Method for analyzing mass spectrometric data, program, and device for analyzing mass spectrometric data

Abstract

The present invention relates to a method for analyzing mass spectrometry data, a program, and a device for analyzing mass spectrometry data. A method for analyzing mass spectrometry data is provided, which can determine identification candidates and / or obtain information on partial structures of an analysis target substance at low cost. The method for analyzing mass spectrometry data of an analysis target substance includes: a mass-to-charge ratio and relative intensity obtaining step of obtaining a mass-to-charge ratio and a relative intensity of the analysis target substance; a mass data preparing step of preparing mass data of the analysis target substance; and an identification candidate determining step of determining identification candidates of the analysis target substance. Another aspect of the present invention relates to a program for executing the method for analyzing mass spectrometry data of an analysis target substance and a device for analyzing mass spectrometry data of an analysis target substance.

Description

Technical Field

[0001] This invention relates to a method for parsing quality analysis data, a program for performing the method for parsing quality analysis data of a substance, and an apparatus for parsing quality analysis data of a substance. Background Technology

[0002] Mass analysis is widely used in various technical fields as a means of identifying and analyzing substances.

[0003] For example, Patent Document 1 describes a method for analyzing mass analysis data, which involves causing precursor ions from one or more unknown components to fragment in stage n-1 (n≧2), and then performing mass analysis on the resulting fragment ions using MS. n The analysis results, and the method for analyzing mass analysis data of components similar to the target component selected from the aforementioned unknown components, are characterized by using the aforementioned MS... n The obtained spectral data and MS of the target components were analyzed. n The spectral data is used to derive the specified variables. By using multivariate analysis of these variables, the similarity between the target component and each unknown component is calculated. Based on this similarity, components that are similar to the target component are selected.

[0004] Patent Document 2 describes a mass analysis data analysis device, which is a mass analysis data analysis device for exploring the products generated by the chemical change after separating the samples before and after the chemical change by chromatography and based on the data obtained by MS determination and MSMS determination using a mass analysis device. The device is characterized by having a product exploration unit, wherein, for the samples before and after the chemical change, the chromatogram of the mass-to-charge ratio of the precursor ions determined by MSMS is compared, and the peaks that exist only in the changed sample are determined to be peaks from the products.

[0005] Patent Document 3 discloses a data analysis device for chromatographic quality analysis, which is a data analysis device for chromatographic quality analysis that analyzes data collected by a chromatographic quality analysis device. The chromatographic quality analysis device includes: a chromatogram that separates components in a sample over time; a quality analysis device, i.e., a main detector, that detects components in a sample containing components separated by the chromatogram; and a secondary detector that is different from the quality analysis device that detects components in a sample containing components separated by the chromatogram. The device is characterized by including a calculation processing unit and a mass-to-charge ratio extraction unit.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2007-285719

[0009] Patent Document 2: International Publication No. 2008 / 065704

[0010] Patent Document 3: International Publication No. 2018 / 087824 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] Currently, in the analysis of mass analysis data used to identify the target substance, the mass analysis spectrum of the target substance is compared with a mass analysis database of known compounds prepared based on the mass analysis spectra of known compounds, and the identification candidates are determined by the consistency of the spectral patterns. Conventional analysis methods require high-resolution mass analysis equipment capable of isotope ratio identification, resulting in high economic costs. Furthermore, conventional methods determine identification candidates based on the consistency of spectral patterns; therefore, when the data of the target substance contained in the sample is not yet recorded in the mass analysis database of known compounds, it is difficult not only to identify identification candidates but also to obtain partial structural information. In cases where low-resolution mass analysis equipment can be used for analysis at low cost and / or where the data of the target substance contained in the sample is not yet recorded in the mass analysis database of known compounds, the determination of identification candidates and / or the acquisition of partial structural information rely on the experience of experienced analyzers. In such cases, the human and time costs of analysis are high.

[0013] Therefore, the object of the present invention is to provide a method for analyzing the quality analysis data of the target substance that enables the identification of candidates and / or the acquisition of information on partial structures at low cost.

