Control method of fractionation liquid chromatograph and fractionation liquid chromatograph

Abstract

To provide a control method of a fractionation liquid chromatograph for, in performing automatic fractionation following to sample injection of multiple times, suppressing a use number of a collection container without performing preliminary injection, and facilitating handling of a collected object.SOLUTION: There is provided a control method of a fractionation liquid chromatograph, the method is configured so that: in fractionation of a sample component following to each injection of sample out of multiple injection times, in fractionation of a sample component following to first sample injection, a sample component corresponding to each peak appearing on a chromatograph, is fractionated by a fractionation part, a start time of each peak on the chromatograph is stored, in fractionation of a sample component following to second and following injection of sample, for every time when a peak appears on the chromatograph, the peak is regarded as a determination object peak, and it is determined whether the determination object peak is derived from a same component of any of respective peaks, on the basis of the start time of the determination object peak, and start times of respective peaks, and a predetermined fractionation operation is performed by the fractionation part on the basis of the determination result.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for controlling a preparative liquid chromatograph and a preparative liquid chromatograph. [Background technology]

[0002] As an apparatus for separating and individually collecting multiple components contained in a sample, a preparative liquid chromatograph is known, which separates each component over time using a column such as a high-performance liquid chromatograph, and then collects each component using a fraction collector.

[0003] A preparative liquid chromatograph comprises an LC section having a liquid delivery pump, a column, and a detector, a fraction collector provided downstream, and a control section for controlling these. The sample components separated over time by the column and eluted are detected sequentially by a detector such as an ultraviolet-visible spectrophotometer, and then introduced into the fraction collector downstream. The fraction collector switches its internal flow path according to instructions from the control section, and the target components are collected in a collection container such as a vial.

[0004] Many preparative liquid chromatographs are equipped with a function called automatic fraction collection, which automatically collects components eluted from a column. In automatic fraction collection, the controller detects peaks that appear on a chromatogram based on the output signal from the detector, and controls the fraction collector to collect the portion of the eluate from the column corresponding to the peak into a separate collection container. Note that the conditions for detecting the peak (e.g., a threshold value for the signal level of the chromatogram or a threshold value for the slope of the chromatogram curve) are set in advance by the user. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 1-221663 Summary of the Invention [Problem to be solved by the invention]

[0006] In the preparative liquid chromatograph described above, multiple sample injections of the same content and multiple subsequent automatic fraction collections may be performed. Here, multiple sample injections of the same content refer to sequential injection of multiple samples believed to have the same composition into the LC section, or injection of the same sample into the LC section in multiple batches. In such cases, peaks that did not appear in the chromatogram obtained with the first sample injection may appear with the second or subsequent sample injections. This is thought to be due to components remaining in the flow path during previous use of the preparative liquid chromatograph being eluted with the second or subsequent sample injections, variations in the procedures used in preparing the multiple samples, or contamination with components remaining in the sample containers. Therefore, peaks that appear only with the second or subsequent sample injections are due to impurity components that do not necessarily need to be fractionated. However, in conventional preparative liquid chromatographs that perform automatic fraction collection, components corresponding to such peaks are also collected by a fraction collector, resulting in problems such as an increased number of collection containers being used and cumbersome handling of the collected materials.

[0007] Furthermore, in multiple automated fraction collection operations involving multiple injections of the same sample, as described above, it may be desirable to collect the same components contained in each sample injection into a single collection container. In such cases, the operation of the fraction collector is controlled so that the component corresponding to the first peak appearing in the chromatogram obtained after each sample injection is collected in the first collection container, the second peak is collected in the second collection container, and the component corresponding to the Nth peak is collected in the Nth collection container. However, when such control is performed, if the number of peaks appearing in each sample injection is different, different components will be collected in a single collection container. Specifically, for example, if peaks 1 and 2 appear as shown in Figure 4 following the first sample injection, peaks 3, 4, and 5 appear following the second sample injection, and peaks 6, 7, 8, and 9 appear following the third sample injection, the components corresponding to peaks 1, 3, and 6 that appear first on each chromatogram will be collected in the first collection container in the fraction collector, and the components corresponding to peaks 2, 4, and 7 that appear second on each chromatogram will be collected in the second collection container, resulting in a mixture of different components (i.e., components with different retention times) in each collection container.

[0008] In addition, some conventional preparative liquid chromatographs that perform automatic fractionation have a function that allows a user to specify peaks to be fractionated on a chromatogram obtained by injecting a test sample into the LC section in advance, and stores the signal level, slope, and retention time at the start and end points of each peak. When actually fractionating a sample, fractionation is performed if the signal level of each peak appearing on the chromatogram of the sample matches the stored signal level and the slope and retention time are within a predetermined range around the stored values ​​(see, for example, Patent Document 1). Using such a preparative liquid chromatograph, only components corresponding to peaks with retention times close to those of the peaks appearing in the test sample injection (pre-injection) are fractionated, thereby eliminating the above-mentioned problems. However, such a method requiring pre-injection consumes time and sample, making it particularly unsuitable for valuable samples for which it is difficult to secure an amount for pre-injection.

