Valve control system, liquid chromatography system, and valve control method

Abstract

The objective is to extend the life of a flow path switching valve. [Solution] The device comprises a stator (110) having a plurality of ports (111), which are holes that connect from one end face to the other end face, and a rotor having grooves so that two adjacent ports (111) of the plurality of ports (111) can be connected. When port (111a) and port (111b) are not connected by groove (121), the control device reduces the pressure at port (111b) using a liquid transfer pump, and then connects port (111a) and port (111b) via groove (121b).

Description

[Technical Field]

[0001] The present invention relates to a valve control system, a liquid chromatography system, and a valve control method. [Background technology]

[0002] Mass spectrometers are capable of separating ions by the m / z of molecular ions in a vacuum. This allows them to detect ions with high sensitivity and precision. In mass spectrometry, ions are separated by m / z. Mass spectrometers are commonly used as detectors for separation analysis in liquid chromatography (LC). An analytical technique called liquid chromatography mass spectrometry (LC / MS), which combines liquid chromatography and mass spectrometry, is often used.

[0003] In a liquid chromatography system, a sample is passed through a separation column by pressurization using a liquid delivery pump. Then, the components of the sample are separated and detected due to differences in the interactions (adsorption, distribution, etc.) between the sample and the stationary phase and mobile phase of the separation column. In a liquid chromatography system, a sample under atmospheric pressure is introduced into a sample loop by a sample injection unit. Then, the flow path switching valve to which the sample loop is connected is switched, and the sample is introduced between the liquid delivery pump and the separation column.

[0004] While the inside of the sample injection section is generally atmospheric pressure, the pressure of the liquid delivery pump and separation column is on the order of several tens of MPa, which causes large pressure fluctuations when switching at the flow path switching valve. It is known that when a high-pressure flow path connects to a low-pressure flow path, the pressure difference generates a high-speed flow, which can damage the flow path switching valve. For this reason, flow path switching valves generally have a short lifespan.

[0005] Patent Document 1 discloses a technique for adjusting the length of the flow path to reduce the pressure of the mobile phase by making the length of the grooves in the rotor longer than the distance between the ports. According to Patent Document 1, the life of the valve can be extended. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] US Patent Application Publication No. 2009 / 0145205 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the technique described in Patent Document 1 has a problem in that a dead volume occurs in the flow path of the valve where no solution flows, resulting in carryover.

[0008] The present invention has been made in view of the above background, and an object of the present invention is to suppress carryover while extending the life of a flow path switching valve. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the present invention provides a flow path switching valve that switches between one or more flow paths, a pump that pressurizes a flow path connected to the flow path switching valve, and a control unit that controls the flow path switching valve and the pump. The flow path switching valve includes a stator having a plurality of ports that are holes that communicate from one end face to the other end face, and a rotor that is provided with a groove so that two adjacent ports of the plurality of ports can be connected. The stator includes a first port that is the port, and a second port that is provided separately from the first port and to which the pump is connected. The control unit reduces the pressure of the second port using the pump when the first port and the second port are not connected by the groove, and then connects the first port and the second port via the groove. Other solutions will be described as appropriate in the embodiments. [Effects of the Invention]

[0010] According to the present invention, it is possible to extend the life of the flow path switching valve and suppress carryover. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the configuration of a liquid chromatography system used in this embodiment. [Figure 2] FIG. 2 is a diagram illustrating a hardware configuration of a control device. [Figure 3] FIG. 2 is a diagram showing a configuration of a flow path switching valve. [Figure 4] 4 is an enlarged view of a port having an elongated hole shape provided in the flow path switching valve of FIG. 3. FIG. [Figure 5A] FIG. 1 is a diagram (part 1) showing the procedure of a valve control method by a control device. [Figure 5B] FIG. 2 is a diagram (part 2) showing the procedure of the valve control method by the control device. [Figure 5C] FIG. 3 is a diagram (part 3) showing the procedure of the valve control method by the control device. [Figure 5D]FIG. 4 is a diagram (part 4) showing the procedure of the valve control method by the control device. [Figure 5E] FIG. 5 is a diagram (part 5) showing the procedure of the valve control method by the control device. [Figure 6] FIG. 10 is a diagram relating to the length of a groove. [Figure 7] FIG. 2 is a diagram showing an example of the configuration of a liquid feed pump used in the present embodiment. [Figure 8] FIG. 10 is a diagram relating to the operation of a liquid feed pump. [Figure 9A] FIG. 1 is a diagram (part 1) showing the switching operation of the auto-purge valve. [Figure 9B] FIG. 2 is a diagram (part 2) showing the switching operation of the auto-purge valve. [Figure 9C] FIG. 3 is a diagram (part 3) showing the switching operation of the auto-purge valve. DETAILED DESCRIPTION OF THE INVENTION

[0012] Next, modes for carrying out the present invention (referred to as "embodiments") will be described in detail with reference to the drawings as appropriate.

[0013] [First embodiment] First, a first embodiment of the present invention will be described with reference to FIGS.

[0014] (Liquid Chromatography System Z) FIG. 1 is a diagram showing the configuration of a liquid chromatography system Z used in this embodiment.

[0015] The liquid chromatography system Z, which is a valve control system, includes a liquid chromatography apparatus Y, a detector 10, and a control device 9, which is a control unit. The liquid chromatography apparatus Y also includes two tanks 3 (tanks 3a and 3b) and two liquid delivery pumps 4 (liquid delivery pumps 4a and 4b). The liquid chromatography apparatus Y also includes an auto-purge valve 2, a sample injection unit 5, a sample dispensing syringe 6, a flow path switching valve 1, a separation column 7, and two waste liquid containers 8 (waste liquid containers 8a and 8b). In the example shown in FIG. 1, two tanks 3, two liquid delivery pumps 4, and two waste liquid containers 8 are provided, but the number of these is not limited to two.

[0016] Also, the tank 3 side is defined as the upstream side, and the detector 10 side is defined as the downstream side.

[0017] The liquid delivery pump 4, which is a pump, pressurizes the flow path connected to the flow path switching valve 1 (pressurizing the mobile phase flowing through the flow path). Specifically, the liquid delivery pump 4 delivers the mobile phase in the tank 3 by applying pressure. Typically, a liquid delivery pump 4 capable of delivering liquid within a pressure range of approximately 0.1 to 100 MPa is generally used. This is to ensure a flow rate sufficient for analysis when a separation column 7 with low conductance is installed in the flow path. In this embodiment, a serial-connected dual plunger pump or a parallel-connected dual plunger pump can be used as the liquid delivery pump 4. By using these pumps as the liquid delivery pump 4, the control device 9 synchronizes the pushing and retracting operations of the two plungers 412 (see FIG. 7). This allows the discharge flow rate from the liquid delivery pump 4 to be kept constant and pressure pulsation to be reduced. The operation of the liquid delivery pump 4 will be described later.