[0014] Methods for solving problems

[0015] The inventors have conducted various studies on methods for solving the aforementioned problems. The inventors discovered that by measuring the mass analysis spectrum of the target substance, obtaining the mass-to-charge ratio and relative intensity of one or more detected ion peaks, and calculating the difference in mass-to-charge ratio between each of the detected ion peaks and other ion peaks, and by preparing mass data of the target substance including the relative intensity, mass-to-charge ratio, and mass-to-charge ratio difference of one or more ion peaks, this mass data can be compared with the mass data of one or more reference substances, thereby identifying candidate substances or parts thereof. Based on the above understanding, the inventors completed this invention.

[0016] That is, the present invention includes the following schemes and implementation methods.

[0017] (1) Methods for analyzing the mass analysis data of the target substance, including:

[0018] The process of obtaining data elements of the target substance includes determining the mass analysis spectrum of the target substance and obtaining the mass-to-charge ratio and relative intensity of one or more detected ion peaks.

[0019] The process for preparing mass data of the target substance includes, for each of the detected ion peaks (one or more), calculating the difference in mass-to-charge ratio between that ion peak and other ion peaks, and preparing mass data of the target substance containing the relative intensities, mass-to-charge ratios, and differences in mass-to-charge ratios of the one or more ion peaks; and

[0020] The identification candidate determination process for the target substance involves comparing the quality data of the prepared target substance with the quality data of one or more reference substances or their partial structures to determine the identification candidates for the target substance or its partial structures.

[0021] (2) The method according to the above embodiment (1) further includes: a mass data preparation step of a reference material or a part thereof, wherein the mass analysis spectrum of one or more reference materials is measured, and for each of the one or more reference materials, the difference in mass-to-charge ratio between the detected one or more ion peaks and other ion peaks is calculated, and for each of the one or more reference materials, mass data of the reference material or a part thereof containing the relative intensity, mass-to-charge ratio and the difference in mass-to-charge ratio of one or more ion peaks is prepared.

[0022] (3) The method according to embodiment (1) or (2) above, wherein the identification candidate determination step of the target substance further includes:

[0023] A threshold n for the relative intensity of ion peaks is set (where n ≧ 0). Mass data of the target substance containing relative intensities, mass-to-charge ratios, and differences in mass-to-charge ratios above the threshold n are compared with mass data of one or more reference substances or their partial structures to determine candidate identification structures for the target substance or its partial structures; and

[0024] The process of determining the identification candidates for the target substance or its partial structure by varying the threshold n within the range of the maximum relative intensity of more than one detected ion peak is repeated. The identification candidates determined based on more ion peak mass data and the identification candidates under a larger threshold n are then sorted as identification candidates with higher reliability.

[0025] (4) A program for performing the method for analyzing the mass analysis data of the target substance according to any one of the embodiments (1) to (3) described above.

[0026] (5) An analytical apparatus for analyzing the mass analysis data of the target substance, which has the following features:

[0027] Mass analysis spectrum determination unit for determining the mass analysis spectrum of the target substance;

[0028] A data element acquisition unit for the analytical substance that obtains the mass-to-charge ratio and relative intensity of one or more ion peaks detected by the mass analysis spectroscopy unit;

[0029] For each of the detected ion peaks (one or more), the difference in mass-to-charge ratio between that ion peak and other ion peaks is calculated. A mass data preparation unit for the target substance is then prepared, containing the relative intensities, mass-to-charge ratios, and differences in mass-to-charge ratios of the target substance with one or more ion peaks.

[0030] The mass data of the prepared target substance are compared with the mass data of one or more reference substances or their partial structures to determine the identification candidate determination unit of the target substance or its partial structure.

[0031] The effects of the invention

[0032] According to the present invention, a method for analyzing the quality analysis data of the target substance is provided, which enables the identification of candidates and / or the acquisition of information on partial structures at low cost. Attached Figure Description

[0033] Figure 1 This is a flowchart illustrating the steps in one embodiment of a method for analyzing the quality analysis data of a substance according to one aspect of the present invention.

[0034] Figure 2 The flowchart illustrates the steps in a specific embodiment of a method for analyzing the quality analysis data of a substance according to a scheme of the present invention.

[0035] Figure 3 This is the mass analysis spectrum of the target substance determined in Experiment I-2. Detailed Implementation

[0036] The preferred embodiments of the present invention are described in detail below.

