Ion source and mass analyser

Abstract

The present application provides an ion source and a mass spectrometer that further reduce the dead volume of the connecting portion of a pipe and a capillary. The ion source has a capillary and a pipe. The capillary has a large-diameter portion that forms a capillary upstream end surface on the upstream side, and the large-diameter portion has a large-diameter portion downstream surface on the downstream side. The pipe has a pipe downstream end surface on the downstream side. The capillary holding portion has a hole through which the capillary downstream end surface can pass and a surface on which the large-diameter portion downstream surface can be disposed. The ion source has a pipe holding portion that holds the pipe. The capillary holding portion and the pipe holding portion are configured to connect the capillary and the pipe by bringing the capillary upstream end surface and the pipe downstream end surface into contact.

Description

TECHNICAL FIELD

[0001] The present application relates to an ion source and a mass spectrometer, and particularly to an ion source and a mass spectrometer capable of achieving high maintenance. In addition, part of the present application relates to an ion source and a mass spectrometer capable of achieving high analysis stability and high analysis reproducibility. BACKGROUND

[0002] As a general ionization method for mass spectrometry and the like, an electrospray ionization method (hereinafter referred to as "ESI method") is a method in which a sample solution is introduced from an upstream end of a capillary, and ions and droplet mist are ejected from a downstream end by an electric field or the like.

[0003] Figure 1 A structure of a general existing mass spectrometer is shown. The mass spectrometer 101 mainly includes an ion source 102 and a vacuum container 104 having a mass analysis section 103 inside. The ion source 102 mainly includes an ion generation section 105 and an ion source chamber 106.

[0004] Ions generated by the ion source 102 are introduced into the vacuum container 104 from a hole 108 of an introduction electrode 107, and analyzed by the mass analysis section 103. The mass analysis section 103 is applied with various voltages by a power source 109. Timing and voltage values of the voltage application by the power source 109 are controlled by a control section 110.

[0005] As a general detailed structure of the ion generation section 105, a sample solution is introduced to a capillary 112 through a pipe 111, and ions and droplets are ejected in mist from a downstream end 113 of the capillary 112 by an electric field or the like.

[0006] In the ion source as above, it is important to connect the pipe 111 and the capillary 112 in a manner that the sample solution does not leak.

[0007] As a known example in which the connection method of the pipe 111 and the capillary 112 is described, there is Non-Patent Literature 1. In this known example, as shown in FIG. 1 of Non-Patent Literature 1, the pipe 111 and the capillary 112 are connected via a connector 114. Figure 2

[0008] With respect to the pipe 111 and the connector 114, the inside of the solution is sealed by a tapered portion 116 of a connector 115. Specifically, by screwing the connector 115 using a threaded portion 117, the tapered portion 116 enters a tapered portion 118 inside the connector, the diameter of the tapered portion 116 becomes smaller and enters the outer diameter of the pipe 111, and thus the connector 114 and the pipe 111 are sealed.

[0009] ​The capillary 112 and the connector 114 are sealed by a tapered portion 120 of the ferrule 119. Specifically, by screwing a push screw 122 using a threaded portion 121, the tapered portion 120 enters a tapered portion 123 inside the connector, the diameter of the tapered portion 120 becomes smaller, and enters the outer diameter of a resin tube 124, thereby sealing the connector 114 and the capillary 112 via the resin tube 124. The reason for passing through the resin tube 124 is because the outer diameter of the capillary 112 is small.

[0010] Prior Art Documents

[0011] Non-Patent Literature

[0012] Non-Patent Literature 1: Waters Micromass Quattro Premier Mass Spectrometer Operator's Guide 7.12.2 Removing the Existing Capillary and 7.12.3 Installing the New Capillary, [online], Internet <URL: https: / / www.waters.com / waters / supportList.htm?cid=511442&locale=ja_JP> SUMMARY

[0013] PROBLEMS TO BE SOLVED BY THE INVENTION

[0014] However, in the existing technology, there is a problem that the dead volume of the connection portion of the pipe and the capillary is large.

[0015] For example, in the sealing method using a tapered portion as in Figure 2 , a slight gap is generated on the downstream side of the sealing portion on the pipe 111 side where the tapered portion 116 and the tapered portion 118 are connected, and on the upstream side of the sealing portion on the capillary 112 side where the tapered portion 120 and the tapered portion 123 are connected, and thus the dead volume becomes large.

