Multiple sample analysis method

Abstract

To provide a multiple sample analysis method which enables efficient analysis of multiple samples having a main constituent in common.SOLUTION: A multiple sample analysis method includes: a first analysis step in which first chromatography analysis is conducted under a condition allowing mutual separation of multiple components, a three-dimensional chromatogram of a sample is acquired, and spectral data of the multiple components respectively is extracted from the three-dimensional chromatogram; a second analysis step in which second chromatography analysis is conducted under a condition that a chromatogram can be obtained in shorter time than in the first chromatography analysis, for other samples with the same main constituent as the sample mentioned above, in order to acquire three-dimensional chromatograms of the other samples; and a peak separation step for applying peak separation processing based on the spectral data extracted in the first analysis step, to the three-dimensional chromatograms of the other samples that were acquired in the second analysis step, in order to acquire peak separation data for the other samples in which peaks of the multiple components contained in the other samples are mutually separated.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a multiple sample analysis method for obtaining chromatogram data for multiple samples that share a common main component, with the peaks of the components separated from one another. [Background technology]

[0002] In the pharmaceutical industry, for example, it is sometimes necessary to quantify the concentrations of impurities contained in a large number of samples that share a common main component. Liquid chromatography analysis is a common method for quantifying the concentrations of multiple components contained in a sample (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 027880 Summary of the Invention [Problem to be solved by the invention]

[0004] To quantify multiple components in a sample using liquid chromatography, it is necessary to separate the peaks of the multiple components. When multiple components with similar properties are mixed in a sample, complete separation of these component peaks requires adjusting analytical conditions, such as adjusting the packing material packed in the analytical column, lengthening the analytical column, or narrowing the analytical column's inner diameter to significantly reduce the mobile phase flow rate. However, performing such analysis under such conditions results in a longer time required for all components in the sample to elute from the analytical column, resulting in a longer analysis time for a single sample. However, when a large number of samples are to be analyzed, performing such lengthy analyses on all of them is impractical due to the enormous financial, time, and labor costs involved.

[0005] The present invention has been made in consideration of the above problems, and aims to provide a multiple sample analysis method that can efficiently analyze multiple samples that share a common main component. [Means for solving the problem]

[0006] The multiple sample analysis method of the present invention includes a first analysis step of performing a first chromatography analysis using a photodiode array for at least one sample under conditions capable of separating multiple components contained in the at least one sample from one another to obtain a three-dimensional chromatogram of the at least one sample, and extracting spectral data of each of the multiple components contained in the at least one sample from the three-dimensional chromatogram of the at least one sample; a second analysis step of performing a second chromatography analysis using a photodiode array for another sample having the same main component as the at least one sample under conditions capable of obtaining a three-dimensional chromatogram in a shorter time than the first chromatography analysis to obtain a three-dimensional chromatogram of the other sample; and a peak separation step of applying a peak separation process based on the spectral data extracted in the first analysis step to the three-dimensional chromatogram of the other sample obtained in the second analysis step to obtain peak separation data for the other sample in which peaks of multiple components contained in the other sample are separated from one another.

[0007] That is, in the present invention, for some samples among a plurality of samples that share a common main component, a long-term first chromatographic analysis that achieves high resolution is performed to obtain spectral data for the plurality of components, and for the remaining samples, a second chromatographic analysis is performed that provides a three-dimensional chromatogram at high speed, although with a lower resolution than the first chromatographic analysis, and peak separation data for the remaining samples is obtained by applying a peak separation process based on the spectral data obtained by performing the first chromatographic analysis to the three-dimensional chromatogram with a relatively low resolution obtained by the second chromatographic analysis. [Effects of the Invention]

[0008] As described above, according to the multiple sample analysis method of the present invention, among multiple samples that share a common main component, a first chromatographic analysis that takes a long time to achieve high resolution is performed on only some of the samples, and a second chromatographic analysis that provides a lower resolution than the first chromatographic analysis but can quickly obtain a three-dimensional chromatogram is performed on the remaining samples. This makes it possible to obtain high-precision peak separation data for all samples without having to perform the first chromatographic analysis that takes a long time for all of the multiple samples that share a common main component. Therefore, it is possible to efficiently analyze multiple samples that share a common main component. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of the configuration of a liquid chromatography analysis device. [Figure 2] FIG. 1 is a conceptual diagram illustrating an example of a multiple sample analysis method. [Figure 3] 2 is a flowchart showing an example of a procedure according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the multiple sample analysis method according to the present invention will be described below with reference to the drawings.