[0037] <1. Methods for analyzing the mass analysis data of the target substance>

[0038] The inventors have discovered that by measuring the mass analysis spectrum of a target substance, obtaining the mass-to-charge ratio (m / z) and relative intensity of one or more detected ion peaks, and calculating the difference in mass-to-charge ratio between each of the detected ion peaks and other ion peaks, mass data of the target substance containing the relative intensity, mass-to-charge ratio, and mass-to-charge ratio difference of one or more ion peaks is prepared. This mass data is then compared with the mass data of one or more reference substances, thereby enabling the identification of the target substance or its partial structures as potential candidates. Therefore, one aspect of this invention relates to a method for analyzing mass analysis data of a target substance.

[0039] The various solutions of this invention can be applied not only to high-resolution mass analysis devices capable of isotope ratio identification, but also to low-resolution mass analysis devices where analysis can be performed at low cost. Mass analysis devices using the solutions of this invention typically only require a mass resolution of 100 or higher. By implementing the solutions of this invention using a low-resolution mass analysis device, it is possible to determine candidate substances for analysis and / or obtain partial structural information at low cost.

[0040] The various solutions of the present invention can be applied to various quality analysis devices with ion sources and mass analysis units commonly used in this technical field. The quality analysis devices using the solutions of the present invention can be in the form of chromatographic quality analysis devices such as liquid chromatography or gas chromatography.

[0041] In various embodiments of the present invention, the target substance can be a pre-purified and isolated single substance, or a mixture comprising one or more other substances. As explained below, each embodiment of the present invention is characterized by comparing the mass data of the target substance, including the relative intensities of ion peaks, mass-to-charge ratios, and differences in mass-to-charge ratios, with the mass data of one or more reference substances. Therefore, even if the target substance is a mixture, identification candidates for the target substance or a portion thereof can be easily determined. When the target substance is a mixture, it is preferable to use a chromatographic mass analysis apparatus as described in the embodiments of the present invention.

[0042] A flowchart illustrating the steps of one embodiment of the method of this solution is shown below. Figure 1 In the middle. For example Figure 1 As shown, the method of this scheme includes: a step of acquiring data elements of the target substance (step S1), a step of preparing quality data of the target substance (step S2), and a step of determining the identification candidates of the target substance (step S3). Each step is described in detail below.

[0043] [1-1. Process for obtaining data elements of the target substance]

[0044] This process (process S1) includes: determining the mass analysis spectrum of the substance to be analyzed, and obtaining the mass-to-charge ratio and relative intensity of one or more detected ion peaks.

[0045] In this process, the mass analysis spectrum of the target substance can be determined using the various mass analysis apparatuses exemplified above. Generally, the number of ion peaks of the target substance, including data elements such as mass-to-charge ratio and relative intensity, varies not only based on the structure of the target substance but also based on the measurement conditions of the mass analysis spectrum. Therefore, it is preferable to measure the mass analysis spectrum of the target substance under conditions that increase the number of detected ion peaks. By obtaining more mass-to-charge ratios and relative intensities of ion peaks, the reliability in identifying candidates for the target substance or its partial structures can be improved.

[0046] [1-2. Procedure for preparing mass data of the target substance]

[0047] This step (step S2) includes: for each of the more than one ion peaks detected in the data element acquisition step (step S1) of the target substance, calculating the difference in mass-to-charge ratio between the ion peak and other ion peaks, and preparing mass data of the target substance containing the relative intensity, mass-to-charge ratio and mass-to-charge ratio difference of the more than one ion peak.

[0048] In this process, the mass data of the target substance can be prepared, for example, using the following steps: The mass-to-charge ratio and relative intensity of one or more ion peaks obtained in the data element acquisition process of the target substance are output from the mass analysis device and input into the cells of the first row and first column of a spreadsheet consisting of multiple rows and columns. In this spreadsheet, the difference in mass-to-charge ratio between each ion peak and other ion peaks is input into the cell corresponding to the row of that ion peak and the column of the other ion peaks. In this method, a difference of 0 or less does not contribute to the determination of the target substance or its partial structure as a candidate for identification. Therefore, in this embodiment, when the difference is 0 or less, it is preferable to output 0 or a blank value in the corresponding cell.