[0016] In addition, in the sealing method via the resin tube 124, there is also a gap between the resin tube 124 and the capillary 112 on the upstream side of the sealing portion, and thus the dead volume becomes large.

[0017] When there is a dead volume, the replacement of the sample solution takes time, and thus there is a concern that this leads to a decrease in the analysis performance due to a delay or the like. In addition, it is also possible that dirt is accumulated in the dead volume where the solution replacement is difficult, and thus the life of the component is shortened due to clogging or the like caused thereby.

[0018] The present application has been made to solve such a problem, and aims to provide an ion source and a mass spectrometer in which the dead volume of a connection portion of a pipe and a capillary tube is further reduced.

[0019] Solution to the problem

[0020] An example of the ion source of the present application has:

[0021] a capillary tube which is introduced into a sample solution, and which supplies ions or droplets; and

[0022] a pipe which supplies a sample solution to the capillary tube,

[0023] The ion source described above is characterized in that

[0024] The capillary tube has a capillary tube upstream end face on the upstream side, and a capillary tube downstream end face on the downstream side, and the outer diameter of the capillary tube upstream end face is larger than the outer diameter of the capillary tube downstream end face,

[0025] The capillary tube has a large-diameter portion which forms the capillary tube upstream end face on the upstream side, and the large-diameter portion has a large-diameter portion downstream face on the downstream side,

[0026] The pipe has a pipe downstream end face on the downstream side,

[0027] The ion source described above has a capillary tube holding portion which holds the capillary tube,

[0028] The capillary tube holding portion has a hole through which the capillary tube downstream end face can pass, and a face on which the large-diameter portion downstream face can be disposed,

[0029] The ion source described above has a pipe holding portion which holds the pipe,

[0030] The capillary tube holding portion and the pipe holding portion are configured so that the capillary tube and the pipe are connected by bringing the capillary tube upstream end face and the pipe downstream end face into contact with each other.

[0031] In addition, an example of the mass spectrometer of the present application has the ion source described above.

[0032] This specification includes the disclosure of Japanese Patent Application No. 2019-229656, which is the basis for the priority of this application.

[0033] Effects of the invention

[0034] The ion source and the mass spectrometer of the present application can further reduce the dead volume of the connection portion of the pipe and the capillary tube. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a structural diagram of a general existing mass spectrometer.

[0036] Figure 2 This is a diagram showing the connection between the piping and the capillary tube in Non-Patent Document 1.

[0037] Figure 3 This is a structural diagram of the quality analyzer in Example 1.

[0038] Figure 4 This is a structural diagram of the ion generation section in Example 1.

[0039] Figure 5 yes Figure 4 The structural diagram of each element of the ion generation section.

[0040] Figure 6 It is Figure 5 The diagram shows the structure in which the capillary retainer and the capillary are combined.

[0041] Figure 7 This is a structural diagram of the capillary in Example 2.

[0042] Figure 8 This is a structural diagram of the capillary in a modified example of Example 2.

[0043] Figure 9 This is a structural diagram of the piping in a modified example of Example 2.

[0044] Figure 10 Based on Figure 7 Experimental results for the pressure resistance evaluation of the structure (time-pressure curve).

[0045] Figure 11 Based on Figure 7 The experimental results of the pressure resistance evaluation of the structure (load-pressure curve).

[0046] Figure 12 This is a structural diagram of the ion generation section in Example 3.

[0047] Figure 13 This is a structural diagram of the ion generation section in Example 4.

[0048] Figure 14 This is a structural diagram of the ion generation section in Example 5.

[0049] Figure 15 This is a structural diagram of the ion generation section in Example 6.

[0050] Figure 16 This is a structural diagram of the ion generation section of a modified example of Example 6.

[0051] Figure 17 This is an experimental structural diagram of the ion generation section in Example 6.

[0052] Figure 18 is an experimental result (current value measurement) of the ion generation section of Example 6.

[0053] Figure 19 is an experimental result (pressure measurement) of the ion generation section of Example 6.

[0054] Figure 20 is an experimental result (flow dependence) of the ion generation section of Example 6.

[0055] Figure 21 is a structural view of the ion generation section of Example 7.

[0056] Figure 22 is a structural view of the ion generation section of Example 8.