[0018] As shown in Figure 1, it is also possible to connect a pump 4 for delivering the organic phase and a pump 4 for delivering the aqueous phase in parallel. A gradient can be applied to the mobile phase composition by independently changing the flow rate of each pump 4. An auto-purge valve 2, a type of flow path switching valve 1, connects the pump 4 to a waste flow path and a waste container 8 when replacing the mobile phase inside the pump 4. This allows the mobile phase to be delivered to the waste container 8 at a high flow rate.

[0019] The mobile phase that has passed through the auto-purge valve 2 is introduced into the flow path switching valve 1 .

[0020] The flow path switching valve 1 switches between one or more flow paths.

[0021] The sample injection unit 5 injects the sample into the mobile phase using the sample dispensing syringe 6. That is, the sample dispensing syringe 6 injects the sample from the sample injection unit 5 into the mobile phase. Specifically, the sample is injected into the mobile phase by being sucked into the sample injection unit 5. The injected sample is introduced into the flow path switching valve 1 and mixed with the mobile phase.

[0022] Components constituting the sample mixed with the mobile phase are separated in the separation column 7. The components of the sample separated in the separation column 7 are introduced into the detector 10 in the order in which they were separated, and are detected by the detector 10.

[0023] An ultraviolet absorbance detector (UV detector), a photodiode array detector (PDA detector), a mass spectrometer, etc. can be used as the detector 10. The control device 9 calculates the time at which the sample is eluted from the separation column 7 by plotting the signal intensity of the detector 10 against time.

[0024] The control device 9 also controls the liquid pump 4, the auto-purge valve 2, the flow path switching valve 1, and the detector 10.

[0025] Incidentally, the auto-purge valve 2 can be omitted.

[0026] (Control device 9) FIG. 2 is a diagram showing the hardware configuration of the control device 9. As shown in FIG.

[0027] As shown in Fig. 2, the control device 9 is configured with a PC (Personal Computer) or the like. The control device 9 is equipped with a memory 901 configured with a RAM (Random Access Memory) or the like, and an arithmetic device 902 configured with a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), or the like. The control device 9 also has a storage device 903 configured with an HDD (Hard Disk Drive), an SSD (Solid State Drive), or the like. The control device 9 also has a communication device 904 that transmits instructions to the liquid feed pump 4, the flow path switching valve 1, the auto-purge valve 2, or the like, and receives detection signals from the detector 10. The control device 9 is also equipped with an input device 905 such as a keyboard or a mouse, and an output device 906 such as a display.

[0028] Furthermore, a program stored in storage device 903 is loaded into memory 901, and the loaded program is executed by calculation device 902. This embodies an execution unit (not shown) that executes the processes shown in Figures 5A to 5E and 9A to 9C.

[0029] (Flow path switching valve 1) 3 is a diagram showing the configuration of the flow path switching valve 1. FIG. 1 will be referred to as appropriate.

[0030] The flow path switching valve 1 includes a stator 110 and a rotor 120. In the example shown in Fig. 3, the stator 110 and the rotor 120 are separated, but in practice, the stator 110 and the rotor 120 are used in a state where they are in close contact with each other.

[0031] Stator 110 has a plurality of ports 111, which are holes that communicate from one end face to the other end face. In the example shown in Fig. 3, six ports 111 are provided, but two or more ports may be provided.

[0032] Further, the rotor 120 is provided with grooves 121 so that two adjacent ports 111 among the plurality of ports 111 can be connected to each other.

[0033] When the rotor 120 is rotated by the control device 9, adjacent ports 111 are connected via grooves 121 provided in the rotor 120. This switches the flow path of the mobile phase.

[0034] Among the ports 111 provided in the stator 110, the first port 111a has an elongated hole shape.

[0035] (Port 111a) FIG. 4 is an enlarged view of a port 111a having an elongated hole shape provided in the flow path switching valve of FIG.

[0036] In FIG. 4, a white arrow 501 indicates the direction of rotation of the rotor 120.

[0037] Port 111a has a configuration in which the length of major axis 502, which is the length in the rotation direction of rotor 120, is longer than the length of minor axis 503, which is the length in the direction perpendicular to the rotation direction of rotor 120. Specifically, port 111a has an elliptical long hole shape as shown in FIG. 4. The direction of major axis 502 of the ellipse (long axis direction) is the rotation direction of rotor 120 (white arrow 501). The shape of port 111 is not limited to a circle or an ellipse, and may be a quadrangle (square, rectangle), etc.

[0038] (Operation of flow path switching valve 1) Next, the flow path switching operation by the flow path switching valve 1 will be described with reference to FIGS. 5A to 5E.

[0039] 5A to 5E are diagrams showing the procedure of the valve control method performed by the control device 9. FIG.

[0040] 5A to 5E are views of the flow path switching valve 1 viewed from the stator 110 side. In addition, in FIGS. 5A to 5E, thick dots indicate high pressure (10 to 100 MPa), and light dots indicate low pressure (atmospheric pressure). In addition, in FIGS. 5B to 5E, elements similar to those in FIG. 5A are designated by the same reference numerals, and description thereof will be omitted.

[0041] 5A to 5E, six ports 111 (ports 111a to 111f) are provided in the stator 110. Furthermore, three grooves 121 (grooves 121a to 121c) are provided in the rotor 120 (see FIG. 3).

[0042] At the loading position P11 shown in FIG. 5A, a sample loop 131 is connected to port 111a, which is connected to port 111c via the sample loop 131. The sample loop 131 is a tube through which a sample flows. In this embodiment, the term "position" refers to the positional relationship between port 111 and groove 121. The sample loop 131 is made of a tube or the like. Port 111a and port 111e are connected via groove 121a, which is a first groove. A sample dispensing syringe 6 is connected to port 111e. A sample injection unit 5 is connected to port 111f, which is connected to port 111c via groove 121c.

[0043] Port 111b is connected to port 111d via groove 121b, which is a second groove. Groove 121b is a groove 121 separate from groove 121a. A liquid feed pump 4 is connected to port 111b, and a separation column 7 is connected to port 111d. In the configuration example shown in FIG. 1, both liquid feed pump 4a and liquid feed pump 4b are connected to port 111b. Port 111b is a port 111 provided separately from the first port, and is a second port to which liquid feed pump 4 is connected.

