Control device, separation analysis device, separation analysis method, and separation analysis program
The control device and method address the challenge of distinguishing between hemoglobin species with similar retention times by calculating thresholds based on sample amounts, enabling accurate peak identification without concentration adjustments.
Patent Information
- Application Number
- JP2022069020
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-04-19
- Publication Date
- 2026-01-14
- Estimated Expiration
- 2042-04-19
Smart Images

Figure 0007798677000002 
Figure 0007798677000003 
Figure 0007798677000004
Abstract
Description
[Technical Field]
[0001] The present disclosure relates to a control device, a separation analysis device, a separation analysis method, and a separation analysis program. [Background technology]
[0002] For example, Patent Document 1 describes a chromatography data processing device that receives a chromatogram from a chromatography, converts it into digital data using an A / D converter, imports it, and performs a predetermined analysis process. This chromatography data processing device includes a recording means for plotting the imported data, a peak detection means for detecting chromatogram peaks from the data, an allowable time width storage means for pre-storing an allowable time width of the peak for component identification, a means for determining whether the time corresponding to the detected peak value is within the allowable time width, and, if the determination result indicates that the time is within the allowable time width, a means for recording the name of the component near the peak value of the recorded chromatogram in the recording means.
[0003] Patent Document 2 also describes a method for determining whether a predetermined target substance is present in a sample using a gas chromatography analyzer. This method uses a column capable of ensuring a target detection limit, measures a standard substance of the target substance, and calculates a correlation equation for the target substance between the peak area and retention time according to the sample load from the results obtained. The area of a detected peak near the retention time at which the target substance peak can be detected in a chromatogram obtained by analyzing the target substance is obtained, and the correlation equation is used to estimate the retention time at which the target substance peak appears from the area of the detected peak. The estimated retention time is compared with the retention time of the detected peak in the chromatogram of the target substance to determine whether the target substance is present in the target substance.
[0004] The above-mentioned separation and analysis methods are also used to identify and measure the components of various hemoglobins (hereinafter also referred to as "Hb") in blood. In particular, there is a high demand for identification of major hemoglobin variants such as HbD, HbE, HbS, and HbC, which can be identified from the peak retention time. [Prior art documents] [Patent documents]
[0005] [Patent Document 1] Japanese Patent Application Publication No. 1-079656 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-163476 Summary of the Invention [Problem to be solved by the invention]
[0006] However, with recent Hb separation and analysis devices, the intervals between the peak retention times of Hb species have narrowed due to shorter measurement times. This makes it difficult to distinguish between Hb species with similar retention times. For example, when HbD is analyzed using cation exchange chromatography, the HbD peak retention time is close to the HbE peak retention time. In some cases, an HbE peak is detected within the allowable time range of the HbD peak retention time. Even if an allowable time range is set as in Patent Document 1, it is difficult to distinguish between HbD and HbE peaks. Furthermore, while it is possible for the analyst to adjust the sample concentration in advance, this is a cumbersome process, making it desirable to be able to measure the blood in its original state.
[0007] The present disclosure has been made in consideration of the above points, and aims to provide a control device, a separation analysis device, a separation analysis method, and a separation analysis program that can identify peaks in a chromatogram that have similar retention times without adjusting the sample concentration. [Means for solving the problem]
[0008] In order to achieve the above-mentioned object, a control device according to one embodiment of the present disclosure is a control device for a separation and analysis device that separates and analyzes samples by chromatography, and includes: a memory unit that stores correlations between the retention time of a reference peak of a reference component, thresholds between the retention time of a first peak of a first component and the retention time of a second peak of a second component, and index values that represent the amounts of components in the samples, which are obtained by performing chromatography on a plurality of samples prepared in advance; an acquisition unit that performs chromatography on a sample containing the reference component and an analyte component that is the first component or the second component, and acquires the retention time of the reference peak, the index value, and the peak retention time of the analyte component; and an identification unit that calculates the threshold based on the correlation stored in the memory unit and the retention time of the reference peak and the index value acquired by the acquisition unit, and compares the threshold with the peak retention time of the analyte component to identify whether the peak of the analyte component is the first peak or the second peak.
[0009] Furthermore, in order to achieve the above-mentioned object, a separation analysis apparatus according to one embodiment of the present disclosure comprises a sample preparation unit for preparing a sample to be introduced into an analytical column, an analytical unit having the analytical column and for controlling the adsorption and desorption of components in the sample to the packing material of the analytical column, a photometric unit for optically detecting components contained in the desorption liquid from the analytical column, and the above-mentioned control device to which the sample preparation unit, the analytical unit, and the photometric unit are each connected.
[0010] Furthermore, in order to achieve the above-mentioned object, a separation analysis method according to one embodiment of the present disclosure performs chromatography on a plurality of samples prepared in advance to obtain a correlation between the retention time of a reference peak of a reference component, a threshold between the retention time of a first peak of a first component and the retention time of a second peak of a second component, and an index value representing the amount of the component in the sample; performs chromatography on a sample containing the reference component and an analyte component that is the first component or the second component to obtain the retention time of the reference peak, the index value, and the peak retention time of the analyte component; determines the threshold based on the correlation and the obtained retention time of the reference peak and the index value; and compares the threshold with the peak retention time of the analyte component to identify whether the peak of the analyte component is the first peak or the second peak.
