Preparative liquid chromatograph

Abstract

To surely collect all of components to be collected in a container.SOLUTION: A preparative fluid chromatograph device comprises: a fraction collector which is provided on the downstream side of a detector and collects an eluent from a separation column separately in a plurality of containers; and a control part which detects each of components separated from each other by the separation column as a peak on the basis of a signal output from the detector, controls the operation of the fraction collector such that each of components detected as a peak is collected in the mutually-different containers, and executes a preparative operation for each sample injected at once to a moving phase. The control part sets the number of components in the sample injected to the moving phase as a reference number, counts the number of components detected as a peak for each sample injected at once to the moving phase by an injector, and determines that the preparative operation of the sample is finished when the number of counted components reaches the reference number and all the components in the same number as the reference number are collected in the containers.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to preparative fluid chromatographs, including preparative liquid chromatographs (hereinafter referred to as preparative LC) and supercritical fluid chromatographs (hereinafter referred to as preparative SFC). [Background technology]

[0002] Preparative LC and preparative SFC are devices that separate components in a sample by chromatography using a liquid or supercritical fluid, and collect the separated components in individual containers using a fraction collector (see Patent Document 1). The fraction collector is controlled so that the components eluted from the separation column and detected as peaks in the detector signal are collected in order into separate containers.

[0003] When collecting a large amount of components using a preparative liquid chromatograph, a so-called stack injection method is performed in which the same sample is injected into the mobile phase multiple times at regular time intervals to prevent overlapping of components injected at different times. In this case, the fraction collector repeats the same collection operation for each sample injected at different times so that the same components in the sample are collected in the same container. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 185872 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional preparative liquid chromatographs typically require the user to set the time required to collect all components of a sample (a sample injected into the mobile phase at one time) (hereinafter referred to as the end time). In this specification, when the set end time elapses after the sample is injected, the fraction collector terminates the current fraction collection operation and moves on to preparation for the collection of the next sample. However, the set end time may differ from the actual time required to collect all components. In such cases, the end time may occur while the fraction collector is collecting components into a container, resulting in problems such as the sample collection operation ending without some components being collected or a system error. Furthermore, when repeating sample collection operations using stack injection, if the actual time required to collect all components differs from the set end time, problems such as components being collected in unexpected containers may occur.

[0006] The present invention has been made in view of the above problems, and has as its object to ensure that all of the components to be collected are collected in a container. [Means for solving the problem]

[0007] The preparative liquid chromatograph apparatus according to the present invention comprises a separation flow path through which a mobile phase flows, an injector for injecting a sample into the mobile phase flowing through the separation flow path, a separation column provided on the separation flow path downstream of the injector for separating a plurality of components in the sample injected into the mobile phase by the injector, a detector provided on the separation flow path downstream of the separation column for outputting a signal corresponding to the concentration of the component eluted from the separation column, a fraction collector provided downstream of the detector for dividing and collecting the eluate from the separation column into a plurality of containers, and a detector for detecting the concentration of each component separated from the other components in the separation column based on the signal output from the detector. and a control unit configured to detect components in a sample as peaks, control the operation of the fraction collector so that the individual components detected as peaks are collected in different containers, thereby performing a fraction collection operation for each sample injected into the mobile phase at one time, wherein the control unit is configured to set the number of components in the sample injected into the mobile phase as a reference number, count the number of components detected as peaks for each sample injected into the mobile phase at one time by the injector, and determine that the fraction collection operation for the sample has ended when the counted number of components reaches the reference number and all components equal in number to the reference number have been collected in the containers. [Effects of the Invention]

[0008] In the preparative fluid chromatograph apparatus of the present invention, the number of components in a sample is set as a reference number, and after the actual sample preparatory operation has begun, the number of components detected as peaks for each sample injected into the mobile phase at one time is counted until it reaches the reference number, and when all of the components counted up to the reference number have been collected in a container, it is determined that the preparative operation for each sample has been completed, thereby ensuring that all of the components to be collected are collected in a container. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a configuration diagram showing an embodiment of a preparative fluid chromatograph device. [Figure 2] 10 is a flowchart showing an example of a fraction collection operation in the same embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of a preparative liquid chromatograph according to the present invention will now be described with reference to the drawings.

[0011] As shown in FIG. 1, the preparative liquid chromatograph of this embodiment is a preparative SFC, and includes a liquid delivery device 4, an injector 6, a separation column 8, an oven 9, a detector 10, a back pressure controller (BPR) 12, a fraction collector 14, and a control unit 16.

[0012] The liquid delivery device 4 delivers a mixture of liquefied carbon dioxide and modifier through the separation channel 2. The injector 6 injects a sample into the mobile phase flowing through the separation channel 2. The separation column 8 is located downstream of the injector 6 on the separation channel 2 and separates the components of the sample injected into the mobile phase by the injector 6. The separation column 8 is housed in an oven 9, and the temperature of the separation column 8 is controlled to a set temperature. The detector 10 is located downstream of the separation column 8 on the separation channel 2 and outputs a signal corresponding to the concentration of each component separated by the separation column 8. The BPR 12 is located at the downstream end of the separation channel 2 and controls the pressure within the separation channel 2 to a set pressure. The BPR 12 creates a high pressure state within the separation channel 2, causing the carbon dioxide in the mobile phase to flow through the separation column 8 in a supercritical state.

