WO2022270469A1 - Mass spectroscope, mass spectrometry system, and mass spectrometry method - Google Patents

Abstract

In order to achieve reduction in size, this mass spectroscope is characterized by comprising: an ion source (200) for continuously generating ions (23); a pre-trap chamber (130) capable of trapping the ions (23); an ion trap chamber (140) provided after the pre-trap chamber (130) and capable of having the ions (23) introduced thereinto from the pre-trap chamber (130) and capable of trapping the ions (23); a third small hole (141) provided in a third isolating wall (147) partitioning the pre-trap chamber (130) and the ion trap chamber (140); and a slider valve (101) capable of opening and closing the third small hole (141), the pre-trap chamber (130) having an inner pressure adjusted to be higher than an internal pressure of the ion trap chamber (140), wherein the opening and closing of the third small hole (141) is performed intermittently by the slider valve (101).

Description

Mass spectrometer, mass spectrometry system and mass spectrometry method

The present invention relates to techniques for mass spectrometers, mass spectrometry systems, and mass spectrometry methods.

Simple, on-the-spot and high-sensitivity measurement of trace substances in mixed samples, such as soil and air pollution measurement, food pesticide testing, blood metabolite diagnosis, urine drug testing, and explosives detection. A portable analyzer is desired. In such a mass spectrometer, mass spectrometry is performed by converting a substance into gaseous ions in an ion source and introducing the ions into a vacuum section of the mass spectrometer. At this time, the mass spectrometer requires a vacuum pump in order to keep the inside of the vacuum section in a vacuum state.

The size of the vacuum pump correlates with its suction amount, and if the vacuum pump is made smaller, the suction amount will decrease. In this case, in the mass spectrometer, it is necessary to reduce the pore size of the partition separating the atmosphere and the vacuum chamber. However, smaller pore sizes reduce the sensitivity of the mass spectrometer. Therefore, there is generally a trade-off relationship between the size and sensitivity of a mass spectrometer.

In order to eliminate such a trade-off, Patent Literature 1 discloses a technique in which a pulse valve is installed in the partition wall and ions generated under atmospheric pressure are intermittently introduced into the mass spectrometer via the pulse valve. ing.

In addition, in Non-Patent Document 1, in order to improve the analysis accuracy, a valve is set between the ion trap and the ion funnel, ions are introduced into the ion trap, and then the valve is closed to reduce the pressure inside the ion trap. is disclosed.

U.S. Patent No. 9058967

In the method described in Patent Document 1, a valve is installed on a partition wall that separates atmospheric pressure from vacuum (about 0.1 Pa). However, due to the large pressure difference across the septum, it is necessary to use valves with a tight seal. Also, if electrospray is used as the ion source, the sample droplets pass through the valve. Also, if a discharge ion source is used, a high concentration of sample gas passes through the valve. In either case, there is a risk of contamination of the valve. Heating the contaminated valve may vaporize the contaminant and remove the contaminant from the valve. However, heating the valve is not trivial, and in the event of heavy contamination, previous measurements can affect subsequent measurements as contaminants carry over.

In the methods described in Patent Document 1 and Non-Patent Document 1, ions can be stored in the ion trap only while the valve is open. Therefore, even if you want to improve the analytical sensitivity by accumulating a large amount of ions, the pressure in the ion trap increases while the valve is open. It is not preferable to keep the valve open for a long time. Also, if the pores of the partition wall are made small enough to withstand the pump even if the valve is open for a long time, the ion transmittance is lowered and the sensitivity is lowered.

The present invention has been made in view of such a background, and an object of the present invention is to realize miniaturization of a mass spectrometer.

In order to solve the above-described problems, the present invention includes an ion source that continuously generates ions, a first mass spectrometer that can trap the ions, and is provided after the first mass spectrometer, A second mass analysis unit capable of introducing the ions from the first mass analysis unit and capable of trapping the ions is separated from the first mass analysis unit and the second mass analysis unit. a partition wall hole provided in a partition wall, an opening/closing portion capable of opening and closing the partition wall hole, a first vacuum pump section for evacuating the inside of the first mass analysis section, and the second mass analysis section. and a second vacuum pump section for evacuating the inside of the mass analysis section, and the internal pressure of the first mass analysis section is reduced to the second The internal pressure is adjusted to be higher than the internal pressure of the mass spectrometry unit, and the opening and closing of the partition hole is intermittently performed by the opening and closing section.
Other solutions will be described as appropriate in the embodiments.

According to the present invention, miniaturization of the mass spectrometer can be realized.

1 is a configuration diagram (part 1) showing an example of a mass spectrometer according to a first embodiment; FIG. FIG. 2 is a configuration diagram (part 2) showing an example of the mass spectrometer according to the first embodiment; BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structural example of the mass spectrometry system which concerns on 1st Embodiment. It is a figure which shows the operation sequence of the mass spectrometry system which concerns on 1st Embodiment. FIG. 10 is a diagram showing an operation sequence in parallel processing of a plurality of mass spectrometry processes; It is a figure which shows the example of the internal pressure change of an ion trap chamber. 1 is a diagram (1) showing an example of the structure of a slider valve; FIG. FIG. 2 is a diagram (part 2) showing an example of the structure of a slider valve; It is a figure which shows an example of a valve drive device. FIG. 10 is a diagram showing an example of an operation sequence of a mass spectrometer according to a second embodiment; FIG. FIG. 11 is a configuration diagram showing an example of a mass spectrometer according to a third embodiment; FIG. 5 is a diagram showing another configuration example of the slider valve; It is a lineblock diagram showing an example of a mass spectrometer concerning a 4th embodiment. It is a figure which shows the hardware structural example of a control apparatus.

Next, a form for carrying out the present invention (referred to as "embodiment") will be described in detail with reference to the drawings as appropriate.

[First embodiment]
1 and 2 are configuration diagrams showing an example of a mass spectrometer 1 according to the first embodiment. 1 shows a view in which the slider valve 101 closes the third hole 141, and FIG. 2 shows a view in which the slider valve 101 opens the third hole 141. FIG. The slider valve 101 and the third aperture 141 (partition wall aperture) will be described later.
As shown in FIG. 1, the mass spectrometer 1 is mainly composed of an ion source 200 and a mass spectrometer 100 . In the example shown in FIGS. 1 and 2, an atmospheric pressure chemical ionization ion source is used as the ion source 200, and the sample gas is ionized by applying a high voltage to the needle electrode 21 to generate the discharge plasma 22. However, the ion source 200 is not necessarily an atmospheric pressure chemical ionization ion source, and may be other discharge ion sources, an electrospray ion source, or the like. In this embodiment, positive ions are generated in the ion source 200, but negative ions may be generated.

The mass spectrometer 100 is divided into a differential evacuation chamber 120, a pre-trap chamber 130, and an ion trap chamber 140. The differential exhaust chamber 120 is connected to the atmosphere through the first aperture 121 . The first aperture 121 is provided in a first partition wall 123 that separates the atmosphere from the differential exhaust chamber 120 . Ions 23 generated by the ion source 200 are introduced into the differential pumping chamber 120 through the first apertures 121 .

The differential pumping chamber 120 and the pre-trapping chamber 130 are connected via a second hole 131 . A second aperture 131 is provided in a second partition wall 135 that separates the differential pumping chamber 120 and the pre-trap chamber 130 .
The pre-trapping chamber 130 and the ion trapping chamber 140 are connected through the third aperture 141 . The third aperture 141 is provided in a third partition 147 that separates the pre-trap chamber 130 and the ion trap chamber 140 .