[0011] Furthermore, in order to achieve the above-mentioned object, a separation analysis program according to one embodiment of the present disclosure causes a computer to perform the following steps: perform chromatography on a plurality of samples prepared in advance to obtain a correlation between the retention time of a reference peak of a reference component, a threshold between the retention time of a first peak of a first component and the retention time of a second peak of a second component, and an index value representing the amount of the component in the sample; perform chromatography on a sample containing the reference component and an analyte component that is the first component or the second component to obtain the retention time of the reference peak, the index value, and the peak retention time of the analyte component; determine the threshold based on the correlation and the obtained retention time of the reference peak and the index value; and compare the threshold with the peak retention time of the analyte component to identify whether the peak of the analyte component is the first peak or the second peak. [Effects of the Invention]
[0012] As described above, according to the present disclosure, it is possible to obtain the effect that, for a plurality of peaks in a chromatogram having similar retention times, peaks can be identified without adjusting the sample concentration. [Brief explanation of the drawings]
[0013] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of an HPLC device that uses high-performance liquid chromatography. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of a control system of an HPLC device. [Figure 3] FIG. 1 is a diagram showing an example of a chromatogram. [Figure 4] FIG. 1 shows an example of a chromatogram including HbA0, HbE, and HbD. [Figure 5] FIG. 1 is a scatter plot showing an example of a correlation of peak retention times created using a chromatogram. [Figure 6] FIG. 2 is a block diagram illustrating an example of a functional configuration of a control device according to the embodiment. [Figure 7] 10 is a flowchart showing an example of the flow of a correlation derivation process by the separation analysis program according to the embodiment. [Figure 8] 10(A) to 10(D) are scatter plots showing an example of the correlation between peak retention times and total peak areas. [Figure 9] 8(A) to 8(D) are diagrams showing examples of approximate expressions obtained from the scatter diagrams of FIGS. 8(A) to 8(D). [Figure 10] (A) is a diagram showing an example of an approximate formula between the slope and the total peak area (index value), and (B) is a diagram showing an example of an approximate formula between the intercept and the total peak area (index value). [Figure 11] 10 is a flowchart showing an example of the flow of a peak identification process by a separation analysis program according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0014] An example of an embodiment of the technology of the present disclosure will be described in detail below with reference to the drawings. Note that components and processes that perform the same operations, actions, and functions are given the same reference numerals throughout the drawings, and duplicated descriptions may be omitted as appropriate. Each drawing is merely a schematic illustration to allow a sufficient understanding of the technology of the present disclosure. Therefore, the technology of the present disclosure is not limited to the illustrated examples. Furthermore, in this embodiment, descriptions of configurations that are not directly related to the present disclosure or well-known configurations may be omitted.
[0015] 1 is a diagram showing a schematic configuration of a high performance liquid chromatography (HPLC) apparatus X. This HPLC apparatus X is an example of a separation analysis apparatus.
[0016] The HPLC device X is configured to automatically measure the concentration of glycated hemoglobin (HbA1c) in whole blood by setting a blood collection tube 11. The HPLC device X includes a device main body 2 including a plurality of eluent bottles 12A, 12B, 12C, 12D, and 12E (five in FIG. 1 ).
[0017] The eluent bottles 12A to 12E respectively hold eluents A to E to be supplied to the analytical column 60 (described later). The eluents differ in composition, component ratio, pH, osmotic pressure, etc. depending on the application.
[0018] The device main body 2 has a sample preparation unit 5, an analysis unit 6, and a photometry unit .
[0019] The blood collection tubes 11 are stored, for example, in a rack (not shown) and are configured to be moved to a position where they can be collected by a nozzle 51 in the sample preparation unit 5, which will be described later.
[0020] The sample preparation unit 5 is used to prepare a sample to be introduced into the analytical column 60 from the blood collected from the blood collection tube 11. The sample preparation unit 5 has a nozzle 51 and a dilution tank 53.
[0021] The nozzle 51 is used to collect various liquids, including the blood sample 13 in the blood collection tube 11, and is capable of aspirating and discharging liquids, as well as being movable in the vertical and horizontal directions. The operation of the nozzle 51 is controlled by the control device 100, which will be described later.
[0022] The analytical unit 6 controls the adsorption and desorption of biological components onto the packing material of the analytical column 60, and supplies various biological components to the photometric unit 7. The set temperature in the analytical unit 6 is, for example, about 40°C. The analytical column 60 holds a packing material for selectively adsorbing hemoglobin in the sample. For example, a methacrylic acid-methacrylic acid ester copolymer is used as the packing material.
[0023] In addition to the analytical column 60 , the analytical unit 6 includes a manifold 61 , a liquid delivery pump 62 , and an injection valve 63 .
[0024] The manifold 61 is used to selectively supply eluent from a specific eluent bottle among the plurality of eluent bottles 12A to 12E to the analytical column 60. The manifold 61 is connected to the eluent bottles 12A, 12B, 12C, 12D, and 12E via pipes 80A to 80E, respectively, and is connected to the injection valve 63 via pipe 84.
[0025] The liquid sending pump 62 is provided in the middle of the pipe 84 to provide power for moving the eluent to the injection valve 63 .
[0026] The injection valve 63, which collects a fixed amount of sample to be introduced and allows the sample to be introduced into the analytical column 60, is equipped with multiple inlet and outlet ports (not shown). An injection loop 64 is connected to the injection valve 63. The injection loop 64 is capable of holding a fixed amount of liquid (e.g., several μL). By appropriately switching the injection valve 63, it is possible to select a state in which the injection loop 64 is connected to the dilution tank 53, thereby supplying the sample to be introduced from the dilution tank 53 to the injection loop 64, or a state in which the injection loop 64 is connected to the analytical column 60 via the prefilter PF and piping 85, thereby introducing the sample to be introduced from the injection loop 64 into the analytical column 60. A six-way valve, for example, can be used as the injection valve 63. The prefilter PF is a filter for filtering the sample and eluent.
[0027] The photometric unit 7 is used to optically detect hemoglobin contained in the desorbed liquid from the analytical column 60, and is connected via piping 87 to a waste liquid tank 88 for discharging the desorbed liquid from the analytical column 60.
[0028] FIG. 2 is a block diagram showing an example of the configuration of the control system of the HPLC apparatus X.
[0029] 2, the HPLC apparatus X is equipped with a control device 100. The control device 100 is configured such that a CPU (Central Processing Unit) 100A, a ROM (Read Only Memory) 100B, a RAM (Random Access Memory) 100C, and an input / output interface (I / O) 100E are connected to each other via a bus 100F. The HPLC apparatus X also has an operation unit (not shown) that accepts input from an operator.
[0030] A sample preparation unit 5, an analysis unit 6, and a photometry unit 7 are connected to the I / O 100E.
[0031] The eluent containing various hemoglobins discharged from the analytical column 60 is supplied to the photometric unit 7 via a pipe 86. This eluent is led to a waste liquid tank 88 via a pipe 87.
[0032] In the photometry unit 7, light is continuously irradiated onto the eluent, and the light reception result (absorbance) is output to the control device 100. Then, the control device 100 calculates a chromatogram.
