JP2014021048A - Sample plate and mass spectroscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sample plate capable of dealing with various retainer plates.SOLUTION: A sample plate 1 is a sample plate for a mass spectroscope which ionizes a sample S by irradiating it with energy beams. This sample plate includes: a base 10; a retainer plate 20 capable of retaining the sample; and a fixing plate 30 having a through-hole 32 through which the energy beams pass. The retainer plate 20 is fixed by being sandwiched between the base 10 and the fixing plate 30.

Description

  The present invention relates to a sample plate and a mass spectrometer.

  In mass spectrometry, it is necessary to ionize a compound contained in a sample. There are various methods for ionization, one of which is laser ionization. Laser ionization is a method in which a sample is irradiated with a laser to ionize a compound in the sample.

  As a widely used laser ionization technique, there is a matrix-assisted laser desorption ionization (MALDI) method. In the MALDI method, a sample is mixed and dissolved in a matrix (liquid, crystalline compound, metal powder, etc.) having an absorption band at the wavelength of the laser light to be used, and then solidified. It is a method of ionization.

  In addition to the method of promoting ionization with a matrix such as the MALDI method, surface-assisted laser desorption ionization (SALDI) that promotes ionization by utilizing the fine structure of the surface of metal, semiconductor, etc. without using a matrix. There is a law. Advantages of the SALDI method include that there is no need to mix the matrix and the sample, and that there is no influence of ions derived from the matrix.

  Further, as an analysis method using laser ionization, there are a TLC-MALDI method in which a matrix is sprayed on a sample plate for thin layer chromatography and measurement is performed, a mass imaging in which a matrix is sprayed on a tissue section, and measurement is performed.

  In a mass spectrometer that performs analysis using such mass spectrometry, a sample is generally dropped onto a holding plate to be fixed and introduced into the apparatus. Specifically, in the MALDI method, for example, a sample mixed and dissolved in a matrix is dropped and fixed on a stainless steel plate and introduced into the apparatus (see Patent Document 1). In the SALDI method, for example, a sample is dropped and fixed on a metal plate having a fine structure formed on the surface and introduced into the apparatus. In the TLC-MALDI method, for example, a sample is sprayed and fixed on a thin glass plate stretched with silica gel, alumina, polyamide resin or the like and introduced into the apparatus. In mass imaging, for example, a matrix is sprayed on a tissue section (sample) on ITO glass and introduced into the apparatus.

  Thus, in the mass spectrometer, the shape and material of the holding plate for holding the sample are selected according to the analysis technique and the sample to be measured. In the mass spectrometer, the holding plate is introduced into the apparatus as a sample plate.

JP 2009-52994 A

  However, when a thin holding plate is introduced as a sample plate into the mass spectrometer, the sample plate may bend. When the sample plate is bent, for example, in a time-of-flight mass spectrometer, an error in time of flight may increase.

  In addition, when an electrically insulating holding plate is introduced as a sample plate into a mass spectrometer, for example, a voltage cannot be applied to the sample plate, and the sample plate cannot be used as an electrode for accelerating ions. There's a problem.

  Thus, the mass spectrometer has a problem that various holding plates may not be used as the sample plate.

  The present invention has been made in view of the above-described problems, and one of the objects according to some aspects of the present invention is to provide a sample plate that can be used for various holding plates. . Another object of some aspects of the present invention is to provide a mass spectrometer having the sample plate.

(1) The sample plate according to the present invention is:
A sample plate for a mass spectrometer that ionizes a sample by irradiating it with an energy beam,
Base and
A holding plate capable of holding the sample;
A fixing plate having a through hole through which the energy beam passes;
Including
The holding plate is sandwiched and fixed between the base and the fixing plate.

  According to such a sample plate, since the holding plate is sandwiched and fixed between the base and the fixing plate, it can correspond to various holding plates.

(2) In the sample plate according to the present invention,
At least one of the base and the fixing plate may be conductive.

  According to such a sample plate, the sample plate can be used as an electrode for accelerating ions.

(3) In the sample plate according to the present invention,
The fixing plate may have a plurality of the through holes.