[0009] The present invention has been made in consideration of the above points, and its object is to reduce the number of collection containers used and facilitate the handling of the collected material without pre-injection when performing automatic collection involving multiple injections of the same sample using a preparative liquid chromatograph, or to ensure that the same components are collected in the same container without pre-injection. [Means for solving the problem]

[0010] In order to solve the above problems, the method for controlling a preparative liquid chromatograph according to the present invention comprises: A method for controlling a preparative liquid chromatograph having a separation column that separates a plurality of sample components contained in a sample injected into a flow path, a detector provided downstream of the separation column, a chromatogram creation unit that creates a chromatogram based on a detection result by the detector, and a fractionation unit that fractionates sample components corresponding to peaks on the chromatogram from an eluate from the separation column, the method comprising: When fractionating sample components associated with each of a plurality of sample injections into the channel, When fractionating sample components following a first sample injection of the plurality of sample injections, the fractionating unit fractionates sample components corresponding to each peak appearing on a first chromatogram, which is a chromatogram created by the chromatogram creating unit following the first sample injection, and stores the start times of each of the peaks on the first chromatogram; When collecting sample components following the second or subsequent sample injection of the multiple sample injections, each time a peak appears on a target chromatogram, which is a chromatogram created by the chromatogram creation unit following the second or subsequent sample injection, the peak is designated as a peak to be determined, and a determination is made as to whether the peak to be determined is derived from the same component as any of the peaks based on the start time of the peak to be determined on the target chromatogram and the start times of the peaks on the first chromatogram, and a predetermined collection operation is performed by the collection unit based on the determination result.

[0011] Further, a preparative liquid chromatograph according to the present invention, which has been made to solve the above problems, comprises: A preparative liquid chromatograph comprising: a separation column for separating a plurality of sample components contained in a sample injected into a flow path; a detector provided downstream of the separation column; a chromatogram creation unit for creating a chromatogram based on the detection results by the detector; a fractionation unit for fractionating sample components corresponding to peaks on the chromatogram from an eluate from the separation column; and a fractionation control unit for controlling the fractionation unit, When fractionating sample components associated with each of a plurality of sample injections into the channel, The fractionation control unit When fractionating sample components following a first sample injection of the plurality of sample injections, the fractionation unit is controlled to fractionate sample components corresponding to each peak appearing on a first chromatogram, which is a chromatogram created by the chromatogram creation unit following the first sample injection, and the start times of each of the peaks on the first chromatogram are stored; When collecting sample components following the second or subsequent sample injection of the multiple sample injections, each time a peak appears on the target chromatogram, which is a chromatogram created by the chromatogram creation unit following the second or subsequent sample injection, the peak is treated as a peak to be determined, and a determination is made as to whether the peak to be determined is derived from the same component as any of the peaks based on the start time of the peak to be determined on the target chromatogram and the start times of the peaks on the first chromatogram, and the collection unit is controlled to perform a predetermined collection operation based on the determination result. [Effects of the Invention]

[0012] According to the above-described method for controlling a preparative liquid chromatograph of the present invention or the above-described preparative liquid chromatograph of the present invention, when performing automatic fractionation involving multiple injections of the same sample, it is possible to reduce the number of collection containers used and facilitate the handling of the collected material without performing pre-injection, or to ensure that the same components are collected in the same container without performing pre-injection. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a preparative liquid chromatograph according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the main configuration of a control unit in the embodiment. [Figure 3] 4 is a flowchart showing the operation of the preparative liquid chromatograph according to the embodiment. [Figure 4] FIG. 10 shows an example of a chromatogram created for each of multiple sample injections of the same content. [Figure 5] 10 is a flowchart showing another example of the operation of a preparative liquid chromatograph according to the present invention. [Figure 6] FIG. 1 is a diagram showing a schematic configuration of a preparative liquid chromatograph according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] [Embodiment 1] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a schematic diagram of a preparative liquid chromatograph according to one embodiment of the present invention. This preparative liquid chromatograph comprises an LC section 10, a fraction collector 50, and a control / processing section 60. In this embodiment, the fraction collector 50 corresponds to the fractionation section in the present invention.

[0015] The LC section 10 includes a mobile phase container 11, a mobile phase flow path 12, a mobile phase supply pump 13 provided on the mobile phase flow path 12, an automatic sample injector 20, a separation column 30, and a detector 40. The detector 40 may be any detector used in a liquid chromatograph, and may be, for example, an absorbance detector or a differential refractive index detector.

[0016] The automatic sample injection device 20 includes a sample container storage section 22 that stores multiple sample containers 21 containing liquid samples, an aspirating section 23 that aspirates a predetermined amount of sample from a selected sample container 21, and an injector 24 that injects the sample aspirated by the aspirating section 23 into the mobile phase flow path 12.

[0017] The fraction collector 50 includes a container storage section 52 that stores multiple collection containers 51 (corresponding to the fraction collection destinations in this invention), a nozzle head 54 with a dispensing nozzle 53 at its lower end, a dispensing valve 55 built into the nozzle head 54 that switches the destination of the liquid sent from the LC section 10 to either the drain or the dispensing nozzle 53, and a drive section (not shown) that moves the nozzle head 54 back and forth, up and down, and left and right.

[0018] The control / processing unit 60 is configured by a general-purpose computer such as a personal computer, a dedicated computer, or a combination of these, and controls the above-mentioned units and performs predetermined data processing based on the output signal from the detector 40 of the LC unit 10.

