Sample plate holder for mass spectrometer

Abstract

A sample plate holder (6) for a mass spectrometer is provided with: biasing members (631-633) that press one surface of a sample plate toward the other surface at three locations that are not positioned on the same straight line; and abutting members (612-614) that abut the other surface of the sample plate (5) at positions corresponding to the three locations in plan view. This sample plate holder (6) can be preferably used in a mass spectrometer (1) provided with a laser irradiation unit (13) for irradiating a sample placed on a sample plate with laser light, and a mass spectrometer unit (30) for mass-analyzing ions generated from the sample (S) by irradiation with the laser light.

Description

Technical Field

[0001] The present invention relates to a sample plate holder for holding a sample plate used in a mass spectrometer that irradiates a sample with laser light and performs mass analysis on ions generated from the sample. Background Art

[0002] In order to measure the distribution of the target substance in the sample, imaging mass analysis using a mass spectrometer equipped with MALDI is performed (for example, Patent Document 1). MALDI is an ion source that ionizes a sample by a matrix-assisted laser desorption / ionization method.

[0003] In the imaging mass analysis using MALDI, a pretreatment is performed by coating the surface of the sample placed on the sample plate with a matrix substance as a substance that is easily ionized, so that the surface of the sample forms microcrystals of the matrix substance into which the molecules of the sample are taken. If the sample plate carrying the pretreated sample is set at a specified position of MALDI and the sample surface is irradiated with laser, the microcrystals of the matrix substance are heated, and the sample molecules are separated and ionized. The ions generated from the sample molecules are taken into the mass analysis unit, and are separated and detected according to each mass-to-charge ratio by measuring the difference in speed after acceleration by the electric field, and a mass spectrum with the horizontal axis being the mass-to-charge ratio and the vertical axis being the signal intensity is obtained. By performing such ionization and mass analysis processes at multiple measurement points located two-dimensionally on the sample surface, the mass spectrum of each measurement point can be obtained. By making the intensity of the mass spectrum peak corresponding to the target substance on the mass spectrum obtained at each measurement point correspond to each measurement point (mapping), an image showing the distribution of the target substance on the sample surface can be obtained.

[0004] In imaging mass analysis, in order to irradiate each measurement point with a laser of the highest energy density that maximizes the ionization efficiency of the sample, the laser is focused by a focusing optical system such as a lens or a concave mirror. Therefore, if the height of the sample plate deviates from the predetermined position, the energy density of the laser irradiated to the sample surface decreases, the ionization efficiency deteriorates, and the measurement sensitivity decreases. In addition, the irradiation spot diameter of the laser irradiated to the sample surface increases, and the spatial resolution of the mass distribution image decreases. Therefore, in MALDI, the sample plate needs to be fixed at a specified position and height.

[0005] In order to fix the sample plate at the specified position and height of MALDI, a sample plate holder is used. The sample plate holder has various forms. Non-patent document 1 describes a sample plate holder, which uses a push-out pin located below the center of the two short sides of a rectangular sample plate to push the sample plate upward, so that the two ends of the short side of the upper surface of the sample plate abut against the abutment surface provided on the sample plate holder to fix the sample plate. Non-patent document 2 describes a sample plate holder, which inserts an extension portion provided in a manner extending outward along the two long sides of the rectangular sample plate into an insertion groove provided in MALDI, and fixes the sample plate by pushing the center of the lower surface of the sample plate upward by a compression spring. Non-patent document 3 describes a sample plate holder, which uses a compression spring to push the center of the lower surface of the two short sides of a rectangular sample plate upward, so that the upper surface of the sample plate abuts against the protruding edge provided above it to hold the sample plate.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2021-196303

[0009] Non-patent literature

[0010] Non-patent document 1: "rapifleXR MALDI TissuetyperR", [Online], Bruker Corporation, [retrieved on July 6, 2022], Internet <URL:https: / / www.bruker.com / ja / products-and-solutions / mass-spectro metry / maldi-tof / rapiflex-maldi-tissuetyper.html>

[0011] Non-patent document 2: "Desktop Linear Dedicated Machine MALDI-8020", [Online], Shimadzu Corporation, [retrieved on July 6, 2022], Internet<URL:https: / / www.an.shimadzu.co.jp / ms / maldi8020 / index.htm>

[0012] Non-patent document 3: “Imaging Quality Microscope iMScope QT”, [Online], Shimadzu Corporation, [retrieved on July 6, 2022], Internet<URL:https: / / www.an.shimadzu.co.jp / bio / imscope_qt / index.htm> Summary of the invention

[0013] Technical problem to be solved by the invention

[0014] In the sample plate holders of non-patent documents 1 and 2, the point (position) where the sample plate is pushed up from below by the push pin or the compression spring and the point (position) where the upper surface of the sample plate contacts the sample plate holder are at different positions when viewed from above. In these sample plate holders, the positions where the force is applied to the sample plate from below and from above are different, so strain is generated in the sample plate. For example, a sample plate obtained by coating the surface of glass with a conductive film has a thickness of about 1 mm, but even then, the sample plate may sometimes generate a strain of about tens of μm in the height direction due to such force.

[0015] In imaging mass analysis, in most cases, the laser is irradiated to the surface of the sample plate from an oblique direction. Therefore, if there is strain on the sample plate, the laser will be irradiated to a position that deviates from the original measurement point. If the position of the measurement point deviates, even if an image showing the distribution of the target substance on the sample surface is produced from the mass analysis data obtained at each measurement point, an image showing the correct distribution of the target substance cannot be obtained. In addition, when strain is generated in the height direction of the sample plate, the height of the sample placed on its surface also deviates, and as mentioned above, the measurement sensitivity is reduced or the spatial resolution is deteriorated.

[0016] In addition, in vacuum MALDI-TOF (both MALDI and TOF are housed in a vacuum chamber), ions generated by MALDI are directly introduced into the flight space, so the deviation of the height of the sample surface is directly related to the deviation of the flight distance, resulting in a decrease in mass accuracy in mass analysis. Furthermore, in a mass spectrometer equipped with atmospheric pressure MALDI, in order to maintain a high vacuum in the vacuum chamber provided with a mass analysis unit, the diameter of the ion inlet is set to a minimum size (e.g., about several mm), and if the position of the measurement point deviates, the amount of ions introduced into the ion inlet is reduced, and the measurement sensitivity is reduced.

[0017] In the sample plate holder of non-patent document 3, when there is a slight strain on the lower surface of the extension piece due to tolerance in manufacturing the sample plate holder, or when the lower surfaces of the two extension pieces are not parallel, the upper surface of the sample plate and the lower surface of the extension piece are partially in contact at a point. If the point where the sample plate is pushed up from below by the compression spring and the point where the upper surface of the sample plate and the lower surface of the extension piece are in contact are in different positions when viewed from above, the sample plate is strained as in the sample plates of non-patent documents 1 and 2, resulting in the same problem as described above.

[0018] The technical problem to be solved by the present invention is to provide a sample plate holder for a mass analysis device that can hold a sample plate in a manner that does not generate strain.

