WO2018109920A1

WO2018109920A1 - Mass spectrometry device

Info

Publication number: WO2018109920A1
Application number: PCT/JP2016/087512
Authority: WO
Inventors: 良弘上野; 治古橋; 勇介立石
Original assignee: 株式会社島津製作所
Priority date: 2016-12-16
Filing date: 2016-12-16
Publication date: 2018-06-21

Abstract

A time-of-flight mass spectrometry unit (7) and an ion trap (6) are provided on either side of an ion expelling unit (5) that is capable of ejecting ions in a direction substantially perpendicular to a direction in which the ions are introduced. In a flight space (8) of the time-of-flight mass spectrometry unit (7), a pair of MR reflectors (9A, 9B) are provided on either side of a main reflector (10), and a non-destructive sub-ion detector (12) is also provided. When in a Q-TOF mode, ions ejected from the ion expelling unit (5) are caused to fly along a flight path (A) and are detected by a main ion detector (11). When in an MR-TOFMS mode, ions discharged from the ion expelling unit (5) are trapped by the ion trap (6), and ions ejected from the ion trap (6) are introduced into the flight path (A), are caused to go back and forth a plurality of times between the pair of MR reflectors (9A, 9B), and are then detected by the main ion detector (11). When in an FT-MS mode, ions going back and forth between the pair of MR reflectors (9A, 9B) are detected by the sub-ion detector (12), and the resulting detection signal is subjected to Fourier transform to obtain a mass spectrum. This enables measurements with different mass resolutions and measurement periods by using a single device.

Description

Mass spectrometer

The present invention relates to a mass spectrometer, and more particularly, to a mass spectrometer equipped with a time-of-flight mass analyzer.

In a time-of-flight mass spectrometer (hereinafter referred to as “TOFMS”), in general, a constant kinetic energy is imparted to ions derived from sample components to fly through a space of a certain distance, and the time required for the flight is measured and the flight is performed. The mass-to-charge ratio of ions is calculated from the time. For this reason, when ions are accelerated and flight is started, if there are variations in the position of ions or the initial energy of ions, variations in the flight time of ions with the same mass-to-charge ratio will result in a decrease in mass resolution and mass accuracy. It leads to. As a technique for solving such a problem, an orthogonal acceleration type TOFMS (hereinafter referred to as “OA-TOFMS”) in which ions are accelerated in a direction orthogonal to the incident direction of an ion beam and sent to a flight space is known.

Since OA-TOFMS is configured to pulse-accelerate ions in a direction orthogonal to the direction of introduction of an ion beam derived from a sample component, various ion sources that ionize components contained in a sample introduced continuously, For example, a combination with an atmospheric pressure ion source such as an electrospray ion source or an electron ion source is possible. Recently, in order to analyze the structure of a compound, a quadrupole mass filter that selects ions having a specific mass-to-charge ratio from ions derived from sample components, and the selected ions are dissociated by collision-induced dissociation or the like. A Q-TOF type mass spectrometer that combines a collision cell and OA-TOFMS is also widely used (see Non-Patent Document 1). In the Q-TOF mass spectrometers currently on the market, reflectron type TOFMS is generally used, and the measurement cycle is about 10 kHz, that is, the time required for one measurement is about 100 μsec. The maximum mass resolution is about 50,000.

Depending on the purpose of measurement, such as conducting structural analysis of biopolymer compounds using mass spectrometry, the above mass resolution may be insufficient. A multi-circular TOFMS (hereinafter referred to as “MT-TOFMS”) or a multi-reflection TOFMS (hereinafter referred to as “MR-TOFMS”) is known as one that can obtain a higher mass resolution than the reflectron type TOFMS. The former revolves ions a plurality of times along a circular orbit such as an elliptical shape or an 8-shaped shape, and the latter reciprocates ions a plurality of times along a linear reciprocating orbit (Non-Patent Document 2). reference). In any of these TOFMS, it is possible to secure a long flight distance and obtain a high mass resolution while suppressing the space of the flight space. For example, in MR-TOFMS in practical use, the measurement cycle is about 100 Hz and the mass resolution is about 100,000 at the maximum.

A Fourier transform type mass spectrometer (hereinafter referred to as “FT-MS”) is known as a mass spectrometer capable of achieving even higher mass resolution. In any of the OA-TOFMS, MT-TOFMS, and MR-TOFMS, ions flying over a predetermined flight distance are introduced into an ion detector and detected. In contrast, in FT-MS, ions that continue to circulate (or reciprocate) on the same trajectory are repeatedly detected by the non-destructive ion detector for each lap. Since ions with the same mass-to-charge ratio move at the same frequency (frequency), the detection signal obtained when ions with various mass-to-charge ratios are mixed is a spectrum in which signals of various frequencies are superimposed. Signal. Therefore, in FT-MS, a mass spectrum is obtained by performing a Fourier transform process on such a spectrum signal.

