Ion analysis device

Abstract

The ion analysis device (1) of the present invention comprises: an ionization chamber (10); an ionization section (3) for generating ions from a sample (11) in the ionization chamber (10); an analysis chamber (20) separated from the ionization chamber (10) by a partition wall (21) having an opening (211); an ion transport section (22, 23, 24) disposed in the analysis chamber (20) for transporting ions generated by the ionization section; an ion capture section (25) disposed in the analysis chamber (20) for capturing ions transported by the ion transport section (22, 23, 24); an ion detection section (26) disposed in the analysis chamber (20) for detecting ions emitted from the ion capture section (25); and a single exhaust mechanism (28) connected only to the analysis chamber (20) so that the analysis chamber reaches 10 ‑3 Pressure below Pa.

Description

Technical Field

[0001] The present invention relates to an ion analysis device. Background Art

[0002] As one of the ionization methods of the sample used in the mass spectrometer, there is the matrix-assisted laser desorption / ionization (MALDI) method (e.g., patent documents 1-3). In the matrix-assisted laser desorption / ionization method, a substance (matrix substance) that easily absorbs laser light or easily ionizes is applied to the surface of the sample to capture the sample molecules. Then, the matrix substance of the captured sample molecules is microcrystallized and irradiated with laser light, thereby ionizing the sample molecules. The ions generated from the sample molecules are used in plasma analysis devices for mass analysis and ion mobility analysis. The ion source that generates ions by the MALDI method is called a MALDI ion source, and a mass spectrometer equipped with a MALDI ion source is called a MALDI-MS.

[0003] In the MALDI ion source, in most cases, a vacuum MALDI ion source is used that ionizes sample molecules under a vacuum atmosphere. The ions generated by the vacuum MALDI ion source in the ionization chamber are introduced into a mass analysis chamber connected to the ionization chamber through an ion introduction port. The mass analysis chamber is provided with, for example, an ion transport optical system composed of an ion lens, an ion trap, and an ion detection unit. The ions introduced through the ion introduction port are converged by the ion transport optical system and introduced into the ion trap. A high-frequency voltage is applied to the ion trap for capturing ions. In addition, a cooling gas such as helium is introduced into the interior of the ion trap, and the ions are cooled and captured near the center of the ion trap by collision with the cooling gas. Afterwards, the ions are sequentially released from the ion trap and detected by the ion detection unit.

[0004] In the above-mentioned MALDI-MS, the ion transport optical system and the ion detection unit are required to be 10 -3 Therefore, the ion transport optical system and ion detection unit are exhausted by a turbomolecular pump. On the other hand, the vacuum MALDI ion source requires 10 -1 ~10 -2 However, in order not to reduce the vacuum degree of the ion transport optical system connected to the ionization chamber, the ionization chamber that provides the ion source is also evacuated by a turbomolecular pump. In addition, when the cooling gas is introduced into the ion trap, the vacuum degree in the ion trap temporarily reaches 10 -1 ~10 -2Pa. Therefore, in the mass analysis chamber, in order to prevent the inflow of cooling gas from the ion trap from reducing the vacuum degree of the space containing the ion transport optical system and the ion detection unit, the space where the ion trap is located and the space containing the ion transport optical system and the ion detection unit are separated by a partition wall and exhausted by turbomolecular pumps.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 10-228881

[0008] Patent Document 2: International Publication No. 2018 / 092271

[0009] Patent Document 3: Japanese Patent Application Publication No. 2016-115565 Summary of the invention

[0010] Technical problem to be solved by the invention

[0011] As described above, in conventional MALDI-MS, in order to exhaust a plurality of spaces having different required vacuum degrees, a plurality of turbomolecular pumps must be used, which results in a problem of increasing the size and cost of the apparatus.

[0012] Here, MALDI-MS is described as an example, but the same problems as above also exist in devices using a vacuum ionization source other than the MALDI ion source and in devices that perform mobility analysis of ions captured in an ion trap.

