JP4228502B2 - Liquid chromatograph and flow path switching valve - Google Patents

Description

[0001]
BACKGROUND 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 path switching valve used for switching a flow path in a liquid chromatograph or other apparatus. It is about.
[0002]
[Prior art]
FIG. 1 is a schematic flow path configuration diagram showing a conventional HPLC.
The sample is collected from the column 5 for separating the sample, the pump unit 1 for feeding the mobile phase to the column 5, and 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. The auto-injector 3 introduced into the upstream mobile phase flow path, the detection unit 7 for detecting the sample separated by the column 5, and the control unit 41 for controlling the operation of the pump unit 1 and the auto-injector 3. .
[0003]
The pump unit 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 suctioned to the secondary pump head 17 via a check valve 13b. Connected to the side. The discharge side of the secondary pump head 17 is connected to the auto injector 3 via a drain valve 19 and a line filter 21. A pressure sensor 23 is provided in the flow path between the secondary pump head 17 and the drain valve 19. The drain valve 19 can be connected by switching the discharge side of the secondary pump head 17 to the auto injector 3 or the drain by manually switching the lever 25.
[0004]
The autoinjector 3 is provided with a 2-position 6-port valve 29 for switching the flow path from the pump unit 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 the 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 metering 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.
A detection unit 7 that detects the sample separated by the column 5 is connected downstream of the column 5.
Thin tubes are used in 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 in order to prevent dilution of the sample.
[0005]
In this conventional example, when the mobile phase is filled with the mobile phase or the mobile phase is replaced when the apparatus is started up, the volume of the inside of the pump 9 is relatively large. When flowing, replacement of the mobile phase inside the pump takes a long time. However, if the mobile phase is allowed to flow at a high speed, the pressure after the injection port 35 including the column 5 is so thin that the pressure increases. Therefore, the mobile phase cannot flow at a high speed in the flow path after the injection port 35. Therefore, after the drain valve 19 is switched to the drain side in the pump unit 1, the pump 9 is driven at a high speed to introduce the mobile phase into the pump 9.
[0006]
The operation will be described. First, the lever 25 of the drain valve 19 is manually moved to connect the discharge side of the secondary pump head 17 to the drain. Next, the pump 9 is driven at high speed, and the mobile phase is discharged from the drain via the drain valve 19. After the insides 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 the normal speed, and the lever 25 of the drain valve 19 is switched manually to switch the secondary pump head. The discharge side of 17 is connected to the autoinjector 3 so that a new mobile phase flows through the entire flow path.
[0007]
[Problems to be solved by the invention]
  Since manually opening and closing the drain valve for filling or replacing the mobile phase 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 torque motor is required because a high pressure is applied to the drain valve, which increases the cost of the apparatus.
  In addition, a sample suction / discharge member such as the metering syringe 33 that performs sample suction and discharge must be cleaned each time the sample is changed. This cleaning operation can be performed simultaneously with the filling or replacement of the mobile phase. It is hoped that this will be done.
  ThereforeObject of the present inventionIn liquid chromatographs, the filling or replacement of the mobile phase and the cleaning of the suction / discharge member of the sample introduction unit can be performed simultaneously without increasing the cost, and these operations can be automated.is there.
[0008]
[Means for Solving the Problems]
  The liquid chromatograph of the present invention includes a column for separating a sample, a liquid feeding part for feeding a mobile phase to the column, and a suction / discharge member, and takes a sample from a sampling needle to a sampling loop. A sample introduction section that switches the flow path switching valve and introduces it into the mobile phase flow path upstream of the column, a detection section that detects the sample separated by the column, and a control section that controls the operation of the liquid feeding section and the sample introduction section A drain port for discharging the liquid discharged from the sampling needle to the outside, the flow path switching valve includes first and second flow path switching valves, and the control unit includes each part. In addition to the control of the analysis operation by, the first flow path switching valve is switched to connect the liquid feeding section to the sampling needle through the sampling loop, and the suction / discharge member is switched to the second flow path. While connected to the washing solution flow path connected to one port of the lube, positioning the sampling needle into the drain port, the driving of the liquid supply portionThan at the time of analysisThe operation for switching to high speed driving is also controlled, and the second flow path switching valve is switched to connect the suction / discharge member to the cleaning liquid container while the first flow path connection valve remains in the above-mentioned connection state. Control is also performed to perform an operation of sucking the cleaning liquid and an operation of switching the second flow path switching valve to connect the suction / discharge member to the drain port and discharging the suctioned suction liquid to the drain port. .