[0013] The fraction collector 14 is connected to the outlet flow path 18 of the BPR 12. The fraction collector 14 includes a switching valve 20 for switching the connection destination of the outlet flow path 18 and multiple containers 1 to n for collecting the individual components separated from one another in the separation column 8. The switching valve 20 includes a central common port 20c to which the outlet flow path 18 is connected, multiple container ports 20s connected to the containers 1 to n, and multiple drain ports 20d connected to a drain. The container ports 20s and the drain ports 20d are alternately arranged on the same circumference centered on the common port 20c. In FIG. 1, the switching valve 20 connects the common port 20c to the drain port 20d between the container port 20s connected to the container 1 and the container port 20s connected to the container n. In this embodiment, this state is the initial state of the switching valve 20. By switching the switching valve 20 clockwise from this initial state, the outlet flow path 18 can be connected in the order of drain → container 1 → drain → container 2 → . . . drain → container n.

[0014] The control unit 16 controls the operations of the liquid delivery device 4, the injector 6, the oven 9, the BPR 12, and the fraction collector 14. The control unit 16 can be realized by an electronic circuit equipped with a CPU (central processing unit) and the like. The control unit 16 reads the output signal of the detector 10, detects the individual components eluted from the separation column 8 as peaks, and controls the operation of the fraction collector 14 to sequentially collect each of the components detected as peaks in separate containers.

[0015] Here, the control unit 16 is configured to determine the timing at which the fractionation operation of one sample (a sample injected at one time by the injector 6) ends based on the number of components detected as peaks. The control unit 16 has a function of presetting a reference number for the number of components in one sample. Generally, in preparative LC and preparative SFC, a sample to be fractionated is injected and a preliminary analysis is performed before fractionation begins in order to set fractionation conditions such as the timing of sample injection in stack injection. The number of components in the sample to be fractionated can be obtained from the analysis data obtained in the preliminary analysis. The number of components in the sample to be fractionated can be obtained by the user from the analysis data, or it can be automatically determined by the control unit 16 counting the number of peaks in a chromatogram. If the number of components in the sample to be fractionated is determined by the user, the control unit 16 prompts the user to input a value to be used as the reference number after the preliminary analysis is completed, and sets the value entered by the user as the reference number.

[0016] The control unit 16 counts the number of components detected as peaks in a fraction collection operation for one sample up to a reference number, and determines that the fraction collection operation for that sample has ended when all of the components counted up to the reference number have been collected in containers, and causes the fraction collector 14 to execute an operation to terminate the fraction collection operation. An example of an operation to terminate the fraction collection operation is an operation to return the switching valve 20 to its initial state (the state in FIG. 1). For example, if the reference number is set to m, the switching valve 20 is returned to its initial state when all of the components detected as the mth peak for a sample injected at a certain time have been collected in individual containers.

[0017] An example of the sample sorting operation will be described using the flowchart of Fig. 2 together with Fig. 1. The operation described below is performed for each sample (sample injected at one time by the injector 6).

[0018] The switching valve 20 starts from an initial state where it is the drain port, and when a sample is injected by the injector 6, the control unit 16 monitors the output signal from the detector 10 and counts the number of components detected as peaks for that sample (steps 101 and 102).

[0019] If the peak count number does not reach the preset reference number (step 103: No), the control unit 16 shifts the switching valve 20 of the fraction collector 14 clockwise by one position to collect the detected peak components in a container (step 104), and then shifts the switching valve 20 clockwise by another position to switch to a standby state for the next container (i.e., a state in which it is connected to the drain port 20d just before the container port 20s leading to the container in which the next component is to be collected) (step 105).

[0020] On the other hand, if the peak count reaches a preset reference number (step 103: Yes), the control unit 16 shifts the switching valve 20 of the fraction collector 14 clockwise by one position to collect the detected peak components in a container (step 106), and then returns the switching valve 20 to its initial state (the state in Figure 1) (step 107).

[0021] As described above, in this embodiment, the fractionation operation for one sample continues reliably until all components equal to the predetermined reference number based on the analysis data obtained in the preliminary analysis are collected in their respective containers, so there is no problem of the switching valve 20 being returned to its initial state before the collection of the components is complete.

[0022] Furthermore, when stack injection is being performed, the same peak components can be collected in the same container by returning the switching valve 20 to its initial state and then repeating steps 101 to 107 for the next sample. This method ensures that the same components are collected in the same container without affecting the next collection, even if the time required to collect the components in one sample injection differs from the expected time. The same peak components refer to components that are detected as peaks in the same order during the collection operation for each sample. In other words, all components detected as peaks first after the collection operation for each sample is started are collected in container 1, all components detected as peaks second are collected in container 2, and the component detected as peak m is collected in container m.

[0023] Although the above example is explained using preparative SFC as an example, the present invention can also be applied to preparative LC.