[0033] Fig. 3 is a diagram showing an example of a chromatogram, in which the horizontal axis indicates the elapsed time from the start of measurement, and the vertical axis indicates the absorbance.
[0034] As shown in Figure 3, a chromatogram is expressed as a graph showing the relationship between the time elapsed since the start of measurement and the absorbance as a result of light reception. The position of the peak in this chromatogram indicates which hemoglobin (HbA0, HbD, HbS, or HbC in the example of Figure 3) was detected, and the integrated value of absorbance in the peak (the mountain-shaped part), i.e., the area of the peak, indicates the amount (concentration) of hemoglobin. HbA0 has the largest peak among the various hemoglobins and is easily distinguishable, so it is used as the reference component. The time elapsed from the start of measurement to the appearance of each hemoglobin peak is called the peak retention time.
[0035] In this embodiment, a separation and analysis program for executing the liquid chromatography measurement process according to the present embodiment is stored in advance in ROM 100B, as an example. The CPU 100A writes the separation and analysis program stored in ROM 100B to RAM 100C and executes it. Alternatively, the separation and analysis program may be stored in a storage medium such as a CD-ROM (Compact Disc Read Only Memory) and executed by reading it using a CD-ROM drive or the like.
[0036] The separation and analysis program may be pre-installed in the control device 100, for example. The separation and analysis program may be realized by storing it in a non-volatile non-transitory storage medium or distributing it via a network line and installing or upgrading it as needed in the control device 100. Note that examples of non-volatile non-transitory storage media include CD-ROMs, magneto-optical disks, HDDs (Hard Disk Drives), DVD-ROMs (Digital Versatile Disc Read Only Memory), flash memories, memory cards, etc.
[0037] When HbD is analyzed by cation exchange chromatography, the peak retention times of HbA0, HbE, and HbD are as shown in FIG. 4, for example.
[0038] 4 is a diagram showing an example of a chromatogram including HbA0, HbE, and HbD. In FIG. 4, the horizontal axis represents time, and the vertical axis represents absorbance.
[0039] As shown in Figure 4, the HbA0 peak is easily distinguishable, but the peak retention times of HbE and HbD are close to each other, making it difficult to distinguish between HbD and HbE peaks based on peak retention times alone.
[0040] For example, if a sample containing HbA0 and HbE and a sample containing HbA0 and HbD are prepared, and each sample is adjusted to various dilution concentrations and then measured, and the peak retention times of the HbA0 peak and the HbD peak appearing in each chromatogram obtained by the measurement are plotted against each other to create a scatter plot, as shown in Figure 5. From Figure 5, it can be seen that there is a correlation between the peak retention times of HbA0 and HbE, and between the peak retention times of HbA0 and HbD.
[0041] In Fig. 5, the horizontal axis represents TrA0, which is the peak retention time of HbA0, and the vertical axis represents TrX, which is the peak retention time of HbE or HbD. Fig. 5 is a scatter plot created using a chromatogram in which the total value (value representing the total area of all peaks; hereinafter also referred to as "Tarea") obtained by adding up all the values representing the areas of each peak in the chromatogram falls within a predetermined range (e.g., 0 to 130,000). In Fig. 5, the correlation between the peak retention time of HbA0 and the peak retention time of HbE is referred to as the first correlation, and the correlation between the peak retention time of HbA0 and the peak retention time of HbD is referred to as the second correlation.
[0042] As shown in Figure 5, although there is a certain tendency between HbE and HbD, there is an overlapping portion as indicated by the arrow, making it difficult to distinguish between them based solely on the correlation with the HbA0 retention time. In other words, even if thresholds for the peak retention times of the HbE peak and the HbD peak are determined based on the peak retention time of the HbA0 peak, it is difficult to distinguish between the HbE peak and the HbD peak. This is thought to be because the peak retention times differ depending on the amount of hemoglobin contained in the sample, making it difficult to distinguish between HbE and HbD, which have similar peak retention times.
[0043] In response to this, the present inventors discovered that by determining threshold values for the peak retention times of the HbE peak and the HbD peak based on the amount of hemoglobin in a sample and the peak retention time of the HbA0 peak, it is possible to distinguish between HbE and HbD peaks with similar peak retention times. Hereinafter, as an example, HbA0 will be described as the reference component, HbE as the first component of the analyte components, and HbD as the second component of the analyte components. In this case, the HbA0 peak will be referred to as the reference peak, the HbE peak as the first peak, and the HbD peak as the second peak. The sample to be analyzed is not limited to a sample containing hemoglobin, and the method can be applied to any sample containing components with relatively similar peak retention times.
[0044] The CPU 100A of the control device 100 according to this embodiment writes a separation and analysis program stored in the ROM 100B into the RAM 100C and executes the program, thereby functioning as each unit shown in FIG.
[0045] FIG. 6 is a block diagram showing an example of the functional configuration of the control device 100 according to this embodiment.
[0046] As shown in FIG. 6, a CPU 100A of the control device 100 according to this embodiment functions as a derivation unit 101, an acquisition unit 102, and a recognition unit 103.
[0047] The derivation unit 101 derives a correlation determined by thresholds for the reference peak retention time, which is the retention time of the reference peak of HbA0, the first peak retention time, which is the retention time of the first peak of HbE, and the second peak retention time, which is the retention time of the second peak of HbD, obtained by performing chromatography on multiple samples prepared in advance, and an index value representing the amount of hemoglobin in the sample. The correlation may be expressed as a correlation equation or a correlation table. The index value may be any of the following: the area of all peaks (=Tarea) in the chromatogram, the area of the first peak of HbE, the area of the second peak of HbD, the area of the reference peak of HbA0, the height of the first peak of HbE, the height of the second peak of HbD, and the height of the reference peak of HbA0. These index values are obtained from the chromatogram.