[0049] [1-3. Identification and Candidate Determination Procedures for the Analytical Substance]

[0050] This step (step S3) includes: comparing the mass data of the target substance prepared in the mass data preparation step (step S2) with the mass data of one or more reference substances or their partial structures to determine the identification candidates of the target substance or its partial structures.

[0051] In the mass analysis of a substance, the ions (parent ions) generated due to the ionization of the substance fragment, sometimes producing charged fragment ions and uncharged fragments (fragmentation). The patterns of the parent ions and fragment ions generated due to fragmentation are closely related to the structure of the substance. Therefore, in this process, by comparing the mass data of the target substance containing the relative intensities, mass-to-charge ratios, and differences in mass-to-charge ratios of one or more ion peaks with the mass data of one or more reference substances or their partial structures, identification candidates for the target substance or its partial structures can be more easily determined compared to conventional techniques that determine identification candidates based on the consistency of spectral patterns.

[0052] In this process, it is preferable that the mass data compared to determine the identification candidate of the target substance or a partial structure thereof is a combination of the mass-to-charge ratio and the difference in mass-to-charge ratio of one or more ion peaks. In fragmentation of mass analysis, the difference in mass-to-charge ratio between the parent ion peak and the fragment ion peak corresponds to the mass of the uncharged fragment. Which fragment is charged sometimes varies depending on the structure of the parent ion and the ionization conditions. Therefore, it is preferable to compare the mass-to-charge ratio and the difference in mass-to-charge ratio of the mass data of the target substance with the mass-to-charge ratio and the difference in mass-to-charge ratio of the mass data of one or more reference substances or a partial structure thereof. If the combination of the mass-to-charge ratio and the difference in mass-to-charge ratio of the mass data of the target substance matches the combination of the mass-to-charge ratio and the difference in mass-to-charge ratio of the mass data of a specific reference substance or a partial structure thereof, then that reference substance or partial structure is determined as an identification candidate of the target substance or a partial structure thereof. For example, if the mass-to-charge ratio of the mass data of the target substance is 'a' and the difference in mass-to-charge ratios is 'b', and the mass-to-charge ratio of the mass data of a specific reference substance or a portion of its structure is 'a' or 'b' and the difference in mass-to-charge ratios is 'b' or 'a', then it can be determined that the combination of the mass-to-charge ratio and the difference in mass-to-charge ratio of the target substance's mass data is consistent with the combination of the mass-to-charge ratio and the difference in mass-to-charge ratio of the specific reference substance or a portion of its structure's mass data. By implementing this process with the above steps, compared to conventional techniques that determine identification candidates based on the consistency of spectral patterns, it is easier to determine identification candidates for the target substance or a portion of its structure.

[0053] In this process, the mass data of one or more reference materials or their partial structures can be prepared each time this process is performed, or pre-prepared mass data can be used. The mass data of one or more reference materials or their partial structures used in this process can be prepared by performing the mass data preparation process for reference materials or their partial structures described below. In this process, it is preferable to use pre-prepared mass data of one or more reference materials or their partial structures, and preferably to store the pre-prepared mass data of one or more reference materials or their partial structures in the reference material data storage unit of a data analysis device (e.g., a computer's storage device), and to output it for use during the implementation of this process. With the above-described embodiment, the implementation time of the method of this solution can be shortened, and costs can be reduced.

[0054] This process can be implemented, for example, according to the following steps: The mass-to-charge ratio and mass-to-charge ratio difference of each ion peak column prepared in the mass data preparation process for the target substance are compared with the mass-to-charge ratio and mass-to-charge ratio difference of the mass data of one or more reference substances or their partial structures. If the combination of the mass-to-charge ratio and mass-to-charge ratio difference values ​​is consistent, the name of the consistent reference substance is output to the identification candidate cell of that column. In this embodiment, for the mass data of one or more reference substances or their partial structures, the mass data pre-stored in the reference substance data storage unit (e.g., the storage device of a computer) of the data analysis device can be output to a different spreadsheet than the spreadsheet that outputs the mass data of the target substance.

[0055] In this process, it is preferable to further include:

[0056] A threshold n for the relative intensity of ion peaks is set (where n ≧ 0). Mass data of the target substance containing relative intensities, mass-to-charge ratios, and differences in mass-to-charge ratios above the threshold n are compared with mass data of one or more reference substances or their partial structures to determine identification candidates for the target substance or its partial structures (step S3a).

