JP7163874B2 - Analysis device and X-ray diffraction device - Google Patents

Description

The present invention relates to an analysis device and an X-ray diffraction device for identifying specific substances contained in a sample.

In order to prevent health problems for workers working in a dusty work environment, in Japan, it is obligatory to implement working environment measurements for specific substances that may cause health problems. . Among such substances, an X-ray diffractometer is used for qualitative analysis and quantitative analysis of free silicic acid and asbestos (see Non-Patent Documents 1 and 2).

In an X-ray diffractometer, a sample such as powder is irradiated with X-rays of a predetermined wavelength, and diffracted X-rays generated by scattering or interference by electrons belonging to atoms constituting the sample are detected by a detector. . The diffraction angle at this time depends on the lattice spacing of the substance, and the diffraction intensity depends on the arrangement state and atomic species of atoms and molecules. Therefore, when a sample is irradiated with X-rays of a known wavelength and the relationship between the diffraction angle and the X-ray intensity of the diffracted X-rays obtained from the sample is obtained, a peak of the X-ray intensity is observed near a predetermined diffraction angle. An X-ray diffraction pattern is obtained. By comparing the X-ray diffraction pattern obtained by such actual measurement with the X-ray diffraction patterns of known substances, substances contained in the sample can be identified (see Patent Document 1, etc.).

In the actual X-ray diffraction apparatus described in Non-Patent Document 2, etc., the standard X-ray diffraction pattern of the various substances recorded in the database and the measured X-ray diffraction patterns are combined by the identification software running on the computer. The similarity with the pattern is evaluated, and substances judged to have high similarity are displayed as identification candidates in a list on the screen of the display unit. The user, for example, confirms the consistency between the X-ray diffraction pattern of the identification candidate substance and the measured X-ray diffraction pattern on the screen, and furthermore, based on the knowledge and experience of the sample to be analyzed, In other words, it is determined whether or not the identification candidate is the correct substance.

JP 2018-21836 A

"Working Environment Measurement Guidebook 1: Mineral Dust, Asbestos, RCF", published 6th edition on September 25, 2018 by the Japan Working Environment Measurement Association "XRD-6100 Ideal for qualitative and quantitative analysis of free silicic acid and asbestos (asbestos) in working environments.", [online], Shimadzu Corporation, [searched March 26, 2019], Internet <URL: https: //www.an.shimadzu.co.jp/surface/xd/use04.htm>

However, the conventional X-ray diffraction apparatus has the following problems.
In general, the number of substances recorded in databases for substance identification in X-ray diffraction is very large. For example, the mineral subfile of "ICDD PDF-2 2018", a representative powder X-ray diffraction database used to identify asbestos, etc., contains a huge number of substances of about 30,000. In addition, many of the X-ray diffraction patterns of such a huge number of substances have very similar waveform shapes. As a result, an automated search in identification software usually results in a fairly large number of candidates.

When analyzing asbestos and free silicic acid contained in powder samples such as building materials, the samples contain various contaminants other than the target substances. Therefore, the substance candidate list includes many candidates for contaminants in addition to the target substance. Since the user needs to carry out the identification work while confirming the X-ray diffraction patterns one by one for such a large number of candidates, the work is very complicated and time consuming. Further, if the number of substance candidates to be listed is limited, target substance candidates such as asbestos and free silicic acid may be omitted from the list.

In particular, even if asbestos is usually contained in dust generated from construction sites, the content is often small. Therefore, in X-ray diffraction, the three strong lines that characterize the substance (up to the third peak in order of relative intensity) are often small, and therefore the standard X-ray diffraction pattern of the correct substance recorded in the database It may be difficult to identify as asbestos due to reduced similarity to

The present invention has been made to solve the above problems, and the object thereof is to identify specific substances such as asbestos and free silicic acid based on analysis results such as X-ray diffraction patterns, An object of the present invention is to provide an analysis device and an X-ray diffraction device that can reduce user's troublesome work and identify a substance efficiently and with high accuracy.