It is well known that FT-MS uses an ICR (ion cyclotron resonance) cell that periodically moves ions by the action of a magnetic field. Orbitrap, multiple orbital time-of-flight mass analyzer, multiple reflection flight There are also known time-type mass analyzers that periodically move ions using an electric field (see Patent Document 1). In a general FT-MS, the measurement period is as long as about 10 Hz, but the mass resolution is about 500,000, which is about 10 times as high as that of Q-TOFMS.

As described above, in the mass spectrometer, the measurement cycle and the mass resolution are usually in a trade-off relationship. Therefore, a mass spectrometer capable of obtaining a measurement period and mass resolution in accordance with the purpose of measurement and the like is selected. For example, when measuring a sample containing components separated by liquid chromatograph (LC) or gas chromatograph (GC) with a mass spectrometer, in order to eliminate component detection omission or increase the accuracy of the chromatogram peak waveform It is necessary to repeat the measurement with a short measurement cycle. Therefore, in such a case, Q-TOFMS with a short measurement period is often used while sacrificing mass resolution to some extent. On the other hand, MT-TOFMS, MR-TOFMS, FT-MS, etc. are used for measurement in which mass resolution is more important than measurement cycle and measurement throughput.

JP 2007-280655 A

In the conventional mass spectrometer, the measurement period and the mass resolution may be adjusted to some extent, but basically, the measurement period and the mass resolution are almost determined by the method, in other words, the configuration of the apparatus. . Therefore, when it is desired to measure various samples for various purposes or when it is necessary to measure them, it is necessary to prepare various types of mass spectrometers as described above. However, since these mass spectrometers are quite expensive, it is very expensive for the user to prepare a plurality of mass spectrometers with different methods. If a plurality of mass spectrometers having different methods are prepared, the management and maintenance of the apparatus is troublesome, and there is a problem in securing the installation location.

The present invention has been made in order to solve the above-mentioned problems. The object of the present invention is to perform high-speed measurement with a short measurement cycle although the mass resolution is not so high depending on the purpose of measurement, and conversely, the measurement cycle. A high-resolution measurement that can provide a very high mass resolution but a measurement period and mass resolution that are both high-speed and high-resolution measurements can be switched with a single device. It is providing the mass spectrometer which can be performed.

The mass spectrometer of the first aspect of the present invention, which has been made to solve the above problems,
a) an ion guide for transporting ions derived from sample components;
b) an operation of ejecting the ions transported by the ion guide in a first direction different from the traveling direction of the ions, and the transported ions in either the traveling direction of the ions or the first direction. An ion extruding unit that selectively performs an operation of deflecting in a different second direction,
c) A flight time including a flight space in which ions ejected from the ion pusher in the first direction fly, and a first detection unit provided at a position where the ions flying in the flight space arrive. Type mass spectrometer,
d) Ion trap that captures and temporarily holds ions traveling in the second direction from the ion pusher and ejects the held ions toward the flight space of the time-of-flight mass spectrometer And
e) a pair of ion optical elements disposed along a flight trajectory until ions ejected from the ion pusher in the first direction reach the first detector, the flight trajectory A pair of ion reflectors that each form a reflected electric field such that ions reciprocate between the pair of ion optical elements along
f) a second detection unit that detects non-contact and non-destructive ions flying between the pair of ion reflection units;
g) a first analysis mode in which ions are ejected from the ion pusher in the first direction, fly in the flight space and detected by the first detector, and the second from the ion pusher. After ions are advanced in the direction and trapped in the ion trapping part, ions are ejected from the ion trapping part and introduced into the flight space, and the reciprocating motion is performed one or more times by the pair of ion reflecting parts. A second analysis mode to be detected by the first detection unit; and after the ions are advanced from the ion extrusion unit in the second direction and captured by the ion capture unit, the ions are ejected from the ion capture unit and Each part is controlled to selectively perform one of the third analysis mode that is introduced into the flight space and repeatedly detected by the second detection unit while reciprocating a plurality of times by the pair of ion reflection units. A control unit;
h) In the first and second analysis modes, ion mass information is obtained based on the detection signal obtained by the first detection unit, while in the third analysis mode, at least the second detection is performed. A signal analysis unit for obtaining ion mass information by Fourier transform operation based on the detection signal obtained by the unit;
It is characterized by having.

In the mass spectrometer according to the first aspect of the present invention, the ion trapping unit may be an ion trap that traps ions by the action of a high-frequency electric field. This ion trap may be either a three-dimensional quadrupole ion trap or a linear ion trap.