A pre-trap electrode 133 that is a quadrupole electrode is provided in the pre-trap chamber 130 . Further, the ion trapping chamber 140 is provided with an ion trapping electrode 143 which is a quadrupole electrode. Furthermore, the ion trap chamber 140 is provided with a slider valve 101 , an in-cap electrode 144 , an end-cap electrode 145 and a detector 146 . Each of the in-cap electrode 144 and the end-cap electrode 145 has a disk-like shape, and has an opening in the center for the ions 23 to pass through. A valve driving device 110 for driving the slider valve 101 is provided outside the ion trap chamber 140 .

Furthermore, the pressure in the differential evacuation chamber 120 is reduced by a differential evacuation vacuum pump 122 . The pressure in the pre-trap chamber 130 is reduced by a pre-trap vacuum pump 132 . Further, the ion trap chamber 140 is depressurized by an ion trap vacuum pump 142 . Note that three pumps are not necessarily required, and one pump may be used to depressurize two or more locations. Also, either pump may be utilized to reduce the back pressure of the other pump.

As described above, the pre-trapping chamber 130 and the ion trapping chamber 140 are provided with quadrupole electrodes as the pre-trapping electrode 133 and the ion trapping electrode 143, respectively. However, in FIGS. 1 and 2, each of the pre-trapping electrodes 133 and the ion trapping electrodes 143 shows two out of four electrodes.

Both the pre-trapping chamber 130 and the ion trapping chamber 140 function as linear ion traps due to the pre-trapping electrode 133 and the ion trapping electrode 143, respectively. That is, both the pre-trapping chamber 130 and the ion trapping chamber 140 trap the ions 23 generated by the ion source 200 .

Hereinafter, for the sake of explanation, the linear ion trap in the pre-trapping chamber 130 will be referred to as a pre-trap, and the linear ion trap in the ion trapping chamber 140 will be referred to as an analytical ion trap. In the pre-trapping chamber 130 , ions 23 of either positive or negative polarity can be trapped under the voltage condition of the voltage applied to the pre-trapping electrode 133 . Also, in the ion trapping chamber 140, ions 23 of either positive or negative polarity can be trapped under voltage conditions applied to the ion trap electrode 143, the incap electrode 144, and the end cap electrode 145. FIG. Furthermore, the low mass cutoff is set by the voltage applied to the pre-trap electrode 133 and the ion trap electrode 143 . Therefore, voltage conditions for the pre-trap and analytical ion trap are determined in consideration of the polarity and molecular weight of the ions 23 to be detected.

The pre-trap and analytical ion trap need not necessarily be quadrupole linear ion traps as long as they can trap ions 23 . A quadrupole linear ion trap is a linear ion trap using quadrupole electrodes. For example, the pre-trap may be an octapole trap or an ion funnel trap. The pre-trap chamber 130 is generally about 10 Pa, and the ion trap chamber 140 is generally about 0.1 to 1 Pa, but these values are not necessarily required. However, the internal pressure of each ion trap chamber 140 is set to be lower than that of the pre-trap chamber 130 .

Ions 23 generated by the ion source 200 pass through the first aperture 121 and are introduced into the differential pumping chamber 120 . Subsequently, the ions 23 pass through the second aperture 131 and are introduced into the pre-trap chamber 130 . After that, the ions 23 pass through the third aperture 141 and are introduced into the ion trap chamber 140 .

A slider valve 101 is provided in the third hole 141 arranged between the pre-trap chamber 130 and the ion trap chamber 140 . The slider valve 101 is connected to a valve driving device 110 via a push rod 111 . Then, the valve driving device 110 moves the slider valve 101 in the up-down direction of the drawing through the push rod 111 . The valve driving device 110 will be described later.

The slider valve 101 is provided with an opening 102, and when the slider valve 101 slides in the vertical direction of the drawing, the opening 102 and the third hole 141 are aligned as shown in FIG. 130 and the ion trap chamber 140 are brought into a conducting state. That is, the third pores 141 are opened.

Further, when the slider valve 101 slides and the opening 102 and the third hole 141 do not match as shown in FIG. That is, the third pore 141 is closed.

Then, when the third aperture 141 is opened by the slider valve 101, the ions 23 pretrapped in the pretrapping chamber 130 flow into the ion trapping chamber 140 (see FIG. 2). This increases the internal pressure of the ion trap chamber 140 . Also, when the third aperture 141 is closed by the slider valve 101, the flow of the ions 23 flowing into the ion trap chamber 140 is stopped. Then, the inside of the ion trap chamber 140 is evacuated by the ion trap vacuum pump 142 provided in the ion trap chamber 140 while the pre-trap chamber 130 and the ion trap chamber 140 are in a non-conducting state. As a result, the internal pressure in the ion trap chamber 140 is lowered (see FIG. 1). A change in internal pressure in the ion trap chamber 140 will be described later.

In this way, by intermittently opening and closing the third aperture 141 by the slider valve 101, it is possible to intermittently introduce the ions 23 pre-trapped in the pre-trapping chamber 130 into the ion trapping chamber 140. . It should be noted that intermittence means that something occurs or stops after a certain (predetermined) period of time.

In the ion trap chamber 140, an incap electrode 144 is provided in front of the ion trap electrode 143, and an end cap electrode 145 is provided in the rear. The in-cap electrode 144 and the end-cap electrode 145 function as a linear ion trap together with the ion trap electrode 143 to trap the ions 23 (analytical ion trap). A detector 146 is arranged in the ion trap chamber 140 to detect the ions 23 ejected from the ion trap for analysis. The ion trap for analysis and ejection of ions 23 will be described later.

The detector 146 is generally composed of a conversion dynode, a scintillator, a photomultiplier tube, and the like. In the detector 146, the ions 23 are converted into electrons by the conversion dynode, further converted into light by the scintillator, and detected by doubling the light by the photomultiplier tube.

FIG. 3 is a diagram showing a configuration example of the mass spectrometry system Z according to the first embodiment.
The control device 3 can independently control the voltages applied to the first partition 123, the second partition 135, and the third partition 147 of the mass spectrometry unit 100, respectively. By controlling the voltage applied to the first partition 123, the second partition 135, and the third partition 147, the voltage applied to the first pore 121, the second pore 131, and the third pore 141 is controlled. be.

In addition, the control device 3 can independently control the voltages applied to the pre-trap electrode 133, the ion trap electrode 143, the in-cap electrode 144, and the end-cap electrode 145, respectively. In addition, the control device 3 controls the differential pumping vacuum pump 122, the pre-trap vacuum pump 132, and the ion trap vacuum pump 142, respectively. Furthermore, the control device 3 acquires the detection signal of the ions 23 from the detector 146 . Further, the control device 3 controls the movement of the slider valve 101 by controlling the valve driving device 110 . The controller 3 controls generation of the ions 23 by controlling the needle electrode 2121 .

[Operation sequence]
FIG. 4 is a diagram showing the operation sequence of the mass spectrometry system Z according to the first embodiment. Reference will be made to FIGS. 1 to 3 as appropriate.
In FIG. 4, the voltage of the needle electrode 21, the offset voltage (pre-trap offset voltage) applied to the pre-trap electrode 133, the voltage of the third aperture 141, the opening and closing of the third aperture 141, and the ion ejection AC vibrations, ion trap RF amplitudes are shown. A pre-trap offset voltage is a voltage applied to the pre-trap electrode 133 to pre-trap the ions 23 . The voltage applied to the third aperture 141 is the voltage applied to the third aperture 141 (the third partition wall 147), and the opening and closing of the third aperture 141 is the opening and closing of the third aperture 141 by the slider valve 101. be.

The ion ejection AC amplitude is the amplitude of the AC voltage (ion ejection AC voltage) applied to the ion trap electrode 143 when ejecting the ions 23 from the analysis ion trap in order to detect the ions 23 with the detector 146. is.
The ion trap RF amplitude is the amplitude of the high frequency voltage (ion trap RF voltage) applied to the ion trap electrode 143 to trap the ions 23 for analysis. As will be described later, in order to detect the ions 23 with the detector 146, the ion trap RF amplitude is varied when the ions 23 are ejected from the analysis ion trap.