[0009]
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 feed section and the sample introduction section to set the first flow path switching valve. By switching, the liquid feeding part is connected to the sampling needle side, the suction / discharge member is connected to the cleaning liquid flow path side, the sampling needle is moved from the injection port to the drain port, and the flow rate of the liquid feeding part is increased. The mobile phase is discharged from the liquid supply unit to the outside of the apparatus at high speed 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 controller 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 connection state, and causes the suction / discharge member to perform the suction operation. The suction 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 bring the suction / discharge member to the drain port side. The suction discharge member is discharged and the cleaning liquid is discharged from the suction discharge member to perform the purification operation of the suction discharge member.
[0010]
  FirstFlow path switching valveExampleAre equally spaced on the circumferenceIn order6 ports arranged(1)From(6)With stator and port(1)The port(2)Or(6)Channel groove A, port for switching to and connecting to(3)The port(2)Or(4)Channel groove B and port for switching to and connecting to(5)The port(4)Or(6)A flow path switching valve having a flow path groove C for switching and connecting to the flow path, wherein the flow path groove A is a port(1)From(2)Or port(1)From(6)The channel groove is longer than the distance up to(2)From(3)Or port(3)From(4)With a channel groove longer than the distance toThe port (1) is connected to the liquid feeding section, the port (2) is connected to the sampling loop, the port (3) is connected to the suction / discharge member, and the port (4) is connected to the second flow path switching valve. A flow path for the washing liquid connected to one port is connected, an injection port is connected to port (5), and a column is connected to port (6)It is what.
  The numbers in parentheses in this paragraph and in the claims mean the numbers in circles in the following paragraphs and drawings.
[0011]
Part of the channel grooves A and B is formed by extending the channel groove beyond the distance between the ports. As a result, in addition to the two positions where the channel grooves A, B, and C each connect between the ports, the port {circle around (1)} is changed to the port {circle around (2)} by the channel groove A and the port {circle around (3)} by the channel groove B. Is connected to port (4), or channel (1) is connected to port (6) by channel groove A, port (3) is connected to port (2) by channel groove B, and channel groove C is connected. Can take a state where the ports are not connected.
This flow path switching valve can be applied not only to the liquid chromatograph of the present invention but also to other analyzers and other apparatuses that require various flow path switching.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The first flow path switching valve includes at least a first position for connecting the liquid feeding unit to the column via the sampling loop, a first position for directly connecting the liquid feeding unit to the column, and connecting the suction / discharge member to the sampling loop. A third position for connecting the liquid feeding section to the sampling loop, closing the upstream of the column, and connecting the suction / discharge member to the flow path for the cleaning liquid connected to one port of the second flow path switching valve; The second flow path switching valve is at least a first position where 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 / discharge member Is not connected to the drain port, and is preferably switched between a second position where the cleaning liquid flow path is connected to the cleaning liquid container.
In order to facilitate the replacement of the mobile phase, a plurality of mobile phase containers containing different mobile phases are connected to the suction side of the liquid feeding unit via respective solenoid valves or liquid feed pumps. It is preferable that the mobile phase can be selected by opening / closing a valve or driving a liquid feed pump.
[0013]
【Example】
FIG. 2 is a schematic flow path configuration diagram showing an embodiment.
From a pump unit (liquid feeding unit) 2 for feeding a mobile phase, an autoinjector (sample introduction unit) 4 for introducing a sample into a flow path, a column 6 for separating a sample, and a detection unit 8 for sequentially detecting the separated sample It is configured.
The pump unit 2 includes a double plunger reciprocating liquid feeding pump 10 as an example. The suction side of the primary pump head 12 of the pump 10 is connected to the mobile phase container 16 in which the mobile phase is stored via the check valve 14a, and the secondary side pump head 18 is connected to the discharge side via the check valve 14b. Connected to the inhalation side. The discharge side of the secondary pump head 18 is connected to the auto injector 4 via a line filter 20 that removes foreign matters mixed in the mobile phase. A pressure sensor 22 is provided in the flow path between the secondary pump head 18 and the line filter 20.