[0019] The configuration of the control / processing unit 60 is shown in FIG. 2. The control / processing unit 60 includes an LC control unit 61 that controls the LC unit 10, a collection control unit 62 (corresponding to the fraction collection control unit in this invention) that controls the fraction collector 50, a chromatogram creation unit 63 that creates a chromatogram in approximately real time based on the output signal from the detector 40, a peak detection unit 64 that detects the start and end points of peaks that appear on the chromatogram over time, and a determination unit 65 that makes predetermined determinations (described below). All of these are functional blocks realized in software by a CPU provided in a computer constituting the control / processing unit 60, which reads into the computer's memory and executes a dedicated program installed in a mass storage device such as a hard disk drive (HDD) provided in the computer. The control / processing unit 60 also includes a memory unit 66, which is provided with a start time memory unit 67 (described in detail below). The function of the memory unit 66 is realized, for example, by a mass storage device provided in the computer. The computer constituting the control / processing unit 60 is connected to an input unit such as a keyboard or a mouse, and a display unit such as a liquid crystal display (both not shown).

[0020] Next, the operation of the preparative liquid chromatograph according to this embodiment will be described with reference to the flowchart of FIG.

[0021] When performing automatic fractionation using the preparative liquid chromatograph of this embodiment, a plurality of sample containers 21 (e.g., each containing a sample of the same composition) are set in advance in the automatic sample injection device 20, and a plurality of collection containers 51 for containing various components (sample components) in the sample are set in the fraction collector 50. Furthermore, by operating the above-mentioned input unit, the user inputs injection conditions indicating the order and amount of sample to be collected from the plurality of sample containers 21 in the automatic sample injection device 20, as well as detection conditions for the peak start and end points in the peak detection unit 64 (e.g., threshold values ​​for the signal level of the chromatogram or threshold values ​​for the slope of the chromatogram curve), and stores these in the memory unit 66.

[0022] When the user issues an instruction to start automatic fraction collection via the input unit, under the control of the LC control unit 61, a predetermined amount of sample is collected from a pre-specified sample container 21 in the automatic sample injection device 20 and injected from the injector 24 into the mobile phase flow path 12 (step 101). Hereinafter, the sample injection in step 101 will be referred to as the "first sample injection."

[0023] A mobile phase drawn from a mobile phase container 11 by a mobile phase supply pump 13 flows through the mobile phase flow path 12, and the sample injected into the mobile phase flow path 12 by the automatic sample injection device 20 is carried by the flow of this mobile phase and introduced into the inlet end of a separation column 30. Then, each sample component is separated as it passes through the separation column 30 and is eluted sequentially from the outlet end of the separation column 30. The liquid flowing out from the outlet end of the separation column 30 (hereinafter referred to as the eluate) passes through a detector 40 and is then discharged to the drain via a dispensing valve 55 of a fraction collector 50. The output signal of the detector 40 at this time is converted into a digital value by an A / D converter (not shown) and input to a control / processing unit 60.

[0024] In the control / processing unit 60, the chromatogram creation unit 63 starts creating a chromatogram showing the time change of the detection signal from the detector 40 based on the digital value. Then, the peak detection unit 64 determines whether or not a peak has appeared on the chromatogram at predetermined time intervals (step 102). The determination of whether or not a peak has appeared is made based on whether or not the start point of the peak has been detected. The method of detecting the start point of the peak is not particularly limited, and may be any of various conventionally known methods, such as a method based on the signal level of the chromatogram, a method based on the slope of the chromatogram curve, or a method based on both.

[0025] When it is determined in step 102 that a peak has appeared, the control / processing unit 60 stores the time (the time elapsed since the first sample injection) as the peak start time of the peak in the start time memory unit 67 (step 103). Furthermore, the control / processing unit 60 collects a portion of the eluate from the separation column 30 that corresponds to the peak in a predetermined collection container 51 in the fraction collector 50 (step 104). Specifically, under the control of the collection control unit 62, the fraction collector 50 moves the nozzle head 54 over the predetermined collection container 51, and switches the dispensing valve 55 from the drain side to the dispensing nozzle 53 side at the timing when the portion of the eluate that corresponds to the start point of the peak reaches the dispensing valve 55, thereby discharging the eluate from the dispensing nozzle 53 into the predetermined collection container 51. Thereafter, when the peak detection unit 64 detects the end point of the peak, the dispensing valve 55 is switched from the dispensing nozzle 53 side to the drain side at the timing when the portion of the eluate corresponding to the end point of the peak reaches the dispensing valve 55, thereby discharging the eluate from the drain. The method for detecting the end point of the peak is not particularly limited, and any of various conventionally known methods may be used, for example, a method based on the signal level of a chromatogram, a method based on the slope of the chromatogram curve, or a method based on both.

[0026] The switching of the dispensing valve 55 as described above is performed at a timing that takes into consideration the time required for the eluate to reach the dispensing valve 55 from the detector 40 .

[0027] Next, it is determined whether a predetermined time has elapsed since the first sample injection (step 105), and if it is determined that a predetermined time has not elapsed, the process returns to step 102. If it is determined that a new peak has appeared on the chromatogram (i.e., if step 102 returns Yes), the peak start time of the new peak is recorded (step 103), and the sample components corresponding to the new peak are collected (step 104). In step 104, the sample components corresponding to each peak on the chromatogram are collected in different collection containers 51.

[0028] Then, in step 105, when it is determined that a predetermined time has elapsed since the first sample injection, the automatic fraction collection associated with the first sample injection is terminated.