[0013] The technical problem to be solved by the present invention is to reduce the size and cost of an ion analysis device that captures and analyzes ions from a sample generated by a vacuum ion source using an ion capture unit.

[0014] Solutions for solving the above technical problems

[0015] The ion analysis device of the present invention completed in order to solve the above-mentioned technical problems comprises:

[0016] Ionization chamber;

[0017] an ionization unit that generates ions from a sample in the ionization chamber;

[0018] an analysis chamber separated from the ionization chamber by a partition wall formed with an opening;

[0019] An ion transport unit, disposed in the analysis chamber, transporting ions generated by the ionization unit;

[0020] An ion capture unit, disposed in the analysis chamber, for capturing ions transported by the ion transport unit;

[0021] An ion detection unit is provided in the analysis chamber and detects ions emitted from the ion capture unit;

[0022] A single exhaust mechanism is connected only to the analysis chamber so that the analysis chamber is 10 -3 Pressure below Pa.

[0023] Effects of the Invention

[0024] In an ion analysis device, the ion transport unit and ion detection unit are generally required to have a -3 On the other hand, the vacuum required for the ion source configured in the ionization chamber is 10 -1 ~10 -2 Pa, which is lower than the vacuum required for the ion transport unit and the ion detection unit. -3 A single exhaust mechanism with a pressure below Pa is connected only to the analysis chamber to directly exhaust the analysis chamber and to indirectly exhaust the ionization chamber through an opening. Then, after the analysis chamber and the ionization chamber are exhausted to a specified vacuum degree respectively, the ionization unit is operated to generate ions from the sample. In addition, at the same time as the ions are generated from the sample, or slightly later than that, a specified type of gas (cooling gas) is introduced into the ion capture unit. The ions introduced into the ion capture unit are cooled by collision with the cooling gas and captured near the center of the ion capture unit. The cooling gas introduced into the ion capture unit gradually flows out into the analysis chamber, thereby reducing the vacuum degree in the analysis chamber. Therefore, the gas is discharged by the exhaust mechanism until the specified vacuum degree is reached in the analysis chamber, and the ions are captured in the ion capture unit. Then, after the specified vacuum degree is reached in the analysis chamber, ions are released sequentially from the ion capture unit and detected by the ion detection unit.

[0025] The single exhaust mechanism is composed of, for example, a main pump such as a turbomolecular pump for main suction and an auxiliary pump such as a diaphragm pump for rough suction. The main pump for main suction is generally large and expensive. In the ion analysis device of the present invention, since it only has a single exhaust mechanism connected only to the analysis chamber, it can be miniaturized and cost-effective compared to the previous ion analysis devices having multiple such exhaust mechanisms. In addition, the term "single exhaust mechanism" is used in conjunction with the main pump (i.e., the connected space is 10 -3 The limitations on the exhaust mechanism for a pressure below Pa do not exclude, for example, connecting a rough suction pump for performing a load lock operation in the ionization chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1It is a diagram showing the main structure of a mass spectrometer as one embodiment of the ion analysis device of the present invention. DETAILED DESCRIPTION

[0027] Hereinafter, a mass spectrometer as an embodiment of the ion analysis device of the present invention will be described with reference to the accompanying drawings. The mass spectrometer of this embodiment is a matrix laser desorption ionization-ion trap (MALDI-IT) type mass spectrometer that mass-separates and detects ions generated by a MALDI (Matrix Assisted Laser Desorption / Ionization) ion source using an ion trap (IT).

[0028] Figure 1 The main components of the mass spectrometer 1 of this embodiment are shown. The mass spectrometer 1 is roughly composed of an ionization chamber 10, a mass analysis chamber 20, a voltage application unit 30, and a control unit 40. A partition wall 21 is provided between the ionization chamber 10 and the mass analysis chamber 20. A tapered opening 211 is formed in the partition wall 21, which gradually widens toward the mass analysis chamber 20 side.

