JP2024025429A - Mass spectroscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mass spectroscope comprising an ion detector disposed in a vacuum vessel, the ion detector being replaceable at low operation costs without a lot of effort and time.

SOLUTION: A mass spectroscope in one embodiment of the invention comprises a vacuum vessel (7) having an interior to be made into a vacuum atmosphere by evacuation, an analysis unit that is disposed in the interior of the vacuum vessel and includes a mass separator (3) and an ion detector (4), an opening (7C) formed at a predetermined position on a wall face of the vacuum vessel in such a size that the ion detector can pass through, a lid (11) for sealing the opening, and a detector supporting part (10) formed by integrating connections (12 to 14) connecting the lid and the ion director.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a mass spectrometer.

An ion trap time-of-flight mass spectrometer includes an ion trap and a time-of-flight mass separator, as disclosed in Patent Document 1 and the like. In an ion trap time-of-flight mass spectrometer, various ions generated from a sample are captured inside the ion trap, and then the various ions are accelerated all at once and ejected from the ion trap. to be introduced. Each accelerated ion has a velocity according to its mass-to-charge ratio (hereinafter sometimes referred to as "m/z"), and while flying through the flight space of the time-of-flight mass separator, the ion has a velocity corresponding to its mass-to-charge ratio (hereinafter sometimes referred to as "m/z"). It is separated according to z, reaches the ion detector, and is detected.

In a time-of-flight mass spectrometer (hereinafter referred to as TOFMS), generally, the longer the distance that ions fly, the higher the mass resolution can be obtained. Therefore, compared to a linear configuration in which ions fly in a straight line, a reflectron configuration in which ions fly in a folded manner, as disclosed in Patent Document 1, is easier to obtain higher mass resolution.

As a TOFMS capable of further extending the flight distance of ions, the multiturn TOFMS disclosed in Patent Documents 2 and 3 is known. Multiturn TOFMS extends the flight distance of ions by making them orbit multiple times along the same or nearly the same trajectory. With multiturn TOFMS, it is possible to significantly extend the flight distance without increasing the size of the device, and it is possible to achieve high mass resolution despite its small size.

International Publication No. 2008/072377 US Patent No. 9082602 Japanese Patent Application Publication No. 2022-34939

In the above-described mass spectrometer, a microchannel plate (MCP), a secondary electron multiplier, or the like is used as an ion detector. These detectors are a type of consumable item, and in order to maintain sufficient sensitivity and accuracy, they must be replaced with new ones periodically or every time they are used for a predetermined period of time.

Generally, in TOFMS, the ion detector is often integrated with the time-of-flight mass separator, and when the ion detector is replaced, the time-of-flight mass separator and ion detector are housed together. It is necessary to remove the lid of the chamber. On the other hand, in TOFMS, especially multi-turn TOFMS with a long flight distance, the chamber is required to have high strength in order to increase the degree of vacuum inside the chamber. Therefore, the chamber body and the lid have a fairly thick structure and are heavy, making it difficult for a person to attach and detach the lid by themselves from a safety standpoint. As a result, it is usually necessary to use a small crane to attach and detach the lid of the chamber, and there is a problem in that replacing the ion detector takes effort, time, and cost.

The present invention was made to solve these problems, and its main purpose is to easily install an ion detector installed in a chamber, in other words, without requiring much time and effort, and at low operating costs. The object of the present invention is to provide a mass spectrometer that can be replaced.

One aspect of the mass spectrometer according to the present invention, which has been made to solve the above problems, is as follows:
A vacuum container whose interior is made into a vacuum atmosphere by evacuation,
an analysis section including a mass separator and an ion detector disposed inside the vacuum container;
an opening formed at a predetermined position on the wall surface of the vacuum container and having a size that allows the ion detector to pass through;
a detector holding part formed by integrating a lid part that closes the opening, and a connection part that connects the lid part and the ion detector;
Equipped with

According to the above aspect of the mass spectrometer according to the present invention, the lid of the detector holding part that closes the opening formed in the vacuum container is removed, and the ions held in the detector holding part are detected. By pulling the container through the opening, the ion detector can be taken out to the outside of the vacuum container. This makes it possible to replace the ion detector installed inside the vacuum container at low work costs without requiring time and effort, without removing the heavy lid for opening and closing the vacuum container, for example. Can be done.

