Liquid chromatograph

A liquid chromatograph includes a plurality of units that execute each function of the liquid chromatograph, and a system controller connected to the plurality of units, wherein the system controller includes a status provider that acquires a status from any unit and provides the acquired status to a computer connected to the system controller, a data accumulator that accumulates the status to be provided to the computer in a database, and a data provider that provides the status accumulated in the database to any unit.

TECHNICAL FIELD

The present invention relates to a liquid chromatograph.

BACKGROUND ART

A liquid chromatograph includes a plurality of units such as a pump unit, an autosampler unit and a column unit. The plurality of units are connected to a device referred to as a system controller. The system controller controls each unit. For example, the below-mentioned Patent Document 1 discloses a liquid chromatograph including a system controller.

The system controller is connected to a computer via a network. An operator creates a method file in which an analysis condition is written in a computer. The method file created in the computer is transferred to the system controller. The system controller assigns parameters written in the method file to respective units in accordance with the content of the parameters to output the parameters. In each unit, setting is performed in accordance with an analysis condition written in a parameter. The analysis condition includes a temperature condition and so on.

Meanwhile, each unit outputs a current status such as its current temperature, etc. to the system controller. The system controller integrates the statuses output from respective units and transfers the statuses to the computer via the network.[Patent Document 1] JP 2017-227491 A

SUMMARY OF INVENTION

Technical Problem

As described above, the system controller outputs a parameter to each unit and performs setting for each unit. Further, the system controller receives a status from each unit, and performs feedback control or the like with respect to each unit in accordance with the status of each unit. In a case where a new function is added to the behavior of the liquid chromatograph, a program corresponding to the new function is incorporated into the system controller. In this manner, control of each unit is left to the system controller. Each unit behaves in accordance with an instruction in response to receiving the instruction from the system controller.

Thus, a load applied to the system controller is increased. When the number of functions added to the liquid chromatograph is increased, the number of programs added to the system controller is also increased. Further, a load applied to the CPU (Central Processing Unit) of the system controller increases as the number of functions increases.

An object of the present invention is to reduce a load to be applied to a system controller in control of a liquid chromatograph.

Solution to Problem

A first aspect of the present invention relates to a liquid chromatograph that includes a plurality of units that execute each function of the liquid chromatograph, and a system controller connected to the plurality of units, wherein the system controller includes a status provider that acquires a status from any unit and provides the acquired status to a computer connected to the system controller, a data accumulator that accumulates the status to be provided to the computer in a database, and a data provider that provides the status accumulated in the database to any unit.

Advantageous Effects of Invention

The present invention can reduce a load to be applied to a system controller in control of a liquid chromatograph.

DESCRIPTION OF EMBODIMENTS

(1) Overall Configuration of Liquid Chromatograph

The configuration of the liquid chromatograph1according to embodiments of the present invention will be described next with reference to the attached drawings.FIG.1is an overview of the liquid chromatograph1according to the present embodiment. The liquid chromatograph1includes a system controller2, units3and a computer5. The units3are the units that share and execute the functions included in the liquid chromatograph1. In the present embodiment, the liquid chromatograph1includes a pump unit3A, an autosampler unit3B, a column unit3C and a detector unit3D as the units3as shown in the diagram.

The pump unit3A includes a liquid sending pump. The liquid sending pump sends a mobile phase (an eluent) contained in a mobile phase tank to an analysis flow path of the liquid chromatograph1.

The autosampler unit3B is provided at a position farther downstream than the pump unit3A. The autosampler unit3B has a sampling flow path for holding a sample temporarily. The autosampler unit3B can be selectively switched between an injecting mode in which the sampling flow path is incorporated into the analysis flow path of the liquid chromatograph1and a loading mode in which the sampling flow path is not incorporated into the analysis flow path. When the autosampler unit3B is put in the injecting mode with a sample held by the sampling flow path, the sample is injected into the analysis flow path.

The column unit3C is provided at a position farther downstream than the autosampler unit3B. The column unit3C includes a separation column and a column oven containing the separation column. The column oven includes a heater and heats the separation column. The sample that has been injected into the analysis flow path in the autosampler unit3B flows through the separation column together with the mobile phase. The sample is separated while passing through the separation column.

The detector unit3D is provided at a position farther downstream than the column unit3C. In the detector unit3D, the sample that is separated in the column unit3C is detected. The detector unit3D provides detection data to the system controller2.