[0057] Figure 23 is a structural view of the ion generation section of Example 9. DETAILED DESCRIPTION

[0058] Hereinafter, an embodiment of the present application will be described based on the drawings.

[0059] (Example 1)

[0060] Example 1 is an ion source and mass spectrometer of a structure in which a pipe and a capillary are directly face-sealed with an elastic force.

[0061] Figure 3 A structural view of the mass spectrometer of Example 1 is shown. The mass spectrometer 1 is provided with an ion source 2 and a vacuum vessel 4 having a mass analysis section 3 and the like inside. The ion source 2 is provided with an ion generation section 5, an ion source chamber 6, and the like.

[0062] The mass spectrometer 1 is provided with an introduction electrode 7 and a power source 9. Ions generated in the ion source 2 are introduced into the vacuum vessel 4 from a hole 8 of the introduction electrode 7, and analyzed in the mass analysis section 3. Various voltages are applied to the mass analysis section 3 by the power source 9. The timing of voltage application and the voltage value of the power source 9 are controlled by a control section 10.

[0063] The ion generation section 5 is provided with a pipe 11 and a capillary 12. The pipe 11 supplies a sample solution to the capillary 12, whereby the sample solution is introduced into the capillary 12. The capillary 12 supplies ions or droplets of the introduced sample solution. The supply of ions or droplets by the capillary 12 is performed, for example, by mist-like spraying of the sample solution from a downstream end 13 (capillary downstream end surface) of the capillary 12 by use of an electric field or the like. In the ion generation section 5, the pipe 11 and the capillary 12 are connected in such a manner that the sample solution does not leak (details of the connection will be described later).

[0064] In the ion source 2, the ion source cavity 6, the vacuum container 4, and their connecting parts are sometimes made in a sealed (or nearly sealed) state so that excess sample solution (including droplets that are not introduced into the vacuum container 4, components formed by their vaporization, etc.) does not leak to the outside of the mass analyzer 1.

[0065] The mass analyzer 1 may also have an exhaust port 14 for discharging excess sample solution (especially vaporized components). Additionally, a window 15 made of a transparent component such as glass may be provided in a part of the ion source chamber 6 for observing the spray state at the downstream end 13 of the capillary 12.

[0066] like Figure 3 As shown, the vacuum container 4 may have multiple vacuum chambers 16, 17, and 18 inside, or these vacuum chambers may be separated from each other. However, in this case, these vacuum chambers are connected to each other, for example, vacuum chamber 16 and vacuum chamber 17 are connected via a small-diameter hole 19, and vacuum chamber 17 and vacuum chamber 18 are connected via a small-diameter hole 20.

[0067] Alternatively, these holes 19, 20, and the hole 8 for introducing the electrode 7 can serve as ion channels, applying a voltage to components having each hole (e.g., partitions, especially around the holes). In this case, it is preferable to insulate the voltage-applied portion from the housing portion of the vacuum container 4 via an insulator (not shown).

[0068] Furthermore, the number of vacuum chambers only needs to be one or more, sometimes more. Figure 3 More, sometimes than Figure 3 Vacuum chambers 16, 17, and 18 are vented by vacuum pumps 21, 22, and 23, respectively, maintaining different vacuum levels. For example, they are maintained at approximately several hundred Pa, several Pa, and below 0.1 Pa, respectively.

[0069] An ion transport section 24 is provided inside the vacuum chamber 17 to allow ions to converge and pass through simultaneously. Multipolar electrodes, electrostatic lenses, etc., can be used in the ion transport section 24. The location of the ion transport section 24 is not limited to the vacuum chamber 17; it can also be installed in other vacuum chambers such as the vacuum chamber 16 or vacuum chamber 18. In addition to high-frequency voltage, DC voltage, AC voltage, and voltages combining these, a combination of voltages is applied to the ion transport section 24 from the power supply 9.

[0070] The mass analysis unit 3 includes, for example, an ion analysis unit 25 and a detector 26. The ion analysis unit 25, which separates and decomposes ions, can use a structure that combines ion traps, quadrupole filters, collision units, time-of-flight mass analyzers (TOF), etc.

[0071] The ions that have passed through the ion analysis section 25 are detected by the detector 26. The detector 26 can use an electron multiplier tube, a multi-channel plate (MCP), or the like. The ions detected by the detector 26 are converted into an electric signal or the like.