[0029] The ionization chamber 10 is provided with a sample stage 12 for placing a sample plate 111 having a plurality of holes for accommodating the sample 11. The sample stage 12 is positioned at a measurement position ( Figure 1 The stage moving mechanism 13 is provided at the measuring position for approaching / separating from the opening 211. In addition, a valve 14 and a valve for closing the opening 211 at the blocking position ( Figure 1 The valve moving mechanism 15 is configured to move between the position shown in the figure and the retreat position. The valve 14 and the valve moving mechanism 15 constitute a load lock mechanism. The ionization chamber 10 is also provided with a mechanism (not shown) for opening and closing the ionization chamber 10 so that the analyst can replace the sample plate 11. In addition, the ionization chamber 10 is connected to a valve that allows the ionization chamber 10 to reach 10 during the load lock operation. 3 A diaphragm pump (rough suction pump, not shown) with a pressure of about Pa is used. In the present embodiment, a diaphragm pump is connected to the ionization chamber 10, but the configuration including such a rough suction pump is a preferred mode and is not essential to the present invention.

[0030] Furthermore, outside the ionization chamber 10 and the mass analysis chamber 20 , a laser light source 3 for irradiating a sample 11 on a sample stage 12 at a measurement position with laser light and a camera 5 for observing the surface of the sample via a half mirror 4 are arranged.

[0031] In the mass analysis chamber 20, a first ion lens 22, a deflection unit 23, a second ion lens 24, an ion trap 25, and an ion detector 26 are provided in order from the side close to the ionization chamber 10. The first ion lens 22 and the second ion lens 24 are composed of a plurality of annular electrodes arranged along the central axis (ion optical axis) of the flight path of the ions.

[0032] The deflection unit 23 includes four rod electrodes 231 to 234. Under the control of the control unit 40, a voltage having a polarity opposite to that of the ions is applied from the voltage application unit 30 to the rod electrode 231, and a voltage having the same polarity as that of the ions is applied to the other rod electrodes 232 to 234.

[0033] The ion trap 25 is a three-dimensional ion trap including a ring-shaped annular electrode 251 and a pair of end cap electrodes (entrance side end cap electrode 252, exit side end cap electrode 253) arranged opposite to each other with the annular electrode 251 sandwiched therebetween. An ion introduction hole 254 is formed in the entrance side end cap electrode 252, and an ion ejection hole 255 is formed in the exit side end cap electrode 253. Under the control of the control unit 40, a voltage of either a high-frequency voltage or a direct current voltage or a voltage synthesized from the voltage application unit 30 is applied to each of the electrodes 251, 252, and 253 at a predetermined timing. By appropriately changing these voltages, ions are captured inside the ion trap 25, or the captured ions are released. The ions released from the ion trap 25 are detected by the ion detector 26.

[0034] The entrance side end cap electrode 252 and the annular electrode 251, and the exit side end cap electrode 253 and the annular electrode 251 are connected and fixed by means of an annular insulating member 256. The insulating member 256 has a plurality of (e.g., four) openings arranged at equal intervals in the circumferential direction, thereby connecting the internal space of the ion trap 25 with the mass analysis chamber 20. The opening of the insulating member 256 is formed to be sufficiently larger than the ion introduction hole 254 of the entrance side end cap electrode 252 and the ion ejection hole 255 of the exit side end cap electrode 253.

[0035] In addition, the ion trap 25 is provided with a gas supply unit 27 for supplying one or more inert gases (helium, nitrogen, argon, etc.) at a predetermined flow rate to the interior of the ion trap 25. The gas supply unit 27 includes a plurality of gas sources 271 for selectively supplying one gas, a gas flow path 272 connecting the gas source 271 and the ion trap 25, and a valve 273 provided on the gas flow path 272.