A first aspect of the analyzer according to the present invention, which has been made to solve the above problems, is an analyzer that identifies substances contained in a sample using a waveform pattern obtained by analyzing the sample. There is
A database containing standard waveform patterns of many known substances,
Evaluate the similarity between the measured waveform pattern obtained by analyzing the sample and the standard waveform pattern of each substance recorded in the database, and a substance that exhibits a highly similar standard waveform pattern. as an identification candidate; and
a first display field for displaying information on one or more identification candidates extracted by the candidate extraction unit; A display processing unit that creates a display screen in which a second display column for displaying information on the substance including the similarity evaluation result by the extraction unit is arranged and displays it on the display unit;
is provided.

A first aspect of the X-ray diffraction apparatus according to the present invention, which has been made to solve the above problems, uses an X-ray diffraction pattern obtained by analyzing a sample to identify substances contained in the sample. An X-ray diffraction device that
a database containing standard X-ray diffraction patterns of many known substances;
The similarity between the measured X-ray diffraction pattern obtained by analyzing the sample and the standard X-ray diffraction pattern of each substance recorded in the database is evaluated, and the standard X with high similarity a candidate extraction unit that extracts a substance exhibiting a line diffraction pattern as an identification candidate;
a first display field for displaying information on one or more identification candidates extracted by the candidate extraction unit; creating a display screen on which a second display column for displaying information of the substance including the similarity evaluation result in the extraction unit and a waveform display column for displaying the actually measured X-ray diffraction pattern are arranged; a display processing unit for displaying on the display unit;
is provided.

In addition, in the X-ray diffraction apparatus according to the present invention, the predetermined specific one or more substances can be substances classified into asbestos and free silicic acid.

In the analysis device or X-ray diffraction device according to the first aspect of the present invention, the object substance to be inspected, such as asbestos or free silicic acid, is predetermined to be displayed in the second display column, thereby achieving such a purpose. Even if many candidate substances for impurities with waveform patterns (X-ray diffraction patterns) that are more similar than substances are extracted, the user can display the result of the similarity evaluation of the target substance in the second display column. can be confirmed. As a result, the results of the similarity evaluation of the target substance can be used to quickly confirm the conformity of the waveform patterns as necessary, and to identify the target substance, that is, to determine whether or not the target substance is contained in the sample. can be checked efficiently.

In addition, the similarity between the measured waveform pattern and the standard waveform pattern of the target substance is relatively low, and if it is displayed in the first display column, it will be displayed in a considerably lower position or displayed due to restrictions on the number of displays. According to the present invention, the target substance is displayed in the second display field even if the target substance is not identified, so that it can be identified with high accuracy. Furthermore, for contaminants other than the target substance, based on the information displayed in the first display column, detailed identification work can be performed in the same manner as in the conventional method.

1 is a configuration diagram of a main part of an X-ray diffraction apparatus that is an embodiment of the present invention; FIG. FIG. 4 is an explanatory diagram of display processing of automatic search results in the X-ray diffraction apparatus of the present embodiment; FIG. 4 is a diagram showing an example of a display screen of automatic search results in the X-ray diffraction apparatus of the present embodiment;

An X-ray diffraction apparatus according to one embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a configuration diagram of the main part of the X-ray diffraction apparatus of this embodiment.
The X-ray diffraction apparatus of this embodiment includes an X-ray diffraction measuring section 1, a data processing section 2, an input section 3, and a display section 4, as shown in FIG.

The X-ray diffraction measurement unit 1 includes an X-ray irradiation unit 11 including an X-ray tube, a goniometer 12, a sample holder 13, and an X-ray detection unit 14. The sample 15 is placed so that its surface is at the center of the goniometer 12 . The goniometer 12 measures the angle θ formed between the X-ray incident on the sample 15 from the X-ray irradiation unit 11 and the surface (crystal plane) of the sample 15 and the output X-ray directed toward the X-ray detection unit 14 from the surface of the sample 15 . The sample holder 13 and the X-ray detector 14 are rotated so that the angle θ formed by them is always equal. An X-ray diffraction pattern can be obtained by performing such angular scanning and obtaining the relationship between the rotation angle 2θ and the X-ray intensity.
Note that the X-ray diffraction measuring unit 1 may be an energy dispersive X-ray diffraction device instead of such an angular scanning type X-ray diffraction device.