[0011] First, an example of the configuration of a liquid chromatography analyzer used to carry out the multiple sample analysis method will be described with reference to FIG.

[0012] The liquid chromatography analyzer includes a liquid delivery pump 2, an injector 4, an analytical column 6, a PDA detector 8, an oven 10, and a processor 12. The liquid delivery pump 2 delivers a mobile phase. The injector 4, the analytical column 6, and the PDA detector 8 are connected downstream of the liquid delivery pump 2, in this order from upstream to downstream. The injector 4 injects a sample into the mobile phase delivered by the liquid delivery pump 2. The analytical column 6 separates components in the sample injected into the mobile phase by the injector 4. The analytical column 6 is housed inside the oven 10 and is controlled to a temperature according to the analysis conditions. The PDA detector 8 measures the time change in absorbance of the eluate from the analytical column 6 for each wavelength band. Specifically, the PDA detector 8 acquires analytical data including chromatogram information representing the time change in absorbance in each measurement wavelength band and spectral information representing the spectrum at each time during the analysis.

[0013] The arithmetic processing device 12 is realized by a computer device equipped with a CPU (central processing unit), a data storage device, etc. The arithmetic processing device 12 receives the analytical data output from the PDA detector 8. The arithmetic processing device 12 has the function of performing various analytical processes using the analytical data output from the PDA detector 8. The analytical processing functions of the arithmetic processing device 12 include the function of creating a three-dimensional chromatogram that combines chromatographic information and spectral information about the sample, the function of extracting spectral data for each component separated from each other in the analytical column 6 based on the created three-dimensional chromatogram, and the function of performing peak separation processing on the three-dimensional chromatogram using the extracted spectral data. Specifically, the arithmetic processing device 12 has the function of performing an analytical process once, storing the spectral data extracted from the three-dimensional chromatogram in a database, and using the spectral data stored in the database for peak separation processing on another three-dimensional chromatogram.

[0014] Next, the concept of the multiple sample analysis method will be explained with reference to FIG.

[0015] Assume that there are multiple samples 1 to n to be analyzed. These samples 1 to n have a common main component. The purpose of the analysis is to quantify the concentration of each of the multiple components contained in samples 1 to n, and the analysis is carried out using a liquid chromatography apparatus having the configuration shown in Figure 1.

[0016] For sample 1, high-resolution conditions are searched for that will provide high peak resolution between the main component peak and the peaks of its neighboring components, and analysis is performed under those high-resolution conditions (first chromatographic analysis). The analytical conditions include factors such as the inner diameter and length of analytical column 6, the type of packing material in analytical column 6, the set temperature of oven 10, the composition of the mobile phase delivered by solvent delivery pump 2, the delivery flow rate of solvent delivery pump 2, and the injection conditions of injector 4. These factors are determined so that at least the peak of the main component of sample 1 and the peaks of other components that appear near the main component are isolated, and preferably so that all components contained in sample 1 are isolated.

[0017] The first chromatographic analysis produces a three-dimensional chromatogram in which the peaks of the multiple components contained in sample 1 are separated from one another, and spectral data for each of the components isolated in the first chromatographic analysis is obtained from the three-dimensional chromatogram.

[0018] Generally speaking, an analysis under conditions optimized to completely separate the peaks of multiple components in a sample, such as the first chromatographic analysis, takes a relatively long time to elute all of the components from the analytical column 6. Therefore, if such a high-resolution analysis is performed on all of the multiple samples 1 to n, it will take an enormous amount of time to obtain the analytical results for all of the samples 1 to n.

[0019] Therefore, each of Samples 2 to n other than Sample 1 is analyzed under conditions such that all components are eluted from analytical column 6 in a shorter time than in the first chromatographic analysis (second chromatographic analysis). In the second chromatographic analysis, an analytical column different from that used in the first chromatographic analysis can be used. That is, the first analytical column used in the first chromatographic analysis and the second analytical column used in the second chromatographic analysis may differ from each other in inner diameter, length, and / or type of packing material.

[0020] In the three-dimensional chromatogram obtained by the second chromatographic analysis, the intervals between peaks are shorter than those in the first chromatographic analysis, resulting in lower resolution and the peaks of multiple components overlapping each other. In this case, the analytical data obtained by the second chromatographic analysis is incomplete and cannot be used as is to quantify the components contained in samples 2 to n.