[0019] Solutions for solving the above technical problems

[0020] The sample plate holder for a mass spectrometer of the present invention, which is completed in order to solve the above-mentioned technical problems, comprises:

[0021] a force applying member pressing one surface of the sample plate at three locations that are not located in a straight line; and

[0022] The contact member contacts the other surface of the sample plate at positions corresponding to the three locations in plan view.

[0023] Effects of the Invention

[0024] In the sample plate holder of the present invention, the force-applying member presses the other surface (e.g., the lower surface) of the sample plate at three locations (three points) that are not located on a straight line, so that the sample plate abuts against the abutting member at positions corresponding to the three locations when viewed from above. In the sample plate holder of the present invention, the force point pressing the sample plate and the fulcrum abutting against and supporting the sample plate are located at positions corresponding to each other when viewed from above, so that the sample plate does not generate strain. In addition, a single plane is defined by three points that are not located on a straight line, so by using the sample plate holder of the present invention, the sample plate can be maintained in a manner such that the surface of the sample plate is always at the same position and height. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a diagram showing the main components of a mass spectrometer using the sample plate holder of the present invention.

[0026] Figure 2 This is an external view of the sample plate holder according to the first embodiment.

[0027] Figure 3 It is a diagram for explaining the structure of the upper frame member of the sample plate holder according to the first embodiment.

[0028] Figure 4 It is a cross-sectional view of the sample plate holder according to the first embodiment.

[0029] Figure 5 It is a diagram for explaining the structure of an upper frame member of a sample plate holder according to a modified example of the first embodiment.

[0030] Figure 6 It is a diagram for explaining the shape of the compression spring of the sample plate holder according to the second embodiment.

[0031] Figure 7 This is an enlarged view of the contact portion between the sample plate holder and the sample plate according to the second embodiment.

[0032] Figure 8 It is a figure explaining the state which warped the sample plate.

[0033] Fig. 9 It is a diagram for explaining the structure of a sample plate holder according to the third embodiment.

[0034] Fig.10 This is an enlarged view of the contact portion between the sample plate holder and the sample plate according to the third embodiment.

[0035] Fig.11 This is a diagram for explaining how the sample plate holder according to the third embodiment holds the sample plate without causing warping.

[0036] Fig.12 It is a diagram for explaining the tapered portion of the protruding portion in the sample plate holder according to the third embodiment.

[0037] Fig.13 It is a diagram for explaining a modified example of the third embodiment in which the compression spring is fixed by being tilted. DETAILED DESCRIPTION

[0038] Hereinafter, embodiments of a sample plate holder for a mass spectrometer according to the present invention will be described with reference to the drawings.

[0039] Figure 1 1 is a diagram showing the main components of a mass spectrometer using a sample plate holder of each embodiment described below. The mass spectrometer 1 is a MALDI-TOF MS. That is, it has an ion source (in this embodiment, vacuum MALDI) that ionizes a sample by a matrix-assisted laser desorption / ionization method, and a time-of-flight mass spectrometer that allows ions generated by the ion source to fly and separate and detect them according to their mass-to-charge ratio.

[0040] The mass spectrometer 1 of the present embodiment comprises: a workbench 12 provided with a sample plate holder 6 for holding a sample plate 5 on which a sample S is placed; a laser irradiation unit 13 for emitting laser light; a concave reflection mirror 14 for focusing the laser light emitted from the laser irradiation unit 13 on the sample S; and a photographing unit 17 for photographing the sample S. In addition, a workbench driving unit 18 is provided, including a control unit for moving the workbench 12 to a photographing position of the sample S (at a position where the sample S is photographed). Figure 1 left side) and measurement position (on Figure 1 The workbench moves between the right and left sides of the measuring position, and moves the workbench in the horizontal direction ( Figure 1 A motor that moves in the two directions of the X-axis and the Y-axis.

[0041] In addition, directly above the measurement position of the workbench 12, there are: an accelerating electrode 21 for upwardly extracting and accelerating ions generated from the sample S placed on the sample plate holder 6; and an ion lens 22 as an ion transport optical system for transporting ions accelerated by the accelerating electrode 21 to the mass spectrometer 30 described later.

[0042] The mass spectrometer 30 has a reflective structure, including: a flight tube 31, which is a cylindrical electrode that defines a free flight space where ions can fly freely without being affected by an electric field; a reflector 32, which is a ring-shaped electrode that causes ions to return to flight by the action of a DC electric field; and a back plate 33, which is a disk-shaped electrode. An ion detector 34 is arranged at the terminal of the flight path of the ions defined by these electrodes. The detection signal of the ion detector 34 is converted into digital data by an analog-to-digital converter (not shown) and input into the control and processing unit 40.

[0043] The above-mentioned components are housed in the chamber 10. The chamber 10 is located Figure 1 The gate valve 19 at the lower position shown by the dotted line in the middle divides the space into an atmospheric pressure space including the imaging position of the sample S and a vacuum space including the measurement position and the mass spectrometer 30. When the stage 12 is moved between the imaging position and the measurement position, the gate valve 19 is released (moved to the position where the sample S is imaged). Figure 1 The upper position indicated by the solid line in the middle). The vacuum space is evacuated by a vacuum pump (not shown). Here, for ease of explanation, the chamber 10 is divided into an atmospheric pressure space and a vacuum space. However, in addition to the atmospheric pressure space for photographing the sample S and the high vacuum space for mass analysis of ions, one or more spaces with intermediate vacuum degrees can be appropriately set between the two.

[0044] The control and processing unit 40 is provided with a storage unit 41. The storage unit 41 stores a compound database including information such as measurement conditions and analytical parameters of various compounds, information (mass conversion information) for converting the flight time of ions into the mass-to-charge ratio of ions, etc. In addition, the control and processing unit 40 has a measurement control unit 42 for controlling the actions of the above-mentioned units to perform measurements, and an analytical processing unit 43 for analyzing the data obtained by the measurements. The control and processing unit 40 is composed of, for example, a conventional computer, and these functional blocks are realized by executing pre-installed dedicated software by a processor. An input unit 44 for the user to input appropriate information and a display unit 45 for displaying various information are connected to the control and processing unit 40.

[0045] Next, the flow of performing imaging mass analysis on a sample in the mass spectrometer 1 of the present embodiment is described. The measurement of the sample for imaging mass analysis is performed by the control of each part by the measurement control unit 42 (e.g., applying voltage to each electrode from a power supply not shown in the figure), and the analysis of the data obtained by the measurement is performed by the analysis processing unit 43.

[0046] The user first places a sample S to be analyzed on the sample plate 5 and applies a matrix substance, which is a substance that is easily ionized, on the surface of the sample S. Thus, microcrystals of the matrix substance in which molecules of the sample S are incorporated are formed on the surface of the sample S.

[0047] Next, the sample plate 5 carrying the processed sample S is held on the sample plate holder 6 and placed on the workbench 12. Then, the workbench 12 is arranged at the photographing position of the sample S, and the surface of the sample S on the sample plate holder 6 is photographed. The image acquired by the photographing unit 17 is displayed on the screen of the display unit 45. The user confirms the screen and sets a region of interest (ROI) for imaging quality analysis, and sets a plurality of measurement points two-dimensionally (e.g., in a grid pattern) in the region of interest.