(4) In the sample plate according to the present invention,
The fixing plate may be provided with a mark for specifying the position of the sample.

  According to such a sample plate, the position of the sample can be easily specified.

(5) In the sample plate according to the present invention,
Including a plurality of the holding plates;
The plurality of holding plates may be fixed by being sandwiched between the base and the fixing plate.

  According to such a sample plate, since a plurality of holding plates can be introduced into the apparatus, measurement can be performed efficiently.

(6) In the sample plate according to the present invention,
The holding plate may be electrically insulating.

(7) In the sample plate according to the present invention,
The mass spectrometer may ionize the sample by a surface-assisted laser desorption ionization method.

(8) In the sample plate according to the present invention,
The mass spectrometer may ionize the sample by a matrix-assisted laser desorption ionization method.

(9) A mass spectrometer according to the present invention comprises:
A sample plate according to the present invention is included.

  According to such a mass spectrometer, since the sample plate according to the present invention is included, it can be used for various holding plates.

The perspective view which shows typically the sample plate which concerns on this embodiment. The top view which shows typically the sample plate which concerns on this embodiment. Sectional drawing which shows the sample plate which concerns on this embodiment typically. The top view which shows typically the sample plate which concerns on the 1st modification of this embodiment. The top view which shows typically the sample plate which concerns on the 2nd modification of this embodiment. Sectional drawing which shows typically the sample plate which concerns on the 2nd modification of this embodiment. The figure for demonstrating the structure of the mass spectrometer which concerns on this embodiment. The figure for demonstrating the structure of the ion source and acceleration part of the mass spectrometer which concerns on this embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are essential constituent requirements of the present invention.

1. Sample Plate First, the configuration of the sample plate 1 according to this embodiment will be described. FIG. 1 is a perspective view schematically showing a sample plate 1 according to the present embodiment. FIG. 2 is a plan view schematically showing the sample plate 1 according to the present embodiment. FIG. 3 is a cross-sectional view schematically showing the sample plate 1 according to the present embodiment. 3 is a cross-sectional view taken along line III-III in FIG.

  As shown in FIGS. 1 to 3, the sample plate 1 includes a base 10, a holding plate 20, and a fixing plate 30. 2 and 3 show a state in which the holding plate 20 is sandwiched and fixed between the base 10 and the fixing plate 30. The sample plate 1 is a sample plate for a mass spectrometer that irradiates the sample S with an energy beam such as a laser beam or an ion beam to perform ionization.

  The base 10 has a flat plate shape, for example. The shape of the base 10 is not particularly limited as long as the holding plate 20 can be sandwiched together with the fixing plate 30. The base 10 is, for example, a rectangular parallelepiped having a length of 2 to 10 cm, a width of 6 to 12 cm, and a height of about several mm. The base 10 has conductivity. The material of the base 10 is, for example, a metal such as stainless steel or aluminum. A mark 12 is provided on the surface of the base 10 that faces the fixed plate 30. The mark 12 is, for example, a groove or a protrusion provided on the surface of the base 10. The mark 12 serves as a mark for specifying the position of the sample S on the holding plate 20.

  The holding plate 20 can hold the sample S. The holding plate 20 is fixed by being sandwiched between the base 10 and the fixed plate 30. In the sample plate 1, since the holding plate 20 is sandwiched and fixed between the base 10 and the fixing plate 30, various shapes and materials can be used. Specifically, as the holding plate 20, for example, a metal plate or a plate for SALDI method having a fine structure formed on the surface of a semiconductor substrate, a thin layer chromatograph in which silica gel, alumina, polyamide resin or the like is thinly stretched on a glass plate. A plate for lithography, a plate for mass imaging made of a glass slide having an ITO film formed on the surface, and the like can be used. Further, the holding plate 20 may be a thin plate or film of 1 mm or less, for example. The holding plate 20 may be conductive or electrically insulating. Further, the size of the holding plate 20 is not particularly limited as long as it can be fixed between the base 10 and the fixing plate 30.