[0048] The correlation equation or correlation table is determined by, for example, a first correlation representing the correlation between the reference peak retention time and the first peak retention time, a second correlation representing the correlation between the reference peak retention time and the second peak retention time, and an index value. That is, the derivation unit 101 classifies chromatograms by index value, and plots the first peak retention time and the second peak retention time of each chromatogram to create a scatter diagram for each index value. From the first and second correlations, the derivation unit 101 derives a correlation equation or correlation table for deriving a threshold value used to identify the peak of the analyte, using the reference peak retention time, the index value, and the threshold value used to identify the peak of the analyte as variables. The correlation equation or correlation table derived by the derivation unit 101 is stored in the ROM 100B. If the control device 100 includes the ROM 100B storing a correlation equation or correlation table using the reference peak retention time, the index value, and the threshold value used to identify the peak of the analyte as variables, the derivation unit 101 is not required. For example, when manufacturing the control device 100 using a ROM that stores a correlation equation or a correlation table in advance, the derivation unit 101 can be omitted from the configuration of the control device 100. An example of the correlation equation is shown below as equation (1) (hereinafter referred to as "correlation equation (1)"). Note that the specific process of generating this correlation equation (1) will be described later.
[0049] y=(c×Tarea+d)×TrA0+(e×Tarea+f) ···(1)
[0050] where y is the threshold, Tarea is the total peak area (index value), TrA0 is the peak retention time of the reference peak HbA0 (reference peak retention time), and c, d, e, and f are constants obtained from the first correlation and the second correlation for each total peak area (index value).
[0051] The acquisition unit 102 performs chromatography on the sample to be analyzed to acquire a chromatogram. Specifically, it controls the sample preparation unit 5, analysis unit 6, and photometric unit 7 to perform chromatography. It then acquires absorbance, which is an optical measurement value output by the photometric unit 7, and creates a chromatogram using the acquired absorbance and the elapsed time from the start of measurement. From the chromatogram, the acquisition unit 102 acquires the reference peak retention time, total peak area (index value), and peak retention time of the analyte component. The sample referred to here includes HbA0, an example of a reference component, and HbE or HbD, an example of an analyte component. However, it is unknown whether the sample contains HbE or HbD.
[0052] The discrimination unit 103 discriminates, from the correlation pre-stored in the ROM 100B, whether the peak of the component to be analyzed obtained from the chromatogram acquired by the acquisition unit 102 is the first peak of HbE or the second peak of HbD.
[0053] Specifically, for example, the identification unit 103 uses the correlation equation (1) above to determine a threshold value corresponding to the reference peak retention time and total peak area (index value) obtained from the chromatogram acquired by the acquisition unit 102, and compares the determined threshold value with the peak retention time of the analyte obtained from the chromatogram to identify whether the peak of the analyte is the first peak or the second peak. In the case of HbE and HbD, if the peak retention time of the analyte is shorter than the threshold value, it is identified as HbE, and if the peak retention time of the analyte is equal to or longer than the threshold value, it is identified as HbD.
[0054] Next, the operation of the control device 100 according to this embodiment will be described with reference to FIGS.
[0055] 7 is a flowchart showing an example of the flow of correlation derivation processing by the separation analysis program according to this embodiment. In the example of FIG. 7, processing for generating the correlation equation (1) for distinguishing between the two peaks of HbE and HbD will be specifically described.
[0056] The correlation derivation process using the separation and analysis program is executed by the CPU 100A of the control device 100 writing the separation and analysis program stored in the ROM 100B into the RAM 100C.
[0057] In step S101 of FIG. 7, CPU 100A acquires a plurality of chromatograms used to generate the correlation equation (1).
[0058] Here, an example of the eluents and specimens used to create the chromatogram will be specifically described. The following eluents A, B, and C were prepared. The elution strength of hemoglobin was eluent A<eluent C<eluent B.
[0059] Eluent A: Contains sodium dihydrogen phosphate dihydrate with a concentration of 1.44 wt% and disodium hydrogen phosphate with a concentration of 0.16 wt% as raw materials, and is adjusted to pH 5.08. Eluent B: Contains sodium dihydrogen phosphate dihydrate at a concentration of 0.02 wt% and disodium hydrogen phosphate at a concentration of 0.50 wt% as raw materials, and is adjusted to pH 8.0. Eluent C: Contains sodium dihydrogen phosphate dihydrate with a concentration of 0.12 wt% and disodium hydrogen phosphate with a concentration of 0.33 wt% as raw materials, and is adjusted to pH 6.82.
[0060] As specimens, 22 blood specimens containing HbA0 and HbD but not HbE were prepared, and 19 blood specimens containing HbA0 and HbE but not HbD were prepared.
[0061] Next, using the above-mentioned HPLC apparatus X, the blood sample prepared above is measured multiple times according to the following procedure.
[0062] (S1) Eluent A is passed through the main body 2 of the apparatus to equilibrate the analytical column 60. (S2) A predetermined amount of the hemolyzed blood sample is introduced into the analytical column 60. (S3) Eluent A is allowed to flow for a predetermined time (for example, 13 seconds). (S4) A liquid obtained by mixing eluent A and eluent C in a predetermined ratio (for example, 1:9) is passed through the column for a predetermined time (for example, 5 seconds) to elute HbA0. (S5) Eluent C is allowed to flow for a predetermined time (e.g., 17 seconds) to elute HbA2, HbE, and HbD. Eluent B is allowed to flow for a predetermined time (e.g., 2 seconds) to elute all of the hemoglobin remaining in the analytical column 60. (S6) Eluent A is allowed to flow for a predetermined time (for example, 5 seconds). (S7) A chromatogram is created from the absorbance obtained by the photometric unit 7 (optical detector) having a detection wavelength of, for example, 420 nm.
[0063] (S8) Based on the retention times and peak sizes of the peaks appearing in the chromatogram, the second peak derived from HbD, the first peak derived from HbE, and the reference peak derived from HbA0 are identified. Specifically, the second peak derived from HbD is the peak that appears at approximately 25 seconds. The first peak derived from HbE is the peak that appears at approximately 23 seconds. The reference peak derived from HbA0 is the peak that appears at approximately 19 seconds and is the peak with the largest peak height or area. (S9) The retention time of the second peak derived from HbD (TrHbD), the retention time of the base peak derived from HbA0 (TrA0), and the total peak area of the chromatogram (Tarea) are obtained for each sample containing HbD and HbA0. (S10) Similarly, the first peak retention time (TrHbE) derived from HbE, the reference peak retention time (TrA0) derived from HbA0, and the total peak area (Tarea) of the chromatogram are obtained for each sample containing HbE and HbA0.