FIG. 1 is an overall configuration diagram of an ion trap TOFMS that is an embodiment of the present invention. FIG. 1 is a schematic configuration diagram of main parts of a mass spectrometer according to this embodiment. An enlarged view of section A in FIG. 2. FIG. 4 is an explanatory diagram of work performed when replacing an ion detector in the mass spectrometer of the present embodiment. Schematic diagram showing a modification of the ion detector holding mechanism. FIG. 2 is an overall configuration diagram of a mass spectrometer according to another embodiment of the present invention. The vertical cross-sectional view (A) and top view (B) of an example of a multi-turn mass separator. FIG. 8 is a top view showing ion trajectories in the multiturn mass separator shown in FIG. 7;

EMBODIMENT OF THE INVENTION Hereinafter, one embodiment of the mass spectrometer according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an overall configuration diagram of a mass spectrometer that is an embodiment of the present invention. FIG. 2 is a configuration diagram of the main parts of the mass spectrometer of this embodiment. Moreover, FIG. 3 is an enlarged view of the vicinity of section A shown in FIG.

The mass spectrometer of this embodiment is an ion trap TOFMS, and includes an ion source 1, an ion trap 2, a mass separator 3, and an ion detector 4, as shown in FIG. The ion source 1 is placed in an ionization chamber 5A formed in the first chamber 5, and the ion trap 2 is placed in a first vacuum chamber 5B formed in the same first chamber 5. The ionization chamber 5A and the first vacuum chamber 5B are partitioned by a partition wall 6, and the inside of the first vacuum chamber 5B is evacuated by a vacuum pump 8.

The ion source 1 ionizes a target component contained in a liquid sample or a gas sample. When the sample is a liquid sample, the ion source 1 is an ion source based on an ionization method such as electrospray ionization or atmospheric pressure chemical ionization. When the sample is a gas sample, an ion source based on an ionization method such as an electron ionization method or a chemical ionization method is used as the ion source 1. Further, when the sample is a solid sample, an ion source using an ionization method such as a matrix-assisted laser desorption ionization method is used.

The ion trap 2 is composed of one ring electrode 21 and a pair of end cap electrodes 22 and 23 arranged to sandwich the ring electrode 21. Although the ion trap 2 has a three-dimensional quadrupole configuration here, it may have a linear configuration.

The mass separator 3 and the ion detector 4 are arranged inside a second chamber (corresponding to the vacuum container in the present invention) 7 having a substantially rectangular parallelepiped box shape. Here, the mass separator 3 is a multiturn TOF type mass separator. The second chamber 7 includes a main body 7A forming five sides excluding the top, and a lid 7B forming the top. The mass separator 3 is supported so as to float in the internal space of the second chamber 7 by a plurality of pillars 40 erected on the bottom surface of the second chamber 7 or on members fixed to the bottom surface. The ion detector 4 is fixed to the mass separator 3. An exhaust opening 7E is formed in the bottom of the main body 7A, and the inside of the second chamber 7 is evacuated to a predetermined degree of vacuum by a vacuum pump 9 disposed outside the exhaust opening 7E.

An example of a typical measurement operation in the mass spectrometer described above will be briefly described.
The ion source 1 ionizes compounds contained in the introduced sample. The generated ions are introduced into the internal space of the ion trap 2. At this time, a predetermined voltage is applied to the ring electrode 21 and the end cap electrodes 22 and 23 from a power source (not shown), respectively, and the ions are trapped in the internal space of the ion trap 2 by the electric field formed thereby. Thereafter, a predetermined voltage is applied from the power source to the end cap electrodes 22 and 23, and the ions are given kinetic energy in the X-axis direction in FIG. 1 and ejected from the ion trap 2 all at once. The ejected ions enter the internal space of the second chamber 7 through an ion passage hole 7F formed in the second chamber 7, and are introduced into the mass separator 3.