[0044] Furthermore, port 111d is a third port, and port 111e is a fourth port. Each of ports 111d and 111e is a port 111 provided separately from ports 111a and 111b.

[0045] Thus, at the introduction position P11 shown in FIG. 5A, which is the eleventh step, the controller 9 connects the port 111a to the port 111e via the groove 121a. The controller 9 connects the port 111b to the port 111d via the groove 121b. The controller 9 then applies pressure to the port 111b using the liquid delivery pump 4 (arrow 141a). As indicated by the arrows 141a and 142, the separation column 7 is in a high-pressure state due to the pressurization (delivery of the mobile phase) by the liquid delivery pump 4.

[0046] Also, the sample loop 131 is connected to the sample injection unit 5. Then, the sample is introduced into the sample loop 131 (arrow 144) by the sample dispensing syringe 6 connected to the sample injection unit 5 via the sample loop 131 and sucking in the sample (arrow 143).

[0047] Generally, the inside of the sample injection part 5 is at atmospheric pressure. Therefore, the pressure in the sample loop 131 and the grooves 121a and 121c connected to the sample loop 131 is atmospheric pressure. Therefore, the internal pressure of the sample loop 131 when connected to the sample loop 131 is atmospheric pressure.

[0048] On the other hand, the flow path connecting the liquid delivery pump 4 and the separation column 7 is subjected to a high pressure (high pressure) of about 10 MPa to 100 MPa because the separation column 7, which has a low conductance, is installed on the flow path. The high pressure state is indicated by dark dots in Figures 5A to 5E.

[0049] Then, the control device 9 rotates the rotor 120 from the introduction position P11 in the direction of the outlined arrow in Fig. 5B. As a result, the connections between the ports 111a to 111f are cut off as shown in Fig. 5B. In other words, Fig. 5B shows a state in which the ports 111a and 111b are not connected by the groove 121. Specifically, the control device 9 cuts off the connections between the ports 111a, 111b, 111d, and 111e by the groove 121.

[0050] 5B, which corresponds to the first step and the twelfth step, the control device 9 performs suction (decompression) by the liquid feed pump 4 (arrow 141b in the dashed line region 140a). That is, the liquid feed pump 4 decompresses the port 111b.

[0051] The duration of the suction operation by the liquid feed pump 4 is approximately several milliseconds to several seconds. The suction operation by the liquid feed pump 4 may be performed while the rotor 120 is rotating, or the control device 9 may stop the rotor 120 at the transient position P12 in Fig. 5B while the liquid feed pump 4 is sucking the mobile phase.

[0052] After the pressure at port 111b is reduced by the liquid feed pump 4, that is, from the state shown in Fig. 5B, the control device 9 further rotates the rotor 120 in the direction of the outline arrow shown in Fig. 5B, thereby switching the position from the transitional position P12 shown in Fig. 5B to the transitional position P13 shown in Fig. 5C, which is the second and thirteenth steps.

[0053] At a transient position P13 shown in FIG. 5C , the control device 9 places port 111a and port 111b in a state where they are connected via groove 121b. As a result, the control device 9 reduces the pressure at port 111b, which is the second port, using the liquid feed pump 4, and then connects port 111a, which is the first port, to port 111b, which is the second port, via groove 121b. The control device 9 also places port 111d and port 111e in a state where they are not connected to either port 111 via groove 121. Then, when port 111a and port 111b are connected via groove 121b, the control device 9 pressurizes port 111a and port 111b using the liquid feed pump 4.

[0054] Port 111a and port 111b are connected via groove 121b, thereby connecting sample loop 131 and liquid feed pump 4. Furthermore, separation column 7 (port 111d) and sample loop 131 are not connected. At transient position P13 in FIG. 5C, port 111a has an elongated hole shape. This connects port 111a and port 111b via groove 121b. However, ports 111c, 111d, 111e, and 111f are not connected to any of ports 111. At transient position P13 in FIG. 5C, control device 9 causes liquid feed (pressurization) by liquid feed pump 4 (arrow 141c). This causes the inside of sample loop 131 to be pressurized.

[0055] At the transient position P12 in Fig. 5B, suction (decompression) is performed by the liquid feed pump 4, and the pressure in the groove 121b connected to the liquid feed pump 4 is reduced from a high pressure state. By performing this operation, when the ports 111b and 111a are connected in Fig. 5C, it is possible to reduce the pressure difference between the port 111a connected to the sample loop 131 at atmospheric pressure and the port 111b.

[0056] Damage to the flow path switching valve 1 occurs when a high-pressure port 111 is connected to a low-pressure port 111, and a high-speed flow due to a pressure difference collides with the end of the groove 121. Therefore, in Figure 5B, the pressure difference between the inside of the groove 121b and the port 111b becomes smaller, thereby reducing damage (failure) to the flow path switching valve 1.

[0057] Specifically, it is believed that valve damage can be significantly reduced by reducing the pressure generated by the liquid feed pump 4 (the pressure at the groove 121b in FIG. 5B) below the average of the high and low pressures (atmospheric pressure). Performing the liquid feed pump 4 suction operation at a position where the port 111b to which the liquid feed pump 4 is connected is not connected to any other port 111, as shown in FIG. 5B, has the following advantages. First, by performing suction by the liquid feed pump 4, the flow path to be depressurized can be limited to the range from the liquid feed pump 4 to the groove 121b. This enables rapid pressure reduction. Furthermore, the influence of suction by the liquid feed pump 4 on parts connected to other ports 111, such as the separation column 7, can be prevented.

[0058] As described above, port 111a has an elongated hole shape. This allows the distance between port 111a and port 111b to be shorter than the distance between port 111c and port 111d. With this configuration, the sample loop 131 can be connected to the liquid delivery pump 4 before the separation column 7 (port 111d) and the sample loop 131 (port 111c) are connected. In other words, because port 111a has an elongated hole shape, when port 111b is connected to port 111a, the connection between ports 111c and 111d can be incomplete.