[0029] Next, under the control of the LC control unit 61, a predetermined amount of sample is collected from a pre-specified sample container 21 in the automatic sample injection device 20 and injected into the mobile phase flow path 12 (step 106). Hereinafter, this will be referred to as the "second sample injection."

[0030] When the second sample injection is performed, the chromatogram creation unit 63 starts creating a chromatogram associated with the second sample injection, and the peak detection unit 64 determines at predetermined time intervals whether a peak has appeared on the chromatogram (step 107).

[0031] When it is determined in step 107 that a peak has appeared (i.e., when the peak start point is detected by peak detection unit 64), determination unit 65 determines whether the peak is the same as any of the peaks that appeared in the first sample injection (i.e., whether they originate from the same component) based on the peak start time, i.e., the elapsed time from the immediately preceding sample injection (here, the second sample injection) until the start point of the peak is detected (step 108). Specifically, the peak start times of each peak detected in the first sample injection (hereinafter referred to as "peaks to be compared") are read from start time storage unit 67, and if the difference between any of the peak start times and the start time of the peak detected in step 107 (hereinafter referred to as "peak to be determined") is within a predetermined allowable error range, the peak to be determined is the same as the peak that appeared in the first sample injection. On the other hand, if the differences between the start time of the peak to be determined and the start times of each of the comparison peaks are not within the allowable error range, the peak to be determined is not the same as the peak that appeared in the first sample injection. The value of the allowable error is set in advance by the user or manufacturer of the preparative liquid chromatograph according to this embodiment and stored in the storage unit 66. As described above, in the preparative liquid chromatograph according to this embodiment, by determining whether the peak to be determined is the same as the peak that appeared in the first sample injection based on the peak start time, the time required for the determination can be shortened compared to when the determination is based on peak waveform processing, such as the similarity of the peak shape.

[0032] If it is determined in step 108 that the peak to be determined is the same as the peak that appeared in the first sample injection, the fraction collector 50 collects the portion of the eluate from the separation column 30 that corresponds to the peak to be determined in a predetermined collection container 51 (step 109). At this time, an empty collection container 51 that has not been used in the automatic fractionation following the first sample injection is used as the collection container 51. Note that the specific collection method is the same as in step 104 described above, and therefore will not be described here.

[0033] On the other hand, if it is determined in step 108 that the peak to be determined is not the same as the peak that appeared in the first sample injection, the portion of the eluate corresponding to the peak to be determined is not collected but is discharged to the drain via the dispensing valve 55 of the fraction collector 50.

[0034] Thereafter, it is determined whether a predetermined time has elapsed since the second sample injection (step 110), and if it is determined that the predetermined time has not elapsed, the process returns to step 107 and steps 107 to 110 are repeated.

[0035] Then, at the point in time when it is determined in step 110 that a predetermined time has elapsed since the second sample injection, the automatic fraction collection associated with the second sample injection is terminated, and it is determined whether or not all pre-specified sample injections have been completed (step 111). If it is determined that all sample injections have not been completed, the process returns to step 106 and a third sample injection is performed.

[0036] Thereafter, steps 106 to 111 are repeatedly executed until it is determined in step 111 that all sample injections have been completed, at which point the series of processes ends.

[0037] As described above, the preparative liquid chromatograph according to this embodiment can prevent the recovery of components that are detected only in the second or subsequent sample injections during automatic fraction collection involving multiple sample injections. This makes it possible to prevent the recovery of impurity components without pre-injection when multiple automatic fraction collections are performed involving multiple sample injections of the same content, thereby reducing the number of collection containers 51 used and avoiding cumbersome handling of the collected materials.

[0038] In the above embodiment, the sample components are collected in different collection containers 51 for the automatic fraction collection associated with the first sample injection and for the automatic fraction collection associated with each subsequent sample injection. As a result, for example, if peaks 1 and 2 appear as shown in Figure 4 following the first sample injection, peaks 3 to 5 appear following the second sample injection, and peaks 6 to 9 appear following the third sample injection, peaks 1, 2, 4, 5, 7, and 8 are collected in different collection containers 51 (for example, the first to sixth collection containers 51 in the fraction collector 50) in the order in which they were detected, while peaks 3, 6, and 9, which appear only in the second and subsequent injections, are not collected but discarded.

[0039] However, the present invention is not limited to this, and in the automatic fractionation associated with each of the second and subsequent sample injections, among the peaks (the peaks to be determined) detected in the second and subsequent sample injections, sample components corresponding to peaks determined to be the same as the peaks that appeared in the first injection (the peaks to be compared) may be collected in the same collection container 51 as the sample components corresponding to the peaks to be compared that were determined to be the same. In this case, in the example shown in Figure 4, the sample components corresponding to peaks 1, 4, and 7 are collected together in one collection container 51 (e.g., the first collection container 51 in the fraction collector 50), the sample components corresponding to peaks 2, 5, and 8 are collected together in another collection container 51 (e.g., the second collection container 51 in the fraction collector 50), and the components corresponding to peaks 3, 6, and 9 that did not appear in the first sample injection are not collected but are discarded. This reduces the number of collection containers 51 used compared to when the sample components corresponding to peaks 1, 4, and 7 and the sample components corresponding to peaks 2, 5, and 8 are all collected in separate collection containers 51, and also prevents different sample components from being collected in one collection container 51.