Ions that fly while orbiting in the mass separator 3 as described later finally reach the ion detector 4. Since each ion has a velocity that depends on its m/z value when ejected from the ion trap 2, ion species with different m/z values are separated while flying in the mass separator 3, and there is a time difference between them. and enters the ion detector 4. The ion detector 4 outputs a detection signal according to the amount of incident ions. The detection signal from the ion detector 4 is input to a data processing unit (not shown), which converts the flight time starting from the time of ion injection into an m/z value, and calculates the relationship between the m/z value and the ion intensity. Create a mass spectrum showing .

Here, an example of a multiturn TOF type mass separator will be explained. FIG. 7 is a vertical cross-sectional view (A) and a top view (B) of an example of a multi-turn TOF mass separator, and FIG. 8 is a top view showing ion trajectories in the multi-turn TOF mass separator shown in FIG. It is a diagram. These are the configurations described in Patent Document 3.

The mass separator 3 includes a main electrode 31 consisting of an outer electrode 311 and an inner electrode 312, each having a substantially spheroidal shape. FIG. 7A shows a Z plane that includes a Z axis that is a rotation axis of the outer electrode 311 and an inner electrode 312 in a substantially spheroid, and an X axis that is an axis in one direction perpendicular to the Z axis. FIG. 3 is an end view (vertical end view) of the main electrode 31 in the -X plane. When the main electrode 31 is cut along a plane including the Z-axis, it has substantially the same shape as shown in FIG. 7A, regardless of the azimuth angle (angle around the Z-axis) of the cross section. FIG. 7(B) is a top view of the main electrode 31 viewed from the positive direction of the Z-axis. The axis perpendicular to the Z axis and the X axis is the Y axis, and the plane including the X axis and the Y axis is the XY plane.

The outer electrode 311 and the inner electrode 312 are three partial electrode pairs S ₁ , S ₂ , and S ₃ in which a pair of curved electrodes face each other in the ZX plane, and a straight electrode in the ZX plane. This is a combination of four partial electrode pairs L ₁ , L ₂ , L ₃ , and L ₄ in which a certain pair of electrodes face each other. The partial electrode pair S ₂ is arranged at both ends of the main electrode 31 in the X-axis direction in the ZX plane, and has a line-symmetrical shape with respect to the X-axis. The partial electrode pair S ₁ is arranged on the positive side in the Z-axis direction than the partial electrode pair S ₂ . The partial electrode pair S ₃ is arranged on the negative side of the partial electrode pair S ₂ in the Z-axis direction and is line-symmetrical with the partial electrode pair S ₁ with respect to the X-axis. The partial electrode pair L ₂ is arranged between the partial electrode pairs S ₁ and S ₂ . The partial electrode pair L ₃ is arranged between the partial electrode pairs S ₂ and S ₃ and has a shape that is line symmetrical to the partial electrode pair L ₂ with respect to the X axis. The partial electrode pair L ₁ has a donut plate shape perpendicular to the Z-axis, and is arranged on the positive side of the Z-axis direction and inside the partial electrode pair S ₁ in the XY plane. The partial electrode pair L ₄ is disposed on the negative side in the Z-axis direction and is line-symmetrical with the partial electrode pair L ₁ with respect to the X-axis. Due to the combination of the plurality of partial electrode pairs, each of the outer electrode 311 and the inner electrode 312 has an approximately spheroidal shape as a whole.

A voltage is applied from a power source (not shown) to the partial electrode pairs S ₁ , S ₂ , and S ₃ having a curved shape in the ZX plane so as to form an electric field directed from the outer electrode 311 to the inner electrode 312. Ru. On the other hand, a voltage such that the outer electrode 311 and the inner electrode 312 are at the same potential is applied to the partial electrode pairs L ₁ , L ₂ , L ₃ , and L ₄ that are linear in the ZX plane from the power supply section. applied. As a result, a circulating electric field is formed in the circulating space 319 between the outer electrode 311 and the inner electrode 312, causing the ions to circulate within the space.