[0059] When the switching time of the flow path switching valve 1 is short, that is, when the time in which the state shown in Figures 5B and 5C is maintained is short, the pressure in the flow path to which the separation column 7 is connected is maintained at a high pressure. Then, by pressurizing the sample loop 131 to a pressure close to that applied to the separation column 7, the pressure difference between the flow path to which the separation column 7 is connected and the sample loop 131 can be reduced. That is, at the transient position P13 shown in Figure 5C, the liquid delivery pump 4 and the sample loop 131 are connected, but the separation column 7 is not connected to anything. Therefore, the separation column 7 maintains a high pressure state, and the sample loop 131 is connected to the liquid delivery pump 4 and pressurized, thereby becoming a high pressure state.

[0060] In this way, the sample loop 131 can be brought to a high pressure state before it is connected to the separation column 7, which is in a high pressure state.

[0061] If port 111a were not an elongated hole, port 111a would be connected to port 111b and port 111c to port 111d approximately simultaneously. As described above, the pressure in the sample loop 131 is low at transient position P12 in FIG. 5B. Therefore, if port 111a is connected to port 111b and port 111c to port 111d are connected approximately simultaneously, the liquid feed pump 4 may not be able to pressurize the sample loop 131 in time. As a result, when transient position P13 in FIG. 5C is reached, the sample loop 131 (port 111c) connects to the separation column 7 (port 111d) without being sufficiently pressurized. This could cause a pressure fluctuation (injection shock) from low pressure to high pressure in port 111d (i.e., separation column 7).

[0062] As described above, because port 111a has an elongated hole shape, port 111a is connected to port 111b before port 111c is connected to port 111d. As a result, port 111c is connected to port 111d, that is, sample loop 131 is connected to separation column 7, after sample loop 131 reaches a sufficiently high pressure state, so pressure fluctuations in separation column 7 can be suppressed.

[0063] In this way, since the port 111a has an elongated hole shape, it is possible to suppress pressure fluctuations that occur on the separation column 7 when the separation column 7 and the sample loop 131 are connected.

[0064] Pressure fluctuations destroy the packed structure of the particles in the separation column 7 and deteriorate the separation column 7. Therefore, reducing pressure fluctuations has the advantage of extending the life of the separation column 7.

[0065] The control device 9 further rotates the rotor 120 in the direction of the outline arrow shown in Fig. 5C from the transitional position P13 (the state of the thirteenth step) in Fig. 5C, thereby switching the position to the injection position P14 (the injection position) shown in Fig. 5D, which is the fourteenth step.

[0066] At injection position P14 in Fig. 5D, port 111a remains connected to port 111b via groove 121b. Furthermore, controller 9 connects ports 111c and 111d via groove 121c, which is a third groove. By connecting ports 111c and 111d, port 111a is connected to port 111d via sample loop 131, port 111c, and groove 121c.

[0067] Ports 111e and 111f are then connected by groove 121a, so that sample loop 131 is inserted between liquid feed pump 4 and separation column 7. Then, the sample in sample loop 131 is injected into separation column 7 by liquid feed from liquid feed pump 4 (arrow 141d).

[0068] The control device 9 rotates the rotor 120 from the injection position P14 in FIG. 5D (the state of the fourteenth step) in the direction of the outlined arrow in FIG. 5E. This switches the position to the introduction position P11 in FIG. 5A via the transitional position P15 in FIG. 5E. The connection relationship between the port 111 and the groove 121 in the transitional position P15 in FIG. 5E, which is the fifteenth step, is the same as that in the transitional position P13 in FIG. 5C. That is, the control device 9 cuts off the connection between the port 111d via the groove 121, while maintaining the connection between the port 111a and the port 111b via the groove 121b. Then, the control device 9 depressurizes the liquid feed pump 4 (arrow 141e).

[0069] At the transient position P15 in FIG. 5E, as described above, the connection between port 111c and port 111d is interrupted, while the connection between port 111a and port 111b is maintained. That is, the sample loop 131 is connected to the liquid feed pump 4 but not to the separation column 7. At the transient position P15 in FIG. 5E, the control device 9 causes the liquid feed pump 4 to perform suction (depressurization) (arrow 141e in the dashed-line region 140b). This causes the internal pressure of the sample loop 131 to become low-pressure. Therefore, when the introduction position P11 in FIG. 5A is reached, the sample loop 131, which is in a low-pressure state, is connected to the sample injection unit 5 and the sample dispensing syringe 6, which are at atmospheric pressure. This reduces the pressure difference between the groove 121a and the sample injection unit 5, and between the groove 121c and the sample dispensing syringe 6, and prevents damage to the flow path switching valve 1.

[0070] (length of groove 121) FIG. 6 is a diagram relating to the length of the groove 121.

[0071] 6, maximum path length 511 is the maximum length of groove 121 along path 512 through which the mobile phase flows. This maximum path length 511 has a length that is at least sufficient to connect two ports 111. Furthermore, maximum path length 511 is equal to or less than the maximum length between two ports 111 along path 512 (which coincides with maximum path length 511 in FIG. 6). In other words, the length of groove 121 is designed so that when groove 121 connects two adjacent ports 111, groove 121 does not extend outside the two connected ports 111.

[0072] The technology described in Patent Document 1 reduces the momentum of a high-speed mobile phase flow caused by pressure fluctuations by making the maximum path length 511 in Figure 6 longer than the maximum length between two ports 111 along the path. The groove 121 is configured to extend outside the two connected ports 111. However, as described above, the portion of the groove 121 extending outside the two connected ports 111 becomes a dead volume, which is a cause of carryover.

[0073] According to the first embodiment, suction is performed by the liquid feed pump 4 at the stages shown in Fig. 5B and Fig. 5E. Thereafter, as shown in Fig. 5C, the low-pressure port 111a and the depressurized port 111b are connected via the groove 121b. This prevents damage to the rotor 120 due to pressure fluctuations even without providing a portion of the groove 121 that extends outside the two connected ports 111. Therefore, carryover does not occur.

[0074] (liquid transfer pump 4) Next, the configuration of the liquid feed pump 4 will be shown with reference to FIG. 7, and the operation of the liquid feed pump 4 will be described with reference to FIG.

[0075] FIG. 7 is a diagram showing an example of the configuration of the liquid feed pump 4 used in this embodiment.

[0076] In this embodiment, an example is shown in which a single serially connected dual plunger pump is used as the liquid feed pump 4.

[0077] The liquid feed pump 4 includes two cylinder sections 400 (a first cylinder section 400a and a second cylinder section 400b). That is, the liquid feed pump 4 includes the first cylinder section 400a and the second cylinder section 400b, which feed liquid by the operation of the plunger 412, connected in series with respect to the flow of the mobile phase. A tank 3 containing the mobile phase is connected to the first cylinder section 400a. A pressure sensor 402 is connected to the downstream side of the second cylinder section 400b. The tank 3 side of the liquid feed pump 4 is the upstream side (upstream side with respect to the flow of the mobile phase), and the auto-purge valve 2 side of FIG. 1 is the downstream side (downstream side).