Also, as shown in FIG. 4, the operation sequence of the mass spectrometry system Z consists of a pre-trapping period T1, an ion movement period T2, a cooling period T3, an ion detection period T4, and a cleaning period T5.

The outline of each voltage and the opening and closing of the third aperture 141 in each of the pre-trapping period T1, the ion moving period T2, the cooling period T3, the ion detecting period T4, and the cleaning period T5 is as follows.
First, the voltage applied to the needle electrode 21 (the voltage of the needle electrode 21) is a constant voltage (4 kV in the example of FIG. 4) from the pretrapping period T1 to the cleaning period T5.
As the pre-trapping offset voltage, a constant voltage (4 kV in the example of FIG. 4) is applied from the pre-trapping period T1 to the cleaning period T5.
The voltage applied to the third aperture 141 (the voltage of the third aperture 141) is constant (10 V in the example of FIG. 4) during periods other than the ion migration period T2. Then, only during the ion migration period T2, a voltage lower than the voltage applied during the other periods is applied (1 V in the example of FIG. 4).

The third aperture 141 is opened (“open”) only during the ion migration period T2, and is closed (“closed”) during other periods.
Further, the AC amplitude for ion discharge is set to 1 V only during the ion detection period T4, and is set to 0 V during other periods.
The ion trap RF amplitude is set to 200 V during the pre-trapping period T1 to the cooling period T3. Also, after the ion trap RF amplitude rises from 200 V to 1 kV during the ion detection period T4, it is set to 0 V during the cleaning period T5.

Hereinafter, a detailed description of the pre-trap period T1 to the cleaning period T5 will be given.
First, the needle electrode 21 of the ion source 200 to which a predetermined voltage (4 kV in the example of FIG. 4) is applied generates ions 23 from the sample gas. In the example of FIG. 4, it is assumed that positively charged ions 23 (positive ions) are generated. As described above, 4 kV continues to be applied to the needle electrode 21 during the pre-trapping period T1 to the cleaning period T5. That is, the ion source 200 continues to generate positive ions.

(Pre-trap period T1)
The generated ions 23 are continuously introduced into the differential pumping chamber 120 through the first aperture 121 by being attracted by the voltage applied to the first aperture 121 . Furthermore, the ions 23 are continuously introduced into the pretrapping chamber 130 through the second aperture 131 by being attracted by the voltage applied to the second aperture 131 introduced into the differential pumping chamber 120 . The ions 23 introduced into the pre-trap chamber 130 are trapped (pre-trapped) by the pre-trap electrode 133 to which a pre-trap offset voltage is applied.

The polarity and mass range of the ions 23 that can be pre-trapped are determined by the voltage conditions of the pre-trap offset voltage applied to the pre-trap electrode 133 . In FIG. 4, 3V is applied to the pretrapping electrode 133 as the pretrapping offset voltage. Pre-trapped ions 23 and non-pre-trapped ions 23 are separated by the voltage condition of the pre-trap offset voltage. Ions 23 that are not pre-trapped are discharged out of the system of the pre-trap electrode 133 . In this way, the ions 23 are mass-separated in the pre-trapping stage, in other words, the ions 23 are coarsely separated in the pre-trapping. As such, the pre-trapping chamber 130 can be considered a first mass analysis section. Along with this, the ion trap chamber 140 can be considered as a second mass spectrometer.

Also, in the pretrapping period T1, the voltage of the third aperture 141 is set higher than the pretrapping offset voltage so that the third aperture 141 serves as a barrier for the ions 23 (positive ions). In the example of FIG. 4, the pretrapping offset voltage in the pretrapping period T1 is set to 3V, and the voltage of the third pore 141 is set to 10V.

(Ion migration period T2)
When a sufficient amount of ions 23 are pre-trapped, the controller 3 opens the third aperture 141 and sets the voltage of the third aperture 141 lower than the pre-trapping offset voltage (in the example of FIG. 4, 1 V) (time t1). As a result, the voltage applied to the third aperture 141 becomes lower than the pre-trap offset voltage. Therefore, positively charged ions 23 are attracted to the voltage of the third aperture 141 and introduced into the ion trap chamber 140 (ion migration period T2).
In addition, in order to control the pre-trapping of the ions 23 and the introduction of the ions 23 after the slider valve 101 , an electrode may be additionally arranged between the third aperture 141 and the pre-trapping electrode 133 . By controlling the voltage applied to the third aperture 141 in this manner, reliable pre-trapping can be achieved and the ions 23 can be reliably moved to the ion trapping chamber 140 .

(Cooling period T3)
When the ions 23 are introduced into the ion trap chamber 140, the controller 3 drives the slider valve 101 to close the third aperture 141 (time t2). Also, the control device 3 raises the voltage of the third aperture 141 (time t2). In the example of FIG. 4, the voltage of the third aperture 141 is increased from 1V to 10V. After time t2, the control device 3 maintains the voltage of the third aperture 141 at the voltage increased at time t2.

During the cooling period T3, the ions 23 are trapped in the ion trap chamber 140 by the ion trap electrode 143, the incap electrode 144, and the end cap electrode 145 (analytical ion trap). Here, an ion trap RF voltage having an ion trap RF amplitude of 200 V is applied to the ion trap electrode 143 .

As for the ion trapping RF voltage, an in-phase RF voltage is applied to the facing electrodes of the ion trapping electrodes 143, which are quadrupole electrodes, and an opposite-phase RF voltage is applied to the adjacent electrodes. Although not shown in FIG. 4, during the cooling period T3, while the ions 23 are trapped (analytical ion trap) in the ion trap chamber 140, the in-cap electrode 144 and the end-cap electrode 145 are grounded. It's becoming

A typical opening time of the third aperture 141 by the slider valve 101 is about 50 ms. As described above, the ion trap chamber 140 has a lower pressure than the pre-trap chamber 130 . Therefore, when the slider valve 101 opens the third aperture 141 , the gas flows in together with the ions 23 from the pre-trap chamber 130 . As a result, the internal pressure of the ion trap chamber 140 rises. The internal pressure of the ion trap chamber 140 typically rises to about 10 Pa.

As described above, after the ions 23 move from the pre-trapping chamber 130 to the ion trapping chamber 140, the control device 3 closes the third aperture 141 by the slider valve 101 (time t2). Closing the third aperture 141 by the slider valve 101 limits the amount of gas that flows from the pre-trapping chamber 130 into the ion trapping chamber 140 together with the ions 23 . Specifically, the inflow of gas into the ion trap chamber 140 is stopped. Then, the internal pressure of the ion trap chamber 140 is lowered again by the ion trap vacuum pump 142 . Thus, the cooling period T3 is the time during which the internal pressure of the ion trap chamber 140, which has risen due to the opening of the third aperture 141 by the slider valve 101, is reduced. A change in the internal pressure of the ion trap chamber 140 will be described later.

(Ion detection period T4)
When the internal pressure of the ion trap chamber 140 is lowered to about 0.1 to 1 Pa, the ions 23 are mass-selectively ejected from the analytical ion trap to the detector 146 . As a result, the ions 23 are detected for each mass-to-charge ratio (ion detection period T4). During the ion detection period T4, the ion trap RF amplitude is gradually amplified as shown in FIG. In the example shown in FIG. 4, it is amplified to 1 kV. When the ion trap RF amplitude reaches a predetermined amplitude, the ions 23 trapped for analytical ions become unstable. Further, in the ion detection period T4, an ion ejection AC voltage having a constant ion ejection AC amplitude (1 V in the example of FIG. 4) is applied to the ion trap electrode 143 .