[0048] After multiple measurement points are set in the region of interest, if the user instructs the start of measurement, the gate valve 19 is released, and the workbench 12 is moved from the shooting position of the sample S to the measurement position by the workbench drive unit 18. When the workbench moves to the measurement position, a specified voltage (including grounding) is applied to the sample plate 5 and the sample plate holder 6. As a result, a potential gradient is formed between the sample plate 5 and the sample plate holder 6 and the accelerating electrode 21. Thereafter, the workbench 12 is moved by the workbench drive unit 18 so that the initial measurement point is located at the irradiation position of the laser. Then, the laser is irradiated from the laser irradiation unit 13, reflected and focused by the concave reflector 14, and the focused laser is irradiated to the initial measurement point.

[0049] By irradiating the focused laser light, the microcrystals of the matrix material are heated and the sample molecules are ionized at the measurement point of the sample S. The ions generated at the measurement point of the sample S are drawn upward and accelerated by the potential gradient between the sample plate 5 and the accelerating electrode 21 .

[0050] The ions drawn out above the sample S are converged by the ion lens 22 along the central axis of the flight direction (ion optical axis C) and transported to the mass analysis unit 30. The ions entering the mass analysis unit 30 travel straight in the free flight space surrounded by the flight tube 31, then return in the space surrounded by the reflector 32 and enter the ion detector 34. In the ion detector 34, signals corresponding to the amount of incident ions are sequentially output. The signal output from the ion detector 34 is digitally converted and sent to the control and processing unit 40.

[0051] At the initial measurement point, when a series of measurements from laser irradiation to ion detection are completed, the workbench drive unit 18 moves the workbench 12 so that the next measurement point is located at the laser irradiation position. Then, the laser is irradiated from the laser irradiation unit 13, and the concave reflector 14 reflects and focuses the laser light, thereby irradiating the focused laser light to the second measurement point. After that, the mass spectrum data of the second measurement point is obtained by the same process as above. When the above series of measurements are completed for all measurement points, the measurement operation is terminated.

[0052] In the control and processing unit 40, the flight time of the ions is converted into the mass-to-charge ratio of the ions based on the mass conversion information stored in the storage unit 41, and mass spectrum data is generated that corresponds the measurement intensity to the mass-to-charge ratio of the ions. The generated mass spectrum data is stored in the storage unit 41 in correspondence with the position information of the measurement point.

[0053] After the mass spectrum data of each measurement point is prepared and saved, for example, when the user inputs the mass-to-charge ratio of the ion unique to the specified target substance, the analysis processing unit 43 extracts the information of the measured intensity of the ion of the mass-to-charge ratio from the mass spectrum data obtained at each measurement point. Then, image data that can identifiably display the measured intensity of the ion (for example, annotated with a color or shade corresponding to the measured intensity) is generated at the position of each measurement point, and the image is displayed on the screen of the display unit 45. The user can know the distribution of the target substance in the sample S by confirming the image displayed on the screen of the display unit 45.

[0054] Next, refer to Figure 2 to Figure 4 The sample plate holder 6 according to the first embodiment will be described. Figure 2 1 is an appearance diagram of the sample plate holder 6 holding the sample plate 5 (the left diagram is a diagram viewed from above, and the right diagram is a diagram viewed from below). Figure 3 This is a diagram of the upper frame member 61 as viewed from the bottom. Figure 4 6 is an A-A' cross-sectional view of the sample plate holder 6. In addition, in the various figures used in the following description, in order to make the relationship and shape of each component easy to understand, each component is appropriately illustrated with a scale different from the actual one, or the shape is exaggerated. In addition, "up and down" in the present specification is recorded for the convenience of description and does not limit the direction when the sample plate holder is used.

[0055] The sample plate holder 6 is roughly composed of an upper frame member 61 and a lower frame member 62 , which are fixed by screws 64 and 65 .

[0056] The upper frame member 61 is generally rectangular in shape, and is a frame member with an opening from the center to one long side, and a protruding piece 611 (equivalent to a reinforcing member described later) having a flat upper surface extending inward is formed at the upper end of the two short sides. The central opening has a size corresponding to the area on the sample plate 5 where the sample S is placed.

[0057] Two contact surfaces are provided on the back of the extension piece 611 on one short side (first short side) of the upper frame member 61. The contact surface is a portion that contacts the upper surface of the sample plate 5 when the sample plate 5 is held, and is formed by extension portions 612 and 613 (equivalent to the contact member in the present invention) that extend further to the back side than other portions of the extension piece 611 (refer to Figure 3). In addition, a contact surface is provided on the back side of the extension piece 611 on the other short side (second short side) of the upper frame member 61. The contact surface is also a portion that contacts the upper surface of the sample plate 5 while the sample plate 5 is held, and is formed by an extension portion 614 (equivalent to the contact member in the present invention) that extends further to the back side than other portions of the extension piece 611.

[0058] The lower frame member 62 is a substantially rectangular member slightly larger in shape than the upper frame member 61 and has an opening in the center. A gripping portion 621 for gripping the sample plate holder 6 when conveying the sample plate holder 6 is provided on one short side thereof.

[0059] On one short side (the first short side) of the lower frame member 62, compression springs 631 and 632 (equivalent to the force applying member in the present invention) are installed at positions below the two extensions 612 and 613 in a plan view to apply force to the sample plate 5 upward. In addition, on the other short side (the second short side) of the lower frame member 62, a compression spring 633 (equivalent to the force applying member in the present invention) is also installed at a position below the extension 614 in a plan view to apply force to the sample plate 5 upward. The compression springs 631, 632, and 633 of this embodiment are all leaf springs with a curved cross section (see Figure 4 ), one end is fixed to the lower surface of the lower frame member 62 by a screw 65 in such a way that the bent portion faces the upper frame member 61 side.

[0060] When the sample plate 5 is held by the sample plate holder 6, the sample plate 5 is inserted between the upper frame member 61 and the lower frame member 62 from the long side opening of the upper frame member 61. The inserted sample plate 5 is pushed up at three locations (three points) by the compression springs 631, 632, and 633 toward the upper frame member 61. The upper surface of the sample plate 5 pushed up to the upper frame member 61 is held in a state of contact with the extensions 612, 613, and 614 at three locations (three points).

[0061] When imaging mass analysis is performed as in the present embodiment, the laser is focused and irradiated in order to irradiate each measurement point with a laser of an energy density that maximizes the amount of ions generated from each measurement point of the sample S (maximizes the ionization efficiency). Therefore, when the height of the sample plate 5 deviates from the predetermined position, the energy density of the laser irradiated to the surface of the sample S decreases, the ionization efficiency deteriorates, and the measurement sensitivity decreases. In addition, the irradiation spot diameter of the laser irradiated to the surface of the sample S becomes larger, and the spatial resolution of the mass distribution image decreases. Therefore, in MALDI, it is necessary to fix the sample plate at a specified position and height.