[0040] Alternatively, sample components corresponding to peaks that appear with the second or subsequent sample injections but do not appear with the first sample injection may also be collected in collection containers 51. In this case, sample components corresponding to peaks that appear only with the second or subsequent sample injections (peaks 3, 6, and 9 in the example of FIG. 4) may all be collected in different collection containers 51, or sample components corresponding to peaks that appear in common in multiple sample injections from the second onwards (peaks 3 and 6 in the example of FIG. 4) may be collected together in a single collection container 51 (for example, the third collection container in fraction collector 50).

[0041] As described above, among peaks that appear only in the second or subsequent sample injections, components corresponding to peaks that appear in common in multiple sample injections from the second onward are collected together in one collection container 51, as described below with reference to the flowchart of Fig. 5. Note that steps 201 to 207 in the flowchart of Fig. 5 are the same as steps 101 to 107 in the flowchart of Fig. 3, and therefore will not be described here.

[0042] In the flowchart of Figure 5, when a peak start point is detected on a chromatogram created following the second or subsequent sample injection (step 206) (i.e., when step 207 returns Yes), the time at that time (the elapsed time since the previous sample injection) is stored in start time memory unit 67 as the peak start time of the peak (step 208).

[0043] Then, the determination unit 65 determines whether the peak detected in step 207 (peak to be determined) is the same as any of the peaks (peaks to be compared) detected in the previous sample injections (if this is the Nth sample injection (N is 2 or more), then the 1st to (N-1th) sample injections) (step 209). Specifically, if the difference between any of the peak start times of the comparison peaks stored in the start time memory unit 67 and the start time of the peak to be determined is within a predetermined allowable error range, the peak to be determined is the same as any of the peaks that appeared in the previous sample injections. On the other hand, if the differences between the start time of the peak to be determined and the start times of any of the comparison peaks are not within the allowable error range, the peak to be determined is not the same as any of the peaks that appeared in the previous sample injections.

[0044] If it is determined in step 209 that the peak to be determined is the same as the peak that appeared in the previous sample injection, the fraction collector 50 collects the sample components corresponding to the peak to be determined in the same collection container 51 as that used to collect the comparison peak determined to be the same as the peak to be determined (step 210). Note that the method for collecting the sample components is the same as in step 104 described above, and therefore will not be described here.

[0045] On the other hand, if it is determined in step 209 that the peak to be determined is different from the peaks that have appeared in the previous sample injections, the fraction collector 50 collects the sample component corresponding to the peak to be determined in a new collection container 51 (if this is the Nth (N is 2 or more) sample injection, a collection container 51 that has not been used in the automatic fractionation associated with the 1st to N-1th sample injections) (step 211).

[0046] Thereafter, it is determined whether a predetermined time has elapsed since the previous sample injection (step 212), and if it is determined that the time has not elapsed, the process returns to step 207 and repeats the processing of steps 207 to 212. Thereafter, if it is determined in step 212 that the predetermined time has elapsed since the previous sample injection, the process proceeds to step 213 and determines whether all pre-specified sample injections have been completed. If it is determined that all sample injections have not been completed, the process returns to step 206 and repeats steps 206 to 213, and the series of processing is completed when it is determined in step 213 that all sample injections have been completed.

[0047] By performing the above operations, for example, in the case shown in Figure 4, peaks 1, 4, and 7 are collected in one collection container 51 (e.g., the first collection container 51 in the fraction collector 50), peaks 2, 5, and 8 are collected in another collection container 51 (e.g., the second collection container 51 in the fraction collector 50), peaks 3 and 6 are collected in yet another collection container 51 (e.g., the third collection container 51 in the fraction collector 50), and peak 9 is collected in yet another collection container 51 (e.g., the fourth collection container in the fraction collector 50).

[0048] In a single preparative liquid chromatograph, it is desirable that the user be able to select in advance whether components corresponding to peaks determined to be the same are collected together in one collection container 51 or collected separately in different collection containers 51. In addition, when components corresponding to peaks determined to be the same are collected together in one collection container 51, it is desirable that the user be able to select in advance whether peaks that appear only in the second or subsequent sample injections are to be collected. Furthermore, when peaks that appear only in the second or subsequent sample injections are to be collected, it is desirable that the user be able to select in advance whether components corresponding to peaks that appear only in the second or subsequent sample injections that appear in common in multiple sample injections from the second onwards are to be collected together in one collection container 51 or collected separately in different collection containers 51.

[0049] In the above example, the present invention is applied to a preparative liquid chromatograph configured to directly fractionate the eluate from the separation column 30 using the fraction collector 50. However, the present invention is not limited to this configuration and can also be applied to a preparative liquid chromatograph configured to temporarily capture various sample components contained in the eluate in a trap column and then recover them. Such a configuration will be described below.

[0050] [Embodiment 2] The main components of a preparative liquid chromatograph according to a second embodiment of the present invention are shown in Figure 6. As shown in Figure 6, the preparative liquid chromatograph according to this embodiment includes, in addition to the LC section 110, fraction collector 150, and control / processing section 160 similar to those described above, a component capture section 200 equipped with multiple trap columns 270, and a solvent supply section 300 that supplies an elution solvent to each trap column 270. In this embodiment, the component capture section 200 corresponds to the fraction collection section in this invention, and the trap columns 270 correspond to the fraction collection destination in this invention. In Figure 6, components that are the same as or correspond to those shown in Figure 1 are designated by reference numerals with the same last two digits, and their explanation will be omitted where appropriate.