[0036] A vacuum exhaust mechanism 28 is connected to a position of the chamber wall constituting the mass analysis chamber 20 facing the ion trap 25 and the ion detector 26. The vacuum exhaust mechanism 28 includes a turbomolecular pump as a main pump and a diaphragm pump as an auxiliary pump. In addition, a vacuum gauge 29 for measuring the pressure in the mass analysis chamber 20 is installed near the ion detector 26 of the mass analysis chamber 20.

[0037] Next, the flow of measurement using the mass spectrometer of this embodiment will be described.

[0038] First, in the ionization chamber 10, the valve moving mechanism 15 is operated to close the opening 211 through the valve 14. Next, the ionization chamber 10 is opened, the stage moving mechanism 13 is operated, the sample stage 12 is moved to the replacement position, and the sample plate 111 is placed. During this series of operations, the inside of the ionization chamber 10 is open to the atmosphere. Thereafter, the ionization chamber 10 is closed, the ionization chamber 10 is roughly evacuated by the diaphragm pump, and the stage moving mechanism 13 is operated to move the sample stage 12 to the measurement position.

[0039] After the sample stage 12 is moved to the measurement position, if the user instructs to start measurement, the control unit 40 operates the above-mentioned components as follows.

[0040] First, the valve moving mechanism 15 is operated to open the opening 211 through the valve 14. Next, the diaphragm pump, which is an auxiliary pump of the vacuum exhaust mechanism 28, is operated to roughly pump the mass analysis chamber 20. In addition, the ionization chamber 10 is also roughly pumped through the opening 211. As a result, the mass analysis chamber 20 and the ionization chamber 10 are roughly pumped to 10 -1 ~10 -2 After that, the turbomolecular pump as the main pump is operated to perform the main pull in the mass analysis chamber 20. At this time, the ionization chamber 10 is also evacuated through the opening 211. Since the ionization chamber 10 is exhausted through the opening 211, it is not limited to reaching the same vacuum degree as that in the mass analysis chamber 20. As long as the vacuum degree required for generating ions from the sample 11 in the ionization chamber 10 is 10 -1 ~10 -2 Pa, and even a vacuum degree of a rough suction level will not cause any particular problem. Thereafter, until the measurement is completed, the mass analysis chamber 20 is continuously evacuated by the vacuum exhaust mechanism 28 .

[0041] The pressure in the mass analysis chamber 20 reaches 10 -3After the pressure drops below Pa, the laser light source 3 is activated to irradiate the surface of the sample 11 on the sample stage 12 at the measurement position with laser. As a result, ions are generated from the sample 11. The ions generated from the sample 11 are introduced into the mass analysis chamber 20 with a higher vacuum degree than the ionization chamber 10 through the opening 211. The ions introduced into the mass analysis chamber 20 are converged by the first ion lens 22, the flight direction is bent by the deflection unit 23, and then converged by the second ion lens 24, and then incident into the ion trap 25 from the ion introduction hole 254 of the entrance side end cap electrode 252. A predetermined high-frequency voltage (or a voltage obtained by superimposing a high-frequency voltage and a DC voltage) is applied to the annular electrode 251, the entrance side end cap electrode 252, and the exit side end cap electrode 253, respectively, thereby capturing ions of a determined mass-to-charge ratio (or a mass-to-charge ratio range) into the ion trap 25.

[0042] At the same time as the laser is irradiated to the sample 11, or slightly later than the laser is irradiated to the sample 11, helium gas is introduced into the ion trap 25 from the gas supply unit 27 at a predetermined time period. The helium gas is used as a cooling gas. The kinetic energy of the ions captured in the ion trap 25 is reduced by collision with the helium gas. Then, these ions are gradually cooled and converged near the center of the ion trap 25.