[0078] In this way, the first cylinder portion 400a is provided upstream of the second cylinder portion 400b with respect to the flow of the mobile phase.

[0079] Furthermore, check valves 403 are provided between the tank 3 and the first cylinder portion 400a, and between the first cylinder portion 400a and the second cylinder portion 400b. The check valve 403 provided between the tank 3 and the first cylinder portion 400a will be referred to as the first check valve 403a as appropriate. The check valve 403 provided between the first cylinder portion 400a and the second cylinder portion 400b will be referred to as the second check valve 403b as appropriate. The check valves 403 prevent the mobile phase from flowing back from the pressure sensor 402 side to the tank 3 side. In this way, the check valve 403 (second check valve 403b) is provided between the first cylinder portion 400a and the second cylinder portion 400b.

[0080] Each cylinder unit 400 includes a driving unit 410, a plunger 412, a container 422, and a seal 423. The driving unit 410 includes a motor 411 and a ball screw 421. The movement of the ball screw 421 by the motor 411 is transmitted to the plunger 412, causing the plunger 412 to perform piston movement. The piston movement of the plunger 412 causes the mobile phase contained in the space 414 of the container 422 to be discharged and sucked.

[0081] The seal 423 prevents the mobile phase contained in the container 422 from leaking out.

[0082] (Operation of liquid delivery pump 4) Next, the operation of the liquid feed pump 4 will be described with reference to Fig. 8. Fig. 7 will also be referred to as appropriate.

[0083] FIG. 8 is a diagram relating to the operation of the liquid feed pump 4. As shown in FIG.

[0084] In FIG. 8, graph G1 shows the liquid transfer operation during a non-switching period, and graph G2 shows the operation of the liquid transfer pump 4 during a depressurizing operation due to the inhalation of the mobile phase, including flow path switching by the flow path switching valve 1. The non-switching period refers to a period during which the flow path switching operation of the flow path switching valve 1 shown in FIGS. 5A to 5E is not performed. In graphs G1 and G2, the horizontal axis represents time, and the vertical axis represents the position of the plunger 412. Note that "0" on the vertical axis represents the position of the plunger 412 when the plunger 412 is fully retracted (in a state of being sucked in). In addition, in graphs G1 and G2, the upward direction of the vertical axis represents the ascent, and the downward direction of the vertical axis represents the descent. Note that the ascent refers to the movement of the plunger 412 in a direction that reduces the volume of the space 414 in FIG. 7, and the retraction refers to the movement of the plunger 412 in a direction that increases the volume of the space 414 in FIG. 7.

[0085] In the graphs G1 and G2, the solid line L1 indicates the operation of the first cylinder portion 400a, and the dashed line L2 indicates the operation of the second cylinder portion 400b.

[0086] The operation of the liquid feed pump 4 is made up of a suction period 301 , a compression period 302 , a crossing period 303 , and a single liquid feed period 304 .

[0087] In the liquid delivery operation during the non-switching period shown in graph G1, the first cylinder portion 400a performs a suction operation (reference symbol 311) during the suction period 301 (time t0 to time t2). Also, during the suction period 301, the second cylinder portion 400b performs a discharge operation (reference symbol 321). The discharge operation (pushing operation) of the second cylinder portion 400b is performed throughout the suction period 301, but the suction operation by the first cylinder portion 400a continues until time t1, and after time t1, the first cylinder portion 400a stops operating. Also, the retraction speed of the plunger 412 in the first cylinder portion 400a from time t0 to time t1 is more than twice the pushing speed of the plunger 412 in the second cylinder portion 400b. However, since a second check valve 403b is provided between the first cylinder portion 400a and the second cylinder portion 400b, the mobile phase does not flow back from the second cylinder portion 400b to the first cylinder portion 400a.

[0088] During the intake period 301, the mobile phase is drawn into the first cylinder portion 400a from the tank 3, and the mobile phase is discharged from the second cylinder portion 400b to the flow path switching valve 1. During the intake period 301, the mobile phase is discharged by the entire liquid delivery pump 4.

[0089] Next, during the compression period 302 (time t2 to time t4), the mobile phase contained in the space 414 in the first cylinder portion 400a is pressurized to near the liquid delivery pressure. Specifically, between time t2 and time t3, the first cylinder portion 400a performs a pressurizing operation (reference numeral 312) and then stops operating. This is because the internal pressure in the space 414 in the first cylinder portion 400a at time t2 is approximately atmospheric pressure, and if this continues, the mobile phase cannot be discharged with sufficient pressure. Note that throughout the compression period 302, the second cylinder portion 400b performs a pressurizing operation (discharge operation: reference numeral 321).

[0090] Thereafter, during the crossing period 303 (time t4 to time t5), the plunger 412 of the second cylinder portion 400b performs a retracting operation (reference symbol 322), and the first cylinder portion 400a performs a pressurizing operation (reference symbol 313). During the crossing period 303, the slope of the solid line L1 indicating the operation of the first cylinder portion 400a is greater than the slope of the dashed line L2 indicating the operation of the second cylinder portion 400b. In addition, at time t4, the internal pressure of the first cylinder portion 400a is increased to a predetermined pressure. Therefore, during the crossing period 303, the discharge force of the first cylinder portion 400a exceeds the suction force of the second cylinder portion 400b, and the liquid feed pump 4 can feed liquid to the flow path switching valve 1.

[0091] Then, during the single liquid transfer period 304 (from time t5), the first cylinder portion 400a transfers the liquid. Specifically, as shown in FIG. 8, during the single liquid transfer period 304, the first cylinder portion 400a performs a discharge operation (reference numeral 313). Also, as shown by the dashed line L2, the second cylinder portion 400b stops operating. As a result, the mobile phase stored in the first cylinder portion 400a is transferred to the flow path switching valve 1 via the container 422 in the second cylinder portion 400b.

[0092] After the single liquid delivery period 304 ends, the operation of the liquid delivery pump 4 returns to the suction period 301 .

[0093] By the above operation, the liquid can be continuously sent from the liquid sending pump 4.

[0094] Next, graph G2 will be described. In graph G2, the operations are the same as those in graph G1 except for the flow path switching period 330. Therefore, in graph G2, the operations that are the same as those in graph G1 will not be described again.