[0057] The threshold n is varied, and the above-described steps for determining identification candidates for the target substance or its partial structure are repeatedly performed, followed by a step (step S3b) to rank the identification candidates with higher reliability. Flowcharts illustrating each step in this embodiment are shown below. Figure 2 .

[0058] In mass analysis spectra, the relative intensity of ion peaks is typically correlated with the ion concentration ratio. Therefore, fragment ions resulting from fragmentation usually have a relative intensity similar to that of the parent ion. Furthermore, ion peaks with higher relative intensities generally originate from ions present in greater quantities. Therefore, in this embodiment, by setting a threshold n for the relative intensity of ion peaks, mass data of the target substance that includes relative intensities, mass-to-charge ratios, and differences in mass-to-charge ratios above the threshold n are screened. Furthermore, by varying the threshold n to repeatedly compare the mass data with the mass data of one or more reference substances or their partial structures, identification candidates of the target substance or its partial structures with higher reliability can be determined.

[0059] In this embodiment, the threshold n for the relative intensity of ion peaks is varied within a range of 0 or higher and the maximum relative intensity of at least one detected ion peak. In this case, the variation range of the threshold n can be appropriately set based on the number of ion peaks and the maximum relative intensity. The variation range of the threshold n is typically a number of 1 or higher, preferably an integer of 1 or higher. Furthermore, the number of repetitions generated based on the change in threshold n is typically 2 or higher, preferably in the range of 2 to 10. If the variation range of threshold n is less than the aforementioned lower limit, it is possible to obtain a result that is essentially the same as the result before the change. If the number of repetitions generated based on the change in threshold n is less than the aforementioned lower limit, it is possible to obtain a result that is essentially the same as the result without repetition. Furthermore, if the number of repetitions generated by the change in threshold n exceeds the aforementioned upper limit, the implementation time of the method in this embodiment may increase. Therefore, by implementing the method of this embodiment under the above conditions, it is possible to determine identification candidates for the target substance or its partial structure with higher reliability at a low cost.

[0060] As explained above, in mass analysis spectra, the relative intensity of ion peaks is typically correlated with the ion concentration ratio. Therefore, identifying candidates determined based on mass data from more ion peaks and those at a higher threshold n can be ranked as more reliable candidates. Ranking the candidates based on the number of ion peaks and a threshold n of relative intensity improves the reliability of the candidate determination results.

[0061] This embodiment can be implemented, for example, according to the following steps: A threshold n for the relative intensity of ion peaks is set. In the spreadsheet prepared during the mass data preparation process of the target substance, only rows with relative intensities above the threshold n are selected and output. The mass-to-charge ratio and mass-to-charge ratio difference of the selected column output to the ion peaks are compared with the mass-to-charge ratio and mass-to-charge ratio difference of the mass data of one or more reference substances or their partial structures. If the combination of the mass-to-charge ratio and mass-to-charge ratio difference values ​​of the two is consistent, the name of the reference substance that matches the identification candidate cell of that column is output. The above steps are repeated, varying the threshold n within the range of the maximum relative intensity of one or more detected ion peaks. After repetition, the names of reference substances in more identification candidate cells output to the column of ion peaks and the names of reference substances in identification candidate cells output under a larger threshold n are sorted as identification candidates with higher reliability. The names and sorting of the reference substances are output to a spreadsheet.

[0062] [1-4. Procedure for preparing mass data of reference materials or parts thereof]

[0063] The method of this scheme may include, as needed, a step of preparing mass data of a reference material or a portion thereof. For example, this step is preferably included when there is no preparation of mass data of one or more reference materials or a portion thereof, and / or when using the pre-prepared mass data of one or more reference materials or a portion thereof to implement the method of this scheme cannot successfully determine the identification candidates of the target substance or a portion thereof.

[0064] This process includes: determining the mass analysis spectrum of one or more reference materials; for each of the one or more reference materials, calculating the difference in mass-to-charge ratio between the detected one or more ion peaks and other ion peaks; and for each of the one or more reference materials, preparing mass data of the reference material or a portion thereof containing the relative intensity, mass-to-charge ratio, and difference in mass-to-charge ratio of one or more ion peaks.