The system controller2is connected to all of the units3via a communication line CL. That is, the system controller2is connected to the pump unit3A, the autosampler unit3B, the column unit3C and the detector unit3D via the communication line CL. The system controller2is also connected to a computer5via a communication network CN.

The computer5is operated by an operator. The operator creates a method file in which a condition for an analysis to be performed in the liquid chromatograph1is written by operating the computer5. The operator also examines a result of analysis performed in the liquid chromatograph1by operating the computer5.

When the operator creates the method file by operating the computer5, the method file is transferred to the system controller2via the communication network CN. The system controller2examines the method file and acquires a parameter to be set for each unit3. The system controller2provides a parameter to be set for each unit3to the unit3for which the parameter is to be set via the communication line CL. Thus, in each unit3, a configuration of the unit3is set in accordance with the parameter.

Each unit3provides a current status to the system controller2via the communication line CL. The system controller2integrates the statuses received from the respective units3and transfers the statuses to the computer5via the communication network CN.

The detector unit3D provides detection data to the system controller2via the communication line CL. The system controller2transfers the detection data received from the detector unit3D to the computer5via the communication network CN. The computer5performs various analyses in regard to a result of detection with the use of the detection data received from the system controller2.

(2) Configuration and Behavior of System Controller

The configuration of the system controller2will be described next with reference toFIGS.2and3.FIG.2is a block diagram of the system controller2. The system controller2includes a CPU (Central Processing Unit)21, a RAM (Random Access Memory)22and a storage device23. A hard disc, a ROM (Read Only Memory) or the like is used as the storage device23.

FIG.3is a block diagram showing the configuration of the controller20. The controller20includes a parameter assigner201, a status provider202, a detection data provider203, a data accumulator204and a data provider205. The parameter assigner201, the status provider202, the detection data provider203, the data accumulator204and the data provider205are functions that are implemented when the CPU21executes the program PG while utilizing the hardware resources such as the RAM22.

Behavior of the system controller2will be described with reference toFIG.3. As described above, the operator operates the computer5and creates a method file in which a condition of an analysis to be performed in the liquid chromatograph1is written. The computer5transfers the method file to the system controller2via the communication network CN. When the system controller2receives the method file, the parameter assigner201acquires a parameter written in the method file. The parameter assigner201examines the parameter written in the method file and specifies a unit3for which the parameter is to be set. Then, the parameter assigner201provides the parameter to the unit3for which the parameter is to be set via the communication line CL. In a case where the method file includes parameters to be set for a plurality of units3, the parameter assigner201assigns the respective parameters to respective units3for which the respective parameters are to be set.

The parameter assigner201also provides a parameter acquired from the method file to the data accumulator204. The data accumulator204registers the acquired parameter in the parameter database DB1stored in the storage device23.

FIG.4is a diagram showing the content of the parameter database DB1stored in the storage device23. InFIG.4, three parameters a “liquid sending pressure,” an “oven temperature,” and a “sampling rate” that are registered in the parameter database DB are shown, by way of example. “P0001” is assigned to the “liquid sending pressure” as a parameter ID. Further, a value “4.5 (Pa)” is registered as the “liquid sending pressure.” The “liquid sending pressure” is a parameter set for the pump unit3A. “P0002” is assigned to the “oven temperature” as a parameter ID. Further, a value “24.5 (° C.)” is registered as the “oven temperature.” The oven temperature is a parameter set for the column unit3C. “P0003” is assigned to the “sampling rate” as a parameter ID. Further, a value “100 (Hz)” is set as the “sampling rate.” The sampling rate is the rate of detection sampling in the detector unit3D.

In this manner, when receiving the method file from the computer5, the system controller2provides a parameter to each unit3and registers the parameter in the parameter database DB1.

As described above, each unit3provides a status of the unit3to the system controller2via the communication line CL. When the system controller2acquires the status, the status provider202transfers the status to the computer5via the communication network CN. The system controller2integrates statuses acquired from the plurality of units3and transfers them to the computer5.

The status provider202also provides the statuses to the data accumulator204. The data accumulator204registers the acquired statuses in the status database DB2stored in the storage device23.

