaning liquid container 44 The rinsing liquid is sucked into the metering pump 30.

FIG. 7 shows an (E) Purge out (measurement pump purge discharge) position. The low pressure valve 28 is switched from the state shown in FIG. 6 to connect the ports b and c, and the port a is closed. Then, the measuring pump 30 is caused to perform a discharging operation, the rinse liquid sucked into the measuring pump 30 is discharged from the drain port 38, and the flow path of the measuring pump 30 is washed. The analysis is continued while the high-pressure valve 26 remains in the state shown in FIG. 6, and the sample component separated in the column 6 is detected by the detection unit 8. Thus, the positions (A) → (B) → (C) in the order shown in FIGS.
By going through the states of (D) and (E), a series of analysis operations of sample collection to the sampling loop 24, injection to the column 6, and separation / analysis are automatically performed. Then, after the rinsing liquid is sucked into the metering pump 30 at the position (D), the low pressure valve 28 is switched to the port b.
And c are connected, and return to position (A). Here, it is preferable to perform the purifying operation of the measuring pump 30 by repeating the positions (D) and (E) during the analysis.

In this embodiment, as another position, there is an (F) Auto Drain (automatic drain) position shown in FIG. In the Auto Drain position (F),
Only the connection to and from the port of the high pressure valve 26 is made, and the sampling needle 36 is moved to the drain port 38. The other ports of the high pressure valve 26 and all ports of the low pressure valve 28 are closed. The mobile phase is sent by the pump unit 2 and is discharged from the high-pressure valve 26 to the drain port 38 via the sampling loop 24.

The case where the mobile phase is filled with the mobile phase or the mobile phase is replaced using the Auto Drain position (F) will be described. High pressure valve 26 and low pressure valve 2
8 and the movement of the sampling needle 36 are performed at the position (A) Ready → (B) De-press →
Control is performed so that (F) Auto Drain → (B) De-press → (A) Ready. That is, initially, the position is at the ready position (A) shown in FIG. Then, it is switched to the Auto Drain position (F) shown in FIG. 8 via the De-press position (B) shown in FIG. In the Auto Drain position (F), the drive of the pump unit 2 is switched to high-speed drive, and the filling or replacement of the mobile phase is performed in a short time. After the filling or replacement of the mobile phase is completed, the mobile terminal returns to the ready position (A) via the de-press position (B). Both the analysis operation of this embodiment and the operation of filling or replacing the mobile phase are controlled by the control unit 40 shown in FIG. According to the present invention, not only is the motor for the drain valve unnecessary, but also the drain valve itself is unnecessary. As a result, the introduction or replacement of the mobile phase can be automated without increasing the cost of the device.

In this embodiment, as other positions, (G) Auto Drain / Purge in (Automatic Drain / Purge in) position shown in FIG. 9 and FIG.
(H) Auto Drain / Purge out (automatic drain / metering pump purge discharge) position. In the position (G), the port a and the port d of the low-pressure valve 28 are connected while the high-pressure valve 26 is in the position (F), and the port b is closed. Then, the measuring pump is operated to suck, and the rinsing liquid is sucked into the measuring pump 30 from the cleaning liquid container 44.

In the position (H), the low-pressure valve 28 is switched while the high-pressure valve 26 is in the position (G) to connect the ports b and c, and the port a is closed. Then, the measuring pump 30 is caused to perform a discharging operation, and the rinse liquid sucked into the measuring pump 30 is discharged from the drain port 38. According to the present invention, by repeating the positions (G) and (H), the purifying operation of the metering pump 30 can be automatically performed while the mobile phase of the pump unit 2 is filled or replaced.

In the present invention, (F) Auto D shown in FIG.
Since the rain position can be taken, the filling and replacement of the mobile phase can be automatically executed by the program. This means that, for example, in the gradient analysis, the mobile phase of the flow path from the plurality of mobile phase containers to each valve is automatically replaced by a program by the analysis start time, thereby shortening the analysis time. Will be able to do it. FIG. 11 shows an example of such a gradient analysis.