[0051] The component capture unit 200 includes a plurality of flow paths, each of which is provided with one of the plurality of trap columns 270, a drainage flow path 280 not provided with a trap column 270, and a flow path switching unit 201 that switches whether the eluate from the separation column 130 flows through one of the plurality of trap columns 270 or the drainage flow path 280. Each trap column 270 is filled with a capturing agent that captures sample components. While FIG. 6 shows a configuration in which six trap columns 270 are provided, the number of trap columns 270 provided in the component capture unit 200 is not limited to this and may be two to five or seven or more.

[0052] The solvent supply unit 300 includes a solvent supply pump 302 that sucks the elution solvent contained in a solvent container 301, and a switching valve 303 that is provided on the flow path between the LC unit 110 and the component capture unit 200. The switching valve 303 selectively switches whether to send the eluate sent from the LC unit 110 or the elution solvent supplied by the solvent supply pump 302 to the component capture unit 200.

[0053] In such a preparative liquid chromatograph, first, a sample is injected by the automatic sample injection device 120 in a state in which the eluate is discharged to the drain via the switching valve 303, the flow path switching unit 201, the drainage flow path 280, and the dispensing valve 155. Then, when a portion of the eluate from the separation column 130 corresponding to the start point of a peak on the chromatogram reaches the flow path switching unit 201, the flow path switching unit 201 is switched to select one of the trap columns 270, and thereafter, when a portion corresponding to the end point of the peak reaches the flow path switching unit 201, the flow path switching unit 201 is switched to select the drainage flow path 280. As a result, the sample component corresponding to the peak is captured in the trap column 270 (hereinafter, this is referred to as the capture step). After the capture step is completed, a predetermined trap column 270 is selected by the flow path switching unit 201, and the solvent supply pump 302 is driven and the switching valve 303 is switched to allow the elution solvent to flow through the predetermined trap column 270, thereby eluting the sample components from the trap column 270 (hereinafter, this is referred to as the elution step). In the elution step, the liquid eluted from the trap column 270 (elution solvent containing the sample components) is introduced into the fraction collector 150 and collected in the collection container 151 corresponding to each trap column 270.

[0054] In the preparative liquid chromatograph according to this embodiment, the above-mentioned capture step is performed as shown in the flowchart of Fig. 3 or as shown in the flowchart of Fig. 5. In this case, however, in steps 104 and 109 of the flowchart of Fig. 3 and steps 204 and 210 or 211 of the flowchart of Fig. 5, the portion of the eluate from the separation column 130 that corresponds to a peak on the chromatogram is introduced into one of the trap columns 270, rather than being collected in the collection container 151.

[0055] 3, in the capture step, in step 104 of the flowchart, portions of the eluate from the separation column 130 following the first sample injection, corresponding to each peak, are introduced into different trap columns 270. As a result, the sample components corresponding to each peak are captured in different trap columns 270. Then, in the subsequent step 109, only portions of the eluate from the separation column 130 following the second or subsequent sample injection, corresponding to peaks determined to be identical to the peaks (comparison peaks) appearing in the first sample injection, are introduced into the trap column 270 (the same trap column 270 as that in which the sample components corresponding to the comparison peaks determined to be identical were captured, or a different trap column 270), and portions corresponding to peaks determined not to be identical to the peaks appearing in the first sample injection are discharged to the drain via the discharge flow path 280 of the component capture section 200 and the dispensing valve 155 of the fraction collector 150.

[0056] 5, in the capture step, in step 204 of the flowchart, portions of the eluate eluted from the separation column 130 following the first sample injection, corresponding to each peak, are introduced into different trap columns 270. Then, in the subsequent step 209, portions of the eluate from the separation column 130 following the second or subsequent sample injection, corresponding to peaks determined to be the same as peaks (comparison peaks) that appeared in the previous sample injections, are introduced into the same trap column 270 in which the sample components corresponding to the comparison peaks determined to be identical are trapped, and portions corresponding to peaks determined not to be the same as peaks that appeared in the previous sample injections are introduced into a new trap column 270 (if this is the Nth sample injection (N is 2 or more), a trap column 270 that has not been used in the capture steps following the 1st to (N-1th) sample injections).

[0057] After the multiple sample injections and the associated multiple capture steps are completed, the elution step described above is performed to elute the sample components captured in each trap column 270 and collect them in the fraction collector 150. As a result, each collection container 151 in the fraction collector 150 contains a liquid containing the sample components eluted from a different trap column 270.

[0058] While specific examples of embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and modifications are permitted within the spirit and scope of the present invention. For example, in the above embodiments, automatic fractionation is performed on all of the multiple samples set in the automatic sample injection device 20, 120 as shown in the flowchart of Figure 3 or 5. However, the present invention is not limited to this. Two or more samples specified in advance by the user among the multiple samples set in the automatic sample injection device 20, 120 may be automatically fractionated as shown in the flowchart of Figure 3 or 5, and the remaining samples may be automatically fractionated in the same manner as in the past.

[0059] Furthermore, in the above embodiment, in each of the multiple sample injections, the sample is collected from a different sample container 21 and injected into the injector 24. Alternatively, in each of the multiple sample injections, the sample may be collected from the same sample container 21 and injected into the injector 24.