FIG.5is a diagram showing the content of the status database DB2stored in the storage device23. InFIG.5, three statuses a “liquid sending pressure,” an “oven temperature,” and a “sampling rate” that are registered in the status database DB2are shown, by way of example. “S0001” is assigned to the “liquid sending pressure” as a status ID. Further, a value “4.0 (Pa)” is registered as the “liquid sending pressure.” The “liquid sending pressure” is a pressure of the liquid sending pump included in the pump unit3A. It indicates that the liquid sending pressure of the liquid sending pump is currently 4.0 Pa. “S0002” is assigned to the “oven temperature” as a status ID. Further, a value “23.0 (° C.)” is registered as the “oven temperature.” The oven temperature is a temperature in the column unit3C. It indicates that the temperature in the column oven is currently 23.0° C. “S0003” is assigned to the “sampling rate” as a status ID. Further, a value “100 (Hz)” is set as the “sampling rate.” It indicates that the sampling rate of the detector unit3D is currently set to 100 Hz.

In this manner, when acquiring a status from each unit3, the system controller2provides the status to the computer5and registers the status in the status database DB2.

The detector unit3D provides detection data to the system controller2via the communication line CL. When the system controller2acquires the detection data, the detection data provider203transfers the detection data to the computer5via the communication network CN. The detection data provider203also provides the detection data to the data accumulator204. The data accumulator204registers the acquired detection data in the detection database DB3stored in the storage device23. In this manner, when acquiring the detection data from the detector unit3D, the system controller2provides the detection data to the computer5and registers the detection data in the detection database DB3. In the detection database DB3, the detection data is managed by a unique ID.

Thus, each unit3can make reference to a parameter set for another unit, a status of another unit3or detection data and control itself in accordance with a referenced value. While each unit3is conventionally controlled in response to receiving a control instruction from the system controller2, each unit2can behave independently in the liquid chromatograph1of the present embodiment. Thus, a load applied to the system controller2can be reduced.

Further, it is possible to reduce the number of components such as a detector by sharing a status among the units3. For example, when utilizing a result of temperature detection included in any unit, it is not necessary for a plurality of units to have temperature detectors.

An application example 1 in which the liquid chromatograph1of the present embodiment is utilized will be described next. In the application example 1, the configurations of a system controller2, units3and a computer5are similar to those of the above-mentioned embodiment described with reference toFIGS.1to5. In the application example 1, as shown inFIG.6, a pump unit3A further includes a liquid sending controller311and a protection flow rate setter312. A column unit3C further includes a temperature detector313.

The liquid sending controller311controls the behavior of a liquid sending pump such that a flow rate of a mobile phase flowing through an analysis flow path is a target flow rate set by a parameter. The target flow rate is provided from the system controller2as a parameter. When the target flow rate is set, the protection flow rate setter312sets a protection flow rate that is lower than the target flow rate in order to protect a separation column. The temperature detector313detects a temperature in the column unit3C.

With the above-mentioned configuration, the pump unit3A behaves independently as described below. First, a status provider202acquires an oven temperature detected by the temperature detector313of the column unit3C as a status. The status provider202transfers the oven temperature to the computer5as a status of the column unit3C and provides the oven temperature to a data accumulator204. The data accumulator204registers the oven temperature of the column unit3C in a status database DB2.

Next, a data provider205of the system controller2provides oven temperature data of the column unit3C registered in the status database DB2to the pump unit3A via a communication line CL. For example, the data provider205provides the oven temperature data to the pump unit3A at a predetermined point in time. Alternatively, the data provider205receives a request for acquiring the oven temperature data from the pump unit3A and provides the oven temperature data in response to the request.

When the pump unit3A starts sending a mobile phase, the liquid sending controller311of the pump unit3A makes reference to the oven temperature data of the column unit3C acquired from the system controller2. Then, the liquid sending controller311controls the liquid sending pump such that a flow rate of the mobile phase flowing through the analysis flow path does not exceed a protection flow rate until the temperature of the column unit3C reaches a target temperature. Thus, the pressure of the mobile phase can be prevented from being increased before the temperature of the column unit3C reaches an appropriate temperature, and the separation column can be prevented from being damaged.

After the oven temperature of the column unit3C reaches the target temperature, the liquid sending controller311controls the liquid sending pump such that the flow rate of the mobile phase flowing through the analysis flow path is the target flow rate. In this manner, the pump unit3A behaves independently by acquiring the status of the column unit3C, and a load applied to the system controller2can be reduced.

An application example 2 in which the liquid chromatograph1of the present embodiment is utilized will be described next. In the application example 2, the configurations of a system controller2, units3and a computer5are similar to those of the above-mentioned embodiment described with reference toFIGS.1to5. In the application example 2, a pump unit3A further includes a pressure detector321as shown inFIG.7. An autosampler unit3B further includes a determiner322.