[0062] However, in the sample plate holder used in the past, the position where the force is applied to the sample plate from the top is different from the position where the force is applied to the sample plate from the bottom, so there is a case where the sample plate is held in a strained state. For example, the sample plate used is a sample plate obtained by coating a conductive film on the surface of glass. The sample plate 5 has a thickness of about 1 mm, but in the previous sample plate holder, a strain of about tens of μm in height is sometimes generated due to such a force.

[0063] In particular, in the MALDI structure in which the laser is irradiated to the surface of the sample plate 5 from an oblique direction as in the present embodiment, when there is strain on the sample plate 5, the laser will be irradiated to a position deviated from the original measurement point. If the position of the measurement point is deviated, even if an image showing the distribution of the target substance on the surface of the sample S is produced from the mass analysis data obtained at each measurement point, an image showing the correct distribution of the target substance cannot be obtained. In addition, when strain is generated in the height direction of the sample plate 5, the height of the sample S placed on its surface is also deviated, and as described above, the measurement sensitivity is reduced or the spatial resolution is deteriorated.

[0064] In addition, in the vacuum MALDI-TOF such as the present embodiment, the ions generated by MALDI are directly introduced into the flight space, so the deviation of the height of the surface of the sample S is directly related to the deviation of the flight distance. As a result, the mass accuracy in the mass analysis is reduced. This problem also occurs in the mass analysis without imaging (for example, in the mass analysis in which the samples mixed with the matrix material are placed in the multiple holes (wells) provided in the sample plate and measured).

[0065] This embodiment is a mass spectrometer equipped with vacuum MALDI, but in a mass spectrometer equipped with atmospheric pressure MALDI, in order to maintain a high vacuum in the vacuum chamber, the diameter of the small hole that divides the atmospheric pressure space for irradiating the sample with laser light and the vacuum space for mass analysis of ions generated from the sample is set to a minimum size (e.g., about several mm). Therefore, when the position of the measurement point deviates, the amount of ions passing through the small hole decreases, and the measurement sensitivity decreases.

[0066] In contrast, in the sample plate holder 6 of the first embodiment, the compression springs 631, 632, and 633 are provided at positions corresponding to the extensions 612, 613, and 614, respectively (positions below the extensions 612, 613, and 614 in a plan view). When the sample plate holder 6 is used to hold the sample plate 5, since force is applied from above and below the sample plate 5 at the same position, the sample plate holder 6 can hold the sample plate 5 without causing strain. In addition, since a single plane is defined by three points that are not located on a straight line, the sample plate holder 6 can be used to hold the sample plate 5 so that the surface of the sample plate 5 is always at the same position and height.

[0067] Furthermore, in the sample plate holder 6 of the first embodiment, the sample plate 5 is held on the sample plate holder 6 at two points along one short side and one point along the other short side. More generally, at least one abutment portion (a portion where the sample plate 5 is held on the sample plate holder 6) is provided in each of two regions divided by a plane passing through the center of gravity of the sample plate 5 and perpendicular to the surface of the sample plate 5. Therefore, compared with a case where three abutment portions are provided in only one of the two regions, the sample plate 5 can be stably held.

[0068] The sample plate holder 6 of the first embodiment is designed based on the technical concept of holding the sample plate 5 from above and below at three points that are not in a straight line as described above, and a sample plate holder that meets this technical concept can be configured without necessarily providing the extension piece 611 .

[0069] Figure 5 The structure of the upper frame member 71 of the sample plate holder 7 according to the modification is shown. The lower frame member of the sample plate holder 7 according to the modification has the same structure as the lower frame member 62 of the above-mentioned embodiment, and therefore the description thereof is omitted.

[0070] like Figure 5 As shown, the upper frame member 71 does not include a member corresponding to the extended piece 611 in the above embodiment, but only includes members corresponding to the extended portions 612, 613, and 614. By using the sample plate holder 7 having such a configuration, the sample plate 5 can be held without generating strain.

[0071] However, when a voltage is applied to the sample plate 5 and the sample plate holder 6 to form a potential gradient with the accelerating electrode 21 (in the case of vacuum MALDI) or the partition wall (in the case of atmospheric pressure MALDI), if the height difference between the upper surface of the sample plate 5 and the upper surface of the sample plate holder 6 becomes large, there is a possibility that the electric field will be disturbed in this part. Therefore, it is necessary to make the extension piece 611 of the sample plate holder 6 as thin as possible. In the sample plate holder 6 of the above embodiment, the thickness of the extension piece 611 is set to 0.5 mm, and the thickness of the extension parts 612, 613, and 614 is set to 0.1 mm. That is, the height difference between the upper surface of the sample plate 5 and the upper surface of the sample plate holder 6 is suppressed to 0.6 mm.

[0072] In the sample plate holder 7 of the modified example, if the extensions 612, 613, 614 are made thinner in order to reduce the height difference between the upper surface of the sample plate 5 and the upper surface of the sample plate holder 6, the strength of each extension 612, 613, 614 is insufficient, and there is a possibility that the extensions 612, 613, 614 will be deformed or damaged during repeated use. In addition, since there is a height difference between the portion where the extensions 612, 613, 614 are provided and the portion where the extensions are not provided on the upper surface of the upper frame member 71 of the sample plate holder 7, there is a possibility that the electric field is disturbed. Considering these points, it is preferable to provide an extension piece 611 having a flat upper surface as in the sample plate holder 6 of the above-mentioned embodiment, and to form the extensions 612, 613, 614 integrally with the extension piece 611.

[0073] When the sample plate 5 is held by the sample plate holders 6 and 7, the strain (warping or twisting) of the sample plate 5 can be suppressed compared with the conventional sample plate. However, the inventors have conducted further research and found a structure that can more reliably suppress the strain of the sample plate 5. Figures 6 to 12 The sample plate holder 8 will be described. In the following description, the same components as those of the sample plate holder 6 are denoted by the same reference numerals, and the description thereof will be appropriately omitted.

[0074] This study was conducted using the sample plate holder 8 of the second embodiment. Figures 6 to 8 The sample plate holder 8 according to the second embodiment will be described. Figure 6 The upper part is a diagram showing the state of the compression springs 631 and 832 as viewed from the upper surface side of the sample plate holder 8. Figure 6 The lower part is a diagram of the compression springs 631 and 832 observed from the outside of the short side of the sample plate holder 8. A plate-shaped fixing portion 834 for fixing the compression springs 631 and 832 is provided on the base side of each of the compression springs 631 and 832, and an opening 8341 for inserting the screw 65 is formed in the fixing portion 834. As shown in these figures, the compression spring 631 is a straight leaf spring, and on the other hand, the compression spring 832 has a straight portion 8321 and an extension portion 8322 extending from the straight portion 8321 to the compression spring 631 side, and the extension portion 8322 abuts against the sample plate 5. In addition, Figure 6 The single-dot chain lines in φ indicate the positions where the compression springs 631 , 832 abut against the extensions 612 , 613 .

[0075] Figure 7 It is an enlarged view of the contact portion between the compression springs 832 and 633 of the sample plate holder 8 and the sample plate 5 , and the contact portion between the sample plate 5 and the extension portions 613 and 614 .