  The fixing plate 30 can be fixed together with the base 10 with the holding plate 20 interposed therebetween. The fixing plate 30 can function as a weight for fixing the holding plate 20 by being placed on the holding plate 20. Further, for example, the holding plate 20 can be fixed by fixing the fixing plate 30 to the base 10. The fixing plate 30 may be fixed to the base 10 by screws (not shown) or may be fixed to the base 10 by magnetic force. The fixed plate 30 has a through hole 32 through which an energy beam passes. The planar shape of the through-hole 32 is a circle in the illustrated example, but the shape is not particularly limited, and may be a polygon such as a rectangle. The fixing plate 30 is provided with a plurality of through holes 32. The arrangement of the through holes 32 is not particularly limited. The through holes 32 may be arranged in accordance with a microtiter plate format. The diameter of the through hole 32 is, for example, about several mm. The fixed plate 30 has a flat plate shape in the illustrated example. The shape of the fixing plate 30 is not particularly limited as long as the holding plate 20 can be sandwiched together with the base 10. The fixed plate 30 is, for example, a rectangular parallelepiped having a length of 2 to 7 cm, a width of 5 to 10 cm, and a height of about several mm. The fixing plate 30 has conductivity. The material of the fixed plate 30 is, for example, a metal such as stainless steel or aluminum.

  Although the case where both the base 10 and the fixing plate 30 are conductive has been described here, one of the base 10 and the fixing plate 30 may be conductive.

  In the sample plate 1, the holding plate 20 is sandwiched and fixed between the base 10 and the fixing plate 30. Then, the sample S is dropped onto the fixed holding plate 20 through the through hole 32. For example, the sample S may be dissolved and mixed in a compound (matrix) or the like that promotes ionization and dropped onto the holding plate 20. The sample S dropped on the holding plate 20 is fixed to the holding plate 20. The sample plate 1 holding the sample S in this way is introduced into the mass spectrometer. In addition, after the sample S is dropped and fixed on the holding plate 20, the holding plate 20 may be fixed by being sandwiched between the base 10 and the fixing plate 30.

  The sample plate 1 according to the present embodiment has the following features, for example.

  In the sample plate 1, the holding plate 20 is fixed by being sandwiched between the base 10 and the fixing plate 30. As a result, various holding plates 20 can be handled. For example, even if the holding plate 20 is a thin plate that is easily bent, the holding plate 20 can be fixed without being bent by being sandwiched between the base 10 and the fixing plate 30. For example, even if the holding plate 20 is electrically insulating, the sample plate 1 can be used as an electrode for accelerating ions by making at least one of the base 10 and the fixing plate 30 conductive. Further, it is possible to prevent ionization from becoming unstable due to charging. Thus, according to the sample plate 1, it can respond to the holding plate 20 of various shapes and materials.

In the sample plate 1, since the holding plate 20 is sandwiched and fixed between the base 10 and the fixing plate 30, the sample plate 1 can be carried without directly touching the holding plate 20.

  In the sample plate 1, at least one of the base 10 and the fixed plate 30 is conductive. Therefore, in the mass spectrometer, the sample plate 1 can be used as an electrode for accelerating ions.

2. Sample plate modification 2.1. First Modification Next, a first modification of the sample plate according to the present embodiment will be described. FIG. 4 is a plan view schematically showing a sample plate 2 according to a first modification of the present embodiment. Hereinafter, in the sample plate 2 according to the first modification of the present embodiment, members having the same functions as those of the constituent members of the sample plate 1 described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the example of the sample plate 1 described above, the fixing plate 30 has a plurality of through holes 32 as shown in FIGS.

  On the other hand, in the sample plate 2, as shown in FIG. 4, the fixing plate 30 has one through hole 32.

  Marks 34 a and 34 b for specifying the position of the sample S are provided around the through hole 32 of the fixing plate 30. In the illustrated example, the mark 34 a is a scale provided along the short side of the rectangular through hole 32, and the mark 34 b is a scale provided along the long side of the rectangular through hole 32. The position of the sample S can be easily specified by the marks 34a and 34b. For example, when the position information of the sample S and the mass spectrum at the position are closely related to each other like TLC-MALDI or mass imaging, the correspondence between the position information and the mass spectrum can be easily obtained by the marks 34a and 34b. Can do. Therefore, measurement can be facilitated. Further, for example, in SALDI that does not use a matrix, TLC-MALDI or mass imaging that sprays the entire matrix, the position of the sample S may not be confirmed by the CCD image of the apparatus. Even in such a case, since the position of the sample S can be easily specified by the marks 34a and 34b, the measurement can be facilitated.