[0095] In graph G2, time t11 indicates the timing at which the transitional positions P12 and P15 shown in Figure 5B or 5E are reached, and time t12 is the timing at which the transitional position P13 shown in Figure 5C is reached. Also, time t13 is the timing at which the injection position P14 shown in Figure 5D is reached. In graph G2, the period other than times t11 to t13 is the state shown in Figure 5A or 5D.

[0096] 5B and 5E, suction is performed by the liquid feed pump 4. Therefore, it is necessary to synchronize the operation of the cylinder portion 400 of the liquid feed pump 4 with the operation of the flow path switching valve 1.

[0097] That is, the control device 9 controls the flow path switching valve 1 so that the timings at which the positions of FIG. 5B and FIG. 5E are reached fall within the crossing period 303 in FIG.

[0098] Specifically, at the timing (time t11) when the flow path switching valve 1 is positioned as shown in FIGS. 5B and 5E, the control device 9 stops the operation of the first cylinder portion 400a, as indicated by reference numeral 331. As a result, while the second cylinder portion 400b is performing a suction operation, the liquid feed pump 4 performs a suction operation by stopping the operation of the first cylinder portion 400a. The operation of the first cylinder portion 400a remains stopped until time t12. Meanwhile, the control device 9 continues the suction operation of the second cylinder portion 400b. As a result, the liquid feed pump 4 as a whole performs a suction operation. Incidentally, as described above, the time during which the liquid feed pump 4 performs a suction operation, i.e., the time from time t11 to t12, is approximately several milliseconds to several seconds. Such a short suction operation is possible because only the operation of the first cylinder portion 400a is stopped.

[0099] Then, at the timing (time t12) when the flow path switching valve 1 is positioned as shown in FIG. 5C, the control device 9 continues the suction operation of the second cylinder portion 400b. Furthermore, while continuing the suction operation of the second cylinder portion 400b, the control device 9 performs a discharge operation (pressurization operation) using the first cylinder portion 400a (reference numeral 332). Because the slope of the solid line L1 from time t12 to time t13 is greater than the slope of the dashed line L2, the liquid delivery pump 4 as a whole performs a discharge operation. As a result, as explained in FIG. 5C, after the sample loop 131 reaches a sufficiently high pressure state, the sample loop 131 connects to the separation column 7 in a high-pressure state in FIG. 5D, thereby suppressing pressure fluctuations in the separation column 7.

[0100] Furthermore, by performing the pressurization operation from time t12 to time t13, the pressurization state of the first cylinder section 400a at time t13 can be aligned with the pressurization state at time t13 in graph G1, so that subsequent operations can be performed in the same manner as in graph G1.

[0101] In this way, when switching the flow path switching valve 1, the suction operation of the liquid feed pump 4 can be achieved by stopping the operation of the first cylinder portion 400a during the suction operation of the second cylinder portion 400b. In other words, the pressure in the flow path to which the liquid feed pump 4 is connected can be reduced.

[0102] Furthermore, a pump other than a serially connected dual plunger pump can be used as the liquid feed pump 4. Even in such a case, suction by the liquid feed pump 4 can be performed by performing the suction operation of the cylinder portion 400 in synchronization with the operation of the rotor 120 without interposing a check valve 403 between the liquid feed pump 4 and the flow path switching valve 1. In other words, the pressure in the flow path to which the liquid feed pump 4 is connected can be reduced.

[0103] In FIG. 1, the liquid chromatography system Z is configured to include a detector 10, but this embodiment can be implemented even in a configuration that does not include the detector 10, thereby reducing damage to the flow path switching valve 1.

[0104] The flow path switching valve 1 according to the first embodiment can suppress pressure fluctuations in the mobile phase when switching the flow path, and can prevent the rotor 120 from being damaged by pressure fluctuations (failure in the rotor 120 due to pressure fluctuations). This allows the flow path switching valve 1 to have a longer life.

[0105] [Second embodiment] Next, the operation of the auto-purge valve 2 will be described with reference to FIGS. 9A to 9C.

[0106] 9A to 9C are diagrams showing the switching operation of the auto-purge valve 2. FIG.

[0107] The auto-purge valve 2 has the same configuration as the flow path switching valve 1, and is equipped with a stator 110 and a rotor 120 as shown in Fig. 3. Since the auto-purge valve 2 has the same configuration as that shown in Fig. 3, a drawing corresponding to Fig. 3 for the auto-purge valve 2 will be omitted.

[0108] At the non-switching position P21 shown in FIG. 9A, which corresponds to the 21st step, a high pressure (high pressure) is applied to the flow path connected to the separation column 7. In addition, in FIGS. 9A to 9C, dark dots indicate a high-pressure state, and light dots indicate a low-pressure state (approximately atmospheric pressure). A high-pressure state is a state in which a pressure higher than approximately 50 MPa is applied, and a low-pressure state is a state in which a pressure lower than approximately 10 MPa is applied.

[0109] A waste liquid container 8 (e.g., waste liquid container 8a in FIG. 1) into which the mobile phase is discharged is connected to port 211a, which is a first port. A waste liquid container 8 (e.g., waste liquid container 8b in FIG. 1) different from the waste liquid container 8 connected to port 211a is connected to port 211e, which is a first port. A liquid feed pump 4 (e.g., liquid feed pump 4a in FIG. 1) is connected to port 211b, which is a second port. A liquid feed pump 4 (e.g., liquid feed pump 4b in FIG. 1) different from the liquid feed pump 4 connected to port 211b is connected to port 211f, which is a second port. Ports 211c and 211d are provided as third ports of the port 211, which are different from ports 211a, 211e, and ports 211b and 211f. A separation column 7 is connected to ports 211c and 211d. Incidentally, as shown in FIG. 1, the same separation column 7 is connected to the ports 211c and 211d.

[0110] 9A, the ports 211b and 211d are connected to each other by the groove 221a. In addition, due to the pressurization (arrow 241a) by the liquid feed pump 4 connected to the port 211b, the flow path from the port 211b to the groove 221a, the port 211d, and the separation column 7 is in a high pressure state (arrow 242).

[0111] Similarly, ports 211f and 211c are connected to each other by groove 221c. Furthermore, due to pressure (arrow 241a) from the liquid feed pump 4 connected to port 211f, the flow path from port 211f to groove 221c to port 211c to separation column 7 is in a high pressure state (arrow 242).