[0065] In the various embodiments of the present invention, there is no particular limitation on the number and type of reference materials. The number and type of reference materials can be appropriately selected based on the structure and / or physicochemical properties of the substance to be analyzed. By implementing the method of the present invention using reference materials having a structure and / or physicochemical properties similar to those of the substance to be analyzed, the reliability in determining the identification candidates for the substance to be analyzed or a portion thereof can be improved.

[0066] This process can be carried out using the same steps as the process for preparing the mass data of the substance to be analyzed as described above.

[0067] In this process, mass data of one or more reference materials or their partial structures can be prepared, for example, according to the following steps: For each of the one or more reference materials, a mass analysis spectrum is measured to obtain the mass-to-charge ratio and relative intensity of one or more detected ion peaks. The obtained mass-to-charge ratio and relative intensity of one or more ion peaks are input into the cells of the first row and first column of a spreadsheet consisting of multiple rows and columns. The difference in mass-to-charge ratio between each ion peak and other ion peaks is output to the cell corresponding to the row of the ion peak and the column of the other ion peaks. In this method, a difference of less than 0 is not helpful in determining the identification candidates of the target substance or its partial structure. Therefore, in this embodiment, when the difference is less than 0, it is preferable to output 0 or a blank value in the corresponding cell.

[0068] Preferably, the mass data of one or more reference materials or their partial structures prepared according to the above steps are stored in the reference material data storage unit of the data analysis apparatus (e.g., the storage device of a computer), and are output from the reference material data storage unit for use during the identification candidate determination step of the target substance to be analyzed. In the above embodiment, the implementation time of the method of this solution can be shortened, and costs can be reduced.

[0069] <2. Program for executing the parsing method of quality analysis data>

[0070] Another aspect of the invention relates to a program for performing a method for parsing quality analysis data.

[0071] The program of this solution can be used to execute the method for analyzing the quality analysis data of the target substance according to one aspect of the present invention on a data analysis device (e.g., a computer). The program of this solution includes: a step of acquiring data elements of the target substance, a step of preparing quality data of the target substance, and a step of determining the identification candidates of the target substance. Each step corresponds to the steps of the method for analyzing the quality analysis data of the target substance according to one aspect of the present invention described above.

[0072] <3. Analysis device for analyzing the mass analysis data of the target substance>

[0073] Another aspect of the present invention relates to an apparatus for analyzing mass analysis data of a target substance. As described above, the method for analyzing mass analysis data of a target substance using one aspect of the present invention enables the identification of candidate substances and / or the acquisition of partial structural information at low cost. Therefore, by using the analysis apparatus of this invention to analyze the mass analysis data of the target substance, the identification of candidate substances and / or the acquisition of partial structural information can be achieved at low cost.

[0074] The analytical device in this scheme has:

[0075] Mass analysis spectrum determination unit for determining the mass analysis spectrum of the target substance;

[0076] A data element acquisition unit for the analytical substance that obtains the mass-to-charge ratio and relative intensity of one or more ion peaks detected by the mass analysis spectroscopy unit;

[0077] For each of the more than one detected ion peaks, the difference in mass-to-charge ratio between that ion peak and other ion peaks is calculated, and a mass data preparation unit for the target substance is prepared, which includes the relative intensity, mass-to-charge ratio and mass-to-charge ratio difference of the target substance for analysis.

[0078] The mass data of the prepared target substance are compared with the mass data of one or more reference substances or their partial structures to determine the identification candidate determination unit of the target substance or its partial structure.

[0079] In the analytical apparatus of this scheme, the mass analysis spectrum determination unit can be the mass analysis apparatus exemplified above.

[0080] In the analytical apparatus of this scheme, the data element acquisition unit, the mass data preparation unit, and the identification candidate determination unit for the target substance can be data analytical apparatuses commonly used in the analysis of mass analysis data in this technical field. A data analytical apparatus typically includes: a central control unit, a spectral data production unit, an analytical processing unit, a measurement data storage unit, a reference material data storage unit, an input unit, and an output unit. Preferably, the data analytical apparatus is a computer with a central processing unit, a storage device such as a hard disk, an input device, and an output device. In this case, in addition to the control program of the mass analysis apparatus, the program of one aspect of this invention is installed on the computer, and the analytical method for mass analysis data of the target substance according to one aspect of this invention is executed, thereby enabling the determination of the mass analysis spectral data of the target substance and the determination of identification candidates and / or the acquisition of partial structural information at low cost.