That is, in addition to the ion trapping RF voltage having the ion trapping RF amplitude, the ion ejection AC voltage having the ion ejection AC amplitude is applied to the ion trap electrode 143 . Although not shown in FIG. 4, a rectangular wave voltage having a predetermined voltage is applied to the in-cap electrode 144 and the end-cap electrode 145 during the ion detection period T4. As a result, ions 23 having a predetermined mass-to-charge ratio are selectively ejected from the ions 23 trapped for analysis to the detector 146 and detected by the detector 146 .

(Cleaning period T5)
When the ion detection ends, the control device 3 sets the ion trap RF amplitude and the ion ejection AC amplitude to zero, thereby exhausting the remaining ions 23 . This is the cleaning period T5. In the cleaning period T5, the ions 23 are ejected from the opening of the endcap electrode 145 by applying a voltage lower than at least the ion trap electrode 143 and the incap electrode 144 to the endcap electrode 145 . Further, the ions 23 are ejected to the outside from an ejection port (not shown) provided in the ion trap chamber 140 .

A sequence from the pre-trapping period T1 to the cleaning period T5 is defined as one sequence, and the mass spectrometer 1 performs measurement while repeating the pre-trapping period T1 to the cleaning period T5.

In this embodiment, the ion trapping RF amplitude is changed during the ion detection period T4 shown in FIG. 4, and an ion ejection AC voltage having a predetermined ion ejection AC amplitude is applied. Thereby, the ions 23 are ejected to the detector 146 and the ions 23 are detected.
However, by electrically connecting the pre-trap electrode 133 and the ion trap electrode 143, the pre-trap electrode 133 and the ion trap electrode 143 may be interlocked and controlled. In such a case, when the ion trapping RF amplitude changes, the amplitude of the RF voltage applied to the pretrapping electrode 133 also changes, which may affect the pretrapping efficiency. Therefore, considering the pre-trapping efficiency, even if the ion trap RF amplitude is kept constant during the ion detection period T4 and the frequency of the ion ejection AC voltage is changed, the ions 23 can be ejected toward the detector 146. good.

(parallel operation)
FIG. 5 is a diagram showing an operation sequence in parallel processing of a plurality of mass spectrometry processes.
Pre-traps S1, S1A and S1B shown in FIG. 5 correspond to the pre-trap period T1 of FIG. Ion migration S2, S2A, and S2B correspond to the ion migration period T2 in FIG. The cooling periods S3 and S3A correspond to the cooling period T3 in FIG. Furthermore, the ion detections S4 and S4A correspond to the ion detection period T4 in FIG. Cleanings S5 and S5A correspond to the cleaning period T5 in FIG.

As shown in FIG. 4, a pre-trap offset voltage is always applied to the pre-trap electrode 133 . That is, the pre-trapping electrode 133 is always in a state capable of pre-trapping the ions 23 . In other words, the pre-trapping electrode 133 is in a state capable of trapping the ions 23 during the cooling S3. Then, as shown in FIG. 4, the ion source 200 continuously generates ions 23 . The ions 23 are continuously introduced into the pre-trap chamber 130 . Therefore, as an actual operation, as shown in FIG. 5, pre-trapping S1A of another ion 23 by the pre-trapping electrode 133 is possible in parallel with cooling S3 to cleaning S5.

Then, at the timing when the cleaning S5 in the ion trap chamber 140 ends, the control device 3 opens the third orifice 141 by the slider valve 101 . As a result, the pretrapped ions 23 are introduced from the pretrapping chamber 130 to the ion trapping chamber 140 (ion transfer S2A).

Then, while the cooling S3A to cleaning S5A are being performed, pre-trapping S1B of yet another ion 23 by the pre-trapping electrode 133 is performed in parallel. Then, when cleaning S5A of the ion trap chamber 140 is completed, the third aperture 141 is opened by the slider valve 101, and the pre-trapped ions 23 move to the ion trap chamber 140 (ion movement S2B).

Thus, according to the present embodiment, new ions 23 can be pre-trapped in the pre-trapping chamber 130 while the ion trapping chamber 140 is undergoing cooling S3, S3A to cleaning S5, S5A. In other words, the mass spectrometry system Z of this embodiment can perform cooling S3, S3A to cleaning S5, S5A and pre-trapping S1, S1A, S1B in parallel. Thereby, mass spectrometry with high throughput can be realized.

(Internal pressure change in ion trap chamber 140)
FIG. 6 is a diagram showing an example of internal pressure changes in the ion trap chamber 140. As shown in FIG. Please refer to FIG. 1 accordingly.
The pre-trapping period T1 to the ion detection period T4 in FIG. 6 are the same as those shown in FIG. 6, the vertical axis indicates the internal pressure of the ion trap chamber 140. As shown in FIG.
The third aperture 141 is closed by the slider valve 101 during the pre-trap period T1. Therefore, the internal pressure of the ion trap chamber 140 is maintained at a low internal pressure of about 0.1 Pa during the pre-trapping period T1.

Then, during the ion movement period T2, when the third aperture 141 is opened by the slider valve 101, the gas flows together with the ions 23 from the pre-trap chamber 130 whose internal pressure is higher than that of the ion trap chamber 140. This increases the internal pressure of the ion trap chamber 140 .

After that, the third orifice 141 is closed by the slider valve 101, and the internal pressure of the ion trap chamber 140 is lowered by the evacuation by the ion trap vacuum pump 142 (cooling period T3). Then, when the internal pressure of the ion trap chamber 140 reaches a predetermined value, for example, about 0.1 Pa, the ion detection period T4 begins. In this manner, ion detection is performed when the internal pressure of the ion trap chamber 140 has decreased to a predetermined value, whereby highly accurate ion detection can be performed.

In general, in order to improve the sensitivity of a mass spectrometer, the permeability of ions 23 is improved by enlarging the pores provided in the partition wall. However, increasing the size of the pores also increases the introduction amount of gases other than the ions 23 . In order to exhaust the introduced gas, a vacuum pump with a large displacement is generally installed.

On the other hand, when trying to downsize the mass spectrometer, a small vacuum pump is installed. However, if the size of the vacuum pump is reduced, it is necessary to reduce the size of the pores in order to reduce the introduction of introduced gas. As a result, the amount of captured ions 23 is reduced, and the sensitivity is reduced. Thus, sensitivity maintenance and miniaturization are generally incompatible.

If the slider valve 101 were omitted from the configuration shown in FIGS. 1 and 2, gases other than the ions 23 would always flow from the pre-trap chamber 130 to the ion trap chamber 140 together with the ions 23 . In this state, if the pre-trap chamber 130 is maintained at 10 Pa and the ion trap chamber 140 at 0.1 Pa, the ion trap vacuum pump 142 connected to the ion trap chamber 140 is used with a large displacement pump, for example, about 100 L/s. It is necessary to use a vacuum pump that can

On the other hand, in the present embodiment, gases other than the ions 23 flow from the pre-trap chamber 130 to the ion trap chamber 140 only at the timing when the slider valve 101 opens the third aperture 141 . Thereafter, the third aperture 141 is closed by the slider valve 101, so that the internal pressure of the ion trap chamber 140 is lowered to 0.1 Pa while the inflow of gas is restricted. Therefore, according to the mass spectrometer 1 of the present embodiment, a compact vacuum pump with a suction flow rate of about 10 L/s can be used as the ion trap vacuum pump 142 .