[0076] In the sample plate holder 8, a wall portion 86 (equivalent to the side member in the present invention) is erected from the extension piece 611 toward the lower frame member 62 on the outside of the side surface of one short side of the sample plate 5 (the surface on the side where the compression springs 631 and 832 are located), and a leaf spring 87 is arranged on the outside of the side surface of the other short side (the surface on the side where the compression spring 633 is located) to press the side surface of the other short side of the sample plate 5 toward the wall portion 86. In the sample plate holder 8, the extension piece 611 and the wall portion 86 are composed of one member, but they can also be composed of different members. Therefore, even if the length of the long side direction of the sample plate 5 of each manufacturer is different, the two side surfaces of the sample plate 5 can be clamped and stably held by the wall portion 86 and the leaf spring 87.

[0077] In the sample plate holder 8, the compression springs 631, 832 and the compression spring 633 are also installed near the two ends of the long side of the lower frame member 62 of the sample plate holder 8 by two screws 65, respectively. At this time, due to the processing error when manufacturing the sample plate holder 8, the surface accuracy of the spring mounting portion of the lower frame member 62 is sometimes deteriorated. As a result, the compression springs 631, 832 or the compression spring 633 are installed obliquely. If the compression springs 631, 832, 633 are installed obliquely in a manner away from the sample plate 5 toward the inside, the outer ends of the compression springs 631, 832, 633 abut against the sample plate 5. On the other hand, if the compression springs 631, 832, 633 are installed obliquely in a manner close to the sample plate 5 toward the inside, the inner ends of the compression springs 631, 832, 633 abut against the sample plate 5.

[0078] In addition, due to the processing error when manufacturing the sample plate holder 6, the contact surface of the extension parts 612 to 614 (the surface that contacts the sample plate 5) is sometimes inclined. If the contact surface of the extension parts 612 to 614 is inclined inwardly away from the surface of the sample plate 5, the outer end (base) of the extension parts 612 to 614 contacts the sample plate 5. On the other hand, if the extension parts 612 to 614 are inclined inwardly close to the sample plate 5, the inner end (front end) of the extension parts 612 to 614 contacts the sample plate 5.

[0079] So, it may produce Figure 8 Status shown. Figure 8 The sample plate holder 8 holding the sample plate 5 is equivalent to Figure 2 In addition, Figure 8 Invert the upside down. Figure 8 The lower surface of the middle sample plate holder 8 is located at the top. Figure 8The upper part is in a state where the outer ends of the compression springs 832 and 633 abut against the sample plate 5, and the front ends of the extensions 613 and 614 abut against the sample plate 5. If the sample plate 5 is held in this state, a slight deviation occurs between the position where the compression springs 832 and 633 press the sample plate 5 and the position where the sample plate 5 is supported by the extensions 613 and 614. As a result, the sample plate 5 warps downward.

[0080] Figure 8 The lower part is in a state where the inner ends of the compression springs 832 and 633 abut against the sample plate 5, and the bases of the extensions 613 and 614 abut against the sample plate 5. When the sample plate 5 is held in this state, there is a slight deviation between the position where the compression springs 832 and 633 press the sample plate 5 and the position where the sample plate 5 is supported by the extensions 613 and 614. As a result, the sample plate 5 warps upward.

[0081] As described above, in order to more reliably avoid the occurrence of warping in the sample plate 5 due to processing errors during manufacturing, the sample plate holder 9 of the third embodiment is further improved and configured.

[0082] Fig. 9 The structure of the sample plate holder 9 according to the third embodiment is shown. Fig. 9 The upper part is a view of the sample plate holder 9 viewed from the bottom. Fig. 9 The lower part is a cross-sectional view showing the structure of the spring mounting portion. In the following description, the same reference numerals are given to the components common to the sample plate holders 6 and 8, and detailed description thereof will be omitted.

[0083] In the sample plate holder 9, the spring mounting surface 9211 of the lower frame member 92 is inclined relative to the horizontal. More specifically, it is inclined 5 degrees relative to the horizontal in a manner that the wall becomes thicker toward the inner side of the sample plate holder 9. In addition, a threaded hole is formed perpendicularly to the inclined surface. Therefore, when the compression springs 631, 832, and 633 are installed, they are also installed in a state of being inclined 5 degrees relative to the horizontal plane.

[0084] In addition, the compression springs 832 and 633 are also installed to be inclined in the horizontal direction (the direction parallel to the surface of the sample plate 5) in a manner that they open outward as they move away from the screw 65. This is to avoid interference with the wall portion 96 and the leaf spring 97 described later. In the case where the wall portion 96 and the leaf spring 97 are arranged at a position that does not interfere with the compression springs 832 and 633, the compression springs 832 and 633 do not need to be inclined in the horizontal direction (they can be arranged parallel to the short side of the sample plate 5).

[0085] Fig.10 The upper part is a perspective view of the sample plate holder 9 as viewed from the lower surface side (however, the lower frame member 62, the compression springs 631, 632, 633, and the screws 64, 65 are not shown). Fig.10The lower part is an enlarged cross-sectional view of the vicinity of both ends of the short side of the sample plate 5 (equivalent to Fig.10 9. In the sample plate holder 9, similarly to the sample plate holder 8, on the outer side of the side surface of one short side of the sample plate 5 (the surface on the side where the compression springs 631, 832 are located), a wall portion 96 (equivalent to the side member in the present invention) is erected from the extension piece 611 toward the lower frame member 62, and on the outer side of the side surface of the other short side (the surface on the side where the compression spring 633 is located), a leaf spring 97 is arranged to press the side surface of the other short side of the sample plate 5 toward the wall portion 96. In the sample plate 9, the extension piece 611 and the wall portion 96 are also composed of one component, but they can also be composed of different components. Thus, similarly to the sample plate holder 8, the two side surfaces of the sample plate 5 whose size (length of the long side) is slightly different for each manufacturer can be clamped and stably held by the wall portion 96 and the leaf spring 97.

[0086] However, in the sample plate holder 9, as Fig.10 As shown in the lower part, the wall portion 96 is formed to be lower than the thickness of the sample plate 5. Fig.10 At the position of the C-C' section in the cross section, a gap is provided between the leaf spring 97 and the sample plate 5. That is, the position where the leaf spring 97 presses the sample plate 5 is offset from the position where the leaf spring 633 presses the sample plate. By forming it in this way, the leaf springs 631, 632, and 633 do not interfere with the wall portion 96 or the leaf spring 97, but abut against the ridgeline of the sample plate 5 (the edge of the short side of the surface of the sample plate 5. The corner in the C-C' section). As a result, the positional relationship between the force point and the fulcrum in the sample plate 5 is precisely consistent when viewed from above, avoiding the problem of becoming Figure 8 The state shown in the lower part. In addition, when various changes are made to the inclination angle of the compression springs 631, 832, and 633, when the inclination angle is set to less than 1 degree, if the processing error of the spring mounting surface of the lower frame member 62 is large, sometimes the compression springs 631, 832, and 633 do not abut against the ridgeline of the sample plate 5. Therefore, it is preferred that the compression springs 631, 832, and 633 be inclined by more than 1 degree relative to the surface of the sample plate 5. On the other hand, if the compression springs 631, 832, and 633 are excessively inclined, the original function, that is, the force pressing the sample plate 5 from the lower side toward the extensions 912 to 914, becomes weak. In view of this, the inclination angle of the compression springs 631, 832, and 633 is preferably set to be less than 60 degrees.