The data processing unit 2 includes, as functional blocks, an X-ray diffraction pattern creation unit 21, an identification database 22, a specific substance information storage unit 23, a substance search processing unit 24, a pattern similarity evaluation unit 25, a search result display processing unit 26, and so on. For the identification database 22, a database corresponding to the type of substance to be analyzed may be used. Mineral subfiles can be used. Although the identification database 22 is included in the data processing unit 2 in FIG. 1, the identification database 22 may be provided externally so as to be accessible from the data processing unit 2 .

It should be noted that the substance of the data processing unit 2 is usually a personal computer in which dedicated data processing software is installed. can do.

Next, a characteristic processing operation for analyzing asbestos/free silicic acid using the X-ray diffraction apparatus of this embodiment will be described with reference to FIGS. 1 and 2. FIG. FIG. 2 is an explanatory diagram of display processing of automatic search results in the X-ray diffraction apparatus of this embodiment.

The X-ray diffraction measurement unit 1 performs X-ray diffraction on a sample 15 to be analyzed, and the data obtained by the X-ray detection unit 14 is input to the data processing unit 2 . In the data processing unit 2, the X-ray diffraction pattern creating unit 21 creates an X-ray diffraction pattern waveform graph in which the horizontal axis is the diffraction angle and the vertical axis is the X-ray intensity. Further, the X-ray diffraction pattern generator 21 detects peaks in the graph according to a predetermined peak detection algorithm, and obtains line peaks corresponding to each of the detected peaks. The position of the line peak indicates the diffraction angle and the height of the line peak indicates the X-ray intensity at that diffraction angle.

The substance search processing unit 24 sequentially reads the information of the compounds recorded in the identification database 22, and the pattern similarity evaluation unit 25 obtains a standard X-ray diffraction pattern associated with each compound by the above actual measurement. Then, an index value (hereinafter referred to as "similarity") indicating the similarity of the waveform shape or line peak pattern is calculated according to a predetermined algorithm. The higher the similarity, the larger the value of the similarity. In a conventional X-ray diffractometer, for example, compounds having a degree of similarity equal to or higher than a predetermined threshold are selected from among all the compounds recorded in the identification database 22, and listed as candidate substances in descending order of degree of similarity. It is displayed on the screen of the display unit 4 . In contrast, the apparatus of this embodiment performs the following characteristic processing.

As shown in FIG. 2(a), the identification database 22 contains related information such as chemical formulas and information such as standard X-ray diffraction patterns for a huge number of compounds. On the other hand, the specific substance information storage unit 23 stores information of specific compounds designated in advance corresponding to the asbestos/free silicic acid analysis among the compounds recorded in the identification database 22 . The information stored in the specific substance information storage unit 23 only needs to be linked to the information recorded in the identification database 22. For example, only the compound name or the number specifying each compound (an example may store only the card number described in FIG. 3 to be described later). Alternatively, as shown in FIG. 2(b), the same information as that recorded in the identification database 22 may be stored for the designated specific compound.

In addition, since the above specific compounds differ depending on the purpose of analysis such as asbestos/free silicic acid analysis, for example, the manufacturer of this device or the manufacturer that provides the data processing software should predetermine the specific compounds for each purpose of analysis. should be In that case, when the user indirectly or directly selects the analysis purpose by using application software corresponding to the analysis purpose, it is preferable to automatically select a specific compound that meets the purpose. In addition, the user may be allowed to newly designate a specific compound, or to delete or add some of the specific compounds that have already been registered.