1 and 2, the pre-trapping chamber 130 and the differential evacuation chamber 120 may be omitted, and the slider valve 101 may be installed between the ion source 200 and the ion trapping chamber 140. be done. However, in such a case, the pressure difference between the atmospheric pressure (0.1 MPa) where the ion source 200 exists and the internal pressure (0.1 Pa) of the ion trap chamber 140 increases. Therefore, the sealing performance of the slider valve 101 becomes a problem in order to prevent air leakage. In addition, since the slider valve 101 is installed at a position close to the ion source 200 , a sample gas with a high concentration other than the ions 23 and sample droplets pass through the slider valve 101 together with the ions 23 . This causes a problem of contamination of the slider valve 101 . Furthermore, in order to increase the amount of ions 23 introduced into the ion trap chamber 140, it is necessary to lengthen the opening time of the third aperture 141 by the slider valve 101. FIG. This means an increase in the amount of gas introduced into the ion trap chamber 140 other than the ions 23, and the load on the ion trap vacuum pump 142 increases.

On the other hand, in the case of this embodiment, the pressure difference on both sides of the third partition 147 provided with the slider valve 101 is the internal pressure of the pre-trap chamber 130 (10 Pa) and the internal pressure of the ion trap chamber 140 (0.1 Pa). difference. This pressure difference is much smaller than the pressure difference between the atmospheric pressure (0.1 MPa) and the internal pressure (0.1 Pa) of the ion trap chamber 140 . Therefore, in the mass spectrometer 1 according to the present embodiment, it is possible to reduce the degree of demand for sealing performance of the slider valve 101 .

Also, since the internal pressure of the pre-trapping chamber 130 is lower than the atmospheric pressure, the ions 23 are diluted in the pre-trapping chamber 130 . That is, the sample gas other than the ions 23 introduced into the pretrapping chamber 130 and the sample droplets are diffused and diluted by the low internal pressure of the pretrapping chamber 130 . Due to such a dilution effect, in the mass spectrometer 1 according to the present embodiment, the amount of sample gas and sample droplets passing through the slider valve 101 is reduced compared to the case where the slider valve 101 is arranged near the ion source 200 . Less is. Therefore, contamination of the slider valve 101 can be reduced.

In addition, in the method of this embodiment in which the ions 23 are once pre-trapped, if it is desired to increase the amount of the ions 23 introduced into the ion trap chamber 140, the pre-trapping time may be lengthened. That is, by lengthening the pre-trapping time, many ions 23 are trapped in the pre-trapping chamber 130 . After that, a large number of ions 23 can be introduced into the ion trap chamber 140 by opening the third aperture 141 with the slider valve 101 . In this case, the amount of ions 23 introduced into the ion trap chamber 140 has nothing to do with the opening time of the third aperture 141 by the slider valve 101 . That is, according to this embodiment, by shortening the opening time of the third aperture 141 by the slider valve 101, the introduction amount of gas other than the ions 23 can be reduced. By lengthening the pre-trapping time, a large number of ions 23 can be introduced into the ion trapping chamber 140 even if the opening time of the third aperture 141 by the slider valve 101 is short.

Thus, according to the present embodiment, it is possible to achieve both miniaturization of the mass spectrometer 1 and improvement in sensitivity maintenance.

(Slider valve 101)
7A and 7B are diagrams showing an example of the structure of the slider valve 101. FIG. 7A shows a view in which the slider valve 101 opens the third hole 141, and FIG. 7B shows a view in which the slider valve 101 closes the third hole 141. FIG. 7A and 7B, the same components as in FIGS. 1 and 2 are denoted by the same reference numerals, and descriptions thereof are omitted.
7A and 7B are views extracting the third hole 141, the slider valve 101 and the in-cap electrode 144 in FIGS. 1 and 2, and the other parts are omitted. As long as the slider valve 101 can close the third hole 141, the material thereof is preferably made of resin rather than metal. Further, when contaminants adhere to the slider valve 101, a heater (not shown) may be connected to the slider valve 101 so that the slider valve 101 is heated to vaporize the contaminants. In this way, the contaminants adhering to the slider valve 101 are vaporized by heating, so that the contaminants adhering to the slider valve 101 can be removed. When such measures against contamination of the slider valve 101 by heating are used, the slider valve 101 is preferably made of a material having good thermal conductivity, that is, made of metal rather than resin.

As described above, the slider valve 101 moves vertically to open and close the third orifice 141 to restrict (stop) the inflow of the ions 23 from the pre-trap chamber 130 to the ion trap chamber 140 . That is, if the inner diameter of the opening 102 of the slider valve 101 is smaller than the inner diameter of the third aperture 141 , some of the ions 23 passing through the third aperture 141 collide with the slider valve 101 . Thus, if the inner diameter of the opening 102 of the slider valve 101 is smaller than the inner diameter of the third aperture 141, the efficiency of introduction of the ions 23 into the ion trap chamber 140 is reduced. In this way, it is preferable that there is no resin plate on the flight path of the ions 23 passing through the third aperture 141, so the inner diameter of the opening 102 of the slider valve 101 is preferably larger than the inner diameter of the third aperture 141. .

Also, as shown in FIGS. 7A and 7B, it is desirable that the inner diameter of the opening 102 of the slider valve 101 expands toward the in-cap electrode 144 . In other words, it is desirable that the inner diameter of the opening 102 is wider on the ion trapping chamber 140 side than on the pretrapping chamber 130 side. Since the ions 23 that have passed through the third aperture 141 diffuse, this structure can prevent the opening 102 from hindering the flight of the ions 23 .

Incidentally, in FIGS. 1 and 2, only the in-cap electrode 144 exists between the slider valve 101 and the ion trap electrode 143, but that configuration is not necessarily required. For example, an Einzel lens may be formed by three disc electrodes and arranged between the incap electrode 144 and the slider valve 101 . Alternatively, a quadrupole electrode separate from the ion trap electrode 143 may be placed in front of the incap electrode 144 to focus the ions 23 .

(Valve drive device 110)
FIG. 8 is a diagram showing an example of a valve driving device 110 for driving the slider valve 101. As shown in FIG.
Valve drive device 110 has push rod 111 , plunger 112 , bobbin 114 and coil 115 .
The push rod 111 is connected to the slider valve 101 and is also connected to the plunger 112 via the support 117 . The plunger 112 is composed of a hollow conductor, and is moved in the vertical direction of the drawing by the magnetic force generated by the current flowing through the coil 115 . Along with the movement of the plunger 112, the push rod 111 and the slider valve 101 move vertically in the plane of the paper (white arrows in FIG. 8). The example shown in FIG. 8 shows a state in which the plunger 112, push rod 111 and slider valve 101 are pulled up to the highest position.

The coil 115 is wound around the bobbin 114 and the plunger 112 is inserted into the tubular portion of the bobbin 114 . The plunger 112 has upper and lower flange portions 112A and 112B. A spring 116 connects the upper portion of the bobbin 114 and the lower surface of the flange portion 112A of the plunger 112 .

The push rod 111 and plunger 112 connected to the slider valve 101 exist inside the ion trap chamber 140 with a low internal pressure. As shown in FIG. 1, the valve driving device 110 is installed outside the mass spectrometer 100, that is, under atmospheric pressure. Therefore, outside air may flow into the ion trap chamber 140 from around the bobbin 114 .
Therefore, in FIG. 8, O-rings 113 are provided above and below the bobbin 114 to maintain the airtightness of the ion trap chamber 140 and prevent external air from entering from around the bobbin 114 .

A change in the magnetic field generated by the coil 115 drives the plunger 112 to move the push rod 111 and the slider valve 101 . With this structure, it is possible to move the slider valve 101 while preventing external air from entering from around the bobbin 114 .
Although the valve driving device 110 is installed outside the mass spectrometer 1 in this embodiment, it may be installed inside the mass spectrometer 1 such as inside the ion trap chamber 140 . However, as in the example shown in FIG. 8, the valve driving device 110 (specifically, the coil 115) is installed outside the mass spectrometry unit 100, that is, in atmospheric pressure, so that the valve driving device 110 (the coil 115 ) into the mass spectrometry unit 100 . That is, the airtightness of the mass spectrometer 100 can be improved.