[0072] The mass spectrometer 1 is provided with a control section 10. The electric signal from the detector 26 is transmitted to the control section 10, and the control section 10 can analyze information such as the mass and intensity of the ions in detail.

[0073] The control section 10 can be configured using a known computer, and can be provided with, for example, an arithmetic unit and a storage unit. The arithmetic unit includes, for example, a processor, and the storage unit includes, for example, a semiconductor memory and a magnetic disk.

[0074] The control section 10 can also be provided with an input / output section. The input / output section accepts an instruction input from a user and outputs a control signal for controlling the voltage or the like. A program can be stored in the storage unit of the control section 10, and the computer can be caused to function as the control section 10 by executing the program by the arithmetic unit of the computer that configures the control section 10.

[0075] The voltage supplied from the power supply 9 to the mass analysis section 3 can use, in addition to a high-frequency voltage, a direct-current voltage, an alternating-current voltage, or the like, a voltage obtained by combining them, or the like.

[0076] Next, a direct connection method of the pipe and the capillary tube, which is one of the features of the ion source 2 of Embodiment 1, will be described. Figure 4 The structure of the ion generation section 5 of the ion source 2 of Embodiment 1 is shown.

[0077] Figure 4 The ion generation section 5 of Embodiment 1 is provided with a pipe holding section 27 that holds the pipe 11, the capillary tube 12, and a capillary tube holding section 28 that holds the capillary tube 12. The pipe holding section 27, the capillary tube 12, and the capillary tube holding section 28 can be easily assembled and disassembled. Hereinafter, the pipe holding section 27, the capillary tube 12, and the capillary tube holding section 28 will be collectively referred to as the "ion generation section 5". Figure 5 Each element will be described. In addition, Figure 3 The internal cavities of the pipe 11 and the capillary tube 12 are indicated by dotted lines in Embodiment 1, but Figure 4 Hereinafter, the drawings of these internal cavities will be omitted.

[0078] Figure 5 (A) indicates the pipe holding section 27. The pipe holding section 27 is provided with a pipe fixing section 29, a nut section 30, and a compression spring 31. The pipe fixing section 29 is forced in the downward direction (i.e., toward the capillary tube holding section 28) with respect to the nut section 30 by the compression spring 31. In addition, Figure 5(A) is an example of the fully extended state of the compression spring 31. When the pipe holding part 27 and the capillary holding part 28 are assembled together, the compression spring 31 is compressed. In addition, in this embodiment, the pipe holding part 27 is equipped with the compression spring 31, but it may be replaced by another spring, or the capillary holding part 28 may be equipped with a compression spring.

[0079] Pipe 11 is fixed to pipe fixing part 29. The fixing of pipe fixing part 29 and pipe 11 can be achieved by various fixing units such as adhesive bonding and riveting.

[0080] The pipe fixing part 29 and the nut part 30 are assembled via a compression spring 31, but preferably with a limiting member 32 to prevent the pipe fixing part 29 from flying off due to the elastic force of the compression spring 31. The limiting member 32 is not limited to... Figure 5 (A) Such a step can also be made using various mechanisms such as retaining rings and pins. The nut part 30 has an internal thread part 33 on the inside.

[0081] A pipe 11 is fixed to the pipe holding part 27. The pipe 11 has a downstream end face 34 on the downstream side. The downstream end face 34 is formed to allow for a face seal. In particular, in order to improve the accuracy of the face seal, it is preferable to process the downstream end face 34 in a way that reduces the surface roughness.

[0082] Figure 5 (B) indicates capillary 12. Capillary 12 has a small diameter portion 12a with a smaller outer diameter and a large diameter portion 12b with a larger outer diameter than the small diameter portion 12a. The outer diameter of the small diameter portion 12a can be set to about 1 mm or less, and the outer diameter of the large diameter portion 12b can be set to about 1 mm or more.

[0083] The small-diameter portion 12a is, for example, composed of a small-diameter component 35 having a first outer diameter. The large-diameter portion 12b is, for example, composed of a large-diameter component 36 having a second outer diameter larger than the first outer diameter. The capillary 12 is located on the upstream side ( Figure 5 (B) has a large-diameter component 36 on the upper side. The large-diameter component 36 has a cylindrical through-hole inside, through which a small-diameter component 35 is inserted and fixed.