[0014]
FIG. 3 is a schematic flow path configuration diagram showing the auto injector 4 in more detail.
The auto injector 4 includes 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 includes six ports (1) to (6) in the stator, and the rotor includes three flow channel grooves A, B, and C for switching the connection between these ports. Ports {circle around (1)} to {circle around (6)} are arranged on the circumference of the stator at equal intervals corresponding to 60 ° rotation of the rotor. The channel A is a channel for switching the port (1) to the port (2) or (6), and the channel (B) is changed from the port (3) to the port (2) or (4). The channel groove C is a channel groove for switching and connecting the port (5) to the port (4) or (6).
[0015]
Channel groove A is provided with a channel groove longer than the distance from port (1) to port (2) or from port (1) to port (6), and channel groove B is from port (2) to port (3) or A channel groove longer than the distance from port (3) to (4) is provided. That is, part of the channel grooves A and B is formed by extending the channel groove beyond the rotation of 60 °. For example, the length of the channel grooves A and B is 90 ° of rotation. is there. As a result, in addition to the two positions where the channel grooves A, B, and C each connect between the ports, as shown in the auto drain position of FIG. 1) can be connected to port (2) and port (3) can be connected to port (4) by channel groove B, while channel groove C can be connected between ports. It becomes a position valve.
[0016]
The stator of the low pressure valve 28 has four ports a to d, and the rotor has a position where the ports b and c are connected, and ports d and a as shown in FIGS. 6 and 9 described later. As shown in FIG. 8, which will be described later, a flow path groove is provided that can take three positions: a position where none of the ports are connected. Therefore, the low pressure valve 28 is also a three-position valve.
[0017]
The port {circle around (1)} of the high pressure valve 26 is connected to a flow path through which the mobile phase of the mobile phase container 16 is supplied by the pump unit 2. A sampling loop 24 is provided in the flow path connected to the port (2), 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 (3) is connected to the port b of the low-pressure valve 28 via a metering pump (suction / discharge member) 30. The port {circle around (4)} is connected to the port a of the low-pressure valve 28 by the cleaning liquid channel 42. An injection port 32 is connected to the port (5). An analysis flow path connected to the detection unit 8 through the column 6 is connected to the port (6).
[0018]
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 supplied to the drain port 38 and the mobile phase is discharged from the sampling needle 36. You can also. The rinse liquid and the mobile phase overflow from the drain port 38 and are discharged to the drain. The flow path connected to the other port d is led to a cleaning liquid container 44 that stores a rinse liquid.
[0019]
Thin pipes are used in the flow path between the injection port 32 and the valve 26, the flow path between the valve 26 and the column 6, and the flow path between the column 6 and the detection unit 8 in order to prevent dilution of the sample.
In order to control the operation of the pump unit 2 and the autoinjector 4, a control unit 40 is provided.
[0020]
In this embodiment, the operation during analysis will be described. 3 to 7 show the sampling operation in the order of positions.
FIG. 3 shows the (A) Ready (under analysis) position. The high pressure valve 26 is connected between ports (1) and (2) and between (5) and (6). The sent mobile phase passes through the sampling loop 24, passes through the connection point between the sampling needle 36 and the injection port 32, and flows through the flow path from the column 6 to the detection unit 8.
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.
[0021]
FIG. 4 shows the (B) De-press (pressure release process) position. When the high pressure valve 26 is switched from the state shown in FIG. 3 and the ports (2) and (3) are connected, 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. Further, the connection between the ports {circle around (1)} and {circle around (6)} of the high-pressure valve 26 allows the mobile phase to continue flowing through the flow path through the column 6 and the detection unit 8.
[0022]
FIG. 5 shows a (C) Load (sample inhalation) 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. The sampling needle 36 is immersed in the sample container 34 containing the sample, the metering pump 30 is inhaled, and the sample is sucked into the sampling loop 24 and collected.
[0023]
FIG. 6 shows the (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, the high pressure valve 26 is switched, and the port ▲ 1 Between ▼ and (2) and between ports (5) and (6) are connected. As a result, the mobile phase passes through the sampling loop 24, passes through the connection point between the sampling needle 36 and the injection port 32, flows through the flow path from the column 6 to the detection unit 8, and the sample collected by the sampling loop 24 enters the column 6. The sample separation is started in column 6.