The pressure detector321detects a liquid sending pressure at which a liquid sending pump included in the pump unit3A sends a mobile phase into an analysis flow path. The determiner322obtains a variation value of the liquid sending pressure in the pump unit3A when the autosampler unit3B is switched between an injecting mode and a loading mode. The determiner322determines presence or absence of clogging in a system incorporated into the analysis flow path in the injecting mode based on the obtained variation value.

FIG.8is a block diagram of the autosampler unit3B. The autosampler unit3B includes a switch valve61, a sampling flow path62, a needle63, a sampling loop64, a syringe pump65, a drain flow path66and an injection port67.

The switch valve61is a multi-port valve having six ports <1> to <6>. The switch valve61can be switched between a first mode in which the ports <1> and <6> are connected, the ports <2> and <3> are connected and the ports <4> and <5> are connected, and a second mode in which the ports <1> and <2> are connected, the ports <3> and <4> are connected and the ports <5> and <6> are connected.

When the switch valve61is switched to the second mode, the ports <5> and <6> are connected. Thus, the pump unit3A and a column unit3C are connected to each other without the sampling flow path62. That is, the sampling flow path62is not incorporated into the analysis flow path. This state is referred to as a loading mode. In the loading mode, the ports <1> and <2> are connected, and the sampling flow path62is connected to the syringe pump65. The needle63can inject a sample from a sample container (not shown) by driving of the syringe pump65.

When the needle63injects the sample from the sample container (not shown), the injected sample is held temporarily in the sampling loop64provided in the sampling flow path62. After the sample is injected from the sample container, the needle63is moved by a moving mechanism (not shown) and is connected to the injection port67. In this state, the switch valve61is switched to the first mode. Thus, the pump unit3A, the sampling flow path62and the column unit3C are connected in series. This state is referred to as an injection mode.

With the above-mentioned configuration, the autosampler unit3B behaves independently as described below. First, a status provider202acquires liquid sending pressure data detected by the pressure detector321of the pump unit3A as a status. The status provider202transfers the liquid sending pressure data to the computer5as the status of the pump unit3A and provides the liquid sending pressure data to a data accumulator204. The data accumulator204registers the liquid sending pressure data of the pump unit3A in a status database DB2.

Next, a data provider205of the system controller2provides the liquid sending pressure data of the pump unit3A registered in the status database DB2to the autosampler unit3B via a communication line CL. For example, the data provider205provides the liquid sending pressure data to the autosampler unit3B at a predetermined point in time. Alternatively, the data provider205receives a request for acquiring the liquid sending pressure data from the autosampler unit3B and provides the liquid sending pressure data in response to the request.

Then, the determiner322obtains a variation value of the liquid sending pressure data when the autosampler unit3B is switched between the injection mode and the loading mode, based on the liquid sending pressure data acquired from the system controller2. The determiner322determines presence or absence of clogging in a system incorporated into the analysis flow path in the injecting mode based on the obtained variation value. That is, presence or absence of clogging in the sampling flow path62incorporated into the analysis flow path and a flow path around the sampling flow path62in the injecting mode is determined.

The determiner322presents warning to an operator in a case where determining that clogging is present in the system incorporated into the analysis flow path. For example, the determiner322lights up a warning lamp provided at a casing of the autosampler unit3B. Alternatively, the determiner322notifies the system controller2of presence of clogging. The system controller2displays warning on a monitor of the system controller2. In this manner, the autosampler unit3B behaves independently by acquiring the status of the pump unit3A, and a load applied to the system controller2can be reduced.

(5) Correspondences Between Constituent Elements in Claims and Parts in Preferred Embodiments

In the following paragraphs, non-limiting examples of correspondences between various elements recited in the claims below and those described above with respect to various preferred embodiments of the present disclosure are explained. In the above-mentioned embodiment, a collective term of the database including the parameter database DB1, the status database DB2and the detection database DB3is an example of a database in claims. In the above-mentioned embodiment, the parameter ID or the status ID is an example of a unique ID.

As each of constituent elements recited in the claims, various other elements having configurations or functions described in the claims can be also used.

(6) Other Embodiments

In the above-mentioned embodiment, the liquid chromatograph1includes the pump unit3A, the autosampler unit3B, the column unit3C and the detector unit3D as the units3, by way of example. Further, each unit3behaves independently because a parameter, a status or detection data are shared among units, by way of example. The liquid chromatograph1may include another function unit and may share data with the other function unit.

Each unit3included in the liquid chromatograph1may be contained in each casing, or all of the units3may be contained in one casing. In a case where each unit3is contained in each casing, the liquid chromatograph1is constituted by a combination of a plurality of casings.