2.2. Second Modification Example Next, a second modification example of the sample plate according to the present embodiment will be described. FIG. 5 is a plan view schematically showing a sample plate 3 according to a second modification of the present embodiment. FIG. 6 is a cross-sectional view schematically showing the sample plate 3. 6 is a cross-sectional view taken along line VI-VI in FIG. Hereinafter, in the sample plate 3 according to the second modified example of the present embodiment, members having the same functions as those of the constituent members of the sample plate 1 described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the example of the sample plate 1 described above, as shown in FIGS. 1 to 3, one holding plate 20 is sandwiched and fixed between the base 10 and the fixing plate 30.

On the other hand, in the sample plate 3, as shown in FIGS. 5 and 6, a plurality of holding plates 20 can be fixed by being sandwiched between the base 10 and the fixing plate 30. In the illustrated example, of the two holding plates 20, one holding plate 20a is electrically insulating, and the other holding plate 20b is conductive. Since the holding plate 20 is sandwiched and fixed between the base 10 and the fixing plate 30, the holding plates 20 of different materials and shapes can be simultaneously introduced into the mass spectrometer. Thereby, it can measure efficiently. Although not shown, a plurality of holding plates 20
May be fixed by being sandwiched between a plurality of fixing plates 30 and one base 10, or one holding plate 20 may be fixed by being sandwiched between a plurality of fixing plates 30 and one base 10.

3. Mass Spectrometer Next, the mass spectrometer according to the present embodiment will be described. FIG. 7 is a diagram for explaining the configuration of the mass spectrometer 100 according to the present embodiment. FIG. 8 is a diagram for explaining the configuration of the ion source 110 and the acceleration unit 120 of the mass spectrometer 100.

  As shown in FIG. 7, the mass spectrometer 100 includes an ion source 110, an acceleration unit 120, and an analysis unit 130. The mass spectrometer 100 is a mass spectrometer that ionizes a sample by irradiating the sample with an energy beam such as a laser beam, an ion beam, or a neutral atom beam. Specifically, the mass spectrometer 100 ionizes the sample with an ion beam such as a mass spectrometer that ionizes the sample with a laser beam such as MALDI-MS or SALDI-MS, or a secondary ion mass spectrometer (SIMS). And a mass spectrometer using a fast atom collision method in which a sample is ionized by irradiation with a neutral atom beam. Here, the case where the mass spectrometer 100 is MALDI-MS will be described.

  The ion source 110 can ionize the sample S by irradiating the laser beam L. As shown in FIG. 8, the ion source 110 includes a sample plate according to the present invention (sample plate 1 in the illustrated example), a laser light source 111 that emits laser light L, and a lens 112 that focuses the laser light L. , A mirror 113 that reflects the laser light L, a mirror 114 that reflects an image from the sample S, a lens 115 that focuses the image reflected by the mirror 114, and a CCD camera that acquires an image incident through the lens 115. 116.

  The acceleration unit 120 includes an intermediate electrode 122 and a base electrode 124 for accelerating the ions I. A pulse voltage is applied to the acceleration unit 120 by a pulse voltage generator (not shown). Thereby, the ions I can be accelerated in a pulse manner. Further, for example, a voltage similar to that of the intermediate electrode 122 is applied to the sample plate 1. That is, the sample plate 1 functions as an electrode for accelerating the ions I.

  In the ion source 110, a mirror 114, a lens 115, and a CCD camera 116 are arranged so that the state of the sample S on the sample plate 1 can be observed. When the position of the sample S is specified by the CCD camera 116, the mark 12 (see FIG. 1) on the sample plate 1 can be used as a mark. Laser light L emitted from the laser light source 111 is applied to the sample S on the sample plate 1 through the lens 112 and the mirror 113. The laser beam L is applied to the sample S through the through hole 32. When the laser beam L is irradiated, the sample S is vaporized and ionized. The generated ions I pass through the through holes 32 and are accelerated in a pulse manner by the acceleration unit 120.