FIG. 11 is a schematic diagram showing a part of another embodiment. Mobile phase containers 43a and 43 each containing a mobile phase are provided on the suction side of the primary side pump head of the pump unit.
b, 43c and a cleaning liquid container 43d containing the cleaning liquid are connected via solenoid valves 45a, 45b, 45c, 45d, respectively. Solenoid valves 45a, 45b, 45c, 45
Since the mobile phase or washing solution can be selected by controlling the opening and closing of d, it is possible to select and replace the mobile phase with just a button operation, and to automate the flow channel washing process after analysis. become. If the (F) Auto Drain position is programmed according to the present invention, the mobile phase containers 43a to 43a-4
The replacement of the mobile phase from 3c to each of the solenoid valves 45a to 45c can be automated.

In this embodiment, the solenoid valves 45a, 45b, 4
The mobile phase and the cleaning liquid are selected by opening and closing the opening and closing of 5c and 45d. However, the present invention is not limited to this. The moving pump is provided with a liquid feeding pump instead of a solenoid valve. Selection of a phase and a washing solution may be performed. In that case, the mobile phase replacement of the flow path from each mobile phase container to the mixer via each liquid sending pump can be automated by a program.

FIG. 12 is a schematic configuration diagram showing still another embodiment. The same parts as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. The stator of the low pressure valve 48 has five ports ae, the rotor of which is connected to the ports b and c described above.
This is a four-position valve that can take a position where ports d and e are connected in addition to a position where ports are connected, a position where ports d and a are connected, and a position where no port is connected. A manual syringe 50 is connected to the port e.

When the rinsing liquid is filled in the flow path between the cleaning liquid container 44 and the port d, the same operation as that described with reference to FIGS. The liquid may be filled in the flow path between the cleaning liquid container 44 and the port d, but in this method, it takes time to fill the rinsing liquid. Therefore, in this embodiment, the low pressure valve 48 is switched to connect the ports d and e, and then the manual syringe 50 is operated to suck the cleaning liquid container 44.
The flow path between the port and the port d is filled with a rinsing liquid. Thereby, the time required for filling the rinsing liquid can be reduced.

In the above embodiment, a three-position valve or a four-position valve is used as the first and second flow path switching valves, but the flow path switching valve constituting the present invention is not limited to this. , The first and second flow path switching valves need only be valves that can be switched between at least three positions, and the first flow path switching valve connects at least the liquid sending section to the column via the sampling loop. A first position and a second position where the liquid sending section is directly connected to the column and the suction / discharge member is connected to the sampling loop
And a third position in which the liquid sending section is connected to the sampling loop, the upstream of the column is closed, and the suction / discharge member is connected to the cleaning liquid flow path, and the second flow path switching valve is At least, a first position in which the suction / discharge member is connected to the drain port and the cleaning flow path is not connected to the cleaning liquid container, and the suction liquid discharge member is not connected to the drain port, and the cleaning liquid flow path is connected to the cleaning liquid container. What is necessary is just to be able to switch between the second position to be connected.

[0036]

According to the liquid chromatograph of the present invention, the drain port for discharging the liquid discharged from the sampling needle to the outside, and the flow path switching valve are provided with first and second flow path switching valves. At the time of filling or replacement, the control section switches the first flow path switching valve to connect the liquid sending section to the sampling needle via the sampling loop, and positions the sampling needle at the drain port to drive the liquid sending section. Operation is switched to high-speed drive, and the mobile phase is discharged from the drain port. This not only eliminates the need for a motor for the drain valve, but also eliminates the need for the drain valve itself, thereby increasing the cost of the device. And the filling or displacement of the mobile phase can be automated. Further, in a state where the first flow path switching valve is filled or replaced with the mobile phase, the control section switches the second flow path switching valve to connect the cleaning liquid flow path to the cleaning liquid container, and sucks the metering pump. The operation is performed such that the cleaning pump is operated to suction the cleaning liquid, and the second flow path switching valve is switched to connect the measuring pump to the drain port, and the measuring pump is discharged to perform the discharging operation of the cleaning liquid. The cleaning operation of the metering pump can be performed automatically during the filling or replacement of the phase.

[Brief description of the drawings]

FIG. 1 is a schematic flow path configuration diagram showing a conventional HPLC.

FIG. 2 is a schematic flow path configuration diagram showing one embodiment.

FIG. 3 is a schematic flow path configuration diagram showing the same embodiment in a ready position.