[0112] Thus, at the non-switching position P21 shown in FIG. 9A, which is the 21st step, the control device 9 connects port 211b and port 211d via groove 221a, which is the first groove. Similarly, the control device 9 connects port 211f and port 211c via groove 221c, which is the first groove. However, ports 211a and 211e are not connected to ports 211b and 211f or ports 211c and 211d via groove 221. Then, at the non-switching position P21 shown in FIG. 9A, the control device 9 pressurizes ports 211b and 211f using the liquid feed pump 4 (arrow 241a).

[0113] Port 211a and port 211e are connected to each other by groove 221b. Since waste liquid container 8 connected to ports 211a and 211e is at low pressure (atmospheric pressure), ports 211a, 211e and groove 221b are in a low pressure state.

[0114] Then, the control device 9 rotates the rotor 120 in the direction of the arrow shown in Fig. 9B from the non-switching position P21 (the state of the 21st step) shown in Fig. 9A. As a result, the control device 9 switches the position to the purge position P23 shown in Fig. 9C. During this process, the control device 9 performs suction by the liquid feed pump 4 at a transitional position P22 shown in Fig. 9B.

[0115] 9B, which corresponds to the first and 22nd steps, all ports 211 are disconnected from each other. Furthermore, the groove 221a is connected to the port 211d, which is connected to the separation column 7, which is in a high-pressure state, and therefore the high-pressure state is maintained.

[0116] Port 211b is connected to the liquid feed pump 4, and as described above, the liquid feed pump 4 performs a suction operation when the transitional position P22 shown in FIG. 9B is reached (arrow 241b in the dashed line region 240a). Therefore, port 211b is in a low-pressure state. Similarly, port 211f is connected to the liquid feed pump 4, and as described above, the liquid feed pump 4 performs a suction operation when the transitional position P22 shown in FIG. 9B is reached (arrow 241b in the dashed line region 240b). Therefore, port 211f is in a low-pressure state.

[0117] 9B, the control device 9 sets the ports 211a to 211f (first port, second port, and third port) in a state where they are not connected to each other by the groove 221. In other words, the ports 211a and 211e are not connected to the ports 211b and 211f by the groove 221. Then, the control device 9 reduces the pressure by the liquid feed pump 4 (arrow 241b).

[0118] Groove 221b is connected to port 211a, which is in a low-pressure state, and is therefore in a low-pressure state similar to port 211a. Groove 221c is connected to port 211f, which is connected to liquid-feed pump 4, which is performing suction, and is therefore in a low-pressure state.

[0119] 9C, which is the second and 23rd steps, ports 211a and 211b are connected by groove 221b. At the stage of FIG. 9B, groove 221b and port 211a are in a low-pressure state, but port 211b is in a low-pressure state due to the suction of liquid feed pump 4. Therefore, the connection between ports 211a and 211b by groove 221b is a connection between ports in a low-pressure state, which can reduce pressure fluctuations.

[0120] Similarly, port 211e and port 211f are connected by groove 221c. At the stage of Fig. 9B, port 211e is in a low-pressure state, but groove 221c and port 211f are in a low-pressure state due to suction by liquid feed pump 4. Therefore, the connection between port 211e and port 211f by groove 221c is a connection between ports in a low-pressure state, which can reduce pressure fluctuations.

[0121] The port 211c and the port 211d are connected by the groove 221a.

[0122] As a result, port 211a and port 211b are connected via groove 221b. Similarly, port 211e and port 211f are connected via groove 221c. That is, groove 221b, which is the second groove, connects port 211a and port 211b, and port 211d is not connected to ports 211a and 211b via groove 221. Similarly, groove 221c, which is the second groove, connects port 211e and port 211f, and port 211c is not connected to ports 211e and 211f via groove 221.

[0123] At the stage of FIG. 9B, groove 221a and ports 211c and 211d are all in a high pressure state, so no pressure fluctuation occurs in the connection between port 211c and port 211d by groove 221a.

[0124] 9C is completed, the control device 9 resumes the pressurizing operation (discharge operation) of the liquid feed pump 4 (arrow 241c). At this time, the control device 9 applies pressure to ports 211b and 211f by the liquid feed pump 4. As a result, the mobile phase is discharged into the waste liquid container 8. Note that because the waste liquid container 8 is in an open state, even when the liquid feed pump 4 applies pressure, the flow paths from port 211b to groove 221b to port 211a (arrow 243) and port 211f to groove 221c to port 211e (arrow 243) remain in a low pressure state.

[0125] 9C, the internal pressure of the groove 221b connected to the liquid feed pump 4 can be reduced from a high pressure state. As a result, the pressure difference between the ports 211a and 211e connected to the waste liquid container 8 at atmospheric pressure and the ports 211b and 211f connected to the liquid feed pump 4 can be reduced. This reduces damage to the flow path switching valve 1.

[0126] The auto-purge valve 2 according to the second embodiment can suppress pressure fluctuations in the mobile phase when switching the flow path, and can prevent damage to the rotor 220 due to pressure fluctuations. This allows the auto-purge valve 2 to have a longer life.

[0127] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those having all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0128] In this embodiment, the grooves 121 and 221 have an arc shape, but are not limited to an arc shape as long as they can connect the adjacent ports 111 and 211. For example, they may be linear.

[0129] Furthermore, some or all of the above-described configurations, functions, control device 9, etc. may be realized in hardware, for example, by designing them as integrated circuits. Furthermore, as shown in Fig. 2, the above-described configurations, functions, etc. may be realized in software by a processor such as a CPU interpreting and executing a program that realizes each function. Information such as the programs, tables, and files that realize each function can be stored in a HD or in a recording device such as memory 901, an SSD, or a recording medium such as an IC (Integrated Circuit) card, an SD (Secure Digital) card, or a DVD (Digital Versatile Disc). In addition, in each embodiment, the control lines and information lines shown are those that are considered necessary for explanation, and not all control lines and information lines in the product are necessarily shown. In reality, it can be considered that almost all components are interconnected. [Explanation of symbols]