  The analysis unit 130 detects a time difference until the ions I accelerated in a pulse manner by the acceleration unit 120 reach the detector 132. The velocity v of the ion I is represented by the following formula from the law of conservation of energy.

ただし、ｍはイオンＩの質量、ｑはイオンＩの電荷、ｅは電気素量、Ｖａはパルス電圧である。ここで、所定の距離Ｌだけ離れた検出器１３２には、イオンＩは飛行時間Ｔで到
達する。飛行時間Ｔは下記式で示される。

Here, m is the mass of the ion I, q is the charge of the ion I, e is the elementary charge, and Va is the pulse voltage. Here, the ions I reach the detector 132 separated by a predetermined distance L at the time of flight T. The flight time T is expressed by the following formula.

上記式より、飛行時間ＴがイオンＩの質量ｍにより異なることがわかる。したがって、分析部１３０が、イオンＩが検出器１３２に到達するまでの時間差を検出することにより質量を分析することができる。サンプルプレート１によれば、保持板２０をたわませることなく固定することができる。したがって、保持板２０がたわむことにより生じる飛行時間の誤差を低減することができる。

From the above formula, it can be seen that the time of flight T varies depending on the mass m of the ions I. Therefore, the analysis unit 130 can analyze the mass by detecting the time difference until the ions I reach the detector 132. According to the sample plate 1, the holding plate 20 can be fixed without being bent. Therefore, it is possible to reduce an error in flight time caused by the holding plate 20 being bent.

  In addition, although the case where the analysis part 130 was a time-of-flight type (Time-of-Flight) type was demonstrated here, the analysis part 130 is not limited to this. The analysis unit 130 may be a quadrupole type, an ion trap type, a magnetic field deflection type, a Fourier transform ion cyclotron resonance type, or the like.

  Since the mass spectrometer 100 includes the sample plate 1, it can correspond to various holding plates 20.

  In addition, each embodiment mentioned above is an example, Comprising: It is not necessarily limited to these. For example, it is possible to combine the embodiment and each modification as appropriate.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

1, 2, 3 ... Sample plate, 10 ... Base, 12 ... Mark, 20, 20a, 20b ... Holding plate, 30 ... Fixed plate, 32 ... Through-hole, 34a, 34b ... Scale, 100 ... Mass spectrometer, 110 ... Ion source, 111 ... laser light source, 112 ... lens, 113 ... mirror, 114 ... mirror, 115 ... lens, 116 ... CCD camera, 120 ... accelerator, 122 ... intermediate electrode, 124 ... base electrode, 130 ... analyzer, 132 …Detector

Claims (9)

A sample plate for a mass spectrometer that ionizes a sample by irradiating it with an energy beam,
Base and
A holding plate capable of holding the sample;
A fixing plate having a through hole through which the energy beam passes;
Including
The holding plate is a sample plate fixed by being sandwiched between the base and the fixing plate. In claim 1,
The sample plate, wherein at least one of the base and the fixing plate is conductive. In claim 1 or 2,
The fixed plate is a sample plate having a plurality of the through holes. In any one of Claims 1 thru | or 3,
A sample plate, wherein the fixing plate is provided with a mark for specifying the position of the sample. In any one of Claims 1 thru | or 4,
Including a plurality of the holding plates;
The plurality of holding plates are sample plates that are sandwiched and fixed between the base and the fixing plate. In claim 2,
The holding plate is a sample plate that is electrically insulating. In any one of Claims 1 thru | or 7,
The mass spectrometer is a sample plate that ionizes the sample by a surface-assisted laser desorption ionization method. In any one of Claims 1 thru | or 7,
The mass spectrometer is a sample plate that ionizes the sample by matrix-assisted laser desorption / ionization.   A mass spectrometer comprising the sample plate according to claim 1.

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