The outer electrode 311 of the partial electrode pair S ₁ is provided with an ion introduction port 34 for introducing supplied ions into the circulating space 319 as shown by arrows in FIGS. 7 and 8. The ion introduction port 34 is provided at a position slightly shifted from the XY plane to the positive side in the Y-axis direction, and is arranged so that ions are incident approximately parallel to the X-axis. Immediately after the ions enter the circulating space 319 from the ion introduction port 34, the ions receive a centripetal force from the circulating electric field generated by the partial electrode pair _S1 . Further, as described above, since the ion introduction port 34 is shifted from the XY plane to the positive side of the Y-axis direction, the ions are subjected to a force directed in the direction of the XY plane. Thereby, the ions orbit around the orbiting space 319 along a substantially elliptical orbit, and each time the ions make a revolution, the orbit moves counterclockwise when viewed from the positive side of the Y-axis direction. 318 (see Figure 8). In FIG. 8, the ion trajectory 318 is shown in a top view in the XY plane.

On the other hand, the outer electrode 311 of the partial electrode pair S ₃ is provided with an ion outlet 35 for leading out of the circulating space 319 ions that have circulated within the circulating space 319 a plurality of times (several tens of times). Ions extracted from the ion outlet 35 fly on a linear trajectory. An ion detector 4 is arranged on this linear trajectory.

With the above configuration, ions having various m/z values ejected from the ion trap 2 fly in the orbiting space 319 within the main electrode 31. During this flight, each ion is spatially separated according to its m/z value and reaches the ion detector 4 with a time difference. In this mass separator 3, since the ion trajectory 318 is determined regardless of the m/z value of the ion, the flight distance is the same for all ions. As shown in FIG. 8, the orbits of the ions are slightly shifted each round, so it is possible to avoid the problem of overtaking the ions that would occur when the ions orbit the same orbit.
It goes without saying that the shape of the orbit in the mass separator 3 or the configuration and structure of the electrodes for forming it are not limited to those shown in FIGS. 7 and 8, and that various well-known shapes can be adopted. stomach.

Not only multi-turn TOF mass separators but also mass spectrometers using TOF mass separators use MCPs (or secondary electron multipliers) as ion detectors. Since the characteristics of such a detector deteriorate with use, it is a type of consumable item and needs to be replaced with a new one periodically or every time a predetermined usage time has elapsed, for example. In the mass spectrometer of the above embodiment, since the internal space of the second chamber 7 is opened by removing the lid 7B of the second chamber 7, the ion detector 4 can be removed from the mass separator 3 and replaced. It is. However, the lid body 7B is quite heavy for the following reasons.

In a TOF mass separator, if there are residual gas molecules in the flight space, there is a high possibility that ions will come into contact with the residual gas molecules during flight, and as a result, ions with the same m/z value will spread out and the resolution will be reduced. There is a possibility that the sensitivity may be lowered or the sensitivity may be lowered due to loss of ions. Therefore, the interior of the vacuum container (in this case, the second chamber 7) in which the mass separator is placed is maintained at a high vacuum (for example, 10 ^-7 to 10 ^-9 Torr), and the vacuum container is subjected to large forces due to atmospheric pressure. is added. If the vacuum container is deformed by that force, the electrode fixed inside the container will be deformed or moved relative to each other, resulting in a decrease in assembly accuracy and failure to achieve the expected performance, or the electrode may be damaged due to the deformation. There is a risk that this may occur. In particular, in a multi-turn TOF mass separator, since ions repeatedly fly many times along trajectories formed by the same electrodes, the deterioration in performance due to deformation or positional deviation of the electrodes as described above is significant. Therefore, the second chamber 7 has a fairly thick and robust structure to prevent deformation even when such a large force is applied from the outside (atmospheric pressure side), and both the main body 7A and the lid 7B are heavy. .

For this reason, a small crane is required to lift and remove the lid body 7B, which is a very troublesome, time-consuming, and costly task. It is a heavy burden on the user to perform such work every time the ion detector 4 is replaced. Therefore, in the mass spectrometer of this embodiment, a structure is used in which the ion detector 4 can be easily replaced, as described below.