[0084] The small-diameter component 35 and the large-diameter component 36 are preferably an integral structure. Various welding and bonding methods can be used for this integration. As an example of welding, when using brazing, it is preferable to insert the small-diameter component 35 into the inner circumference of the large-diameter component 36, and to allow solder to flow into the gap between the inner circumferential surface of the large-diameter component 36 and the outer circumferential surface of the small-diameter component 35 for welding. In this way, the small-diameter component 35 extends along the entire length of the capillary 12, thus achieving a uniform inner diameter of the capillary 12.

[0085] The inner diameter of the capillary 12 can be set to about 1 mm or less, or 1 mm or less, for example, based on the flow rate of the sample solution and the like.

[0086] The capillary 12 has a capillary upstream side end surface on the upstream side. In the present embodiment, as shown in (B) and the like, the capillary upstream side end surface is formed by an upstream side end surface 37 of the large diameter portion 12b. The upstream side end surface 37 is formed in a configuration that enables face sealing. In particular, in order to improve the accuracy of face sealing, it is preferable that the upstream side end surface 37 be processed in a manner that reduces the surface roughness. Figure 5

[0087] As described above, by setting the outer diameter of the large diameter portion 36 to about 1 mm or more, or 1 mm or more, it is possible to ensure the ease of handling, such as insertion and removal, of the capillary 12, and the range of face sealing of the upstream side end surface 37.

[0088] The large diameter portion 36 has a downstream side surface 38 on the side opposite the upstream side end surface 37 (downstream side) as a face on the downstream side. The downstream side surface 38 constitutes a face on the downstream side of the large diameter portion (large diameter portion downstream side surface).

[0089] In addition, a capillary 12 downstream side end surface is formed at the downstream end 13 of the capillary 12. The outer diameter of the upstream side end surface 37 is larger than the outer diameter of the downstream end 13.

[0090] Figure 5 (C) shows the capillary holding portion 28. The capillary holding portion 28 has a hole 39 into which the small diameter portion 35 of the capillary 12 is inserted. The hole 39 is configured to enable the downstream end 13 of the capillary 12 to pass therethrough. A tapered portion 40 is provided on the upstream side of the hole 39, thereby enabling the downstream end 13 of the capillary 12 to be smoothly inserted from the upstream side (however, a configuration that does not have the tapered portion 40 can also be employed).

[0091] The capillary holding portion 28 has a placement surface 41 that opposes the downstream side surface 38. The placement surface 41 is configured to enable the downstream side surface 38 of the large diameter portion 36 to be placed thereon. In addition, the capillary holding portion 28 has an external thread portion 42. Furthermore, according to the present embodiment, when the capillary 12 is replaced, it is not necessary to remove the capillary holding portion 28 from the box portion such as the ion source chamber 6.

[0092] Next, the installation process in the replacement work of the capillary 12 will be described. In the installation process, first, the downstream end 13 of the small diameter portion 35 of the capillary 12 is inserted into the hole 39 of the capillary holding portion 28 from the upstream side, and the downstream side surface 38 is brought into abutment with the placement surface 41 (in the state shown in (D)). Figure 6

[0093] Then, the capillary 12 is rotated relative to the capillary holding portion 28, and the downstream end 13 of the small diameter portion 35 is brought into abutment with the tapered portion 40 of the hole 39. Figure 6 ​​The outer threaded portion 42 of the capillary tube holding portion 28 is screwed to the inner threaded portion 33 of the pipe holding portion 27. In the screwing, the nut portion 30 is rotated with respect to the capillary tube holding portion 28.

[0094] When the nut portion 30 is rotated (clockwise in the case of right-hand screwing, for example), the inner peripheral lower end surface 30a of the nut portion 30 approaches the setting surface 41 of the capillary tube holding portion 28, and eventually the two surfaces abut, becoming a state in which the nut portion 30 cannot be rotated further. Figure 4 That is, the inner threaded portion 33 and the outer threaded portion 42 are a coupling unit that couples the pipe holding portion 27 and the capillary tube holding portion 28.

[0095] Thus, in the present embodiment, the inner peripheral lower end surface 30a of the nut portion 30 functions as a positioning surface of the pipe holding portion 27, and the setting surface 41 of the capillary tube holding portion 28 functions as a positioning surface of the capillary tube holding portion 28. By engaging these positioning surfaces, the pipe holding portion 27 and the capillary tube holding portion 28 are positioned and fixed to each other.