[0087] Furthermore, in the sample plate holder 9, the length of the extensions 912 to 914 (extension length) is reduced compared to the sample plate holder 6 of the first embodiment. Specifically, in the sample plate holder 6, the lengths of the extensions 612 and 613 are set to 3.3 mm, and the length of the extension 614 is set to 2.8 mm. In contrast, in the sample plate holder 9, the lengths of the extensions 912 and 913 are set to 1.5 mm, and the length of the extension 914 is set to 1.0 mm. The extension length referred to here refers to the length of the portion of the entire length of the extension that overlaps with the sample plate 5 when viewed from above. Figure 8 It can be seen that, according to the surface accuracy of the extensions 912 to 914, the position of the fulcrum in the sample plate 5 changes at most in accordance with the length of the extensions 912 to 914. In the sample plate holder 9, by shortening the extensions 912 to 914, even if the contact surfaces of the extensions 912 to 914 are tilted due to processing errors during manufacturing, the position deviation of the fulcrum can be suppressed to be small, thereby suppressing the position deviation of the force point and the fulcrum in a plan view to be small. Therefore, compared with the sample plate holder 6, the strain of the sample plate 5 can be further reduced. As described above, in the sample plate holder 6, the length of the extensions 612 and 613 is set to 3.3 mm, but according to the research of the present inventors, by setting the length of the extensions 912 to 914 to less than 3.0 mm, the strain of the sample plate 5 can be suppressed even if the extensions 912 to 914 are tilted.

[0088] The extensions 912 to 914 may also be provided as inclined surfaces. Specifically, the extensions 912 to 914 are inclined in a direction away from the surface of the sample plate 5 as they move from the outside to the inside. Fig.11 As shown schematically, in addition to the compression springs 832 and 633, the extensions 912 to 914 also abut against the ridgeline of the sample plate 5 (the edge of the short side of the surface of the sample plate 5. The corner in the CC' section). By adopting such a structure, the positions of the force point and the fulcrum in the sample plate 5 are more accurately consistent when viewed from above, and the strain of the sample plate 5 can be more reliably suppressed.

[0089] Alternatively, the extension portions 912 to 914 may not be provided, and the extension piece 911 may be inclined in a direction away from the surface of the sample plate 5 as it moves from the outside to the inside, and the edge line of the sample plate 5 may be linearly abutted against the extension piece 911. However, in this case, the extension piece 911 is required to be a flat inclined surface (with a uniform inclination angle) as a whole. Therefore, as described above, it is preferred to adopt a configuration in which the extension portions 912 to 914 provided on the extension piece 911 are provided as inclined surfaces.

[0090] Furthermore, in the sample plate holder 9, as Fig.12As shown, recesses 9121, 9131, 9141 are provided on the base side of the extensions 912, 913, 914. In addition, V-shaped grooves 981-983 are formed in the portions of the extensions 912-914 located on the side where the sample plate 5 is inserted, thereby making the ends of the extensions 912-914 on the side where the sample plate 5 is inserted into a tapered shape. In the sample plate holder 6 of the first embodiment, flat extensions 612-614 are provided on the extension piece 611. In addition, the extensions 612-614 are not completely rectangular, but have a shape that expands toward the base side ( Figure 3 ). Therefore, a height difference is generated at the boundary between the extension piece 611 and the extension parts 612 to 614. When the sample plate 5 is inserted, the sample plate 5 may be stuck due to the height difference, thereby delaying the operation time.

[0091] In contrast, in the sample plate holder 9 of the third embodiment, the boundary between the extension piece 911 and the extension parts 912 to 914 is tapered, and the bases of the extension parts 912 to 914 are not expanded, so the sample plate 5 can be smoothly inserted. Fig.12 V-shaped grooves 981 to 983 are formed in the sample plate holder, but the tapered portion may be provided by other methods. However, the thickness of the extensions 912 to 914 is 0.1 mm, which is very thin, similar to the extension of the sample plate holder 6, so it is not easy to process them to form inclined surfaces. Fig.12 As shown, by forming V-shaped grooves at the ends of the protruding portions 612 to 614, the tapered portions can be easily provided.

[0092] The above-described embodiment is an example and can be modified appropriately according to the gist of the present invention.

[0093] In the above description, the mass spectrometer 1 is provided with vacuum MALDI, but the sample plate holders 6 to 9 of the above embodiments and modified examples can also be preferably used in mass spectrometers provided with atmospheric pressure MALDI or other ion sources that irradiate a sample with laser light when ionizing the sample. For example, the sample plate holders 6 to 9 of the above embodiments and modified examples can also be preferably used in mass spectrometers provided with an ion source that generates ions from a sample by laser desorption / ionization (LDI) or electrospray laser desorption ionization (ELDI), or laser ablation inductively coupled plasma mass spectrometry (LA-ICP MS).

[0094] In the above embodiment, the mass spectrometer 1 is provided with a reflectance TOF type mass spectrometer. However, the sample plate holder 6 of the above embodiment and the modified example can be preferably used regardless of the configuration of the mass separation unit, such as a linear TOF type, an ion trap type, or a quadrupole type.

[0095] In addition, in the sample plate holders 6 to 9 of the above-mentioned embodiments and modified examples, the extensions 612 to 614, 914 to 916 and the compression springs 631, 632, 633, 832 used as the abutment members and the biasing members are one configuration example and can be replaced by appropriate members that function as the abutment members and the biasing members in the present invention. For example, as the biasing members, springs or push pins that bias the sample plate 5 against the upper frame members 61, 71 from below the abutment portions can also be used.

[0096] In the sample plate holder 9, the compression springs 631, 832, 633 are tilted by tilting the mounting surface 9211 of the screw 65 relative to the surface of the sample plate 5, but other methods can also be used. Fig.13 (Variation of the third embodiment) As schematically shown, the mounting surface 9211 of the screw 65 is preliminarily set to be parallel to the surface of the sample plate 5, on which a gasket 8351 having an inclined surface inclined relative to the surface of the sample plate 5, a fixing portion 834, and a gasket 8352 having an inclined surface inclined to the side opposite to the gasket 8351 are clamped and fixed by the screw 65, thereby enabling the compression springs 631, 832, and 633 to be inclined toward the surface of the sample plate 5.

[0097] [plan]

[0098] It is obvious to those skilled in the art that the above-mentioned exemplary embodiments are specific examples of the following aspects.

[0099] (Item 1)

[0100] A sample plate holder for a mass spectrometer according to one embodiment of the present invention comprises:

[0101] a force applying member pressing one surface of the sample plate at three locations that are not located in a straight line; and

[0102] The contact member contacts the other surface of the sample plate at positions corresponding to the three locations in plan view.