As shown in FIGS. 2 and 3, an opening 7C is formed in the lid 7B directly above the ion detector 4 attached to the mass separator 3. The size of this opening 7C is one size larger than the size of the ion detector 4 when viewed from above. The shape of the opening 7C can be any shape such as a circle, an ellipse, or a rectangle. This opening 7C is closed by a detector holding mechanism 10 that has the function of holding the ion detector 4.

The detector holding mechanism 10 includes a lid part 11 located outside the lid body 7B, a holding part 12 made of an insulating member that holds the ion detector 4, and a plurality of parts, one end of which is fixed to the back surface of the lid part 11. and an elastic section 14 inserted between the other end of the column 13 and the holding part 12. Although the elastic portion 14 is a spring here, it may be another elastic body or elastic member such as rubber. A metal gasket 16 that maintains airtightness is arranged between the lid portion 11 and the lid body 7B.

As shown in FIG. 3, the ion detector 4 is fixed to the mass separator 3 with screws 15. Preferably, the screw 15 is a drop-off prevention screw. In addition, a small-diameter screw attachment/detachment opening 7D is formed in the main body portion 7A of the second chamber 7 on an extension of the screwing position of the screw 15 into the mass separator 3, and the screw attachment/detachment opening 7D is connected to the lid portion 17. It is blocked by The ion detector 4 is fixed to the holding part 12 of the detector holding mechanism 10 with, for example, a screw (not shown), so that the detector holding mechanism 10 and the ion detector 4 are integrated.

As shown in FIG. 3, when the device is assembled, the ion detector 4 is fixed to the mass separator 3 and connected to the lid 11 via the holding part 12, the elastic part 14, and the support column 13. , is also fixed to the lid part 11. However, the elastic portion 14 can be allowed to move within a predetermined range in each of the three axis directions of X, Y, and Z.

When replacing the ion detector 4 from the state shown in FIG. 3, the operator performs the following operations. First, the lid portion 17 is removed, and the tip of a dedicated screwdriver is inserted into the second chamber 7 through the screw attachment/detachment opening 7D. Then, turn the screw 15 and remove the screw 15. Thereby, the ion detector 4 can be separated from the mass separator 3. Then, the operator holds the lid 11 and pulls out the ion detector 4 straight in the Z-axis direction as shown in FIG. The ion detector 4 integrated with the detector holding mechanism 10 including the lid 11 is taken out to the outside of the second chamber 7 through the opening 7C.

After replacing the ion detector 4 with a new one, when installing the new ion detector 4 into the device, insert the ion detector 4 into the second chamber 7 through the opening 7C in the opposite way to the above procedure. After the lid part 11 is attached to a predetermined position on the lid body 7B, the screw 15 may be tightened using a screwdriver inserted into the second chamber 7 through the screw attachment/detachment opening 7D.
As described above, in the mass spectrometer of this embodiment, the ion detector 4 can be easily replaced without opening and closing the lid 7B, which takes time and effort to open and close.

As described above, in the mass spectrometer of this embodiment, the degree of vacuum in the second chamber 7 is high, so although the chamber 7 is strong, the main body 7A and the lid 7B may be damaged inside by a large force from outside. Deformation such as bending or distortion may occur. In this case, a force is applied to move the mass separator 3 via the support 40, and a force to move the ion detector 4 is applied via the lid 11 and the support 13. Even in such a case, the elastic part 14 provided between the support column 13 and the holding part 12 absorbs the force due to movement or deformation. Therefore, it is possible to reduce undesired forces acting on the ion detector 4 itself and its mounting portion, and to prevent deformation and damage thereof.

In the above embodiment, in order to fix the ion detector 4 to the mass separator 3, the screw 15 having both positioning and fixing functions was used, but as shown in FIG. The ion detector 4 may be fixed to the mass separator 3 with a spring-loaded fixing screw 18 after positioning is performed by inserting a positioning pin 19 provided on the mass separator 3 into the provided positioning hole 4A. .

Further, for example, either the ion detector 4 or the mass separator 3 is provided with a guide that guides the other in the Z-axis direction, and when the ion detector 4 is mounted, the ion detector 4 is moved to a predetermined position along the guide. It may be possible to make it easier to fit in the position. Of course, the method of fixing the ion detector 4 to the mass separator 3 is not limited to this, and any known appropriate method can be adopted.