[0096] In addition, in the present embodiment, the capillary tube holding portion 28 and the pipe holding portion 27 are coupled via a direct-acting mechanism, and specifically, the direct-acting mechanism is a screwing mechanism.

[0097] The capillary tube holding portion 28 and the pipe holding portion 29 are coupled by the compression spring 31 being forced to approach each other. As a result, the downstream end surface 34 of the pipe 11 and the upstream side end surface 37 of the capillary tube 12 come into contact. When the nut portion 30 is further rotated, the length of the compression spring 31 is gradually compressed in a state in which the downstream end surface 34 of the pipe 11 and the upstream side end surface 37 of the capillary tube 12 are in contact, and the pipe 11 and the capillary tube 12 are pressed toward each other. As a result, a sealing force is generated between the pipe 11 and the capillary tube 12.

[0098] Thus, the capillary tube holding portion 28 and the pipe holding portion 27 are configured so that the capillary tube 12 and the pipe 11 are connected by bringing the upstream side end surface 37 of the large-diameter member 36 and the downstream end surface 34 of the pipe 11 into contact.

[0099] When the nut portion 30 is further rotated, the inner peripheral lower end surface 30a of the nut portion 30 abuts against the setting surface 41 of the capillary tube holding portion 28, and at this time, the nut portion 30 cannot be rotated further. Here, the length by which the compression spring 31 is compressed is a constant length determined by the shape of the nut portion 30 and the like, and thus the sealing force generated by the compression spring 31 is constant. Therefore, the same sealing force can be applied each time between the downstream end surface 34 of the pipe 11 and the upstream side end surface 37 of the capillary tube 12 every time assembly work is performed for replacement of the pipe 11 or the capillary tube 12 or the like (high sealing reproducibility).

[0100] In the existing ion source (1) described in Non-Patent Literature 1, Figure 2 ), the result of the fastening work of the connector 115, the push screw 122 depends on the proficiency of the worker. For example, since it is performed by a tool such as a wrench, manual fastening of a bolt, etc., there is a concern that a leak is generated, or a component is broken due to overtightening. In contrast, the ion source of the present embodiment can achieve constant positioning regardless of the proficiency of the worker, by rotating the nut portion 30 to a position where further rotation is not possible.

[0101] In addition, in the existing ion source (1) described in Non-Patent Literature 1, Figure 2 ), the fastening of the connector 115, the push screw 122 is required while pressing the pipe 111, the capillary 112 to the connector 114, and thus the fixed position in the long direction of the capillary 112 cannot be reproduced, the positional relationship of the downstream end 113 to the hole 108 of the introduction electrode 107 is deviated, and can become a factor that reduces the reproducibility of the analysis sensitivity.

[0102] In contrast, according to the ion source of the present embodiment, the inner peripheral lower end surface 30a of the nut portion 30 and the setting surface 41 of the capillary holding portion 28 abut, and thus the position Z1 (see Figure 4 , for example, the distance in the axial direction of the capillary 12 from the downstream end 13 to the center of the hole 8 of the introduction electrode 7) is the same each time (high assembly reproducibility). Due to this, the deviation of the analysis sensitivity also becomes small (high analysis reproducibility). In addition, the downstream end surface 34 of the pipe 11 and the upstream side end surface 37 of the capillary 12 directly contact, and thus there is no dead volume. Therefore, for example, the replacement time of the sample solution is shortened, and the delay can also be reduced (high analysis stability).

[0103] Regarding the dismounting process in the replacement work of the capillary 12, the above sequence is basically reversed, and thus the description is omitted. According to the above, the replacement of the capillary 12 under the present structure only requires two processes of the mounting (or dismounting) of the pipe holding portion 27, and the mounting (or dismounting) of the capillary 12, and does not require the dismounting of the ion generating portion 5 from the case portion such as the ion source chamber 6 (good maintainability).