[0103] In the sample plate holder of item 1, the force-applying member presses the other surface (e.g., the lower surface) of the sample plate at three locations (three points) that are not located on a straight line, so that the sample plate abuts against the abutting member at positions corresponding to the three locations (typically, three locations located at the same position) when viewed from above. In the sample plate holder of item 1, the force point pressing the sample plate and the fulcrum that abuts against and supports the sample plate are located at the same position when viewed from above, so that the sample plate does not generate strain. In addition, a single plane is defined by the three points that are not located on a straight line, so by using the sample plate holder of item 1, the sample plate can be held in such a way that the surface of the sample plate is always at the same position and height.

[0104] (Item 2)

[0105] The sample plate holder of item 2 is in the sample plate holder of item 1,

[0106] The abutment member is integrally formed with a reinforcing member having an area larger than that of the abutment member in a plan view.

[0107] (Item 3)

[0108] The sample plate holder of item 3 is in the sample plate holder of item 2,

[0109] The sample plate is roughly rectangular.

[0110] The abutting member is formed integrally with reinforcing members provided on one surface of the sample plate along both short sides of the sample plate.

[0111] In the sample plate holder of item 2, when a predetermined voltage is applied to the sample plate and the sample plate holder, sufficient strength can be ensured by the reinforcing member even when the height difference between the upper surface of the sample plate and the upper surface of the sample plate holder is controlled to be small to suppress the disturbance of the electric field. In addition, when holding a widely used rectangular sample plate, the sample plate holder of item 3 can be preferably used.

[0112] (Item 4)

[0113] The sample plate holder according to item 4 is the sample plate holder according to any one of items 1 to 3,

[0114] At least one of the three locations is located in two regions divided by a plane passing through the center of gravity of the sample plate and perpendicular to the surface of the sample plate.

[0115] By using the sample plate holder according to item 4, the sample plate can be stably held compared to the case where the sample plate is held in only one of the two regions.

[0116] (Item 5)

[0117] The sample plate holder according to item 5 is the sample plate holder according to any one of items 1 to 4,

[0118] The urging member abuts against an edge of the sample plate.

[0119] (Item 6)

[0120] The sample plate holder of item 6 is in the sample plate holder of item 5,

[0121] The urging members are three leaf springs, and the three leaf springs are arranged to be inclined relative to the surface of the sample plate so as to be away from the surface of the sample plate from the outside toward the inside.

[0122] (Item 7)

[0123] The sample plate holder of item 7 is in the sample plate holder of item 6,

[0124] The first leaf spring, which is one of the three leaf springs, is arranged along one side of the sample plate.

[0125] The second leaf spring and the third leaf spring, which are two of the three leaf springs, are arranged along a side opposing the one side.

[0126] (Item 8)

[0127] The sample plate holder of item 8 is in the sample plate holder of item 7,

[0128] The third leaf spring is disposed at a position further inside the sample plate than the second leaf spring, and has a linear portion and an extending portion extending from the linear portion toward the outside of the sample plate.

[0129] In the sample plate holder of item 5, the edge of the sample plate is pressed by the force-applying member, and the positional deviation of the force point on the sample plate is reduced. As such a structure, for example, three leaf springs as described in item 6 can be preferably used. In addition, by configuring the three leaf springs described in item 6 as described in item 7, the sample plate can be held in a manner of pressing the sample plate from the outside of two opposing sides of the sample plate. Furthermore, by setting the third leaf spring, which is arranged at a position closer to the inside than the other leaf springs, to the structure described in item 8, it is possible to configure the edge of the sample plate to be pressed not only by the first leaf spring and the second leaf spring, but also by the third leaf spring.

[0130] (Item 9)

[0131] The sample plate holder according to item 9 is the sample plate holder according to any one of items 6 to 8, further comprising:

[0132] a first frame member provided with the abutting member; and

[0133] The second frame member is a member fixed relative to the first frame member and is provided with the three leaf springs.

[0134] The sample plate is held between the first frame member and the second frame member.

[0135] (Item 10)

[0136] The sample plate holder described in item 10 is the sample plate holder described in item 9,

[0137] The second frame member is provided with a mounting surface inclined with respect to the surface of the sample plate, and the three leaf springs are mounted on the mounting surface.

[0138] (Item 11)

[0139] The sample plate holder described in item 11 is the sample plate holder described in item 9,

[0140] The second frame member is provided with a mounting surface parallel to the surface of the sample plate, and the leaf spring is mounted on the mounting surface via an inclined member having an inclined surface inclined with respect to the surface.

[0141] As described in item 9, one embodiment of the sample plate holder of the present invention comprises a first frame member provided with a contact member, and a second frame member provided with three leaf springs, and can hold the sample plate between the first frame member and the second frame member. Furthermore, as described in item 10, by providing a mounting surface inclined with respect to the surface of the sample plate on the second frame member, or by arranging an inclined member having an inclined surface inclined with respect to the surface of the sample plate as described in item 11, the three leaf springs can be installed with respect to the surface of the sample plate with respect to an inclination.

[0142] (Item 12)

[0143] The sample plate holder according to item 12 is the sample plate holder according to any one of items 9 to 11,

[0144] A portion of the abutment member located on a side where the sample plate is inserted is formed in a tapered shape.

[0145] In the sample plate holder of item 12, the sample plate can be inserted smoothly.

[0146] (Item 13)

[0147] The sample plate holder of item 13 is in the sample plate holder of item 12,

[0148] The abutment member is provided on the surface of a flat reinforcing member. At least a portion of the reinforcing member is located closer to the sample plate insertion side than the abutment member. The reinforcing member is formed into the tapered shape by forming a V-shaped groove at the end portion of the sample plate insertion side.

[0149] The thickness of the abutment member is, for example, about 0.1 mm, and it is not easy to form the end of a member of such thickness into a tapered shape. In the sample plate holder of item 13, the abutment member is provided on the surface of the flat reinforcing member, and a V-shaped groove is formed at the end of the side for inserting the sample plate as its boundary, thereby making it possible to form the end of the abutment member into a tapered shape.

[0150] (Item 14)

[0151] The sample plate holder of item 14 in the sample plate holder of item 12 or item 13,

[0152] It also includes a side member located outside the short side of the sample plate,

[0153] The abutting member is a member extending from the side member toward the inner side of the sample plate and having a recess formed in a base portion on a side where the sample plate is inserted.

[0154] In the sample plate holder of item 14, the abutment member is extended from the side member provided on the outside of the short side of the sample plate toward the inside of the sample plate. For example, in the case of forming the abutment member having a rectangular shape when viewed from above, it is difficult to completely form the end portion of the side for inserting the sample plate into a straight line, and most of the time, the end portion is formed to expand toward the base side. Therefore, when the sample plate is inserted, the sample plate gets stuck due to the height difference at the end portion. In the sample plate holder of item 14, a depression is provided at the base of the abutment member on the side for inserting the sample plate, so that the sample plate will not get stuck when inserted.