[0024]
Further, the high pressure valve 26 is also connected between the ports (3) and (4) in the state of FIG. The low pressure valve 28 is switched from the state shown in FIG. 5 to a state where the ports b and c are connected while the port a is closed. Then, the metering pump 30 is discharged, and the rinse liquid and the sample in the metering pump 30 are discharged to the drain port 38. Thereafter, the low-pressure valve 28 is switched again, and the ports a and d are connected as shown in FIG. 6. After the port b is closed, the metering pump 30 is inhaled and the cleaning liquid container 44 is discharged. Rinse solution is sucked into the metering pump 30
.
[0025]
FIG. 7 shows the (E) Purge out (measuring 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 metering pump 30 is discharged, the rinse liquid sucked into the metering pump 30 is discharged from the drain port 38, and the flow path of the metering 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 components separated by the column 6 are detected by the detection unit 8.
In this way, through the positions (A) → (B) → (C) → (D) → (E) in the order shown in FIG. 3 to FIG. 7, sampling into the sampling loop 24, column 6 A series of analysis operations of injection, separation and analysis are automatically performed. Then, after the rinse liquid is sucked into the metering pump 30 at the position (D), the low-pressure valve 28 is switched to connect between the ports b and c, and the position (A) is returned. Here, it is preferable to perform the purification operation of the metering pump 30 by repeating the positions (D) and (E) during the analysis.
[0026]
In this embodiment, as another position, there is a (F) Auto Drain (automatic discharge) position shown in FIG.
In the Auto Drain position (F), only the ports (1) and (2) and the ports (3) and (4) of the high-pressure valve 26 are connected, and the sampling needle 36 is moved to the drain port 38. The other ports (5) and (6) of the high pressure valve 26 and all the ports of the low pressure valve 28 are closed. Then, the mobile phase is sent by the pump unit 2 and discharged from the high pressure valve 26 to the drain port 38 through the sampling loop 24.
[0027]
The case where the entire flow path is filled with the mobile phase or the mobile phase is replaced using the Auto Drain position (F) will be described.
The switching of the high-pressure valve 26 and the low-pressure valve 28 and the movement of the sampling needle 36 are in the position (A) Ready → (B) De-press → (F) Auto Drain → (B) De-press → (A) Ready. To be controlled.
That is, initially, the position is at the Ready position (A) shown in FIG. 4 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 driving of the pump unit 2 is switched to high-speed driving, and the mobile phase is filled or replaced in a short time. After the mobile phase is filled or replaced, the mobile phone is returned to the Ready position (A) through the De-press position (B).
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 the drain valve motor is 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 apparatus.
[0028]
In this embodiment, as another position, (G) Auto Drain / Purge in (automatic drain / purge inhalation) position shown in FIG. 9 and (H) Auto Drain / Purge out ( There is an automatic discharge / metering pump purge discharge) position.
At the position (G), the ports a and d of the low pressure valve 28 are connected and the port b is closed while the high pressure valve 26 is in the position (F). Then, the metering pump is inhaled, and the rinse liquid is sucked into the metering pump 30 from the cleaning liquid container 44.
[0029]
At the position (H), the low pressure valve 28 is switched while the high pressure valve 26 is in the position (G), the port b and c are connected, and the port a is closed. Then, the metering pump 30 is operated to discharge, and the rinse liquid sucked into the metering pump 30 is discharged from the drain port 38.
According to the present invention, by repeating the positions (G) and (H), the purification operation of the metering pump 30 can be performed automatically while filling or replacing the mobile phase of the pump unit 2.
[0030]
In the present invention, since the (F) Auto Drain position shown in FIG. 8 can be taken, the filling and replacement of the mobile phase can be automatically executed by a program. This means, for example, that the mobile phase replacement from the plurality of mobile phase vessels to the respective valves in gradient analysis is automatically executed by the program before the analysis start time, thereby shortening the analysis time. Will be able to. The next FIG. 11 is an example of such a gradient analysis.
[0031]
FIG. 11 is a schematic configuration diagram showing a part of another embodiment.