[0064] Although the total peak area (Tarea) of the chromatogram is used as an indicator of the amount of hemoglobin introduced into the analytical column 60, this is not limiting and any value that serves as an indicator of the amount of hemoglobin introduced into the analytical column 60 may be used. For example, the area of the reference peak of HbA0, which accounts for a significant amount of the total hemoglobin, the area of the second peak of HbD, a variant hemoglobin that accounts for a certain amount of the total hemoglobin, or the area of the first peak of HbE may be used. Furthermore, peak heights may be used instead of peak areas. Furthermore, the total peak area (Tarea) may be indirectly obtained by estimating it from the area of a specific peak that is correlated with the total peak area (Tarea).
[0065] In step S102, CPU 100A classifies the multiple chromatograms acquired in step S101 by the magnitude of the index value (for example, total peak area Tarea). Specifically, as an example, as shown in Figures 8(A) to 8(D), the chromatograms are classified by total peak area Tarea, and the first peak retention time and second peak retention time of each chromatogram are plotted for each total peak area Tarea, thereby creating a scatter diagram for each total peak area Tarea.
[0066] 8(A) to 8(D) are scatter plots showing an example of the correlation between the peak retention time for each total peak area Tarea. In Fig. 8(A) to 8(D), the horizontal axis represents TrA0, and the vertical axis represents TrX (TrHbD and TrHbE).
[0067] FIG. 8(A) is a scatter plot (sample 1) showing the first and second correlations of a chromatogram in which the total peak area Tarea is in a first range (e.g., 90,001 to 130,000). FIG. 8(B) is a scatter plot (sample 2) showing the first and second correlations of a chromatogram in which the total peak area Tarea is in a second range (e.g., 60,001 to 90,000). FIG. 8(C) is a scatter plot (sample 3) showing the first and second correlations of a chromatogram in which the total peak area Tarea is in a third range (e.g., 30,001 to 60,000). FIG. 8(D) is a scatter plot (sample 4) showing the first and second correlations of a chromatogram in which the total peak area Tarea is in a fourth range (e.g., 0 to 30,000). The ranges of the total peak area Tarea are exemplified by values representing the areas obtained from the chromatograms. In addition, the average value of Tarea in the chromatogram used in the scatter plot of Figure 8(A) is 117,517, the average value of Tarea in the chromatogram used in the scatter plot of Figure 8(B) is 77,826, the average value of Tarea in the chromatogram used in the scatter plot of Figure 8(C) is 38,936, and the average value of Tarea in the chromatogram used in the scatter plot of Figure 8(D) is 11,027.
[0068] 8(A) to 8(D), it is clear that HbE and HbD can be clearly distinguished from each other in the scatter diagrams. In other words, it is considered that the first peak derived from HbE and the second peak derived from HbD can be distinguished by setting thresholds for the first peak retention time TrHbE and the second peak retention time TrHbD according to the total peak area Tarea and the reference peak retention time TrA0.
[0069] In step S103, CPU 100A derives an approximation formula with reference peak retention time TrA0 as a variable. Specifically, as an example, an approximation formula capable of distinguishing between the first correlation and the second correlation for each of the scatter diagrams in Figures 8(A) to 8(D) described above is derived. An example of this approximation formula is shown in the following formula (2). This approximation formula is an example of the first correlation formula.
[0070] y = a × TrA0 + b (2)
[0071] where y is the threshold value between the first peak retention time TrHbE and the second peak retention time TrHbD, TrA0 is the reference peak retention time, a is a constant indicating the slope, and b is a constant indicating the intercept.
[0072] As an example, the slope a and intercept b are set by appropriately adjusting equation (2), which is a linear function of the threshold value y and the reference peak retention time TrA0, as shown in Figures 9(A) to 9(D).
[0073] 9(A) to 9(D) are diagrams showing examples of approximate expressions obtained from the scatter diagrams of FIGS. 8(A) to 8(D).
[0074] The approximate formula D1 shown in FIG. 9(A) is obtained from the scatter diagram in FIG. 8(A) (average value of Tarea=117,517), and is, for example, as follows:
[0075] y=2.4×TrA0-22
[0076] The approximate formula D2 shown in FIG. 9(B) is obtained from the scatter diagram in FIG. 8(B) (average value of Tarea=77,826), and is, for example, as follows:
[0077] y=2.3×TrA0-20.1
[0078] The approximate formula D3 shown in FIG. 9(C) is obtained from the scatter diagram of FIG. 8(C) (average value of Tarea=38,936), and is, for example, as follows:
[0079] y=2.2×TrA0-18.5
[0080] The approximate formula D4 shown in FIG. 9(D) is obtained from the scatter diagram of FIG. 8(D) (average value of Tarea=11,027), and is, for example, as follows:
[0081] y=2.12×TrA0-17.35
[0082] For the above-mentioned approximate formulas D1 to D4, the correspondence between the average value of Tarea, the slope a, and the intercept b is summarized in Table 1 below.
[0083] (Table 1) JPEG0007798677000001.jpg29106
[0084] Note that the function does not have to be a linear function as long as it can distinguish between the first peak retention time TrHbE and the second peak retention time TrHbD. For example, a function that can distinguish between the first peak retention time TrHbE and the second peak retention time TrHbD may be derived by appropriately adjusting the coefficients of a quadratic or cubic function.
[0085] In this example, the slope a and intercept b were appropriately adjusted to obtain a linear function that can distinguish between the first peak retention time TrHbE and the second peak retention time TrHbD. As another method, for example, a first approximate equation for the first peak retention time TrHbE of HbE and the reference peak retention time TrA0 of HbA0 is calculated using the following equation:
[0086] TrHbE=g×TrA0+h
[0087] Further, a second approximation formula for the second peak retention time TrHbD of HbD and the reference peak retention time TrA0 of HbA0 is calculated by the following formula.
[0088] TrHbD=j×TrA0+k
[0089] Then, a linear function may be obtained in which the average value of the slope g of the first approximate equation and the slope j of the second approximate equation is defined as the slope "(g+j) / 2," and the average value of the intercept h of the first approximate equation and the slope k of the second approximate equation is defined as the intercept "(h+k) / 2." This method also makes it possible to derive a linear function that can distinguish between the first peak retention time TrHbE and the second peak retention time TrHbD.