The mass spectrometer of the second aspect of the present invention, which has been made to solve the above problems,
a) an ion guide for transporting ions derived from sample components;
b) an ion extruding unit that ejects ions transported by the ion guide in a direction different from the direction of travel of the ions;
c) a time-of-flight mass analyzer including a flight space in which ions ejected from the ion pusher fly, and a first detection unit provided at a position where the ions flying in the flight space reach;
d) a pair of ion optical elements disposed along a flight trajectory until ions ejected from the ion pusher reach the first detection unit, and the pair of ion optical elements along the flight trajectory A pair of ion reflectors that each form a reflected electric field so that ions reciprocate between ion optical elements;
e) a second detector that detects non-contact and non-destructive ions flying between the pair of ion reflectors;
f) a first analysis mode in which ions are ejected from the ion push-out unit, fly in the flight space and detected by the first detection unit, and ions are ejected from the ion push-out unit and introduced into the flight space A second analysis mode in which the first detection unit detects the reciprocating motion one or more times by the pair of ion reflecting units, and ions are ejected from the ion pusher and introduced into the flight space. And a control unit that controls each unit to selectively perform any one of the third analysis mode that is repeatedly detected by the second detection unit while reciprocating a plurality of times by the pair of ion reflection units,
g) In the first and second analysis modes, ion mass information is obtained based on the detection signal obtained by the first detection unit, while in the third analysis mode, at least the second detection is performed. A signal analysis unit for obtaining ion mass information by Fourier transform operation based on the detection signal obtained by the unit;
It is characterized by having.

In the mass spectrometers of the first and second aspects according to the present invention, the ion guide, for example, transports ions derived from the sample component to the subsequent stage while converging ions derived from the sample component by the action of a high-frequency electric field. The ions transported by this ion guide, regardless of their type, are derived from various types of molecule-related ions obtained by ionizing compounds in the sample, fragment ions generated during the ionization process, For example, product ions generated by dissociating ions by collision-induced dissociation or the like are included. Ions transported by the ion guide are introduced into the ion extrusion section. The ion path up to this point is common to the first to third analysis modes.

In the mass spectrometer of the first aspect according to the present invention, ions are ejected from the ion extruding unit in the first direction in which ions are ejected from the ion extruding part, and in the mass spectrometer of the second aspect according to the present invention. It is preferable that any of the directions is substantially perpendicular to the direction of ion introduction into the ion extrusion section. In the mass spectrometer according to the first aspect of the present invention, the second direction in which ions travel after being deflected by the ion extruding unit may be a direction almost opposite to the first direction.

In the mass spectrometer according to the first aspect of the present invention, when the control unit controls each unit to execute the first analysis mode, the ion push-out unit converts the introduced ions into the first direction by the action of the electric field. To ejaculate. As described above, when the first direction is substantially perpendicular to the direction of ion introduction into the ion pusher, the ion pusher functions as an orthogonal acceleration unit that sends ions into the flight space of the time-of-flight mass spectrometer. . Ions ejected with a predetermined energy from the ion pusher fly in the flight space, and during that time, each ion reaches a first detector with a position difference according to the mass-to-charge ratio. The signal analyzer obtains the flight time of each ion based on the detection signal from the first detector, and acquires the mass information by converting the flight time into a mass-to-charge ratio. In the case of a mass spectrometer configured to select ions having a specific mass-to-charge ratio derived from a sample component with a quadrupole mass filter, dissociate the selected ions, and introduce the ions into an ion extrusion unit through an ion guide. The first analysis mode is a mode for performing analysis corresponding to Q-TOFMS.

In the mass spectrometer according to the first aspect of the present invention, when the control unit controls each unit to execute the second analysis mode, the ion pusher unit converts the introduced ions into the second direction by the action of the electric field. Spit out. This ion is introduced into the ion trapping part located in the second direction. The ion trapping unit traps and temporarily holds ions by the action of an electric field, and ejects the held ions toward the flight space of the time-of-flight mass analysis unit at a predetermined timing. As described above, when the second direction is substantially opposite to the first direction, the ion trapping unit ejects ions in a direction opposite to the direction in which ions are introduced into the ion trapping unit, thereby The ion pusher can be passed through and sent into the flight space.

In the second analysis mode, ions ejected from the ion trapping part are introduced into the flight space, and after the ions have passed through the ion reflecting part on the side close to the ion pushing part on the flight trajectory of the pair of ion reflecting parts. Each of the pair of ion reflecting portions forms an electric field that reflects ions. Then, ions reciprocate along the flight path between the pair of ion reflecting portions. Then, when the reflected electric field in the ion reflecting portion on the side close to the first detecting portion on the flight trajectory of the pair of ion reflecting portions disappears, the ions pass through the ion reflecting portion and reach the first detecting portion. . Since ions reciprocate one or more times between the pair of ion reflecting portions, the flight distance becomes longer and the mass resolution is improved. In the case of the mass spectrometer configured as described above, wherein ions having a specific mass-to-charge ratio derived from the sample component are selected by the quadrupole mass filter, and the selected ions are dissociated and introduced into the ion extrusion unit through the ion guide. The second analysis mode is a mode for performing analysis corresponding to MR-TOFMS.