[0024] Furthermore, although the fraction collector 14 in the above embodiment is configured to switch between containers for collecting each component by switching the switching valve 20, the present invention is not limited to this. For example, a combination of multiple switching valves may be used to perform the same function as the switching valve 20, or a container for collecting each component may be switched by moving a nozzle for dropping the eluate over the desired container.

[0025] The above example is merely one example of an embodiment of the preparative chromatography device according to the present invention. The embodiment of the preparative chromatography device according to the present invention is as follows.

[0026] In one embodiment of the preparative chromatography apparatus according to the present invention, the apparatus includes a separation flow path through which a mobile phase flows, an injector that injects a sample into the mobile phase flowing through the separation flow path, a separation column that is provided downstream of the injector on the separation flow path and separates a plurality of components in the sample injected into the mobile phase by the injector, a detector that is provided downstream of the separation column on the separation flow path and outputs a signal corresponding to the concentration of the component eluted from the separation column, a fraction collector that is provided downstream of the detector and divides the eluate from the separation column into a plurality of containers and collects it, and a detector that detects the concentration of the component eluted from the separation column based on the signal output from the detector. and a control unit configured to detect individual components detected as peaks as peaks, control the operation of the fraction collector so that the individual components detected as peaks are collected in different containers, thereby performing a fraction collection operation for each sample injected into the mobile phase at one time, wherein the control unit is configured to set the number of components in the sample injected into the mobile phase as a reference number, count the number of components detected as peaks for each sample injected into the mobile phase at one time by the injector, and determine that the fraction collection operation for the sample has ended when the counted number of components reaches the reference number and all components equal in number to the reference number have been collected in the containers.

[0027] In a first aspect of the above embodiment, the control unit is configured to request the user to input a numerical value to be used as the reference number, and to set the numerical value input by the user as the reference number.

[0028] In addition, in a second aspect of the above embodiment, the control unit is configured to read the number of components in the sample from analysis data obtained in a preliminary analysis performed in advance on the sample to be separated, and set the read number of components as the reference number.

[0029] In a third aspect of the above embodiment, the control unit is configured to return the fraction collector to its initial state when it determines that the fraction collection operation has ended, thereby enabling a prompt transition to the fraction collection operation of the next injected sample.

[0030] In the third aspect, when stack injection is performed in which the same sample is injected into the mobile phase multiple times, the control unit can be configured to control the fraction collector to set the fraction collector to the initial state and then perform the fraction collection operation for each of the samples injected into the mobile phase, and to control the fraction collector so that identical components of each of the samples injected into the mobile phase are collected in the same container. This makes it possible to prevent the fraction collection operation for the next sample from being affected even if the time required for the fraction collection operation for one sample differs from expected when stack injection is performed, and to reliably collect identical components of each of the samples injected into the mobile phase in the same container. [Explanation of symbols]

[0031] 2 Separation channel 4. Liquid delivery device 6 injectors 8 Separation column 9. Oven 10 Detector 12 BPR 14 Fraction Collector 16 Control Unit 18 Outlet channel 20 Switching valve

Claims

1. a separation channel through which a mobile phase flows; an injector that injects a sample into the mobile phase flowing through the separation channel; a separation column provided downstream of the injector on the separation flow path for separating a plurality of components in the sample injected into the mobile phase by the injector; a detector that is provided downstream of the separation column on the separation flow path and outputs a signal corresponding to the concentration of a component eluted from the separation column; a fraction collector provided downstream of the detector for collecting the eluate from the separation column into a plurality of containers; a control unit configured to detect individual components separated from one another in the separation column as peaks based on a signal output from the detector, and to control the operation of the fraction collector so that the individual components detected as the peaks are collected in different containers, thereby performing a fraction collection operation for each sample injected into the mobile phase at one time; the control unit is configured to set the number of components in the sample injected into the mobile phase as a reference number, count the number of components detected as the peaks for each sample injected into the mobile phase at one time by the injector, and determine that the sample preparative operation has been completed when the counted number of components reaches the reference number and all components equal to the reference number have been collected in the container.

2. The preparative fluid chromatograph apparatus according to claim 1 , wherein the control unit is configured to request a user to input a numerical value to be the reference number, and to set the numerical value input by the user as the reference number.

3. 2. The preparative fluid chromatograph apparatus according to claim 1, wherein the control unit is configured to read the number of components in the sample from analysis data obtained in a preliminary analysis previously performed on the sample to be separated, and to set the read number of components as the reference number.

4. 4. The preparative fluid chromatograph apparatus according to claim 1, wherein the control unit is configured to, when it determines that the fraction collection operation has ended, return the fraction collector to an initial state, which is the state at the start of the fraction collection operation.

5. 5. The preparative fluid chromatograph apparatus according to claim 4, wherein, when stack injection is performed in which the same sample is injected into the mobile phase multiple times, the control unit is configured to set the fraction collector to the initial state and then perform the fraction collection operation for each of the samples injected into the mobile phase, and to control the fraction collector so that components of each sample injected into the mobile phase that are the same as each other are collected in the same container.

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