As described above, the slider valve 101 is installed between the pre-trap chamber 130 and the ion trap chamber 140 in this embodiment. With the third aperture 141 closed by the slider valve 101, the ions 23 are continuously introduced from the ion source 200 into the pretrapping chamber 130, whereby the ions 23 are mass-selectively generated in the pretrapping chamber 130. Trapped. Ions 23 move from the pre-trap chamber 130 to the ion trap chamber 140 when the slider valve 101 intermittently opens the third aperture 141 . Then, the ions 23 are mass-separated in the ion trap chamber 140 and detected by the detector 146 . By this technique, the ion trap vacuum pump 142 connected to the ion trap chamber 140 can be miniaturized while maintaining sensitivity.

Further, by configuring the third hole 141 to be opened and closed by the slider valve 101, opening and closing of the third hole 141 can be controlled with a simple structure.

[Second embodiment]
FIG. 9 is a diagram showing an example of the operation sequence of the mass spectrometer 1 according to the second embodiment.
The first embodiment shows an example in which only one polarity of the positive and negative ions 23 (positive ions in the example shown in the first embodiment) is repeatedly measured. On the other hand, the second embodiment shows an example in which positive ion measurement and negative ion measurement are alternately performed.

In the second embodiment, the configuration of the mass spectrometer 1 is the same as in the first embodiment, so illustration of the configuration is omitted. Also, as in the first embodiment, the second embodiment shows an example in which an atmospheric pressure chemical ionization ion source is used as the ion source 200 . In this case, the potential of the needle electrode 21 is reversed in order to change the polarity of the ions 23 to be detected.

(operation sequence)
FIG. 9 is a diagram showing the operation sequence of the mass spectrometry system Z according to this embodiment. Please refer to FIG. 1 accordingly. Further, description of the same configuration as that of FIG. 4 will be omitted as appropriate.
In FIG. 9, the pre-trapping period T1, the ion moving period T2, the cooling period T3, the ion detecting period T4, and the cleaning period T5 play the same roles as in FIG. Further, as described with reference to FIG. 5, pre-trapping for the next ion measurement is performed in parallel with the cooling period T3 to cleaning period T5 (pre-trapping period T1a). Then, when the cleaning period T5 ends, the third aperture 141 is opened by the slider valve 101, and the pre-trapped ions 23 move to the ion trap chamber 140 (ion movement period T2a).

Here, an outline of points in FIG. 9 that are different from those in FIG. 4 will be described.
First, the voltage applied to the needle electrode 21 (the voltage of the needle electrode 21) is reversed when the ion migration period T2 is completed. In the example of FIG. 9, it is set from (+) 4 kV to -4 kV.
The pre-trap offset voltage is then reversed upon completion of the ion transfer period T2. In the example of FIG. 9, it is set from (+)3V to -3V.
The voltage applied to the third aperture 141 (the voltage of the third aperture 141) is set to 0 V in the ion migration period T2 and then set to a voltage having a polarity opposite to that in the pre-trapping period T1. be. In the example of FIG. 9, it is set to (+) 10 V during the pretrapping period T1, 0 V during the ion transfer period T2, and -10 V during the cooling period T3 to cleaning period T5. Then, it is set to 0V in the second ion movement period T2a.

The opening and closing of the third aperture 141, the AC amplitude for ion discharge, and the ion trap RF amplitude are generally the same as in FIG. However, during the second ion movement period T2a, the third aperture 141 is opened ("open") and the ion trap RF amplitude is set to 200V.

In the following, each period will be described in detail, focusing on differences from FIG.
First, positive ions are generated by applying a positive voltage ((+) 4 kV in the example of FIG. 9) to the needle electrode 21 . The generated positive ions are attracted by the voltage applied to the first aperture 121 and are continuously introduced from the first aperture 121 into the differential pumping chamber 120 . Furthermore, positive ions are continuously introduced from the second aperture 131 into the pre-trapping chamber 130 by being attracted by the voltage applied to the second aperture 131 introduced into the differential pumping chamber 120 . Positive ions introduced into the pre-trap chamber 130 are trapped (pre-trapped) by the pre-trap electrode 133 to which a pre-trap offset voltage ((+) 3 V in the example of FIG. 9) is applied (pre-trap period T1).

When a sufficient amount of ions 23 (positive ions) are pre-trapped, the controller 3 opens the third aperture 141 by the slider valve 101 and changes the voltage of the third aperture 141 from 10V to 0V. (time t1a). Although not shown in FIG. 9, at time t1a, the control device 3 also sets the voltages of the incap electrode 144 and the endcap electrode 145 according to the polarity of the positive ions. This makes the voltage of the third aperture 141 lower than the pre-trap offset voltage. Therefore, positively charged ions 23 are attracted to the voltage of the third aperture 141 and introduced into the ion trap chamber 140 (ion migration period T2).

When the movement of positive ions is completed (time t2a), the slider valve 101 closes the third aperture 141 . Further, when the movement of the positive ions is completed, the voltage applied to the needle electrode 21 (the voltage of the needle electrode 21) is set to -4 kV in order to generate negative ions.
Also, when the positive ion movement is completed, the controller 3 adjusts the pre-trapping offset voltage and the voltage of the third aperture 141 to the polarity for the next generated and pre-trapped ions 23 (time t2a). In the example of FIG. 9, ions 23 to be generated next are assumed to be negative ions. Therefore, the controller 3 sets the pre-trap offset voltage to -3V and sets the voltage of the third pore 141 to -10V.

By doing so, while cooling (cooling period T3) and cleaning (cleaning period T5) are performed for the positive ions that are generated first, the ions 23 (here, negative ions) that are generated next are pre-trapped. (pre-trap period T1a). During this time, the third hole 141 is closed by the slider valve 101 . In addition, since negative ions are to be processed, the voltage of the third aperture 141 is set to a negative voltage (−10 V in the example of FIG. 9), as described above. The cooling (cooling period T3) to cleaning (cleaning period T5) for the positive ions generated first are the same as in FIG.

When the cleaning period T5 ends for the positive ions generated first (time t5a), the control device 3 opens the third aperture 141 by the slider valve 101 and changes the voltage of the third aperture 141 to 0V. . Although not shown in FIG. 9, at time t5a, the control device 3 also sets the voltages of the incap electrode 144 and the end cap electrode 145 according to the polarity of the negative ions. As a result, negative ions having a potential lower than 0 V, which is the voltage of the third aperture 141 , are attracted to the third aperture 141 and introduced into the ion trap chamber 140 . As a result, the pre-trapped ions 23 are moved to the ion trap chamber 140 (ion movement period T2a).

At the end of the cleaning period T5 for the initially generated positive ions (time t5a), the controller 3 sets the ion trap RF amplitude to 200V. This sets the ion trap RF amplitude to correspond to the negative ions to be subsequently trapped for analytical ions. The changes in the ion ejection AC amplitude and the ion trap RF amplitude for negative ions are the same as those for positive ions (from the pre-trapping period T1 to the cleaning period T5).

Although the voltages of the first pore 121, the second pore 131, etc. are not shown in FIG. be done. Thereby, the polarity of the ions 23 attracted to the pre-trapping chamber 130 is controlled.

Also, in FIG. 9, the pre-trap offset voltage in the pre-trap period T1 and the pre-trap offset voltage in the pre-trap period T1a are reversed. That is, the absolute value of the pre-trap offset voltage in the pre-trap period T1 is the same as the absolute value of the pre-trap offset voltage in the pre-trap period T1a. However, the absolute value of the pre-trapping offset voltage in the pre-trapping period T1 and the absolute value of the pre-trapping offset voltage in the pre-trapping period T1a do not necessarily have to be the same. may

Similarly, in FIG. 9, the voltage of the third hole 141 during the pre-trapping period T1 and the voltage of the third hole 141 during the pre-trapping period T1a are reversed. That is, the absolute value of the voltage of the third pore 141 during the pre-trapping period T1 is the same as the absolute value of the voltage of the third pore 141 during the pre-trapping period T1a. However, the absolute value of the voltage of the third hole 141 in the pre-trapping period T1 and the absolute value of the voltage of the third hole 141 in the pre-trapping period T1a do not necessarily have to be the same. may have different absolute values.