[0155] (Item 15)

[0156] The mass analysis device in item 15 shall have:

[0157] The sample plate holder of any one of items 1 to 14;

[0158] a laser irradiation unit that irradiates a sample placed on a sample plate held by the sample plate holder with laser light; and

[0159] The mass spectrometer performs mass analysis on ions generated from the sample by irradiation with the laser beam.

[0160] The sample plate holders described in Items 1 to 14 can be particularly preferably used in the mass spectrometer of Item 15 having a configuration of generating ions from a sample by irradiation with laser light.

[0161] (Item 16)

[0162] The mass spectrometer according to item 16 is the mass spectrometer according to item 15, further comprising:

[0163] A workbench, provided with the sample plate support;

[0164] a stage moving mechanism for moving the stage so as to irradiate the laser light to a plurality of measurement points distributed on the sample held on the sample plate; and

[0165] The image data creating unit creates image data showing the distribution of a target substance on the surface of the sample based on the mass analysis data obtained at the plurality of measurement points.

[0166] The sample plate holder described in Items 1 to 14 can be particularly preferably used in the mass spectrometer of Item 16 for performing so-called imaging mass analysis, which performs mass analysis on multiple measurement points on the sample and produces image data showing the distribution of the target substance on the surface of the sample based on the mass analysis data obtained at each measurement point.

[0167] (Item 17)

[0168] The mass spectrometer of item 17 is a mass spectrometer of item 15 or 16,

[0169] The laser irradiation unit generates ions from the sample via a matrix substance coated or mixed on the sample.

[0170] The sample plate holders described in Items 1 to 14 can be particularly preferably used in the mass spectrometer of Item 15 having an ion source for ionizing a sample by a matrix-assisted laser desorption / ionization method.

[0171] Description of Reference Numerals

[0172] 1 Mass Analyzer (MALDI-TOF MS)

[0173] 10 Chamber

[0174] 12 Workbench

[0175] 13 Laser irradiation section

[0176] 14 Concave Mirror

[0177] 17 Photography Department

[0178] 18 Workbench drive unit

[0179] 19 Gate valve

[0180] 21 Accelerating electrode

[0181] 22 Ion lens

[0182] 30 Quality Analysis Department

[0183] 31 Flight Tube

[0184] 32 Reflector

[0185] 33 Back panel

[0186] 34 Ion detector

[0187] 40 Control and Processing Department

[0188] 41 Storage

[0189] 42 Measurement control department

[0190] 43 Analysis Processing Unit

[0191] 44 Input section

[0192] 45 Display

[0193] 5 Sample Plate

[0194] 6, 7, 8, 9 Sample plate holder

[0195] 61, 71 upper frame member

[0196] 611 Extension piece (reinforcement member)

[0197] 612-614, 912-914: extension portion (contact member)

[0198] 62 Lower frame member

[0199] 621 Grip

[0200] 631~633、832 Compression spring (force applying member)

[0201] 64, 65 Screws

[0202] 8321 Straight part

[0203] 8322 Extension

[0204] 834 Fixed part

[0205] 8341 Opening

[0206] 8351, 8352 Gasket

[0207] 86, 96 Wall (side member)

[0208] 87, 97 leaf spring

[0209] 9121, 9131, 9141 Depression

[0210] 9211 Screw mounting surface

[0211] 981~983 V-groove

[0212] C Ion optical axis

[0213] S specimen.

Claims

1. A sample plate holder for a mass analysis device, characterized in that: have: a force applying member pressing one surface of the sample plate at three locations that are not located in a straight line; and The contact member contacts the other surface of the sample plate at positions corresponding to the three locations in plan view.

2. The sample plate holder for a mass spectrometer according to claim 1, wherein: The abutment member is integrally formed with a reinforcing member having an area larger than that of the abutment member in a plan view.

3. The sample plate holder for a mass spectrometer according to claim 2, wherein: The sample plate is roughly rectangular. The abutting member is formed integrally with reinforcing members provided on one surface of the sample plate along both short sides of the sample plate.

4. The sample plate holder for a mass spectrometer according to claim 1, wherein: At least one of the three locations is located in two regions divided by a plane passing through the center of gravity of the sample plate and perpendicular to the surface of the sample plate.

5. The sample plate holder according to claim 1, characterized in that: The urging member abuts against an edge of the sample plate.

6. The sample plate holder according to claim 1, characterized in that: The urging members are three leaf springs, and the three leaf springs are arranged to be inclined relative to the surface of the sample plate so as to be away from the surface of the sample plate from the outside toward the inside.

7. The sample plate holder according to claim 6, characterized in that: The first leaf spring, which is one of the three leaf springs, is arranged along one side of the sample plate. The second leaf spring and the third leaf spring, which are two of the three leaf springs, are arranged along a side opposing the one side.

8. The sample plate holder according to claim 7, characterized in that: The third leaf spring is disposed at a position further inside the sample plate than the second leaf spring, and has a linear portion and an extending portion extending from the linear portion toward the outside of the sample plate.

9. The sample plate holder according to claim 6, characterized in that: Also available: a first frame member provided with the abutting member; and The second frame member is a member fixed relative to the first frame member and is provided with the three leaf springs. The sample plate is held between the first frame member and the second frame member.

10. The sample plate holder according to claim 9, characterized in that: The second frame member is provided with a mounting surface inclined with respect to the surface of the sample plate, and the three leaf springs are mounted on the mounting surface.

11. The sample plate holder according to claim 9, characterized in that: The second frame member is provided with a mounting surface parallel to the surface of the sample plate, and the leaf spring is mounted on the mounting surface via an inclined member having an inclined surface inclined with respect to the surface.

12. The sample plate holder according to claim 9, wherein: A portion of the abutment member located on a side where the sample plate is inserted is formed in a tapered shape.

13. The sample plate holder according to claim 12, characterized in that: The abutment member is provided on the surface of a flat reinforcing member. At least a portion of the reinforcing member is located closer to the sample plate insertion side than the abutment member. The reinforcing member is formed into the tapered shape by forming a V-shaped groove at the end portion of the sample plate insertion side.

14. The sample plate holder according to claim 12, wherein: It also includes a side member located outside the short side of the sample plate, The abutting member is a member extending from the side member toward the inner side of the sample plate and having a recess formed in a base portion on a side where the sample plate is inserted.

15. A mass analysis device, characterized in that: have: The sample plate holder according to any one of claims 1 to 14; a laser irradiation unit that irradiates a sample placed on a sample plate held by the sample plate holder with laser light; and The mass spectrometer performs mass analysis on ions generated from the sample by irradiation with the laser beam.

16. The mass spectrometer according to claim 15, wherein: Also available: A workbench, provided with the sample plate support; a stage moving mechanism for moving the stage so as to irradiate the laser light to a plurality of measurement points distributed on the sample held on the sample plate; and The image data creating unit creates image data showing the distribution of a target substance on the surface of the sample based on the mass analysis data obtained at the plurality of measurement points.

17. The mass spectrometer according to claim 15, wherein: The laser irradiation unit generates ions from the sample via a matrix substance coated or mixed on the sample.

Images