[0090] Next, in step S104, CPU 100A derives correlation equation (1) with variables being the total peak area Tarea (index value), the reference peak retention time TrA0, and the retention time threshold value used to distinguish between the first and second peaks. Specifically, as an example, as shown in Figures 10(A) and 10(B), an approximation equation between the slope a and the total peak area Tarea (index value) and an approximation equation between the intercept b and the total peak area Tarea (index value) are created. These approximation equations are examples of the second correlation equation.
[0091] Fig. 10(A) is a diagram showing an example of an approximation formula between the slope a and the total peak area Tarea (index value), and Fig. 10(B) is a diagram showing an example of an approximation formula between the intercept b and the total peak area Tarea (index value).
[0092] The approximate formula shown in Figure 10(A) was obtained by plotting the set of (average value of Tarea, slope a) obtained from each of the scatter diagrams in Figures 9(A) to 9(D) above. That is, point P1 is (117517, 2.4), point P2 is (77826, 2.3), point P3 is (38936, 2.2), and point P4 is (11027, 2.12). The approximate formula shown in Figure 10(A) is expressed by the following formula (3).
[0093] a=c×Tarea+d (3)
[0094] However, the slope c is a constant, for example, c = 2.6 × 10 -6 The intercept d is a constant, for example, d=2.1.
[0095] Similarly, the approximate formula shown in Figure 10(B) was obtained by plotting the pairs of (average value of Tarea, intercept b) obtained from each of the scatter diagrams in Figures 9(A) to 9(D). That is, point Q1 is (117517, -22), point Q2 is (77826, -20.1), point Q3 is (38936, -18.5), and point Q4 is (11027, -17.35). The approximate formula shown in Figure 10(B) is expressed by the following formula (4).
[0096] b = e × Tarea + f (4)
[0097] However, the slope e is a constant, for example, e=-4.3×10 -5 The intercept f is a constant, for example, f=-16.8.
[0098] By substituting the equations (3) and (4) into the above equation (2), the above correlation equation (1) is obtained.
[0099] y=(c×Tarea+d)×TrA0+(e×Tarea+f) =(2.6×10 -6 ×Tarea+2.1)×TrA0+(-4.3×10 -5 ×Tarea-16.8) ···(1)
[0100] is derived. y is the threshold value between the first peak retention time TrHbE and the second peak retention time TrHbD, Tarea is the area value of the total peak area, and TrA0 is the reference peak retention time. c, d, e, and f are constants.
[0101] In the above, a reference peak derived from the HbA0 component contained in the blood sample was used as a reference peak that serves as an indicator of threshold fluctuations due to factors other than differences in the amount of hemoglobin introduced into the analytical column 60 (for example, changes in environmental temperature), and the reference peak retention time TrA0 was used as a function of the correlation equation for the threshold y.
[0102] Any peak other than HbA0 may be used as long as it is detectable by chromatography and is derived from a component contained in the sample.
[0103] In this example, the chromatograms were divided by the size of the total peak area Tarea, and a scatter plot was created with the reference peak retention time TrA0 on the horizontal axis and TrX, which is the first peak retention time TrHbE and the second peak retention time TrHbD, on the vertical axis. Then, a correlation equation was obtained as a function of the threshold value y, the reference peak retention time TrA0, and the total peak area Tarea (index value).
[0104] Alternatively, a scatter plot may be created by dividing the chromatogram by the magnitude of the reference peak retention time TrA0, with the total peak area Tarea on the horizontal axis and TrX, which is the first peak retention time TrHbE and the second peak retention time TrHbD, on the vertical axis. In this case, a correlation equation can be obtained as a function of the threshold value y, the reference peak retention time TrA0, and the total peak area Tarea (index value).
[0105] Specifically, the correlation equation is determined by a first correlation representing the correlation between the total peak area Tarea (index value) and the first peak retention time TrHbE, a second correlation representing the correlation between the total peak area Tarea (index value) and the second peak retention time TrHbD, and the reference peak retention time TrA0. That is, from the results of classifying the first correlation and the second correlation according to the magnitude of the reference peak retention time TrA0, an approximate equation (e.g., y = 1 × Tarea + m) between the threshold y of the first peak retention time TrHbE and the second peak retention time TrHbD and the total peak area Tarea (index value) is determined for each magnitude of the reference peak retention time TrA0. From the correlation equation between the reference peak retention time TrA0 and l (e.g., l = n × TrA0 + o), the correlation equation between the reference peak retention time TrA0 and m (e.g., m = p × TrA0 + q), and the approximation equation between the threshold value y and the total peak area Tarea (index value) (e.g., y = l × Tarea + m), the reference peak retention time TrA0, the total peak area Tarea (index value), and the threshold value y used to identify the peaks of the analyte component are used as variables to derive a correlation equation (y = (n × TrA0 + o) × Tarea + (p × TrA0 + q)) for deriving the threshold value y used to identify the peaks of the analyte component. Note that, to obtain the approximation equations shown in Figures 10(A) and 10(B), for example, the average value of the reference peak retention time TrA0 may be used.
[0106] Alternatively, a three-dimensional plot having three axes of the total peak area Tarea (index value), the reference peak retention time TrA0, and TrX, which is the first peak retention time TrHbE and the second peak retention time TrHbD, may be created, and a correlation equation may be obtained as a function of the threshold value y, the reference peak retention time TrA0, and the total peak area Tarea (index value).
[0107] Next, in step S105, CPU 100A stores correlation equation (1) derived in step S104 in ROM 100B, and ends a series of correlation derivation processes according to this separation analysis program.
[0108] Next, the peak identification process by the control device 100 according to this embodiment will be described with reference to Fig. 11. Naturally, the index value used in the peak identification process is the same as the index value used in the correlation deriving process described above. In other words, if the total peak area Tarea is used in the correlation deriving process, the total peak area Tarea is also used in the peak identification process.
[0109] Fig. 11 is a flowchart showing an example of the flow of peak identification processing by the separation analysis program according to this embodiment. In the peak identification processing, when an unknown peak Xp is eluted at the position where HbE or HbD is eluted, it is determined whether the unknown peak Xp is the first peak of HbE or the second peak of HbD. In the example of Fig. 11, the process of identifying peaks is specifically described using the correlation equation (1) for distinguishing between the first peak of HbE and the second peak of HbD.