[0043] The helium gas introduced into the ion trap 25 flows out from the opening of the insulating member 256 into the mass analysis chamber 20. Therefore, the vacuum degree in the mass analysis chamber 20 is temporarily reduced. Therefore, the system waits until the vacuum degree in the mass analysis chamber 20 reaches the same level or higher than that at the start of the measurement (pressure reaches 10 -3 During this period, ions cooled by the cooling gas are captured in the ion trap 25 .

[0044] The pressure in the mass analysis chamber 20 reaches 10 -3 After it reaches below Pa, the applied voltages to the annular electrode 251, the entrance side end cap electrode 252 and the exit side end cap electrode 253 are appropriately changed, thereby changing the mass-to-charge ratio (or mass-to-charge ratio range) of the ions captured in the ion trap 25, thereby releasing ions of a specific mass-to-charge ratio (or mass-to-charge ratio range) from the ion trap 25 and detecting them by the ion detector 26.

[0045] The above is an example of directly measuring ions generated from a sample, but it is also possible to perform MS / MS measurement in which ions generated from a sample are fragmented and then measured (or MS / MS measurement in which ions are fragmented multiple times and then measured). nIn this case, after the ions are cooled by helium gas, a high-frequency voltage (or a voltage obtained by superimposing a high-frequency voltage and a DC voltage) is applied to the annular electrode 251, the entrance-side end cap electrode 252, and the exit-side end cap electrode 253 so as to screen the precursor ions so that only ions with a predetermined mass-to-charge ratio are captured in the ion trap 25. Thereafter, a collision gas (for example, nitrogen or argon) is introduced into the ion trap 25 from the gas supply unit 27. Furthermore, the precursor ions captured in the ion trap 25 are excited and cleaved by collision with the collision gas to generate product ions.

[0046] Then, the cooling gas and the collision gas flowing out from the opening of the insulating member 256 into the mass analysis chamber 20 are exhausted by the vacuum exhaust mechanism 28 and stand by until the vacuum degree in the mass analysis chamber 20 reaches 10°C, which is the same as that at the start of the measurement. -3 Pa or more. During this period, the product ions are captured in the ion trap 25 in advance.

[0047] The pressure in the mass analysis chamber 20 reaches 10 -3 When the voltage is less than Pa, the voltage applied to the annular electrode 251 , the entrance-side end cap electrode 252 , and the exit-side end cap electrode 253 is appropriately changed to release the ions captured in the ion trap 25 and detect them with the ion detector 26 .

[0048] As described above, in the mass spectrometer 1 of this embodiment, the ionization chamber 10 and the mass analysis chamber 20 are exhausted to a required vacuum level by only one vacuum exhaust mechanism 28. Therefore, compared with a conventional mass spectrometer that uses vacuum exhaust mechanisms for spaces with different required vacuum levels, the mass spectrometer can be manufactured in a small size and at a low cost.

[0049] As described above, a high vacuum degree is required for the mass analysis chamber 20, and it takes time to evacuate the mass analysis chamber 20 once it is opened to the atmosphere. Therefore, in the case of a configuration with a load lock mechanism for opening the ionization chamber 10 to the atmosphere when setting a sample as in the above-mentioned embodiment, when setting a sample, the opening 211 of the mass analysis chamber 20 is closed by the valve 14 and the mass analysis chamber 20 is maintained in a vacuum state, and only the ionization chamber 10 is opened to the atmosphere to set the sample.