In the mass spectrometer according to the first aspect of the present invention, in the third analysis mode, the control unit basically controls each unit in the same manner as in the second analysis mode. Therefore, the ions introduced into the flight space reciprocate between the pair of ion reflecting portions. However, in the second analysis mode, the second detection unit does not substantially function, whereas in the third analysis mode, the second detection unit generates ions once during at least one round trip of ions. Detect and output detection signal. The signal analysis unit obtains mass information of each ion by performing Fourier transform on the spectrum signal obtained based on the detection signal from the second detection unit. That is, the above-described mass spectrometer configured to select ions having a specific mass-to-charge ratio derived from the sample component with a quadrupole mass filter, dissociate the selected ions, and introduce the ions to the ion extrusion unit through the ion guide. In this case, the third analysis mode is a mode for performing analysis corresponding to FT-MS.

Further, in the mass spectrometer according to the first aspect of the present invention, the control unit further ejects ions from the ion push-out unit in the first direction and introduces them into the flight space, and the pair of ion reflection units Then, after reciprocating once or a plurality of times, each part can be controlled to selectively perform the analysis mode detected by the first detection part.
In the analysis mode at this time, ions are not directly captured by the ion trapping part, but are ejected directly from the ion pusher toward the flight space. Therefore, although the mass resolution is slightly sacrificed as compared with the second analysis mode, the ion trapping is performed. Since the ion trapping is not performed in the part, the analysis measurement period corresponding to MR-TOFMS can be shortened.

Further, in the mass spectrometer according to the first aspect of the present invention, the control unit further ejects ions from the ion push-out unit in the first direction and introduces them into the flight space, and the pair of ion reflection units Thus, each part can be controlled so as to selectively perform the analysis mode in which the second detection part repeatedly detects the reciprocating motion multiple times.
Even in the analysis mode at this time, ions are not directly captured by the ion trapping part, but are ejected directly from the ion pusher toward the flight space. Therefore, although the mass resolution is slightly sacrificed compared to the third analysis mode, the ion trapping is performed. Since the ion capture in the part is not performed, the measurement cycle of analysis corresponding to FT-MS can be shortened.

Moreover, in the mass spectrometer according to the first aspect of the present invention, the control unit further causes ions to travel from the ion extrusion unit in the second direction and are captured by the ion capture unit, and then from the ion capture unit. It is also possible to adopt a configuration in which each unit is controlled so as to selectively perform an analysis mode in which ions are ejected to fly in the flight space and detected by the first detection unit.
In this analysis mode, ions are once trapped in the ion trapping part and ejected from the ion trapping part toward the flight space. Therefore, although the measurement cycle is slightly longer than in the first analysis mode, this corresponds to Q-TOFMS. The mass resolution of the analysis can be improved.
By preparing more variations of the analysis mode in this way, the user can select an analysis mode that is closer to the target measurement cycle and mass resolution.

In the mass spectrometer according to the first aspect of the present invention, the time of flight is calculated using the ion trapping unit as the ion ejection source in the second and third analysis modes, whereas the second aspect according to the present invention. In the mass spectrometer, the ion extruding unit serves as an ion ejection source in any of the first to third analysis modes. In general, once the ions are trapped in the ion trapping part, it is easier to improve the energy convergence of the flight time. Therefore, the mass spectrometer of the first aspect is more advantageous for improving the accuracy of the mass information. On the other hand, in the mass spectrometer of the second mode, it is not necessary to provide an ion trapping unit, and the ion push-out unit may be configured to eject ions only in one direction. A mass spectrometer is more advantageous.

In the mass spectrometer according to the first or second aspect of the present invention, preferably, the time-of-flight mass analyzer is a reflectron type time-of-flight having a main ion reflector different from the pair of ion reflectors. It is a type | mold mass spectrometry part, The said pair of ion reflection part is good to set it as the structure arrange | positioned facing both sides which pinched | interposed the said main ion reflection part on the said flight track.
According to this configuration, high energy convergence can be realized in a relatively narrow flight space.

According to the mass spectrometer according to the present invention, the analysis corresponding to Q-TOFMS, the analysis corresponding to MR-TOFMS, and the analysis corresponding to FT-MS can be selectively executed by one apparatus. . That is, depending on the purpose of measurement and the like, it is possible to selectively perform measurement capable of realizing extremely high mass resolution although the measurement period is considerably long, and measurement in a short measurement period although the mass resolution is relatively low. This reduces the economic burden of arranging a plurality of mass spectrometers of different methods, eliminates the complexity of management and maintenance, and reduces the installation space for the apparatus.