As an example, in the case of asbestos/free silicic acid analysis, a compound as described in Non-Patent Document 1 may be determined as a specific compound. Specifically, compounds (substances) classified as free silicic acid include quartz (Q), cristobalite (Cr), tridymite (Tr), and the like. Compounds (substances) classified as asbestos include chrysotile (Chr), crocidolite (Cro), amosite (Amo), tremolite (Tre), actinolite (Act), anthophyllite (Ant), sepiolite (Se), etc. is included.

The substance search processing unit 24 and the pattern similarity evaluation unit 25, like the conventional apparatus, convert the standard X-ray diffraction pattern associated with each compound stored in the identification database 22 into the measured X-ray diffraction pattern. It compares with the pattern and calculates the similarity of the waveform shape or line peak pattern according to a predetermined algorithm. Therefore, the degree of similarity is obtained for each compound recorded in the identification database 22 .

The search result display processing unit 26 creates a search result display screen 100 as shown in FIG. 2(c). A profile display field 101 , a post-processing graph display field 102 , a specific compound list display field 103 , and a general compound list display field 104 are arranged on the search result display screen 100 . A profile display field 101 displays a waveform graph (profile) of an X-ray diffraction pattern obtained by actual measurement. Since this profile is obtained before execution of the process by the substance search processing unit 24 , the profile is displayed in the profile display field 101 when a sample or the like to be subjected to identification processing is specified on the search result display screen 100 .

The specific compound list display field 103 displays a list showing the compound-related information and the degree of similarity of the above-described specific compounds. Although the degree of similarity cannot be obtained until the processing by the substance search processing unit 24 is completed, since the compounds in the list displayed in the specific compound list display column 103 are fixed, as described above, the profile display column 101 At the same time that the profile is displayed in the specific compound list display field 103, a list in which other compound-related information is posted except for similarity information may be displayed.

The general compound list display field 104 displays a list showing compound-related information and similarity for compounds whose similarity is equal to or higher than a predetermined threshold among all the compounds recorded in the identification database 22. be done. The compounds displayed in this list are not finalized until the processing by the substance search processing unit 24 is completed and the degree of similarity is obtained. Therefore, the list is displayed after the process by the substance search processing unit 24 is finished and the degree of similarity is obtained.

In addition, in the post-processing graph display field 102, a graph of line peaks calculated from the actually measured X-ray diffraction pattern, a list displayed in the specific compound list display field 103 and the general compound list display field 104, specified by the user A line peak graph of the standard X-ray diffraction pattern of the compound, a peak difference graph that is the result of calculating the difference between the two line peak graphs, an overlay of all peak graphs of the compounds determined to be contained, etc. is displayed. These graphs are used when the user confirms in detail the X-ray diffraction pattern of the candidate substance extracted as a result of the search to identify the compound.

Similarity of X-ray diffraction patterns for each compound (for example, compounds A, B, C, . . . in FIG. In response to this, the search result display processing unit 26 selects compounds whose similarity is equal to or higher than a predetermined threshold among all the compounds, and creates a list as candidate substances in descending order of similarity. It is displayed in the general compound list display column 104 .

In parallel with this, the search result display processing unit 26 displays the substance search processing unit 24 for each compound (for example, compounds a, b, c, . And the degree of similarity calculated by the pattern similarity evaluation unit 25 is selected, and a list of specific compounds is created and displayed in the specific compound list display field 103 . Alternatively, as described above, when the profile is displayed in the profile display field 101 and the list is displayed in the specific compound list display field 103 at the same time, the similarity of each compound is added to the list.

In the case of asbestos and free silicic acid analysis, this provides compound-related information and X-ray diffraction analysis of the compounds of interest to users such as quartz, cristobalite, tridymite, chrysotile, crocidolite, amosite, tremolite, actinolite, anthophyllite, and sepiolite. A list containing the degree of similarity of patterns as information is displayed in the specific compound list display field 103 separately from the list of other compounds. In the list displayed in the specific compound list display field 103, the order of each compound may be rearranged in descending order of the similarity value, or the compounds may be arranged in a predetermined order regardless of the degree of similarity. good. In any case, the list in the specific compound list display column 103 is also used for compounds whose amount contained in the sample is very small and the similarity between the measured X-ray diffraction pattern and the standard X-ray diffraction pattern is low. The compound information and similarity of the compound are displayed in .