[0021] To resolve incompleteness in the analytical data obtained by the second chromatographic analysis, a peak separation process is applied to each analytical data. Peak separation is a process for estimating the shape and size of each peak of multiple components that overlap on a chromatogram. In peak separation, algorithms that estimate the chromatogram of each component by fitting a model function (peak model) such as an Exponential Modified Gaussian (EMG) function to the waveform of the actual chromatogram (see, for example, International Publication No. 2016 / 035167) can be used. Other algorithms that mathematically estimate the chromatogram of each component by applying matrix decomposition such as Non-negative Matrix Factorization (NMF) to the original three-dimensional chromatogram data without using a model function, and principal component analysis algorithms such as PCA (principal component analysis), can also be used.

[0022] In the above-described peak separation process, it is possible to estimate the number, shape, and size of overlapping peaks in three-dimensional chromatogram data even when there is no information about the components contained in the sample. However, if spectral data exists for at least one of the components whose peaks overlap, the spectral data can be used as basic information for the peak separation process to improve the accuracy of estimating the number, shape, and size of the overlapping peaks.

[0023] In this example, at least a portion of the spectral data extracted from the analytical data of the first chromatographic analysis is used in the peak separation process applied to each analytical data acquired in the second chromatographic analysis. Because Samples 1 to n share a common principal component, spectral data for the principal component extracted from the analytical data of the first chromatographic analysis can be used in the peak separation process, thereby improving the accuracy of the estimation results obtained in the peak separation process for the analytical data of Samples 2 to n. Note that if Samples 1 to n contain the same components, spectral data for all components isolated in the first chromatographic analysis can be used in the peak separation process to obtain highly accurate peak separation data for Samples 2 to n.

[0024] An example of the procedure for the multiple sample analysis method of this embodiment will be described with reference to the flowchart of FIG.

[0025] Of the many samples to be analyzed, some of the samples (which may be one or more samples) are subjected to a high-resolution analysis (first chromatographic analysis) in which at least the main component peak is completely separated from the peaks of other components (step 101). The analytical data obtained in the first chromatographic analysis is analyzed using the processor 12 to extract spectral data for each component isolated in the high-resolution analysis (step 102). For some of the samples, the first chromatographic analysis provides peak separation data necessary for quantifying each component.

[0026] Next, for the remaining samples excluding the portion of the samples that have been subjected to the first chromatographic analysis, a low-resolution analysis (second chromatographic analysis) is performed (step 103), which provides a lower resolution between peaks than the first chromatographic analysis but allows analytical data to be obtained in a shorter time than the first chromatographic analysis. As a result, three-dimensional chromatograms for the remaining samples are obtained (step 104).

[0027] The three-dimensional chromatogram obtained by the second chromatography analysis is subjected to peak separation processing based on the spectral data extracted in step 102 (step 105). This peak separation processing separates multiple overlapping peaks in the initially incomplete analytical data with high estimation accuracy, resulting in peak-separated data that can be used to quantify each component contained in the sample. In other words, by performing the peak separation processing in step 105, it is possible to obtain analytical results equivalent to those obtained by performing a long-term, high-resolution analysis on all samples.

[0028] As described above, in this embodiment, even if there are a huge number of samples to be analyzed, a first chromatographic analysis is performed for only at least one of those samples, taking a long time (and in some cases high cost) under analytical conditions set to isolate the main component from other components, while a second chromatographic analysis is performed for the remaining samples in a short time (and in some cases low cost), thereby obtaining analytical results equivalent to those obtained by performing a long, high-resolution analysis for all samples, thereby significantly reducing the time required to obtain peak separation data for all samples.

[0029] The above-described examples merely exemplify the embodiments of the multiple sample analysis method according to the present invention. The embodiments of the multiple sample analysis method according to the present invention are as follows.

[0030] In one embodiment of the multiple sample analysis method according to the present invention, the method includes a first analysis step of performing a first chromatography analysis using a photodiode array for at least one sample under conditions capable of separating a plurality of components contained in the at least one sample from one another to obtain a three-dimensional chromatogram of the at least one sample, and extracting spectral data of each of the plurality of components contained in the at least one sample from the three-dimensional chromatogram of the at least one sample; a second analysis step of performing a second chromatography analysis using a photodiode array for another sample having the same main component as the at least one sample under conditions capable of obtaining a three-dimensional chromatogram in a shorter time than the first chromatography analysis to obtain a three-dimensional chromatogram of the other sample; and a peak separation step of applying a peak separation process based on the spectral data extracted in the first analysis step to the three-dimensional chromatogram of the other sample obtained in the second analysis step to obtain peak separation data for the other sample in which the peaks of the plurality of components contained in the other sample are separated from one another.