In the example shown in FIG. 9, an ion movement period T2a for the second ions 23 (here, negative ions) is provided immediately after the cleaning period T5 for the first ions 23 (here, positive ions). However, in general, some time is required for the ion trap RF voltage with the ion trap RF amplitude to rise to the set value. Therefore, an ion trap RF stabilization period, which is a period for stabilizing the ion trap RF voltage, may be provided between the cleaning period T5 and the ion movement period T2a. That is, after the ion trap RF voltage is stabilized, the slider valve 101 may open the third aperture 141 to move the ions 23 .

Also, the example shown in FIG. 9 shows an operation sequence when positive ion detection is followed by negative ion detection. Contrary to the operation sequence shown in FIG. 9, when positive ions are detected after negative ions are detected, the positive and negative of each voltage should be opposite to those shown in FIG.

By using the method of the second embodiment, positive ions and negative ions can be analyzed with high throughput. In the second embodiment, the method of alternately detecting positive ions and negative ions was described, but the order is not limited. For example, the sequence may be such that positive ions are detected continuously multiple times and then negative ions are detected continuously multiple times. Also in this case, the operation sequence as shown in FIG. 9 may be applied at the timing when the polarity of the ions 23 to be detected changes. As in the first embodiment, considering the efficiency of pre-trapping, the ion trapping RF amplitude may be kept constant during the ion detection period T4, and the frequency of the ion ejection AC voltage may vary. By doing so, the ions 23 may be ejected toward the detector 146 .

[Third embodiment]
FIG. 10 is a configuration diagram showing an example of a mass spectrometer 1a according to the third embodiment. In FIG. 10, the same components as in FIGS. 1 and 2 are denoted by the same reference numerals, and descriptions thereof are omitted.
FIG. 10 shows a state in which the slider valve 101 closes the third hole 141 .
In the first embodiment, as shown in FIGS. 1 and 2, the slider valve 101 is arranged on the side of the ion trap chamber 140 with respect to the third aperture 141 . On the other hand, in the third embodiment, as shown in FIG. 10, the slider valve 101 is arranged on the side of the pre-trap chamber 130a of the mass spectrometer 100a. In this case, as shown in FIG. 10, a pre-trap end cap electrode 134 for confining the ions 23 is arranged on the ion source 200 side of the slider valve 101 . The pre-trap end cap electrode 134 is provided with an opening through which the ions 23 pass. Further, as the slider valve 101 is arranged on the side of the pre-trap chamber 130a, the valve driving device 110 is also provided above the pre-trap chamber 130a.

In addition, in the mass spectrometer 1a shown in FIG. 10, the voltage of the pre-trapping end cap electrode 134 is set higher than the pre-trapping offset voltage (see FIG. 4) during the pre-trapping period T1 (see FIG. 4). 23 are pre-trapped. Then, during the ion movement period T2 (see FIG. 4), the controller 3 lowers the voltage of the pre-trapping end cap electrode 134 so that the ions 23 can move toward the ion trapping chamber 140 . In this case, the voltage of the third aperture 141 does not have to be changed.

As described above, the internal pressure of the pre-trapping chamber 130a is higher than the internal pressure of the ion trapping chamber 140. Therefore, as shown in FIG. 10, installing the slider valve 101 on the side of the pre-trapping chamber 130a can prevent gas from leaking from the pre-trapping chamber 130a to the ion trapping chamber 140. FIG. That is, since the internal pressure of the pre-trapping chamber 130a is higher than the internal pressure of the ion trapping chamber 140, the slider valve 101 is installed on the side of the pre-trapping chamber 130a, so that the slider valve 101 is attached to the third partition wall 147. It will be pushed. Thereby, the sealing performance of the slider valve 101 can be improved.

In addition, in the mass spectrometer 1a shown in FIG. 10, it is assumed that only the slider valve 101 moves when the third aperture 141 is opened, but this is not the only option. For example, the slider valve 101 and the pre-trap end cap electrode 134 may move together.

Also, the slider valve 101 shown in FIG. 10 is either entirely made of metal or entirely made of resin, as in the first embodiment. However, as shown in FIG. 11, in the slider valve 101, the material 101A on the pre-trap electrode 133 side may be made of metal (conductor), and the material 101B on the third pore 141 side may be made of resin. With such a configuration, the portion of the material 101A made of metal functions as the pre-trapping end cap electrode 134, so the pre-trapping end cap electrode 134 can be omitted. In the example shown in FIG. 11, the slider valve 101 is composed of two layers ( materials 101A and 101B), but may be composed of three or more layers. Even if the slider valve 101 is composed of three or more layers, the layer closest to the pre-trap chamber 130 may be composed of a metal (conductor). By doing so, the layer made of metal may serve as the pre-trapping endcap electrode 134 .

[Fourth embodiment]
FIG. 12 is a configuration diagram showing an example of a mass spectrometer 1b according to the fourth embodiment.
In the mass spectrometer 1b shown in FIG. 12, a state in which the slider valve 101 opens the third aperture 141 is shown. In addition, in FIG. 12, the same reference numerals are assigned to the same configurations as in FIGS. 1 and 2, and the description thereof is omitted.
In the fourth embodiment, an ion source 200 capable of generating both positive and negative ions 23 under the same voltage conditions is used as the ion source 200 . FIG. 12 shows an example in which a low vacuum barrier discharge ion source 200b is used as an example of an ion source 200 capable of generating both positive and negative ions 23 under the same voltage conditions. In the low-vacuum barrier discharge ion source 200b, two annular electrodes 202 are provided around an insulator (a glass tube 201 in the example shown in FIG. 12), and an AC power supply 203 is connected to the annular electrodes 202. there is Electric power is supplied from the AC power source 203 to the annular electrode 202 to generate discharge plasma 22 inside the glass tube 201 . In the low vacuum barrier discharge ion source 200b, positive and negative ions 23 are generated simultaneously as shown in FIG.

Also, the pressure inside the low vacuum barrier discharge ion source 200b is lower than the atmospheric pressure. A sample gas (not shown) passes through the capillary 204 and is introduced into the low vacuum barrier discharge ion source 200 b and ionized by the discharge plasma 22 . As a result, ions 23 are generated (positive and negative ions are generated in the example of FIG. 12). Unlike the atmospheric pressure chemical ionization ion source shown in FIG. 1 and the like, the low vacuum barrier discharge ion source 200b can introduce both positive and negative ions 23 into the mass spectrometer 100 without changing the voltage. Therefore, in the second embodiment (FIG. 9), the potential of the needle electrode 21 is reversed in order to change the polarity of the ions 23 to be analyzed. If so, no such changes are required. The operation of each voltage of the needle electrode 21 is the same as that shown in FIG.

[Hardware configuration of control device 3]
FIG. 13 is a diagram showing a hardware configuration example of the control device 3. As shown in FIG.
The control device 3 is composed of a PC (Personal Computer) or the like, and has a memory 301, a CPU (Central Processing Unit) 302, and a storage device 303 such as an HD (Hard Disk) or an SSD (Solid State Drive). Further, the control device 3 has an input device 304 such as a keyboard and a mouse, an output device 305 such as a display, and a communication device 306 for acquiring information from the mass spectrometer 1 and transmitting instructions.
A program stored in the storage device 303 is loaded into the memory 301 . Each function performed by the control device 3 is realized by the CPU 302 executing the loaded program.