[0081] Example

[0082] The following examples illustrate the invention in more detail. However, the scope of the invention is not limited to these examples.

[0083] <I: Methods for analyzing the mass analysis data of the target substance>

[0084] [I-1: Preparation of Mass Data for Reference Materials]

[0085] Mass analysis spectra of various reference materials were determined. For each of more than one reference material, the mass-to-charge ratio (m / z) and intensity of at least one detected ion peak were obtained. For each of the more than one detected ion peak, the difference in mass-to-charge ratio between that ion peak and other ion peaks was calculated. For each of the more than one reference material, mass data of the reference material or its partial structure, including the relative intensities, mass-to-charge ratios, and differences in mass-to-charge ratios of the more than one ion peak, were prepared (the mass data preparation process for the reference material or its partial structure). The mass data of the reference materials are shown in Table 1.

[0086] Table 1

[0087]

[0088] [I-2: Data Acquisition and Mass Data Preparation of the Target Substance]

[0089] The mass analysis spectrum of the target substance was determined, and the mass-to-charge ratio (m / z) and relative intensity of more than one detected ion peak were obtained (data element acquisition process of the target substance). The mass analysis spectrum of the target substance is shown in... Figure 3 middle.

[0090] like Figure 3 As shown, 28 ion peaks with mass-to-charge ratios (m / z) ranging from 14 to 101 were detected in the mass analysis spectrum of the target substance. For each of these 28 detected ion peaks, the difference in mass-to-charge ratio between that ion peak and the other ion peaks was calculated, and mass data of the target substance containing the relative intensities, mass-to-charge ratios, and differences in mass-to-charge ratios of the 28 ion peaks was prepared (mass data preparation process of the target substance). The prepared mass data are shown in Table 2. In the table, if the difference is less than or equal to 0, 0 is output to the corresponding cell.

[0091] Table 2

[0092]

[0093]

[0094]

[0095] [I-3: Identification of Candidate Substances for Analysis]

[0096] The mass data of the target substances prepared in I-2 (Table 2) are compared with the mass data of one or more reference substances prepared in I-1 (Table 1) to determine the identification candidates for the target substances (identification candidate determination step). In this step, a threshold n = 0 is set for the relative intensity of the ion peaks. The mass data of the target substances with relative intensities, mass-to-charge ratios, and mass-to-charge ratio differences exceeding the threshold n are compared with the mass data of one or more reference substances prepared in I-1 to determine the identification candidates for the target substances. Next, the above step is repeated by changing the threshold n to 1, 2, 3, 4, and 10. When the threshold n is 0 and 1, reference substances or partial structures corresponding to fragment symbols B, E, F, and M shown in Table 1 are determined as identification candidates. When the threshold n is increased to 2, the combinations (41 and 55) of mass-to-charge ratio and mass-to-charge ratio difference corresponding to the reference material or its partial structure corresponding to fragment designation B shown in Table 1 disappear from the mass data of the target substance. Therefore, the reference materials or their partial structures corresponding to fragment designations E, F, and M are identified as identification candidates. When the threshold n is increased to 3, only the reference materials or their partial structures corresponding to fragment designations E and F shown in Table 1 are identified as identification candidates. Furthermore, when the threshold n is increased to 4 and 10, only the combinations (43 and 57) of mass-to-charge ratio and mass-to-charge ratio difference corresponding to the reference material or its partial structure corresponding to fragment designation F shown in Table 1 are consistent with the mass data of the target substance. Therefore, only the reference material or its partial structure corresponding to fragment designation F is identified as an identification candidate. Based on the above results, the reference materials corresponding to fragment designation F, which are identified as identification candidates based on more ion peak mass data and at a larger threshold n, i.e., aliphatic ketones, are ranked as more reliable identification candidates for the target substance.