[0130] 1 Flow path switching valve 2 Auto purge valve (flow path switching valve) 4, 4a, 4b Liquid transfer pump (pump) 5. Sample injection section 6 Sample dispensing syringes 7 Separation column 9 Control device (control unit) 110 Stator Port 111 111a port (first port) 111b port (second port) 111c port 111d port (third port) 111e port (4th port) 111f port 120 rotor 121 Groove 121a Groove (first groove) 121b groove (second groove) 121c groove (third groove) 141a~141e, 142~144 Arrows Port 211 211a port (first port) 211b port (second port) 211c port (third port) 211d port (third port) 211e port (first port) 211f port (second port) 221 Groove 221a Groove (first groove) 221b groove (second groove) 221c Groove (first groove, second groove) 400 Cylinder section 400a first cylinder part 400b Second cylinder part 403 Check valve 403a First check valve 403b Second check valve (check valve) 410 Drive unit 412 Plunger 501 White arrow (rotor rotation direction) 502 Long axis (rotor rotation direction) 503 Minor axis (perpendicular to the direction of rotor rotation) 511 Maximum Path Length 512 routes P11 Introduction Position (11th Step) P12 Transition position (1st step, 12th step) P13 Transition position (2nd step, 13th step) P14 Injection position (14th step) P15 Transition position (15th step) P21 Non-switching position (21st step) P22 Transition position (1st step, 22nd step) P23 Purge position (2nd step, 23rd step) Z Liquid Chromatography System (Valve Control System)

Claims

1. a flow path switching valve for switching one or more flow paths; a pump that pressurizes a flow path connected to the flow path switching valve; a control unit that controls the flow path switching valve and the pump; Equipped with The flow path switching valve is a stator having a plurality of ports, which are holes communicating from one end surface to the other end surface; a rotor having grooves formed therein so that two adjacent ports among the plurality of ports can be connected; Equipped with The stator includes: a first port, the port; a second port that is provided separately from the first port and to which the pump is connected; Equipped with The control unit In a state where the first port and the second port are not connected by the groove, the second port is depressurized by the pump, and then the first port and the second port are connected via the groove. Valve control system.

2. The control unit After the second port is depressurized, the first port and the second port are connected via the groove, and then pressurization is performed by the pump.

2. The valve control system of claim 1.

3. The first port has a length in a direction perpendicular to the rotation direction of the rotor that is longer than the length in the direction perpendicular to the rotation direction of the rotor.

2. The valve control system of claim 1.

4. the first port has an oval shape; The major axis of the ellipse is in the direction of rotation of the rotor.

4. The valve control system according to claim 3.

5. The pump a first cylinder portion and a second cylinder portion for delivering a liquid by the operation of a plunger are provided and connected in series with respect to the flow of a mobile phase; a check valve is provided between the first cylinder portion and the second cylinder portion, the first cylinder portion is provided upstream of the second cylinder portion with respect to a flow of the mobile phase, The control unit When the second cylinder section is performing a suction operation, the operation of the first cylinder section is stopped, thereby performing the suction operation of the pump.

2. The valve control system of claim 1.

6. The maximum path length, which is the maximum length of the groove along the path, is a length that allows two of the ports to be connected, and is equal to or less than the maximum length between two ports 111 along the path.

2. The valve control system of claim 1.

7. a flow path switching valve for switching one or more flow paths; a pump that pressurizes a flow path connected to the flow path switching valve; a control unit that controls the flow path switching valve and the pump; Equipped with The flow path switching valve is a stator having a plurality of ports, which are holes communicating from one end surface to the other end surface; a rotor having grooves formed therein so that two adjacent ports among the plurality of ports can be connected; Equipped with The stator includes: a first port, the port; a second port that is provided separately from the first port and to which the pump is connected; Equipped with The control unit In a state where the first port and the second port are not connected by the groove, the second port is depressurized by the pump, and then the first port and the second port are connected via the groove. Liquid chromatography system.

8. The first port is connected to a sample loop, which is a tube through which a sample flows.

8. The liquid chromatography system of claim 7.

9. A waste liquid container for discharging the mobile phase is connected to the first port.

8. The liquid chromatography system of claim 7.

10. a flow path switching valve for switching one or more flow paths; a pump that pressurizes a flow path connected to the flow path switching valve; a control unit that controls the flow path switching valve and the pump; Equipped with The flow path switching valve is a stator having a plurality of ports, which are holes communicating from one end surface to the other end surface; a rotor having grooves formed therein so that two adjacent ports among the plurality of ports can be connected; Equipped with The stator includes: a first port, the port; a second port that is provided separately from the first port and to which the pump is connected; Equipped with The control unit a first step of reducing the pressure of the second port by the pump while the first port and the second port are not connected by the groove; a second step of connecting the first port and the second port through the groove after the first step; A valve control method for performing the above.

11. a separation column for separating components constituting a sample; a sample dispensing syringe for injecting a sample into a mobile phase from a sample injection portion; Equipped with the first port has a length in a direction perpendicular to the rotation direction of the rotor that is longer than the length of the first port in the direction perpendicular to the rotation direction of the rotor; The flow path switching valve is a third port and a fourth port that are the ports, respectively, in addition to the first port and the second port; a sample loop, which is a tube through which a sample flows, is connected to the first port; the separation column is connected to the third port; the sample dispensing syringe is connected to the fourth port; The control unit an eleventh step of connecting the first port and the fourth port via a first groove, and connecting the second port and the third port via a second groove that is different from the first groove, and pressurizing the second port with the pump; a twelfth step of rotating the rotor from the state of the eleventh step to cut off the connections of the first port, the second port, the third port, and the fourth port through the grooves and decompressing the pump; a thirteenth step of rotating the rotor from the state of the twelfth step to bring about a state in which the first port and the second port are connected via the second groove, but the third port and the fourth port are not connected to any of the ports via the groove, and pressurizing the interior of ... a fourteenth step of connecting the first port and the third port via a third groove that is different from the first groove and the second groove, while maintaining a state in which the first port is connected to the second port via the second groove by rotating the rotor from the state of the thirteenth step; 11. The valve control method according to claim 10, further comprising:

12. a fifteenth step of rotating the rotor from the state of the fourteenth step to cut off the connection through the groove in the third port, while maintaining the connection between the first port and the second port via the second groove, and reducing the pressure by the pump; 12. The valve control method according to claim 11, further comprising:

13. The stator includes: a third port that is a port other than the first port and the second port; a waste liquid container for disposing of the mobile phase is connected to the first port; a separation column for separating components of the sample is connected to the third port; The control unit a 21st step of connecting the second port and the third port by a first groove, but not connecting the first port to the second port or the third port by the groove, and pressurizing the second port by the pump; a 22nd step of rotating the rotor from the state of the 21st step to make the first port, the second port, and the third port disconnected from each other by the groove, and reducing the pressure by the pump; a 23rd step of connecting the first port and the second port by a second groove that is different from the first groove, and not connecting the third port to the first port and the second port via the groove, and pressurizing the second port with the pump; 11. The valve control method according to claim 10, further comprising:

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