[0050] If the ionization chamber 10 is opened to the atmosphere, water vapor contained in the atmosphere will also enter the ionization chamber 10 and adhere to the wall surface. Once the water molecules adhere to the wall surface in the ionization chamber 10, they will not easily detach, but will gradually detach. Even if the vacuum is continued until the water molecules are completely detached from the wall surface, it is difficult to achieve a higher vacuum than a certain pressure. Since the vacuum required for the ionization chamber 10 is not that high, there is no problem. However, if the water molecules detached from the wall surface of the ionization chamber 10 enter the interior of the mass analysis chamber 20 through the opening 211, the vacuum of the mass analysis chamber 20 will deteriorate. Although the pressure requirement for the mass analysis chamber 20 is 10 -3 Pa or less, but if the diameter of the opening 211 is too large, more water molecules than the exhaust volume of the vacuum exhaust mechanism 28 (especially the turbomolecular pump) will enter the mass analysis chamber 20 from the ionization chamber 10, and the required vacuum degree cannot be obtained. Therefore, it is necessary to determine the diameter of the opening 211 in advance so that the inflow speed (inflow amount) of water molecules from the ionization chamber 10 to the mass analysis chamber 20 is less than the exhaust speed (inflow amount) of the turbomolecular pump. An example of a method for determining the diameter of such an opening 211 is described below.

[0051] The pressure in the mass analysis chamber 20 is set to P1 (Pa), the pressure in the ionization chamber 10 is set to P2 (Pa), and the diameter of the opening 211 is set to D (m). Since the molecular velocity (flow rate) of water molecules (H2O) flying in a vacuum atmosphere such as the ionization chamber 10 and the mass analysis chamber 20 in this embodiment is about 600 m / s at room temperature (20°C), the following model is constructed: the area from the ionization chamber 10 to the opening 211 is π / 4×D 2 (m 2 ) opening, water molecules enter the mass analysis chamber 20 from the ionization chamber 10 through the opening 211 at a speed of 600 (m / s).

[0052] The amount of water molecules entering the mass analysis chamber 20 (the volume of water molecules entering the mass analysis chamber 20 in the ionization chamber 10 per second) V2 (m 3 / s) reaches 2π / 4×D 2 (m 2 )×600(m / s)=150πD 2 (m 3 / s). If the ambient temperature of the mass analyzer 1 is constant, R and T in the state equation of the gas PV = nRT are constant. Since the number of water molecules n does not change when passing through the opening 211 and after entering the mass analysis chamber 20, the value on the right is constant, and thus the PV on the left is also constant.

[0053] The value of P2V2 of the water molecule that moves from the ionization chamber 10 to the mass analysis chamber 20 is P2V2=P2×150πD 2 In addition, since the exhaust speed V1 of a conventional turbomolecular pump is about 30 L / s = 30 × 10 -3 (m 3 / s) or more, so the P1V1 value of the water molecules discharged from the mass analysis chamber 20 by the turbomolecular pump is P1V1=P1×30×10 -3 (m 3 / s)=30×10 -3 ×P1.

[0054] Here, when P2V2>P1V1, the amount of water molecules entering the mass analysis chamber 20 from the ionization chamber 10 is greater than the amount of water molecules discharged from the mass analysis chamber 20, and the vacuum degree in the mass analysis chamber 20 deteriorates. Therefore, it is necessary to determine the diameter D of the opening so that P2V2≤P1V1. That is, according to P2×150πD 2 ≤30×10 -3 ×P1, we get the following formula.

[0055] [Number 1]

[0056]

[0057] Therefore, according to the configuration of the mass spectrometer actually used for measurement, by inputting the assumed pressure of the ionization chamber 10 and the pressure required for the mass spectrometer 20 into the above formula, the diameter D of the opening suitable for the configuration of the mass spectrometer can be determined.

[0058] In addition, the inventors set various diameters of the opening 211, and measured the pressure in the mass analysis chamber 20 while exhausting the mass analysis chamber 20 using a turbomolecular pump. It was found that if the diameter of the opening 211 was less than 6.0 mm, the required vacuum degree (10 -3 Pa or less).

[0059] Summarizing the above model and actual measurement results, it can be said that in a mass spectrometer of a general configuration, if the diameter of the opening 211 is 6.0 mm or less, there will be no practical problem (i.e., the vacuum degree of the mass analysis chamber 20 is less than 10 mm). -3 Furthermore, by setting the diameter of the opening 211 to be less than a value obtained by inputting the assumed pressure and the like into the above formula in the mass spectrometer actually used, the mass spectrometry chamber 20 can also be maintained at an ultra-high vacuum.