The schematic block diagram of one Example of the mass spectrometer which concerns on this invention. Operation | movement explanatory drawing at the time of Q-TOF mode execution in the mass spectrometer of a present Example. Explanatory drawing of operation | movement at the time of MR-TOF mode execution in the mass spectrometer of a present Example. Explanatory drawing of operation | movement at the time of MR-FT mode execution in the mass spectrometer of a present Example.

An embodiment of a mass spectrometer according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram of the mass spectrometer of the present embodiment.

The mass spectrometer of the present embodiment includes an ion source 1, a quadrupole mass filter 2, a collision cell 3 having an ion guide 4 therein, and an ion pusher 5 inside a chamber (not shown) maintained in a vacuum. And an ion trap 6 and a time-of-flight mass analyzer 7 including a flight space 8 and a main ion detector 11. In addition, the mass spectrometer of the present embodiment includes a control unit 20, an ion trap power supply unit 22, an extrusion electrode power supply unit 21, an MR reflector power supply unit 24, and an RT unit as functional blocks of a control / processing system. The reflector power supply unit 23, the input unit 25, and the signal analysis unit 30 are provided.

The ion source 1 ionizes sample components in the sample gas by, for example, electron ionization (EI). Of course, the ionization method is not limited to the EI method, and any ionization method can be used. In addition, when using the ion source by atmospheric pressure ionization methods, such as an electrospray ionization (ESI) method, as the ion source 1, this ion source 1 is put under atmospheric pressure.

The quadrupole mass filter 2 includes four rod electrodes arranged so as to surround the ion optical axis C extending in the X-axis direction, and ions introduced into the space surrounded by the four rod electrodes are mass-charged. According to the ratio, ions having a specific mass-to-charge ratio (or mass-to-charge ratio range) are selectively passed.

The collision cell 3 is a box-like body having an ion inlet 3a and an ion outlet 3b, into which a collision gas such as Ar is introduced. Ions entering the collision cell 3 through the ion inlet 3a have appropriate energy and come into contact with the collision gas, and are dissociated by collision-induced dissociation (CID) to generate various product ions.

The ion extruding unit 5 includes a pair of flat plate-shaped extruding electrodes 5a that are arranged to face each other with the ion optical axis C interposed therebetween and extend in the XY plane. The pair of extrusion electrodes 5a have openings through which ions can pass. Or at least one part of the extrusion electrode 5a may be mesh shape. The extrusion electrode power supply unit 21 applies a pulsed DC voltage to the extrusion electrode 5a, and ions are introduced into the space between the extrusion electrodes 5a from the collision cell 3 side along the ion optical axis C. When a predetermined voltage is applied to the extrusion electrode 5a, ions are discharged in a direction substantially orthogonal to the ion optical axis C by the action of an electric field formed thereby. Depending on the relationship between the polarity of the ions and the polarity of the voltage applied to the extrusion electrode 5a, the ions are discharged in one of two directions that are substantially opposite to each other (in the positive direction or the negative direction along the Z axis in FIG. 1). It is.

The ion trap 6 is disposed on an extension in one direction from which ions are ejected from the ion extruding unit 5. In this example, the inner surface disposed so as to surround the axis extending in the Y-axis direction in FIG. It is a linear ion trap including four rod electrodes that are hyperbolic. The ion trap 6 may be a three-dimensional quadrupole ion trap. In one rod electrode 6a of the rod electrode constituting the ion trap 6, an ion entrance / exit port 6b is formed at a position where ions ejected from the ion extruding unit 5 can be received. The ion trap power supply unit 22 applies a high frequency voltage, a direct current voltage, or both to each rod electrode constituting the ion trap 6, and the ions introduced into the ion trap 6 through the ion entrance / exit port 6b are converted into a high frequency electric field. It can be captured by the action of.

The time-of-flight mass analysis unit 7 has a reflectron type configuration, so that the ions ejected from the ion pusher 5 or the ions ejected from the ion trap 6 and passed through the ion pusher 5 are turned back. A main reflector 10 that reflects ions by the action of an electric field is disposed at a predetermined position in the flight space 8. The main reflector 10 is composed of a flat back plate and a plurality of ring electrodes, and a reflected electric field is formed by a DC voltage applied to each electrode from the RT reflector power supply unit 23. A main ion detector 11 is arranged at a position where ions reflected by the main reflector 10 arrive, that is, on an extension of the flight trajectory A in the flight space 8.

Also, along the flight path A, a pair of

MR reflectors

9A and 9B are arranged on both sides of the main reflector 10. Each of the

MR reflectors

9A and 9B includes a plurality of ring electrodes. Due to the DC voltage applied to each electrode of the

MR reflectors

9A and 9B from the MR reflector power supply unit 24, in each of the

MR reflectors

9A and 9B, ions arriving from the main reflector 10 side are substantially specular. Reflected electric field is formed (however, the reflection position differs depending on the velocity of ions). Further, a sub-ion detector 12 that detects passing (flying) ions in a non-contact and non-destructive manner is disposed between the pair of

MR reflectors

9A and 9B along the flight path A.