[0110] The peak identification process using the separation and analysis program is executed by the CPU 100A of the control device 100 writing the separation and analysis program stored in the ROM 100B into the RAM 100C.
[0111] 11, CPU 100A performs chromatography on a sample to be analyzed to obtain a chromatogram. The sample in this case contains HbA0, an example of a reference component, and HbE or HbD, an example of a target component. However, it is unknown whether the target component contains HbE or HbD.
[0112] In step S112, CPU 100A acquires the reference peak retention time TrA0, the peak retention time of the analyte (HbE or HbD) (i.e., the retention time of the unknown peak Xp), and the total peak area Tarea as an index value from the chromatogram acquired in step S111.
[0113] In step S113, CPU 100A substitutes the reference peak retention time TrA0 and the total peak area Tarea (index value) acquired in step S112 into the correlation equation (1) described above to derive threshold value y.
[0114] In step S114, CPU 100A determines whether the peak retention time of the analyte component (HbE or HbD) acquired in step S112 is smaller than threshold y. If it is determined that the peak retention time of the analyte component (HbE or HbD) is smaller than threshold y (positive determination), the process proceeds to step S115, and if it is determined that the peak retention time of the analyte component (HbE or HbD) is equal to or greater than threshold y (negative determination), the process proceeds to step S116.
[0115] In step S115, CPU 100A identifies the peak of the component to be analyzed as the first peak of HbE, and ends a series of peak identification processes according to this separation analysis program.
[0116] On the other hand, in step S116, CPU 100A identifies the peak of the analyte component as the second peak of HbD, and ends a series of peak identification processes according to this separation analysis program.
[0117] In the above, the total peak area Tarea was used as the index value, but it is also possible to identify peaks using other index values in the same way.
[0118] For example, when the area of the first peak of HbE or the second peak of HbD is used as the index value, in the above-mentioned correlation derivation process, the constants c, d, e, and f are calculated based on the reference peak retention time TrA0 and the area of the first peak of HbE or the second peak of HbD, and the reference peak retention time TrA0, the threshold value, and the area of the first peak of HbE or the second peak of HbD are used as variables in the correlation equation.
[0119] In this case, the peak identification process acquires the reference peak retention time TrA0, the peak retention time of the analyte (HbE or HbD) (i.e., the retention time of the unknown peak Xp), and the peak area of the analyte (HbE or HbD) (i.e., the area of the unknown peak Xp) as an index value from the chromatogram. The acquired reference peak retention time TrA0 and the peak area (index value) of the analyte (HbE or HbD) are substituted into a correlation equation to derive a threshold. The peak retention time of the analyte (HbE or HbD) is then compared with the threshold.
[0120] Furthermore, when the area of the reference peak of HbA0 is used as the index value, in the above-described correlation derivation process, the constants c, d, e, and f are determined based on the reference peak retention time TrA0 and the area of the reference peak of HbA0, and the reference peak retention time TrA0, the threshold, and the area of the reference peak of HbA0 are used as variables of the correlation formula.
[0121] In this case, the peak identification process acquires the reference peak retention time TrA0, the peak retention time of the analyte (HbE or HbD) (i.e., the retention time of the unknown peak Xp), and the area of the HbA0 reference peak as an index value from the chromatogram. The acquired reference peak retention time TrA0 and the area of the HbA0 reference peak (index value) are substituted into a correlation equation to derive a threshold. The peak retention time of the analyte (HbE or HbD) is then compared with the threshold.
[0122] Furthermore, when the height of the first peak of HbE or the second peak of HbD is used as the index value, in the above-mentioned correlation derivation process, the constants c, d, e, and f are determined based on the reference peak retention time TrA0 and the height of the first peak of HbE or the second peak of HbD, and the reference peak retention time TrA0, the threshold, and the height of the first peak of HbE or the second peak of HbD are used as variables in the correlation equation.
[0123] In this case, the peak identification process acquires the reference peak retention time TrA0, the peak retention time of the analyte (HbE or HbD) (i.e., the retention time of the unknown peak Xp), and the peak height of the analyte (HbE or HbD) (i.e., the height of the unknown peak Xp) as an index value from the chromatogram. The acquired reference peak retention time TrA0 and the peak height (index value) of the analyte (HbE or HbD) are substituted into a correlation equation to derive a threshold. The peak retention time of the analyte (HbE or HbD) is then compared with the threshold.
[0124] Furthermore, when the height of the reference peak of HbA0 is used as the index value, in the above-described correlation derivation process, the constants c, d, e, and f are determined based on the reference peak retention time TrA0 and the height of the reference peak of HbA0, and the reference peak retention time TrA0, the threshold, and the height of the reference peak of HbA0 are used as variables of the correlation formula.
[0125] In this case, the peak identification process acquires the reference peak retention time TrA0, the peak retention time of the analyte (HbE or HbD) (i.e., the retention time of the unknown peak Xp), and the height of the reference peak of HbA0 as an index value from the chromatogram. The acquired reference peak retention time TrA0 and the height of the reference peak of HbA0 (index value) are substituted into a correlation equation to derive a threshold. The peak retention time of the analyte (HbE or HbD) is then compared with the threshold.
[0126] Thus, this embodiment focuses on the fact that HbE and HbD peaks with similar peak retention times can be distinguished by determining thresholds for the HbE and HbD peaks based on the amount of hemoglobin in a sample and the peak retention time of the HbA0 peak, and uses a correlation determined by the reference peak retention time of HbA0, the first HbE peak retention time, the second HbD peak retention time, and an index value representing the amount of hemoglobin in the sample. This makes it possible to distinguish HbE and HbD peaks that are difficult to distinguish because of their similar peak retention times, without adjusting the sample concentration.
[0127] The present embodiment is not limited to the above-described embodiment and can be modified in various ways. For example, the present embodiment is not limited to an HPLC device for measuring the hemoglobin concentration in blood, but can also be applied to a case where a sample other than blood is used, a case where a component other than the hemoglobin concentration is measured, or a liquid chromatography device other than an HPLC device.