[0060] [Aspect] It will be apparent to those skilled in the art that the above-described exemplary embodiments are examples of the following aspects.

[0061] (Item 1) A method for controlling a preparative liquid chromatograph according to one aspect of the present invention comprises: A method for controlling a preparative liquid chromatograph having a separation column that separates a plurality of sample components contained in a sample injected into a flow path, a detector provided downstream of the separation column, a chromatogram creation unit that creates a chromatogram based on a detection result by the detector, and a fractionation unit that fractionates sample components corresponding to peaks on the chromatogram from an eluate from the separation column, the method comprising: When fractionating sample components associated with each of a plurality of sample injections into the channel, When fractionating sample components following a first sample injection of the plurality of sample injections, the fractionating unit fractionates sample components corresponding to each peak appearing on a first chromatogram, which is a chromatogram created by the chromatogram creating unit following the first sample injection, and stores the start times of each of the peaks on the first chromatogram; When collecting sample components following the second or subsequent sample injection of the multiple sample injections, each time a peak appears on a target chromatogram, which is a chromatogram created by the chromatogram creation unit following the second or subsequent sample injection, the peak is designated as a peak to be determined, and a determination is made as to whether the peak to be determined is derived from the same component as any of the peaks based on the start time of the peak to be determined on the target chromatogram and the start times of the peaks on the first chromatogram, and a predetermined collection operation is performed by the collection unit based on the determination result.

[0062] (Item 2) The method for controlling a preparative liquid chromatograph according to Item 2 is the method for controlling a preparative liquid chromatograph according to Item 1, The predetermined separation operation is such that, if the determination determines that the peak to be determined is derived from the same component as any of the peaks on the first chromatogram, the sample component corresponding to the peak to be determined is separated, and, if the determination determines that the peak to be determined is not derived from the same component as any of the peaks on the first chromatogram, the sample component corresponding to the peak to be determined is not separated.

[0063] (Item 3) The method for controlling a preparative liquid chromatograph according to Item 3 is the method for controlling a preparative liquid chromatograph according to Item 1, When the determination determines that the peak to be determined is derived from the same component as any of the peaks on the first chromatogram, the predetermined fraction collection operation dispenses the sample component corresponding to the peak to be determined into the same fraction collection destination, among the plurality of fraction collection destinations included in the fraction collection unit, as the fraction collection destination into which the sample component corresponding to the peak determined to be derived from the same component as the peak to be determined was dispensed; when the determination determines that the peak to be determined is not derived from the same component as any of the peaks on the first chromatogram, the sample component corresponding to the peak to be determined is not dispensed, or is dispensed into the plurality of fraction collection destinations different from the fraction collection destination into which the sample component corresponding to each peak was dispensed.

[0064] (4) The preparative liquid chromatograph according to 4 is A preparative liquid chromatograph comprising: a separation column for separating a plurality of sample components contained in a sample injected into a flow path; a detector provided downstream of the separation column; a chromatogram creation unit for creating a chromatogram based on the detection results by the detector; a fractionation unit for fractionating sample components corresponding to peaks on the chromatogram from an eluate from the separation column; and a fractionation control unit for controlling the fractionation unit, When fractionating sample components associated with each of a plurality of sample injections into the channel, The fractionation control unit When fractionating sample components following a first sample injection of the plurality of sample injections, the fractionation unit is controlled to fractionate sample components corresponding to each peak appearing on a first chromatogram, which is a chromatogram created by the chromatogram creation unit following the first sample injection, and the start times of each of the peaks on the first chromatogram are stored; When collecting sample components following the second or subsequent sample injection of the multiple sample injections, each time a peak appears on the target chromatogram, which is a chromatogram created by the chromatogram creation unit following the second or subsequent sample injection, the peak is treated as a peak to be determined, and a determination is made as to whether the peak to be determined is derived from the same component as any of the peaks based on the start time of the peak to be determined on the target chromatogram and the start times of the peaks on the first chromatogram, and the collection unit is controlled to perform a predetermined collection operation based on the determination result.

[0065] (Item 5) The preparative liquid chromatograph according to Item 5 is the preparative liquid chromatograph according to Item 4, The predetermined separation operation is such that, if the determination determines that the peak to be determined is derived from the same component as any of the peaks on the first chromatogram, the sample component corresponding to the peak to be determined is separated, and, if the determination determines that the peak to be determined is not derived from the same component as any of the peaks on the first chromatogram, the sample component corresponding to the peak to be determined is not separated.