[0031] In a first aspect of the above embodiment, the first analytical column used in the first chromatographic analysis and the second analytical column used in the second chromatographic analysis differ from each other in inner diameter, overall length, and / or packing material. For example, a relatively expensive analytical column can be used as the first analytical column in the first chromatographic analysis to achieve high peak resolution, while a less expensive analytical column can be used in the second chromatographic analysis. This reduces the cost required to analyze all of the multiple samples.

[0032] In a second aspect of the above embodiment, the mobile phase flow rate in the second chromatographic analysis is greater than the mobile phase flow rate in the first chromatographic analysis. This second aspect can be combined with the first aspect.

[0033] In a third aspect of the above embodiment, when two or more samples share a common principal component, the first analysis step is performed on one of the two or more samples to extract spectral data for each of the components contained in the one sample, the second analysis step is performed on the remaining samples to obtain three-dimensional chromatograms for each of the remaining samples, and the peak separation step is performed on the obtained three-dimensional chromatograms for each of the remaining samples to obtain peak separation data for each of the remaining samples. This aspect allows the first chromatographic analysis, which requires a long time to analyze, to be performed on only one sample, while the second chromatographic analysis, which can be completed in a relatively short time, is performed on the remaining samples, thereby significantly reducing the time required to complete the analysis of all samples. This third aspect can be combined with the first and / or second aspects.

[0034] In a fourth aspect of the above embodiment, the first chromatographic analysis and the second chromatographic analysis are liquid chromatographic analyses. Note that the "chromatographic analysis" in the present invention can include not only liquid chromatographic analysis but also gas chromatographic analysis. This fourth aspect can be combined with the first, second, and / or third aspects.

[0035] In a fifth aspect of the above embodiment, the peak separation process uses an algorithm that estimates the peak of each component by fitting a model function, or an algorithm that estimates the peak of each component mathematically by matrix decomposition without using the model function. This fifth aspect can be combined with the first, second, third, and / or fourth aspects. [Explanation of symbols]

[0036] 2. Liquid transfer pump 4 injectors 6 Separation column 8 PDA detector 10. Oven 12 Processing unit

Claims

1. a first analysis step of performing a first chromatographic analysis on at least one sample using a photodiode array under conditions capable of separating a plurality of components contained in the at least one sample from each other to obtain a three-dimensional chromatogram of the at least one sample, and extracting spectral data of each of the plurality of components contained in the at least one sample from the three-dimensional chromatogram of the at least one sample; a second analysis step of acquiring a three-dimensional chromatogram of another sample having the same main component as the at least one sample by performing a second chromatographic analysis using a photodiode array under conditions that allow a three-dimensional chromatogram to be acquired in a shorter time than the first chromatographic analysis; a peak separation step of applying a peak separation process based on the spectral data extracted in the first analysis step to the three-dimensional chromatogram of the other sample acquired in the second analysis step, thereby acquiring peak separation data for the other sample in which peaks of multiple components contained in the other sample are separated from each other.

2. 2. The multiple sample analysis method according to claim 1, wherein the first analytical column used in the first chromatographic analysis and the second analytical column used in the second chromatographic analysis have different inner diameters, overall lengths, and / or packing materials.

3. 3. The multiple sample analysis method according to claim 1, wherein the mobile phase flow rate in the second chromatographic analysis is greater than the mobile phase flow rate in the first chromatographic analysis.

4. When there are two or more samples that share a common principal component, performing the first analysis step on one sample of the two or more samples to extract spectral data of each of a plurality of components contained in the one sample; 4. The multiple sample analysis method according to claim 1, wherein the second analysis step is performed on the remaining samples of the two or more samples to obtain three-dimensional chromatograms for each of the remaining samples, and the peak separation step is performed on the obtained three-dimensional chromatograms for each of the remaining samples to obtain peak separation data for each of the remaining samples.

5. The multiple sample analysis method according to claim 1 , wherein the first chromatographic analysis and the second chromatographic analysis are liquid chromatographic analyses.

6. 6. The multiple sample analysis method according to claim 1, wherein the peak separation process uses an algorithm that estimates the peak of each component by fitting a model function, or an algorithm that mathematically estimates the peak of each component by matrix decomposition without using the model function.

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