The present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace part of the configuration of each embodiment with another configuration.

In addition, each configuration, function, control device 3, storage device 303, etc. provided in the control device 3 described above may be realized by hardware by designing a part or all of them, for example, with an integrated circuit. . Further, as shown in FIG. 13, each configuration, function, etc. described above may be realized by software by a processor such as the CPU 302 interpreting and executing a program for realizing each function. Information such as programs, tables, files, etc. that realize each function is stored in the HD, and is stored in the memory 301, a recording device such as an SSD, an IC (Integrated Circuit) card, an SD (Secure Digital) card, It can be stored in a recording medium such as a DVD (Digital Versatile Disc).

In addition, in each embodiment, the control lines and information lines are considered to be necessary for explanation, and not all control lines and information lines are necessarily shown on the product. In fact, it can be considered that almost all configurations are interconnected.

Reference Signs List 1, 1, 1a mass spectrometer 3 control device 21 needle electrode 23 ion 100, 100a mass spectrometer 101 slider valve (opening/closing part, slider part)
101A Material (a layer made of a conductor among the layers that make up the slider valve)
101B Material (Layer Constituting Slider Valve)
102 opening (valve hole)
110 Valve Drive Device 120 Differential Evacuation Chamber 121 First Orifice 122 Vacuum Pump for Differential Evacuation 123 First Partition 130 Pretrap Chamber (First Mass Spectrometer, Linear Ion Trap)
130a pre-trap chamber 131 second pore 132 pre-trap vacuum pump (first vacuum pump)
133 pre-trap electrode 134 pre-trap end cap electrode 135 second partition wall 140 ion trap chamber (second mass spectrometer, linear ion trap)
141 third pore (partition wall pore)
142 ion trap vacuum pump 142 (second vacuum pump)
143 ion trap electrode 146 detector (detection unit)
147 third partition (partition)
200 ion source 200b low vacuum barrier discharge ion source S1, S1A, S1B pre-trap S2, S2A, S2B ion transfer S3, S3A cooling S4, S4A ion detection S5, S5A cleaning T1, T1a pre-trap period T2, T2a ion transfer period T3 Cooling period T4 Ion detection period T5 Cleaning period Z Mass spectrometry system

Claims (19)

1. an ion source that continuously generates ions;
   a first mass spectrometer capable of trapping the ions;
   a second mass analysis unit provided downstream of the first mass analysis unit, capable of introducing the ions from the first mass analysis unit and capable of trapping the ions;
   a partition hole provided in a partition separating the first mass analysis unit and the second mass analysis unit;
   an opening/closing part capable of opening/closing the partition wall hole;
   a first vacuum pump unit for evacuating the inside of the first mass analysis unit;
   a second vacuum pump unit for evacuating the inside of the second mass analysis unit;
   has
   The internal pressure of the first mass analysis unit is adjusted to be higher than the internal pressure of the second mass analysis unit by the first vacuum pump unit and the second vacuum pump unit,
   A mass spectrometer, wherein the opening/closing section intermittently opens and closes the partition hole.
2. The mass spectrometer according to claim 1, wherein the opening/closing section is a slider valve capable of opening and closing the partition wall hole by vertically moving a slider section.
3. The mass spectrometer according to claim 2, wherein the slider valve is provided in the second mass spectrometer.
4. The mass spectrometer according to claim 2, wherein the slider valve is provided in the first mass spectrometer.
5. The slider valve is composed of a plurality of layers,
   5. The mass spectrometer according to claim 4, wherein, among the layers, a layer provided closest to the first mass spectrometric section is made of a conductor.
6. The slider valve is
   a valve hole through which the ions that have passed through the partition hole pass when the slider valve is in the open state of the partition hole;
   3. The mass spectrometer according to claim 2, wherein the inner diameter of the valve hole portion widens from the side of the first mass spectrometer toward the side of the second mass spectrometer.
7. The slider valve is operated by a coil,
   3. The mass spectrometer according to claim 2, wherein said coil is installed outside said first mass spectrometer and said second mass spectrometer.
8. 2. A mass spectrometer according to claim 1, wherein said ion source is capable of generating ions of both positive and negative polarities.
9. 2. The mass spectrometer according to claim 1, wherein said ion source generates said ions by a needle electrode.
10. The mass spectrometer according to claim 1, wherein the ion source is a low vacuum barrier discharge ion source.
11. The mass spectrometer according to claim 1, wherein the first mass analysis unit is a linear ion trap that mass-selectively traps the ions.
12. The mass spectrometer according to claim 1, wherein the second mass spectrometer is a linear ion trap.
13. A mass spectrometry system having a mass spectrometer and a controller for controlling the mass spectrometer,
    The mass spectrometer is
    an ion source that continuously generates ions;
    a first mass spectrometer capable of trapping the ions;
    a second mass analysis unit provided downstream of the first mass analysis unit, capable of introducing the ions from the first mass analysis unit and capable of trapping the ions;
    a partition hole provided in a partition separating the first mass analysis unit and the second mass analysis unit;
    an opening/closing part capable of opening/closing the partition wall hole;
    a first vacuum pump unit for evacuating the inside of the first mass analysis unit;
    a second vacuum pump unit for evacuating the inside of the second mass analysis unit;
    has
    The control device controls the first vacuum pump section and the second vacuum pump section so that the internal pressure of the first mass analysis section is higher than the internal pressure of the second mass analysis section. adjusted to be
    A mass spectrometry system characterized by intermittently opening and closing the partition hole by controlling the opening and closing part.
14. In a mass spectrometry system having a mass spectrometer and a controller for controlling the mass spectrometer,
    The mass spectrometer is
    an ion source that continuously generates ions;
    a first mass spectrometer capable of trapping the ions;
    a second mass analysis unit provided downstream of the first mass analysis unit, capable of introducing the ions from the first mass analysis unit and capable of trapping the ions;
    a partition hole provided in a partition separating the first mass analysis unit and the second mass analysis unit;
    an opening/closing part capable of opening/closing the partition wall hole;
    a first vacuum pump unit for evacuating the inside of the first mass analysis unit;
    a second vacuum pump unit for evacuating the inside of the second mass analysis unit;
    has
    The control device
    By controlling the first vacuum pump section and the second vacuum pump section, the internal pressure of the first mass analysis section is adjusted to be higher than the internal pressure of the second mass analysis section. ,
    A mass spectrometry method, wherein the partition hole is intermittently opened/closed by controlling the opening/closing portion.
15. The control device continuously introduces ions into the first mass spectrometry unit by closing the partition hole by the opening/closing unit,
    ions are retained in the first mass analysis unit;
    The control device opens the partition hole by the opening/closing unit, thereby introducing the ions into the second mass analysis unit,
    The control device closes the partition hole by the opening and closing part,
    The mass spectrometry method according to claim 14, wherein the ions are detected by a detector.
16. After the ions are introduced into the second mass spectrometry unit and the partition hole is closed by the opening/closing unit, the internal pressure of the second mass spectrometry unit is lowered to a predetermined value, and the ions are detected by the detection unit. 16. The mass spectrometry method according to claim 15, wherein the ions are detected.
17. The control device is
    applying a voltage to the partition hole so that the partition hole repels the ions while the ions are held in the first mass analysis unit;
    The voltage applied to the partition wall hole is changed so that the voltage applied to the partition wall hole attracts the ions when the partition wall hole is opened by the opening/closing unit. Item 16. The mass spectrometry method according to Item 15.
18. While the ions are being detected by the detection unit, ions different from the ions being detected by the detection unit are introduced into and held inside the first mass analysis unit. The mass spectrometry method according to claim 15.
19. 19. The mass spectrometry method according to claim 18, wherein the other ions are ions having a polarity opposite to that of the ions detected by the detector.

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