FIG. 4 is a schematic flow path configuration diagram showing the same embodiment in a De-press position.

FIG. 5 is a schematic flow path configuration diagram showing the same embodiment in a Load position.

FIG. 6 is a schematic flow path configuration diagram showing the same embodiment at an INJ / Purge in position.

FIG. 7 is a schematic flow path configuration diagram showing the same embodiment in a Purge out position.

FIG. 8 is a schematic channel configuration diagram showing the same embodiment in an Auto Drain position.

FIG. 9 is a schematic flow path configuration diagram showing the same embodiment in an Auto Drain / Purge in position.

FIG. 10 is a schematic flow diagram showing the same embodiment in an Auto Drain / Purge out position.

FIG. 11 is a schematic flow path configuration diagram showing a mobile phase supply part for gradient analysis according to another embodiment.

FIG. 12 is a schematic flow path configuration diagram showing still another embodiment.

[Explanation of symbols]

 2 Pump unit 4 Auto injector 6 Column 8 Detecting unit 10 Double plunger reciprocating liquid feed pump 12 Primary pump head 16 Mobile phase container 18 Secondary pump head 20 Line filter 22 Pressure sensor 24 Sampling loop 26 High pressure valve 28 Low pressure Valve 30 Metering pump 32 Injection port 34 Sample container 36 Sampling needle 38 Drain port 40 Control unit 42 Flow path for cleaning liquid 44 Cleaning liquid container

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G01N 30/50 G01N 30/50 35/10 35/08 C 35/08 35/06 DF

Claims (4)

[Claims] A sample is collected from a sampling needle to a sampling loop, comprising a column for separating a sample, a liquid sending section for sending a mobile phase to the column, and a suction / discharge member. A sample introduction unit that switches a switching valve and introduces the mobile phase flow path upstream of the column,
In a liquid chromatograph including a detection unit that detects a sample separated by the column, and a control unit that controls operations of the liquid sending unit and the sample introduction unit, a liquid discharged from the sampling needle is externally provided. A drain port for discharging, the flow path switching valve includes first and second flow path switching valves, and the control unit switches the first flow path switching valve in addition to controlling the analysis operation by the respective units. The liquid sending section is connected to the sampling needle via the sampling loop, the suction / discharge member is connected to a cleaning liquid flow path connected to one port of a second flow path switching valve, and the sampling needle is connected to the cleaning liquid flow path. Positioning at the drain port, control of the operation of switching the driving of the liquid sending section to high-speed driving is also performed. In the above connection state, the second flow path switching valve is switched to connect the suction / discharge member to the cleaning liquid container, and the operation of sucking the cleaning liquid into the suction / discharge member, and the second flow path switching valve A liquid chromatograph characterized in that the liquid chromatograph is switched to connect the suction / discharge member to the drain port and to perform an operation of discharging the cleaning liquid sucked into the suction / discharge member to the drain port. 2. The first flow path switching valve has at least a first position for connecting the liquid sending section to the column via the sampling loop, and a direct connection for connecting the liquid sending section to the column. A second position for connecting the suction / discharge member to the sampling loop, a liquid supply section connected to the sampling loop, closing the upstream of the column, and connecting the suction / discharge member to the second flow path switching valve. And a third position connected to a cleaning liquid flow path connected to one of the ports. The second flow path switching valve connects at least the suction / discharge member to the drain port, And a first position in which the cleaning flow path is not connected to a cleaning liquid container, and wherein the suction / discharge member is not connected to the drain port, and the cleaning liquid flow path is Liquid chromatograph according to claim 1 in which switches are between the second position to connect to solution purification vessel. 3. A plurality of mobile phase containers accommodating different mobile phases are connected to the suction side of the liquid sending section via respective solenoid valves or liquid sending pumps. 3. The liquid chromatograph according to claim 1, wherein a mobile phase can be selected by driving the liquid pump. 4. A stator having six ports arranged at equal intervals on a circumference, a flow channel A for switching the ports to the ports or the connection, and switching the ports to the ports or the connection. Channel groove B for
And a rotor provided with a flow channel C for switching and connecting the port to the port or the port, wherein the flow channel A is longer than the distance from the port or from the port. A flow path switching valve comprising a groove, wherein the flow path groove B has a flow path groove longer than a distance from a port or from a port.