The detection signals from the main ion detector 11 and the sub ion detector 12 are both input to the signal analysis unit 30 and converted into digital data, respectively, and then a predetermined analysis process is executed to create a mass spectrum. .
In order to avoid complication of the drawing, in FIG. 1, description of circuit blocks for applying voltages to the quadrupole mass filter 2, the ion guide 4 and the like is omitted, but these are provided. Of course.

In the mass spectrometer of the present embodiment, an operator (user) can perform measurement in one of the following three analysis modes by giving a predetermined instruction using the input unit 25. Hereinafter, the measurement operation in each analysis mode will be described in detail.

(I) Q-TOF mode FIG. 2 is a diagram for explaining the operation in the Q-TOF mode in the mass spectrometer of the present embodiment. FIG. 2 (and FIG. 3 and FIG. 4 below) shows only the components necessary for explanation out of the components of the mass spectrometer of the present embodiment shown in FIG.
Literally, the Q-TOF mode is a mode for carrying out measurement equivalent to that of the Q-TOF type mass spectrometer.

The ions derived from the sample components are generated by the ion source 1, and ions having a specific mass-to-charge ratio are selected by the quadrupole mass filter 2 and introduced into the collision cell 3 as precursor ions. The precursor ions are dissociated by contacting the collision gas in the collision cell 3 to generate various product ions. The ion guide 4 has a simple linear ion trap function, temporarily accumulates the generated product ions, and sends them out to the subsequent stage at a predetermined timing. At a predetermined timing after the ion group is introduced into the ion extrusion unit 5 along the ion optical axis C, the extrusion electrode power supply unit 21 applies a predetermined DC voltage to the extrusion electrode 5a. Then, the ion is subjected to a force in the positive direction along the Z axis (downward in FIG. 1) by the electric field formed thereby, and is ejected to the flight space 8 with a predetermined energy. Since ions have traveled in the positive direction along the X axis immediately before being ejected, the direction in which the ions are actually ejected is not the Z axis direction, but is slightly inclined from the Z axis direction.

In this Q-TOF mode, no voltage is applied to the electrodes of the

reflectors

9A and 9B, which is equivalent to the absence of the

reflectors

9A and 9B. Further, the secondary ion detector 12 does not become an obstacle to the flight of ions. Therefore, the ions ejected from the ion pusher 5 travel along the flight path A, are folded back by the reflected electric field in the main reflector 10, and finally reach the main ion detector 11 and are detected. Upon receiving the detection signal from the main ion detector 11, the signal analysis unit 30 obtains the flight time of each ion starting from the time when the ions are ejected by the ion pusher 5, and converts the flight time into a mass-to-charge ratio. Create a mass spectrum.

(Ii) MR-TOF mode FIG. 3 is a diagram for explaining the operation in the MR-TOF mode in the mass spectrometer of the present embodiment.
Precursor ions derived from sample components are dissociated in the collision cell 3, and the behavior of ions until the generated product ions are introduced into the ion extruding unit 5 along the ion optical axis C is the same as in the Q-TOF mode. is there.

The extrusion electrode power supply unit 21 applies a predetermined DC voltage to the extrusion electrode 5a at a predetermined timing after the ion group is introduced into the ion extrusion unit 5. The polarity of the voltage applied at this time is opposite to that in the Q-TOF mode. Therefore, ions are discharged by receiving a force in the negative direction (upward in FIG. 1) along the Z axis by the electric field formed thereby. Therefore, the ions generally travel along the trajectory B and enter the inside of the ion trap 6 through the ion entrance / exit 6b. Ions entering the inside of the ion trap 6 are captured by an electric field formed by a high frequency voltage applied to each rod electrode of the ion trap 6 from the ion trap power supply unit 22. If a large energy is given to the ions when the ions are ejected from the ion extruding unit 5, the ions may pass through or disappear without being captured by the ion trap 6. Therefore, at this time, it is preferable that the energy given to the ions in the ion pusher 5 is made smaller than that in the Q-TOF mode.

The ions trapped in the ion trap 6 are cooled in contact with, for example, a cooling gas supplied into the ion trap 6. Then, the various ions that have been trapped are simultaneously ejected through the ion entrance / exit 6b by the DC high voltage applied to the ion trap 6 from the ion trap power supply unit 22. At this time, an electric field is not formed in the ion extruding unit 5, and ions pass through the ion extruding unit 5 and enter the flight space 8 and travel along the flight trajectory A. After the ion group passes through the MR reflector on the side close to the ion pusher 5 (hereinafter referred to as “first MR reflector”), the ion group is reflected by the main reflector 10 to be the main ion detector. The MR reflector power supply unit 24 uses the electrodes of the first and

second MR reflectors

9A and 9B before reaching the MR reflector 9B on the side close to 11 (hereinafter referred to as “second MR reflector”) 9B. A predetermined voltage is applied to each. Thereby, a reflected electric field is formed in each of the first and

second MR reflectors

9A and 9B.