[0060] The above-described embodiment is an example and can be modified appropriately according to the gist of the present invention.

[0061] The above embodiment is a MALDI-IT type mass spectrometer, but the same structure as above can also be adopted in a mass spectrometer having an ionization source other than MALDI and a mass separation unit other than IT. In addition, not limited to mass spectrometers, the same structure as above can also be adopted in ion mobility analysis devices, etc.

[0062] In the above, various embodiments of the present invention have been described in detail with reference to the accompanying drawings. Finally, various schemes of the present invention will be described.

[0063] The ion analysis device according to the first aspect of the present invention comprises:

[0064] Ionization chamber;

[0065] an ionization unit that generates ions from a sample in the ionization chamber;

[0066] an analysis chamber separated from the ionization chamber by a partition wall formed with an opening;

[0067] An ion transport unit, disposed in the analysis chamber, transporting ions generated by the ionization unit;

[0068] An ion capture unit, disposed in the analysis chamber, for capturing ions transported by the ion transport unit;

[0069] An ion detection unit is provided in the analysis chamber and detects ions emitted from the ion capture unit;

[0070] A single exhaust mechanism is connected only to the analysis chamber, so that the analysis chamber reaches 10 -3 Pressure below Pa.

[0071] In the ion analysis device of the first aspect of the present invention, the connected space is made 10 -3 A single exhaust mechanism with a pressure below Pa directly exhausts the analysis chamber, and also indirectly exhausts the ionization chamber through an opening. Then, after the analysis chamber and the ionization chamber are each exhausted to a specified vacuum degree, the ionization section is operated to generate ions from the sample. In addition, at the same time as the ions are generated from the sample, or slightly later than that, a specified type of gas (cooling gas) is introduced into the ion capture section. The ions introduced into the ion capture section are cooled by collision with the cooling gas and captured near the center of the ion capture section. Since the gas introduced into the ion capture section gradually flows out into the analysis chamber, the vacuum degree in the analysis chamber is reduced, so the gas is discharged through the exhaust mechanism until the specified vacuum degree is reached in the mass analysis chamber, and the ions are captured in the ion capture section. Then, after the specified vacuum degree is reached in the mass analysis chamber, ions are released sequentially from the ion capture section and detected by the ion detection section.

[0072] The above-mentioned single exhaust mechanism is composed of, for example, a main pump such as a turbomolecular pump for main suction and an auxiliary pump such as a diaphragm pump for rough suction. The main pump for main suction is generally large and expensive. In the ion analysis device of the present invention, since only a single exhaust mechanism connected only to the analysis chamber is provided, it is possible to achieve miniaturization and cost reduction compared to the previous ion analysis device having multiple such exhaust mechanisms.

[0073] The ion analysis device according to the second aspect of the present invention is the ion analysis device according to the first aspect,

[0074] The ionization chamber is provided with a valve that opens and closes the opening.

[0075] In the ion analysis device according to the second aspect, by closing the opening with the valve in advance, the sample can be replaced without opening the mass analysis chamber to the atmosphere.

[0076] The ion analysis device according to the third aspect of the present invention is the ion analysis device according to the first aspect or the second aspect,

[0077] The diameter of the opening is 6.0 mm or less.

[0078] In the ion analysis device of the third embodiment, since the diameter of the opening is less than 6.0 mm, the amount of water molecules that may enter the mass analysis chamber from the ionization chamber can be suppressed, and the mass analysis chamber can be reliably maintained at an ultra-high vacuum. In addition, the opening is circular as a premise, but the shape of the opening is not limited to a circle, and an opening of a suitable shape having an area equal to or less than a circle with a diameter of 6.0 mm can be used.