[0128] The above describes an example of a control device according to an embodiment. The embodiment may be in the form of a program for causing a computer to execute the functions of each unit of the control device. The embodiment may be in the form of a non-transitory storage medium that stores the program and is readable by a computer.
[0129] Furthermore, the configuration of the control device described in the above embodiment is merely an example, and may be changed depending on the situation without departing from the spirit of the invention.
[0130] Furthermore, the processing flow of the program described in the above embodiment is also an example, and unnecessary steps may be deleted, new steps may be added, or the processing order may be rearranged within the scope of the main idea.
[0131] In the above embodiment, the processing according to the embodiment is realized by a software configuration using a computer by executing a program, but the present invention is not limited to this. The embodiment may be realized by, for example, a hardware configuration or a combination of a hardware configuration and a software configuration. [Explanation of symbols]
[0132] X HPLC equipment 5. Sample Preparation Unit 6 Analysis Units 7 Photometric Unit 11 Blood collection tube 13 Blood samples 60 Analytical Columns 100 control device 101 Derivation part 102 Acquisition Department 103 Identification unit
Claims
1. A control device for a separation and analysis apparatus that separates and analyzes a sample by chromatography, a storage unit that stores correlations among the retention time of a reference peak of a reference component, thresholds for the retention time of a first peak of a first component and the retention time of a second peak of a second component, and index values that represent the amounts of components in the samples, the correlations being obtained by performing chromatography on a plurality of samples prepared in advance; an acquisition unit that performs chromatography on a sample containing the reference component and an analyte component that is the first component or the second component, and acquires the retention time of the reference peak, the index value, and the peak retention time of the analyte component; an identification unit that calculates the threshold value based on the correlation stored in the storage unit and the retention time of the reference peak and the index value acquired by the acquisition unit, and compares the threshold value with the peak retention time of the component to be analyzed to identify whether the peak of the component to be analyzed is the first peak or the second peak; A control device comprising:
2. The correlation is determined by a first correlation representing a correlation between the retention time of the reference peak and the retention time of the first peak, a second correlation representing a correlation between the retention time of the reference peak and the retention time of the second peak, the threshold, and the index value. The control device according to claim 1 .
3. The correlation is expressed as a correlation equation or a correlation table for deriving a threshold value used to identify the peak of the analyte component from the first correlation and the second correlation, with the retention time of the reference peak, the threshold value, and the index value as variables, for each index value. The control device according to claim 2 .
4. The correlation is determined by a first correlation representing a correlation between the index value and the retention time of the first peak, a second correlation representing a correlation between the index value and the retention time of the second peak, the threshold, and the retention time of the reference peak. The control device according to claim 1 .
5. The correlation is expressed as a correlation equation or a correlation table for deriving a threshold value used to identify the peak of the analyte component from the first correlation and the second correlation, with the retention time of the reference peak, the threshold value, and the index value as variables, for each retention time of the reference peak. The control device according to claim 4.
6. The index value is any one of the area of all peaks, the area of the first peak, the area of the second peak, the area of the base peak, the height of the first peak, the height of the second peak, and the height of the base peak, which are obtained by performing the chromatography. The control device according to claim 1 .
7. the sample contains hemoglobin; The reference component is HbA0, the first component is HbE, and the second component is HbD. The control device according to claim 1 .
8. a sample preparation unit for preparing a sample to be introduced into the analytical column; an analytical unit having the analytical column and for controlling adsorption and desorption of components in the sample onto a packing material of the analytical column; a photometric unit for optically detecting components contained in the desorbed solution from the analytical column; The control device according to any one of claims 1 to 7, to which the sample preparation unit, the analysis unit, and the photometric unit are each connected; A separation and analysis device equipped with the above.
9. Chromatography is performed on a plurality of samples prepared in advance to obtain a correlation between a retention time of a reference peak of a reference component, a threshold value between a retention time of a first peak of a first component and a retention time of a second peak of a second component, and an index value representing the amount of each component in the sample; performing chromatography on a sample containing the reference component and an analyte component that is the first component or the second component to obtain the retention time of the reference peak, the index value, and the peak retention time of the analyte component; determining the threshold value based on the correlation, the acquired retention time of the reference peak, and the index value, and comparing the threshold value with the peak retention time of the component to be analyzed to identify whether the peak of the component to be analyzed is the first peak or the second peak; Separation analysis method.
10. classifying a plurality of chromatograms obtained by performing chromatography on the plurality of samples prepared in advance according to the magnitude of the index value; a first correlation equation between a threshold value between the retention time of the first peak and the retention time of the second peak and the retention time of the reference peak is obtained for each magnitude of the index value, thereby obtaining a plurality of the first correlation equations; determining a second correlation equation of the index value and a coefficient of the first correlation equation corresponding to the index value from the plurality of first correlation equations; obtaining a correlation equation representing the correlation based on the first correlation equation and the second correlation equation; The separation and analysis method according to claim 9.
11. classifying a plurality of chromatograms obtained by performing chromatography on the plurality of samples prepared in advance according to the magnitude of the retention time of the reference peak; a threshold value between the retention time of the first peak and the retention time of the second peak, and a first correlation equation of the index value are obtained for each length of the retention time of the reference peak, thereby obtaining a plurality of the first correlation equations; determining a second correlation equation of the retention time of the reference peak and a coefficient of the first correlation equation corresponding to the retention time of the reference peak from the plurality of first correlation equations; obtaining a correlation equation representing the correlation based on the first correlation equation and the second correlation equation; The separation and analysis method according to claim 9.
12. Chromatography is performed on a plurality of samples prepared in advance to obtain a correlation between a retention time of a reference peak of a reference component, a threshold value between a retention time of a first peak of a first component and a retention time of a second peak of a second component, and an index value representing the amount of each component in the sample; performing chromatography on a sample containing the reference component and an analyte component that is the first component or the second component to obtain the retention time of the reference peak, the index value, and the peak retention time of the analyte component; determining the threshold value based on the correlation, the acquired retention time of the reference peak, and the index value, and comparing the threshold value with the peak retention time of the component to be analyzed to identify whether the peak of the component to be analyzed is the first peak or the second peak; A separation analysis program to be executed by a computer.
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