It is understood by those skilled in the art that the plurality of above-mentioned illustrative embodiments are specific examples of the below-mentioned aspects.

(Item 1) A liquid chromatograph according to one aspect may include a plurality of units that execute each function of the liquid chromatograph, and a system controller connected to the plurality of units, wherein the system controller may include a status provider that acquires a status from any unit and provides the acquired status to a computer connected to the system controller, a data accumulator that accumulates the status to be provided to the computer in a database, and a data provider that provides the status accumulated in the database to any unit.

Each unit can acquire the status of another unit. Thus, each unit can behave independently in accordance with the status of the other unit, and a load applied to the system controller can be reduced.

(Item 2) In the liquid chromatograph described in the item 1, the system controller may further include a parameter assigner that acquires a parameter from the computer and provides the acquired parameter to a unit for which the parameter is to be set, and the data accumulator may accumulate the parameter to be provided to the unit for which the parameter is to be set in the database, and the data provider may provide the parameter accumulated in the database to any unit.

Each unit can acquire a parameter of another unit. Thus, each unit can behave independently in accordance with a parameter set for the other unit, and a load applied to the system controller can be reduced.

(Item 3) In the liquid chromatograph described in the item 1, the system controller may further include a detection data provider that acquires detection data from a detector unit and provides the acquired detection data to the computer, and the data accumulator may accumulate the detection data to be provided to the computer, and the data provider may provide the detection data accumulated in the database to any unit.

Each unit can acquire the detection data. Thus, each unit can behave independently in accordance with the detection data, and a load applied to the system controller can be reduced.

(Item 4) In the liquid chromatograph described in the item 1, the data provider may provide data accumulated in the database to any unit that has made a request in response to the request made by the unit.

Each unit can acquire data accumulated in the database as necessary. Thus, each unit can behave independently in accordance with the data accumulated in the database, and a load applied to the system controller can be reduced.

(Item 5) In the liquid chromatograph described in the item 1, the data accumulator may assign a unique ID to each data accumulated in the database.

Each unit can acquire desired data from the data accumulated in the database by designating the unique ID.

(Item 6) In the liquid chromatograph described in the item 1, the plurality of units may include a pump unit having a liquid sending pump that sends a mobile phase into an analysis flow path, and a column unit that contains a separation column and adjusts a temperature of the separation column to a target temperature, the pump unit may include a liquid sending controller that controls behavior of the liquid sending pump such that a flow rate of a mobile phase flowing through the analysis flow path is the target flow rate, and a protection flow rate setter that sets a protection flow rate that is lower than the target flow rate in order to protect the separation column, when the target flow rate is set, the column unit may include a temperature detector that detects a temperature in the column unit, the data accumulator may accumulate temperature data of the column unit that is acquired from the column unit as the status in the database, the data provider may provide the temperature data to the pump unit, and the liquid sending controller may control behavior of the pump unit based on the temperature data acquired from the system controller such that a flow rate of a mobile phase flowing through the analysis flow path does not exceed the protection flow rate until a temperature of the column unit reaches the target temperature, when the pump unit starts sending the mobile phase.

The pump unit can control the liquid sending pressure of the mobile phase independently by acquiring the temperature data of the column unit. Thus, a load applied to the system controller can be reduced.

(Item 7) In the liquid chromatograph described in the item 1, the plurality of units may include an autosampler unit that has a sampling flow path for holding a sample temporarily, is selectively switched between an injecting mode in which the sampling flow path is incorporated into an analysis flow path of the liquid chromatograph and a loading mode in which the sampling flow path is not incorporated into the analysis flow path, and injects a sample into the analysis flow path by being put in the injecting mode with the sample flow path holding a sample, and a pump unit that sends a mobile phase into the analysis flow path, the pump unit may include a pressure detector that detects a liquid sending pressure of a mobile phase sent into the analysis flow path, the data accumulator may accumulate liquid sending pressure data acquired from the pump unit as the status in the database, the data provider may provide the liquid sending pressure data to the autosampler unit, the autosampler unit may include a determiner that obtains a variation value of the liquid sending pressure data when the autosampler unit is switched between the injection mode and the loading mode, based on the liquid sending pressure data acquired from the system controller, and determines presence or absence of clogging in a system incorporated into the analysis flow path in the injecting mode based on the obtained variation value.

The autosampler unit can independently make determination about clogging in the flow path by acquiring the liquid sending pressure data of the pump unit. Thus, a load applied to the system controller can be reduced.