In addition, the detector holding mechanism 10 is configured such that a member for closing the opening 7C and a member for holding the ion detector 4 are integrated, and the ion detector 4 is held at a predetermined position with respect to the mass separator 3. It is clear that the structure is not limited to the above structure and can be modified as appropriate as long as it is possible to maintain the structure.

In the above embodiment, the mass separator 3 is a multi-turn TOF mass separator, but it may also be a reflectron TOF mass separator, a multiple reflection TOF mass separator, a linear TOF mass separator, etc., as appropriate. It is clear that other types or embodiments of the mass separator may be substituted.

Furthermore, it goes without saying that configurations other than the vacuum vessel in which the mass separator 3 and ion detector 4 are housed can be modified as appropriate. For example, the mass spectrometer of the above embodiment has a configuration in which ions generated by an ion source 1 are stored in an ion trap 2 and sent out to a mass separator 3. It is also possible to adopt a configuration in which ions generated from the sample S in the ion source 100 and accelerated are introduced into the mass separator 3 as they are. In this configuration, specifically, the sample S provided on the sample plate 102 is irradiated with laser light emitted from the laser emitting unit 101, and components contained in the sample S are ionized. The generated ions are extracted from the sample plate 102 by the electric field formed by the extraction electrode 103, accelerated by the acceleration electrode 104, and sent into the second chamber 7.

Furthermore, in addition to the configurations shown in FIGS. 1 and 6, a mass spectrometer capable of MS/MS analysis can be provided by further providing a collision cell or a pre-stage mass separator, for example.

Furthermore, it is clear that the above-mentioned embodiments and the above-mentioned modifications are merely examples of the present invention, and that even if appropriate modifications, changes, and additions are made within the spirit of the present invention, they will still fall within the scope of the claims of the present application. be.

[Various aspects]
It will be appreciated by those skilled in the art that the exemplary embodiments described above are specific examples of the following aspects.

(Section 1) One aspect of the mass spectrometer according to the present invention is
A vacuum container whose interior is made into a vacuum atmosphere by evacuation,
an analysis section including a mass separator and an ion detector disposed inside the vacuum container;
an opening formed at a predetermined position on the wall surface of the vacuum container and having a size that allows the ion detector to pass through;
a detector holding part formed by integrating a lid part that closes the opening, and a connection part that connects the lid part and the ion detector;
Equipped with.

According to the mass spectrometer described in item 1, the lid of the detector holding part that closes the opening formed in the vacuum container is removed, and the ion detector held in the detector holding part is removed. The ion detector can be taken out of the vacuum container by pulling it out through the opening. This makes it possible to replace the ion detector installed inside the vacuum container at low work costs without requiring time and effort, without removing the heavy lid for opening and closing the vacuum container, for example. Can be done.

(Section 2) In the mass spectrometer according to Item 1, the ion detector is attached to the vacuum container in a state in which the detector holder is attached to the vacuum container so that the lid closes the opening. It may further include a fixing part for fixing to the mass separator.

According to the mass spectrometer described in Section 2, the ion detector is securely fixed to the mass separator, and ions separated according to m/z by the mass separator are successfully introduced into the ion detector. can be detected.

(Section 3) In the mass spectrometer according to Item 2, the fixing part can be fixed and released by operation through a sub-opening formed in the vacuum container, which is different from the opening. It may be a member that is.

Here, the member of the fixing part may be a screw that can be screwed in and removed by a rotational operation, preferably a drop-off prevention screw.
According to the mass spectrometer described in item 3, the ion detector can be reliably fixed to the mass separator at a relatively low cost.

(Section 4) In the mass spectrometer according to Item 1, the connecting portion may include an elastic portion that allows a change in the position of the ion detector with respect to the lid portion.