Mobile phase containers 43a, 43b, 43c each containing a mobile phase and a cleaning liquid container 43d containing a cleaning liquid are connected to the suction side of the primary pump head of the pump section via electromagnetic valves 45a, 45b, 45c, 45d, respectively. Has been.
Since the opening and closing of the solenoid valves 45a, 45b, 45c, and 45d can be controlled to select the mobile phase or the cleaning liquid, the mobile phase can be selected and replaced with only a button operation. It is also possible to automate the cleaning process.
If the (F) Auto Drain position is programmed according to the present invention, the replacement of the mobile phase from the mobile phase containers 43a to 43c to the respective electromagnetic valves 45a to 45c can be automated.
[0032]
In this embodiment, the mobile phase and the cleaning liquid are selected by opening and closing the electromagnetic valves 45a, 45b, 45c, and 45d. However, the present invention is not limited to this, and a liquid feed pump instead of the electromagnetic valve is used. The mobile phase and the cleaning liquid may be selected by driving the liquid feeding pump. In that case, the mobile phase replacement of the flow path from each mobile phase container to the mixer through each liquid feed pump can be automated by a program.
[0033]
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 is omitted.
The stator of the low-pressure valve 48 has five ports a to e, and the rotor is in addition to the position where the ports b and c are connected, the position where the ports d and a are connected, and the position where none of the ports are connected. Thus, it is a 4-position valve that can take a position where the ports d and e are connected. A manual syringe 50 is connected to the port e.
[0034]
When the rinsing liquid is filled in the flow path between the cleaning liquid container 44 and the port d, the rinsing liquid is cleaned by repeating the operation similar to the operation described in FIGS. 6 and 7 and repeating the suction and discharge of the metering pump 30. Although the flow path between the container 44 and the port d may be filled, it takes time to fill the rinse 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 inhaled to fill the flow path between the cleaning liquid container 44 and the port d with the rinse liquid. Thereby, the time taken to fill the rinse liquid can be shortened.
[0035]
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 second flow path switching valve only needs to be a valve that can be switched between at least three positions. The first flow path switching valve is a first flow path connecting valve to the column via the sampling loop. The second position where the position and the liquid delivery part are directly connected to the column and the suction / discharge member is connected to the sampling loop, and the liquid delivery part is connected to the sampling loop, the upstream of the column is closed, and the suction / discharge member is used for the cleaning liquid The second flow path switching valve is switched at least between the suction and discharge member to the drain port and is cleaned. As long as it can be switched between a first position where the flow path is not connected to the cleaning liquid container and a second position where the suction / discharge member is not connected to the drain port and the cleaning liquid flow path is connected to the cleaning liquid container Good.
[0036]
【The invention's effect】
In the liquid chromatograph of the present invention, the drain port for discharging the liquid discharged from the sampling needle to the outside, the flow path switching valve includes the first and second flow path switching valves, and the mobile phase is filled or replaced. In addition, the control unit switches the first flow path switching valve to connect the liquid feeding unit to the sampling needle through the sampling loop, positions the sampling needle to the drain port, and switches the driving of the liquid feeding unit to high speed driving. Since the operation is performed and the mobile phase is discharged from the drain port, not only the drain valve motor is unnecessary, but the drain valve itself is unnecessary, and the mobile phase is filled without increasing the cost of the apparatus. Or the replacement can be automated. Further, with the first flow path switching valve in the state of full or replacement of the mobile phase, the controller switches the second flow path switching valve to connect the cleaning liquid flow path to the cleaning liquid container and suck the metering pump. Since the operation of sucking the cleaning liquid by operating and switching the second flow path switching valve to connect the metering pump to the drain port and discharging the cleaning liquid by operating the discharge of the metering pump, move The cleaning operation of the metering pump can be performed automatically during phase filling or replacement.
[Brief description of the drawings]
FIG. 1 is a schematic flow channel configuration diagram showing conventional HPLC.
FIG. 2 is a schematic flow path configuration diagram showing an embodiment.
FIG. 3 is a schematic flow path configuration diagram showing the embodiment in a ready position.
FIG. 4 is a schematic flow path configuration diagram showing the embodiment in a De-press position.
FIG. 5 is a schematic flow path configuration diagram showing the embodiment at a load position.
FIG. 6 is a schematic flow path configuration diagram showing the same example in an INJ / Purge in position.