FIG. 3 is a diagram showing an example of an actual search result display screen 100. As shown in FIG. The respective display columns 101 to 104 in the search result display screen 100 display graphs or lists as described above. R in the list is a value corresponding to similarity.

In this way, when the user designates one compound in the list displayed in the specific compound list display field 103 or in the list in the general compound list display field 104 by a click operation or the like using the input unit 3, the search result display processing unit 26 is the result of calculating the difference between the line peak graph obtained from the standard X-ray diffraction pattern of the designated compound and the line peak graph obtained from the measured X-ray diffraction pattern. The difference graph is displayed in the post-processing graph display field 102 . By checking these graphs, the user can, for example, examine in detail whether a specific compound in the list displayed in the specific compound list display field 103 is included in the sample.

On the other hand, in the list displayed in the general compound list display column 104, the compound-related information and similarity of various compounds including compounds other than asbestos and free silicic acid are displayed in descending order of similarity. . Therefore, identification of contaminants contained in the sample, such as main substances of building materials, can be performed in the same manner as before. If analysis of compounds other than asbestos and free silicic acid is unnecessary, the list displayed in the general compound list display column 104 can be ignored.

The substance search processing unit 24 and the pattern similarity evaluation unit 25 prioritize similarity between the standard X-ray diffraction pattern of each compound stored in the specific substance information storage unit 23 and the measured X-ray diffraction pattern. The search result display processing unit 26 displays the result in a list in the specific compound list display column 103, and then, the X-ray diffraction pattern for each compound recorded in the identification database 22. A degree of similarity may be calculated. This allows quick confirmation of search results for specific compounds classified as asbestos and free silicic acid.

It should be noted that the above-described embodiment is an example of the present invention, and any modifications, changes, and additions made within the scope of the present invention are obviously included in the scope of the claims of the present application.

For example, in the description of the above embodiments, the X-ray diffractometer was used for the analysis of asbestos and free silicic acid in the work environment measurement, but it is also possible to use the X-ray diffractometer for analysis in other fields such as product quality control. be done. In the case of product quality control, one or a plurality of compounds to be managed or reported may be selected as specific compounds, thereby improving the work efficiency of quality control.

In the above embodiment, the analysis apparatus according to the present invention is applied to an X-ray diffraction apparatus. , mass spectra, or chromatograms, comparing their waveform shapes and peak positions with standard graphs of known substances to evaluate similarities, and identifying substances based on the results can also be applied to the analyzer of

[Various aspects]
Those skilled in the art will appreciate that the exemplary embodiments described above are specific examples of the following aspects.

A first aspect of the analysis device according to the present invention is an analysis device that identifies a substance contained in the sample using a waveform pattern obtained by analyzing the sample,
A database containing standard waveform patterns of many known substances,
Evaluate the similarity between the measured waveform pattern obtained by analyzing the sample and the standard waveform pattern of each substance recorded in the database, and the substance that exhibits the standard waveform pattern with high similarity. as an identification candidate; and
a first display field for displaying information on one or more identification candidates extracted by the candidate extraction unit; A display processing unit that creates a display screen on which a second display column for displaying information on the substance including the similarity evaluation result by the extraction unit is arranged and displays it on the display unit;
is provided.

A first aspect of the X-ray diffraction apparatus according to the present invention is an X-ray diffraction apparatus for identifying substances contained in a sample using an X-ray diffraction pattern obtained by X-ray diffraction analysis of the sample. hand,
a database containing standard X-ray diffraction patterns of many known substances;
The similarity between the measured X-ray diffraction pattern obtained by analyzing the sample and the standard X-ray diffraction pattern of each substance recorded in the database is evaluated, and the standard X with high similarity a candidate extraction unit that extracts a substance exhibiting a line diffraction pattern as an identification candidate;
a first display field for displaying information on one or more identification candidates extracted by the candidate extraction unit; creating a display screen on which a second display column for displaying information of the substance including the similarity evaluation result in the extraction unit and a waveform display column for displaying the measured X-ray diffraction pattern are arranged; a display processing unit for displaying on the display unit;
is provided.