Here, the elastic portion can be a member using, for example, a spring or rubber. If the ion detector is fixed so that its position does not move relative to the lid, if the mass separator moves due to, for example, deformation of the chamber during evacuation, the ion detector itself or the mass separation between the ion detector and the ion detector may be affected. There is a risk that force will be applied to the parts that secure the device and cause damage. On the other hand, according to the mass spectrometer described in Section 4, even if the mass separator moves, the elastic part provided at the connection part deforms and absorbs the movement, so the ion detector and It is possible to avoid unnecessary force being applied to the fixing members and the like, and damage to them can be prevented.

(Section 5) In the mass spectrometer according to Item 1, the mass separator is separated from the inner bottom surface of the vacuum container by a plurality of supports that are directly or indirectly fixed to the inner bottom surface of the vacuum container. It may be assumed that the

According to the mass spectrometer described in item 5, even if the vacuum container is deformed due to a pressure difference between the inside and outside of the vacuum container, the force applied to the mass separator can be reduced.

(Section 6) In the mass spectrometer according to any one of Items 1 to 5, the mass separator may be a multiturn time-of-flight mass separator.
By employing a multi-turn time-of-flight mass separator as a mass separator, the flight distance of the ions to be analyzed becomes longer, so it is possible to improve the mass resolution of the ions.

(Section 7) The mass spectrometer according to Item 6 may include an ion source and an ion trap capable of ejecting ions to be analyzed upstream of the mass separator.

According to the mass spectrometer described in Section 7, the ions generated in the ion source are temporarily stored in the ion trap and subjected to mass spectrometry, thereby increasing the amount of ions to be subjected to mass spectrometry, increasing analysis sensitivity and analysis accuracy. can be increased.

(Section 8) In the mass spectrometer according to Item 6 or 7, an ion source using a matrix-assisted laser desorption ionization method may be provided upstream of the mass separator.

In the mass spectrometer described in item 8, for example, it is possible to efficiently ionize a polymer compound without destroying its structure. Therefore, it is possible to provide a mass spectrometer suitable for bio-derived polymer compounds and the like.

1... Ion source 2... Ion trap 3... Mass separator 31... Main electrode 34... Ion introduction port 35... Ion outlet 4... Ion detector 4A... Positioning hole 5... First chamber 5A... Ionization chamber 5B... First vacuum Chamber 6...Partition 7...Second chamber 7A...Main body 7B...Lid 7C...Opening 7D...Screw attachment/removal opening 7E...Exhaust opening 7F...Ion passing holes 8, 9...Vacuum pump 10...Detector holding mechanism 11... Lid 12... Holding part 13... Support 14... Elastic part 15... Screw 16... Metal gasket 17... Cover 18... Fixing screw with spring 19... Positioning pin 40... Support 100... MALDI ion source

Claims (8)

A vacuum container whose interior is made into a vacuum atmosphere by evacuation,
an analysis section including a mass separator and an ion detector disposed inside the vacuum container;
an opening formed at a predetermined position on the wall surface of the vacuum container and having a size that allows the ion detector to pass through;
a detector holding part formed by integrating a lid part that closes the opening, and a connection part that connects the lid part and the ion detector;
A mass spectrometer equipped with. Claim further comprising: a fixing part that fixes the ion detector to the mass separator in a state where the detector holding part is attached to the vacuum container so that the lid closes the opening. The mass spectrometer according to item 1. 3. The mass spectrometer according to claim 2, wherein the fixing part is a member that can be fixed and released by operation through a sub-opening formed in the vacuum container and different from the opening. The mass spectrometer according to claim 1, wherein the connection section includes an elastic section that allows the position of the ion detector to change with respect to the lid section. The mass spectrometer according to claim 1, wherein the mass separator is held apart from the inner bottom surface of the vacuum container by a plurality of supports that are directly or indirectly fixed to the inner bottom surface of the vacuum container. Device. The mass spectrometer according to claim 1, wherein the mass separator is a multiturn time-of-flight mass separator. The mass spectrometer according to claim 6, further comprising an ion source and an ion trap capable of ejecting ions to be analyzed, upstream of the mass separation section. 7. The mass spectrometer according to claim 6, further comprising an ion source based on matrix-assisted laser desorption ionization before the mass separation section.

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