FIG. 7 is a schematic flow path configuration diagram showing the embodiment at a purge out position.
FIG. 8 is a schematic flow path configuration diagram showing the embodiment at an Auto Drain position.
FIG. 9 is a schematic flow path configuration diagram showing the embodiment in an Auto Drain / Purge in position.
FIG. 10 is a schematic flow path configuration diagram showing the embodiment at an Auto Drain / Purge out position.
FIG. 11 is a schematic flow channel configuration diagram showing a mobile phase supply portion for gradient analysis of another embodiment.
FIG. 12 is a schematic flow path configuration diagram showing still another embodiment.
[Explanation of symbols]
2 Pump part
4 Auto injector
6 columns
8 detector
10 Double plunger reciprocating liquid feed pump
12 Primary pump head
16 Mobile phase vessel
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

Claims (4)

A column for separating the sample, a liquid feeding part for feeding the mobile phase to the column, and a suction / discharge member are collected from the sampling needle to the sampling loop, and the collected sample is switched by switching the flow path switching valve. A sample introduction unit for introducing the injection phase into the mobile phase flow path upstream of the column, a detection unit for detecting the sample separated by the column, and a control unit for controlling operations of the liquid feeding unit and the sample introduction unit In a liquid chromatograph equipped with
A drain port for discharging the liquid discharged from the sampling needle to the outside;
The flow path switching valve includes first and second flow path switching valves,
In addition to controlling the analysis operation by each unit, the control unit switches the first flow path switching valve to connect the liquid feeding unit to the sampling needle through the sampling loop, and the suction and discharge member to the second In addition to connecting to the cleaning liquid flow path connected to one port of the flow path switching valve, the sampling needle is positioned in the drain port, and the operation of switching the liquid feeding section to drive at a higher speed than during analysis is also controlled. Do,
Furthermore, with the first flow path connection valve in the above-mentioned connection state, the second flow path switching valve is switched to connect the suction / discharge member to the cleaning liquid container and to suck the cleaning liquid into the suction / discharge member. The second flow path switching valve is switched so that the suction / discharge member is connected to the drain port, and control is performed to cause the suction / discharge member to discharge the cleaning liquid sucked into the drain port. Liquid chromatograph. The first flow path switching valve has at least a first position for connecting the liquid feeding section from the injection port to the column via the sampling loop, and directly connecting the liquid feeding section to the column; A second position for connecting the suction / discharge member to the sampling loop; a liquid feeding unit connected to the sampling loop; an upstream of the column is closed; and the suction / discharge member is connected to the second flow path switching valve. It can be switched between the third position connected to the flow path for cleaning liquid connected to one port,
The second flow path switching valve includes at least a first position where the suction / discharge member is connected to the drain port and the cleaning flow path is not connected to a cleaning liquid container; and the suction / discharge member is connected to the drain port. 2. The liquid chromatograph according to claim 1, wherein the liquid chromatograph is not connected and can be switched between a second position at which the cleaning liquid channel is connected to the cleaning liquid container.   A plurality of mobile phase containers containing different mobile phases are connected to the suction side of the liquid feeding unit via respective electromagnetic valves or liquid feeding pumps, and by opening / closing those electromagnetic valves or driving the liquid feeding pumps. The liquid chromatograph according to claim 1 or 2, wherein a mobile phase can be selected. The first flow path switching valve includes a stator having six ports (1) to (6) sequentially arranged at equal intervals on the circumference, and a port (1) as a port (2) or (6). The channel groove A for switching and connecting to the port (3) , the channel groove B for switching and connecting the port (3) to the port (2) or (4) , and the port (5) to the port (4) or (6 a rotor having a flow channel C for connecting switch to),
The flow channel A includes a flow channel longer than the distance from the ports (1) to (2) or from the ports (1) to (6), and the flow channel B is formed from the ports (2) to (3). Or a channel groove longer than the distance from port (3) to (4) ,
The liquid feeding unit is connected to the port (1), the sampling loop is connected to the port (2), the suction / discharge member is connected to the port (3), and the second flow path switching is performed to the port (4). the washing solution flow path connected to one port of the valve is connected, the port (5) the injection port is connected, a liquid chromatograph according to claim 2, wherein the column port (6) is connected.

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