[0066] (Item 6) The preparative liquid chromatograph according to Item 6 is the preparative liquid chromatograph according to Item 4, When the determination determines that the peak to be determined is derived from the same component as any of the peaks on the first chromatogram, the predetermined fraction collection operation dispenses the sample component corresponding to the peak to be determined into the same fraction collection destination, among the plurality of fraction collection destinations included in the fraction collection unit, as the fraction collection destination into which the sample component corresponding to the peak determined to be derived from the same component as the peak to be determined was dispensed; when the determination determines that the peak to be determined is not derived from the same component as any of the peaks on the first chromatogram, the sample component corresponding to the peak to be determined is not dispensed, or is dispensed into the plurality of fraction collection destinations different from the fraction collection destination into which the sample component corresponding to each peak was dispensed. [Explanation of symbols]

[0067] 10...LC section 20...Automatic sample injection device 21...Sample container 30...Separation column 40...Detector 50...Fraction collector 51...Collection container 53...Dispensing nozzle 60...Control / processing unit 61...LC control section 62... Recovery control unit 63...Chromatogram creation section 64...Peak detector 65…Judgment section 67…Start time storage unit

Claims

1. A method for controlling a preparative liquid chromatograph having a separation column that separates a plurality of sample components contained in a sample injected into a flow path, a detector provided downstream of the separation column, a chromatogram creation unit that creates a chromatogram based on a detection result by the detector, and a fractionation unit that fractionates sample components corresponding to peaks on the chromatogram from an eluate from the separation column, the method comprising: When fractionating sample components associated with each of a plurality of sample injections into the channel, When fractionating sample components following a first sample injection of the plurality of sample injections, the fractionating unit fractionates sample components corresponding to each peak appearing on a first chromatogram, which is a chromatogram created by the chromatogram creating unit following the first sample injection, and stores the start times of each peak on the first chromatogram; When collecting sample components in a second or subsequent sample injection among the multiple sample injections, each time a peak appears on a target chromatogram, which is a chromatogram created by the chromatogram creation unit in connection with the second or subsequent sample injections, the peak is designated as a peak to be determined, and a determination is made as to whether or not the peak to be determined is derived from the same component as any of the peaks based on the start time of the peak to be determined on the target chromatogram and the start times of the peaks on the first chromatogram, and a predetermined collection operation is performed by the collection unit based on the determination result. Methods for controlling preparative liquid chromatographs.

2. 2. The method for controlling a preparative liquid chromatograph according to claim 1, wherein the predetermined fractionation operation fractionates a sample component corresponding to the peak to be determined if it is determined in the determination that the peak to be determined is derived from the same component as any of the peaks on the first chromatogram, and does not fractionate a sample component corresponding to the peak to be determined if it is determined that the peak to be determined is not derived from the same component as any of the peaks on the first chromatogram.

3. 2. The method for controlling a preparative liquid chromatograph according to claim 1, wherein the predetermined fractionating operation, when it is determined in the determination that the peak to be determined is derived from the same component as any of the peaks on the first chromatogram, fractionates the sample component corresponding to the peak to be determined to be derived from the same component as any of the peaks on the first chromatogram, into the same fractionating destination among the plurality of fractionating destinations included in the fractionating unit as that into which the sample component corresponding to any of the peaks determined to be derived from the same component as the peak to be determined is fractionated; and, when it is determined that the peak to be determined is not derived from the same component as any of the peaks on the first chromatogram, either does not fractionate the sample component corresponding to the peak to be determined, or fractionates the sample component to a fractionating destination among the plurality of fractionating destinations different from that into which the sample component corresponding to any of the peaks is fractionated.

4. A preparative liquid chromatograph comprising: a separation column for separating a plurality of sample components contained in a sample injected into a flow path; a detector provided downstream of the separation column; a chromatogram creation unit for creating a chromatogram based on the detection results by the detector; a fractionation unit for fractionating sample components corresponding to peaks on the chromatogram from an eluate from the separation column; and a fractionation control unit for controlling the fractionation unit, When fractionating sample components associated with each of a plurality of sample injections into the channel, The fractionation control unit When fractionating sample components following a first sample injection of the plurality of sample injections, the fractionation unit is controlled to fractionate sample components corresponding to each peak appearing on a first chromatogram, which is a chromatogram created by the chromatogram creation unit following the first sample injection, and the start times of each of the peaks on the first chromatogram are stored; When collecting sample components in a second or subsequent sample injection among the multiple sample injections, each time a peak appears on a target chromatogram, which is a chromatogram created by the chromatogram creation unit in connection with the second or subsequent sample injection, the peak is designated as a peak to be determined, and a determination is made as to whether or not the peak to be determined is derived from the same component as any of the peaks based on the start time of the peak to be determined on the target chromatogram and the start times of the peaks on the first chromatogram, and the fraction collection unit is controlled to perform a predetermined fraction collection operation based on the determination result. Preparative liquid chromatography.

5. 5. The preparative liquid chromatograph according to claim 4, wherein the predetermined fractionation operation fractionates a sample component corresponding to the peak to be determined when it is determined in the determination that the peak to be determined is derived from the same component as any of the peaks on the first chromatogram, and does not fractionate a sample component corresponding to the peak to be determined when it is determined that the peak to be determined is not derived from the same component as any of the peaks on the first chromatogram.

6. 5. The preparative liquid chromatograph according to claim 4, wherein the predetermined fractionating operation, when it is determined in the determination that the peak to be determined is derived from the same component as any one of the peaks on the first chromatogram, fractionates the sample component corresponding to the peak to be determined to be derived from the same component as the peak to be determined, into the same fractionating destination among the plurality of fractionating destinations included in the fractionating unit as that into which the sample component corresponding to the peak determined to be derived from the same component as the peak to be determined is fractionated; and, when it is determined that the peak to be determined is not derived from the same component as any one of the peaks on the first chromatogram, either does not fractionate the sample component corresponding to the peak to be determined, or fractionates the sample component to a fractionating destination among the plurality of fractionating destinations different from that into which the sample component corresponding to the peak to be determined is fractionated.

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