When the ions flying along the flight trajectory A reach the second MR reflector 9B, the ions are reflected by the reflected electric field and return to the flight trajectory A. Further, when the returned ions reach the first MR reflector 9A, they are reflected by the reflected electric field. In this way, the ions are confined on the flight path A between the first MR reflector 9A and the second MR reflector 9B and reciprocate. If the reflected electric field disappears when the ions reach the second MR reflector 9B, the ions pass through the second MR reflector 9B and reach the main ion detector 11 to be detected. Upon receiving the detection signal from the main ion detector 11, the signal analysis unit 30 obtains the flight time of each ion starting from the time when the ions are ejected by the ion pusher 5, and sets the flight distance based on the assumed number of round trips. A mass spectrum is created by converting the time of flight into a mass-to-charge ratio as one condition.

(Iii) FT-MS Mode FIG. 4 is a diagram for explaining the operation in the FT-MS mode in the mass spectrometer of the present embodiment.
The operation until the analysis target ions ejected from the ion trap 6 are introduced into the flight path A between the

MR reflectors

9A and 9B is the same as in the MR-TOFMS mode. The ion behavior itself is the same as in the MR-TOFMS mode, but in this FT-MS mode, the secondary ion detector 12 moves in one direction (for example, the main reflection from the first MR reflector 9A) when the ions repeatedly reciprocate. Ion passing in the direction toward the vessel 10). After the ions are introduced into the flight trajectory A, the secondary ion detector 12 detects the ions almost continuously and outputs a detection signal. The signal analysis unit 30 converts the detection signal from the secondary ion detector 12 into digital data and accumulates it for a predetermined time, and creates a mass spectrum in which the mass information of each ion is reflected by performing a Fourier transform operation on this data. To do.

When necessary measurement is completed, the reflected electric field of the second MR reflector 9B may be canceled in the same manner as in the MR-TOFMS mode, and ions may sequentially reach the main ion detector 11 to be detected. . In this case, the signal analysis unit 30 can also create a mass spectrum based on the detection signal from the main ion detector 11.

As described above, in the mass spectrometer of the present embodiment, any one of the three types of measurement, the Q-TOF mode, the MR-TOF mode, and the FT-MS mode, can be selectively performed according to an operator's instruction. . Mass resolution is highest in the FT-MS mode, and decreases in the order of the MR-TOF mode and the Q-TOF mode. Conversely, the measurement cycle is the shortest in the Q-TOF mode, and becomes longer in the order of the MR-TOF mode and the FT-MS mode. The operator can arbitrarily select one of the modes according to the required mass resolution and measurement period. Of course, the mode may be automatically switched.

In addition to the three types of modes, the Q-TOF mode, the MR-TOF mode, and the FT-MS mode, ions are temporarily held in the ion trap 6, and ions are ejected from the ion trap 6 to cause the main ion detector 11. Mode (deformed Q-TOF mode), and ions ejected from the ion pusher 5 are directly introduced into the flight space 8 and reflected one or more times between the

MR reflectors

9A and 9B, and then the main ions Detection mode by the detector 11 (deformed MR-TOF mode), and ions ejected from the ion pusher 5 are directly introduced into the flight space 8 and reflected between the

MR reflectors

9A and 9B while detecting secondary ions At least one of the modes (modified FT-MS mode) detected by the device 12 may be additionally provided. By increasing the variation of the analysis modes in this way, the range of selection by the user is widened, and analysis can be performed in accordance with the purpose.

It should be noted that the above embodiment is merely an example of the present invention, and it should be understood that modifications, corrections, and additions may be made as appropriate within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Ion source 2 ... Quadrupole mass filter 3 ... Collision cell 3a ... Ion introduction port 3b ... Ion outlet 4 ... Ion guide 5 ... Ion extrusion part 5a ... Extrusion electrode 6 ... Ion trap 6a ... Rod electrode 6b ... Ion entry Exit 7: Time-of-flight mass analyzer 8 ...