[0079] The ion analysis device according to a fourth aspect of the present invention is the ion analysis device according to any one of the first to third aspects, further comprising:

[0080] a gas introduction unit for introducing a predetermined type of gas into the ion capture unit;

[0081] The control unit operates the ionization unit to generate ions from the sample and operates the gas introduction unit at a predetermined time period. After the ions are captured by the ion capture unit until a predetermined vacuum degree is reached in the ion analysis chamber, the ions are released from the ion capture unit and detected by the ion detection unit.

[0082] By using the ion analysis apparatus according to the fourth aspect, ions can be analyzed at an appropriate timing when the ion analysis chamber reaches a predetermined vacuum degree without causing trouble to the analyst.

[0083] An ion analysis device according to a fifth aspect of the present invention is the ion analysis device according to any one of the first to fourth aspects, wherein the ion capturing section is an ion trap.

[0084] Since the ion analysis device according to the fifth aspect can make the ion trap function as both an ion capturing section and a mass separation section, the device can be miniaturized.

[0085] Description of Reference Numerals

[0086] 1. Quality analysis device

[0087] 3 Laser light source

[0088] 4 Half-transparent half-reflective mirror

[0089] 5. Camera

[0090] 10 Ionization chamber

[0091] 11. Sample

[0092] 111 Sample Plate

[0093] 12 Sample carrier

[0094] 13 Stage moving mechanism

[0095] 14 valve

[0096] 15 Valve moving mechanism

[0097] 20 Quality Analysis Room

[0098] 21 Divider Wall

[0099] 211 Opening

[0100] 22. First Ion Lens

[0101] 23 Deflection unit

[0102] 231~234 rod electrodes

[0103] 24 Second ion lens

[0104] 25 Ion Trap

[0105] 251 Ring Electrode

[0106] 252 Inlet side end cap electrode

[0107] 253 outlet side end cap electrode

[0108] 254 Ion introduction hole

[0109] 255 Ion ejection aperture

[0110] 256 Insulation parts

[0111] 26 Ion detector

[0112] 27 Gas supply unit

[0113] 271 Gas Source

[0114] 272 Gas flow path

[0115] 273 Valve

[0116] 28 Vacuum exhaust mechanism

[0117] 29 Vacuum gauge

[0118] 30 Voltage application unit

[0119] 40 Control Department.

Claims

1. An ion analysis device, characterized in that: have: Ionization chamber; an ionization unit that generates ions from a sample in the ionization chamber; an analysis chamber separated from the ionization chamber by a partition wall formed with an opening; An ion transport unit, disposed in the analysis chamber, transporting ions generated by the ionization unit; An ion capture unit, disposed in the analysis chamber, for capturing ions transported by the ion transport unit; An ion detection unit is provided in the analysis chamber and detects ions emitted from the ion capture unit; A single exhaust mechanism is connected only to the analysis chamber, so that the analysis chamber reaches 10 -3 Pressure below Pa; a gas introduction unit for introducing a predetermined type of gas into the ion capture unit; a control unit that operates the ionization unit to generate ions from the sample and operates the gas introduction unit to capture ions in the ion capture unit until a predetermined vacuum degree is reached in the ion analysis chamber, and then releases ions from the ion capture unit and detects them by the ion detection unit; In a state where the analysis chamber is evacuated to a vacuum by the single exhaust mechanism, only the ionization chamber is opened to the atmosphere to set the sample, The diameter of the opening is determined in advance so that the inflow speed of water molecules in the atmosphere from the ionization chamber to the analysis chamber becomes lower than the exhaust speed of the single exhaust mechanism.

2. The ion analysis device according to claim 1, characterized in that The ionization chamber is provided with a valve that opens and closes the opening.

3. The ion analysis device according to claim 1, characterized in that The diameter of the opening is 6 mm or less.

4. The ion analysis device according to claim 1, characterized in that The ion trapping section is a three-dimensional ion trap.

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