[0097] As a comparative example, based on the analysis of the spectral pattern (the relative intensity and m / z of each detected ion peak)... Figure 2The mass analysis spectrum of the target substance is shown in the table. Similar to the examples, the threshold n for the relative intensity of the ion peaks was varied, and spectral patterns with only ion peaks having a relative intensity greater than or equal to the threshold n were repeatedly analyzed. When the threshold n was 0, reference substances or partial structures corresponding to fragment symbols B, F, M, N, and O shown in Table 1 were identified as identification candidates. When the threshold n was increased to 1 and 2, the ion peaks corresponding to reference substances or partial structures corresponding to fragment symbol M shown in Table 1 disappeared from the mass analysis spectrum of the target substance, therefore reference substances or partial structures corresponding to fragment symbols B, F, N, and O were identified as identification candidates. When the threshold n was increased to 3, only reference substances or partial structures corresponding to fragment symbols F, N, and O shown in Table 1 were identified as identification candidates. Furthermore, when the threshold n was increased to 4 and 10, only reference substances or partial structures corresponding to fragment symbol F shown in Table 1 were identified as identification candidates. Based on the above results, the identification candidates determined by the method of the embodiment are consistent with the identification candidates determined by the conventional analysis method based on the spectral pattern of the mass analysis spectrum of the substance being analyzed.

[0098] It should be noted that the present invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above have been explained in detail for ease of understanding of the present invention, but are not necessarily limited to all the configurations described. In addition, for a part of the configuration of each embodiment, other configurations may be added, deleted, and / or replaced.

Claims

1. Methods for analyzing the mass analysis data of the target substance, including: The process of obtaining data elements of the target substance includes determining the mass analysis spectrum of the target substance and obtaining the mass-to-charge ratio and relative intensity of one or more detected ion peaks. The process for preparing mass data of the target substance includes, for each of the detected ion peaks (one or more), calculating the difference in mass-to-charge ratio between that ion peak and other ion peaks, and preparing mass data of the target substance containing the relative intensities, mass-to-charge ratios, and differences in mass-to-charge ratios of the one or more ion peaks; and The identification candidate determination step for the target substance involves comparing the mass data of the prepared target substance with the mass data of one or more reference substances or their partial structures to determine the identification candidates for the target substance or its partial structures. The mass data is a combination of the mass-to-charge ratios and differences between the mass-to-charge ratios of one or more ion peaks. The process of identifying candidate substances for analysis also includes: A threshold n is set for the relative intensity of ion peaks. Mass data of the target substance whose relative intensity, mass-to-charge ratio, and mass-to-charge ratio difference exceed the threshold n are compared with mass data of one or more reference substances or their partial structures to determine identification candidates for the target substance or its partial structures. Here, n ≧ 0. The process of determining identification candidates for the target substance or its partial structure by varying the threshold n within the range of the maximum relative intensities of at least one detected ion peak is repeated. The identification candidates determined based on mass data from more ion peaks and those with a higher threshold n are then ranked as more reliable identification candidates. The number of repetitions generated based on the change of the threshold n ranges from 2 to 10.

2. The method according to claim 1, further comprising: The process of preparing mass data of a reference material or a portion thereof includes: measuring the mass analysis spectrum of one or more reference materials; calculating the mass-to-charge ratio difference between one or more detected ion peaks and other ion peaks for each of the one or more reference materials; and preparing mass data of the reference material or a portion thereof containing the relative intensity, mass-to-charge ratio, and mass-to-charge ratio difference of one or more ion peaks for each of the one or more reference materials.

3. A program for performing the method for analyzing the mass analysis data of the substance to be analyzed according to any one of claims 1 to 2.

4. An analytical apparatus for analyzing the mass analysis data of a substance, comprising: Mass analysis spectrum determination unit for determining the mass analysis spectrum of the target substance; A data element acquisition unit for the analytical substance that obtains the mass-to-charge ratio and relative intensity of one or more ion peaks detected by the mass analysis spectroscopy unit; For each of the detected ion peaks (one or more), the difference in mass-to-charge ratio between that ion peak and other ion peaks is calculated. A mass data preparation unit for the target substance is then prepared, containing the relative intensities, mass-to-charge ratios, and differences in mass-to-charge ratios of the target substance with one or more ion peaks. The mass data of the prepared target substance are compared with the mass data of one or more reference substances or their partial structures to determine the identification candidate determination unit of the target substance or its partial structure.

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