Flight space

9A, 9B ... MR reflector 10 ... Main reflector 11 ... Main ion detector 12 ... Sub ion detector 20 ... Control unit 21 ... Extrusion electrode power supply unit 22 ... Ion trap power supply unit 23 ... RT reflector power supply unit 24 ... MR reflector power supply unit 25 ... Input unit 30 ... Signal analysis unit

Claims

a) an ion guide for transporting ions derived from sample components;
b) an operation of ejecting the ions transported by the ion guide in a first direction different from the traveling direction of the ions, and the transported ions in either the traveling direction of the ions or the first direction. An ion extruding unit that selectively performs an operation of deflecting in a different second direction,
c) A flight time including a flight space in which ions ejected from the ion pusher in the first direction fly, and a first detection unit provided at a position where the ions flying in the flight space arrive. Type mass spectrometer,
d) Ion trap that captures and temporarily holds ions traveling in the second direction from the ion pusher and ejects the held ions toward the flight space of the time-of-flight mass spectrometer And
e) a pair of ion optical elements disposed along a flight trajectory until ions ejected from the ion pusher in the first direction reach the first detector, the flight trajectory A pair of ion reflectors that each form a reflected electric field such that ions reciprocate between the pair of ion optical elements along
f) a second detection unit that detects non-contact and non-destructive ions flying between the pair of ion reflection units;
g) a first analysis mode in which ions are ejected from the ion pusher in the first direction, fly in the flight space and detected by the first detector, and the second from the ion pusher. After ions are advanced in the direction and trapped in the ion trapping part, ions are ejected from the ion trapping part and introduced into the flight space, and the reciprocating motion is performed one or more times by the pair of ion reflecting parts. A second analysis mode to be detected by the first detection unit; and after the ions are advanced from the ion extrusion unit in the second direction and captured by the ion capture unit, the ions are ejected from the ion capture unit and Each part is controlled to selectively perform one of the third analysis mode that is introduced into the flight space and repeatedly detected by the second detection unit while reciprocating a plurality of times by the pair of ion reflection units. A control unit;
h) In the first and second analysis modes, ion mass information is obtained based on the detection signal obtained by the first detection unit, while in the third analysis mode, at least the second detection is performed. A signal analysis unit for obtaining ion mass information by Fourier transform operation based on the detection signal obtained by the unit;
A mass spectrometer comprising:
The mass spectrometer according to claim 1,
The mass spectrometer is characterized in that the ion trapping part is an ion trap that traps ions by the action of a high-frequency electric field.
The mass spectrometer according to claim 1,
The controller further ejects ions in the first direction from the ion pusher and introduces them into the flight space, and after reciprocating one or more times by the pair of ion reflectors, A mass spectrometer characterized by controlling each unit so as to selectively perform an analysis mode detected by a detection unit.
The mass spectrometer according to claim 1,
The control unit further ejects ions from the ion pusher in the first direction and introduces the ions into the flight space, and reciprocates a plurality of times by the pair of ion reflecting units, and is repeatedly performed by the second detection unit. A mass spectrometer characterized by controlling each unit so as to selectively perform an analysis mode to be detected.
The mass spectrometer according to claim 1,
The controller further advances ions from the ion extruding unit in the second direction and traps them in the ion trapping unit, and then ejects ions from the ion trapper to fly through the flight space. A mass spectrometer characterized by controlling each unit so as to selectively perform an analysis mode detected by the detection unit.
a) an ion guide for transporting ions derived from sample components;
b) an ion extruding unit that ejects ions transported by the ion guide in a direction different from the direction of travel of the ions;
c) a time-of-flight mass analyzer including a flight space in which ions ejected from the ion pusher fly, and a first detection unit provided at a position where the ions flying in the flight space reach;
d) a pair of ion optical elements disposed along a flight trajectory until ions ejected from the ion pusher reach the first detection unit, and the pair of ion optical elements along the flight trajectory A pair of ion reflectors that each form a reflected electric field so that ions reciprocate between ion optical elements;
e) a second detector that detects non-contact and non-destructive ions flying between the pair of ion reflectors;
f) a first analysis mode in which ions are ejected from the ion push-out unit, fly in the flight space and detected by the first detection unit, and ions are ejected from the ion push-out unit and introduced into the flight space A second analysis mode in which the first detection unit detects the reciprocating motion one or more times by the pair of ion reflecting units, and ions are ejected from the ion pusher and introduced into the flight space. And a control unit that controls each unit to selectively perform any one of the third analysis mode that is repeatedly detected by the second detection unit while reciprocating a plurality of times by the pair of ion reflection units,
g) In the first and second analysis modes, ion mass information is obtained based on the detection signal obtained by the first detection unit, while in the third analysis mode, at least the second detection is performed. A signal analysis unit for obtaining ion mass information by Fourier transform operation based on the detection signal obtained by the unit;
A mass spectrometer comprising:
The mass spectrometer according to claim 1 or 6,
The time-of-flight mass analyzer is a reflectron type time-of-flight mass analyzer having a main ion reflector different from the pair of ion reflectors, and the pair of ion reflectors A mass spectrometer characterized by being disposed opposite to both sides of the main ion reflecting portion.