According to the analysis device or X-ray diffraction device according to the first aspect, by appropriately determining one or more specific substances according to the purpose of analysis, etc., the waveform pattern (X Even if many contaminant candidate substances with higher similarity in the diffraction pattern) are extracted, the user can confirm the similarity evaluation result of the specific substance from the information displayed in the second display column. can do. As a result, it is possible to identify the target substance, that is, to efficiently confirm whether or not the sample contains the target substance with little effort. That is, it is possible to reduce the user's work load for identifying substances in the sample and shorten the work time.

In addition, even if the similarity of the waveform patterns (X-ray diffraction patterns) is low because the amount of the target substance in the sample is very small, it is possible to identify such substances as candidate substances without omission. It can be performed. Thereby, substance identification in the sample can be performed with high accuracy. Of course, it is also possible to carry out detailed identification work in the same manner as in the conventional method for contaminants other than the target substance.

An X-ray diffraction apparatus according to a second aspect of the present invention is the X-ray diffraction apparatus according to the first aspect, wherein the specific one or more substances are substances classified as asbestos and free silicic acid. be able to.

According to this second aspect, qualitative analysis and quantitative analysis of asbestos and free silicic acid in working environment measurement can be efficiently performed.

REFERENCE SIGNS LIST 1 X-ray diffraction measurement unit 11 X-ray irradiation unit 12 Goniometer 13 Sample holder 14 X-ray detection unit 15 Sample 2 Data processing unit 21 X-ray diffraction pattern creation unit 22 Identification database 23 Identification Substance information storage unit 24 Substance search processing unit 25 Pattern similarity evaluation unit 26 Search result display processing unit 3 Input unit 4 Display unit 100 Search result display screen 101 Profile display field 102 Post-processing graph display field 103 -- Specific compound list display field 104 -- General compound list display field

Claims (4)

An analyzer that identifies substances contained in a sample using a waveform pattern obtained by analyzing the sample,
A database containing standard waveform patterns of many known substances,
Evaluate the similarity between the measured waveform pattern obtained by analyzing the sample and the standard waveform pattern of each substance recorded in the database, and a substance that exhibits a highly similar standard waveform pattern. as an identification candidate; and
a first display field for displaying information on one or more identification candidates extracted by the candidate extraction unit; Display processing for creating a display screen in which a second display column for displaying information of the substance including the similarity evaluation result in the extraction unit is arranged on the same screen , and displaying the display screen on the display unit Department and
Analyzer with 2. The method according to claim 1, further comprising a substance designation unit for the user to designate a new substance as the one or more specific substances, or to delete or add a part of a specific substance that has already been registered. Analysis equipment. An X-ray diffraction apparatus for identifying substances contained in a sample using an X-ray diffraction pattern obtained by X-ray diffraction analysis of the sample,
a database containing standard X-ray diffraction patterns of many known substances;
The similarity between the measured X-ray diffraction pattern obtained by analyzing the sample and the standard X-ray diffraction pattern of each substance recorded in the database is evaluated, and the standard X with high similarity a candidate extraction unit that extracts a substance exhibiting a line diffraction pattern as an identification candidate;
a first display field for displaying information on one or more identification candidates extracted by the candidate extraction unit; A display screen in which a second display column for displaying information of the substance including the similarity evaluation result in the extraction unit and a waveform display column for displaying the actually measured X-ray diffraction pattern are arranged on the same screen. and a display processing unit that displays the display screen on the display unit;
An X-ray diffraction device comprising: 4. The X-ray diffraction apparatus according to claim 3 , wherein said one or more specific substances are substances classified as asbestos and free silicic acid.

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