[0104] Generally, the inner diameter of the capillary in the ion source is very small, and thus depending on the kind of the sample solution, the use conditions, etc., the capillary needs to be frequently replaced. In this regard, in the existing ion source (1) described in Non-Patent Literature 1, the replacement work is complicated, and the assembly reproducibility is also low. If the Figure 2The actual replacement procedure of the conventional structure will be described roughly. First, the ion generator 105 is extracted from the case portion such as the ion source chamber 106 after loosening the connector 115 and removing the pipe 111. Then, the push screw 122 is loosened and the capillary 112 is removed. The operation of installing a new capillary 112 is basically the opposite of the above operation. In comparison with such a complicated procedure, the ion source of the present embodiment enables replacement of the capillary 112 by a simpler procedure.

[0105] In the present embodiment, the structure in which the capillary holding portion 28 has the external thread portion 42 and the pipe holding portion 27 has the internal thread portion 33 is described, but it can be reversed.

[0106] In the present embodiment, the inner peripheral lower end surface 30a of the nut portion 30 and the setting surface 41 of the capillary holding portion 28 function as positioning surfaces, and the sealing force and the reproducibility of the position are achieved by abutment therebetween, but other portions can function as the positioning surfaces, and other members can be used to restrict the sealing force and the position by a structure other than the positioning surfaces. For example, the nut portion 30 can be rotated until the outer peripheral lower end surface 30b of the nut portion 30 abuts against the lower end surface of the external thread portion 42 of the capillary holding portion 28, and at the time of abutment therebetween, the nut portion 30 becomes in a state in which it cannot be further rotated.

[0107] In the present embodiment, the combination unit based on the direct movement by the thread rotation using the nut portion 30 is described. According to such a structure, the structure can be made simple, but the combination unit can be achieved by other mechanisms. It can be manual or automatic. Various direct movement mechanisms such as a lever mechanism, a cam mechanism, a crank gear mechanism, a slider mechanism, and a piston mechanism can be used. If a direct movement mechanism is used, the structure can be made simple, but mechanisms other than the direct movement mechanisms can be used.

[0108] In the present embodiment, the structure using the elastic force of the compression spring 31 which is high in convenience is described, but other elastic bodies can be used as long as a load can be defined by a compression amount. For example, if a system in which a torque amount (that is, a sealing force) of the thread rotation can be managed is used, a structure in which the compression spring 31 is not used can be adopted. For example, a compression spring other than a compression coil spring can be used, a tension spring can be used, a rubber or other elastic member can be used, or an elastic structure using a plurality of members can be used.

[0109] In the structure of the above-described embodiment 1, the pipe and the capillary are directly joined by the elastic force to seal the face, and thus the dead volume of the connection portion of the pipe and the capillary can be eliminated or reduced. Further, an ion source and a mass spectrometer which are high in analysis stability, high in analysis reproducibility, and good in maintainability can be achieved.

[0110] (Example 2)

[0111] Example 2 is an ion source and mass spectrometer in which a resin layer is provided to the end surface (sealing surface) of the capillary or the pipe. The description will be given focusing on the difference from Example 1 for convenience of explanation.

[0112] Figure 7 A structure of the capillary 12 of the present example is shown. Figure 7 The capillary 12 of the present example is characterized in that the upstream side end surface 37 is composed of a resin layer 44. If the resin layer 44 is provided to the upstream side end surface 37, it has an advantage that high sealing performance based on the softness peculiar to the resin can be achieved.

[0113] In addition, by providing the resin layer 44, the progress of deterioration of the connection portion of the pipe 11 and the capillary 12 can be adjusted. For example, in a field in which the capillary 12 is likely to be clogged and the like, it is assumed that the replacement frequency of the capillary 12 is higher than that of the pipe 11. In this case, by providing the resin layer 44 having a lower hardness than the downstream end surface 34 of the pipe 11 to the capillary 12, the deterioration of the pipe 11 side can be delayed, that is, the component of the side having a lower replacement frequency (the component of the side in which long life is desired) can be made durable.

[0114] The resin layer 44 can use various resins, and in most cases, a fluorine-based resin (PTFE, PCTFE, PFA, FEP, ETFE, etc.) having excellent chemical resistance, a polyether ether ketone resin (PEEK), or the like is more preferably used.

[0115] The resin layer 44 has a hole 45. The inner diameter of the hole 45 is made larger than the inner diameter of the pipe 11 and the inner diameter of the capillary 12, so that even if the center axes of the pipe 11 and the capillary 12 slightly deviate, it can be absorbed.

[0116] The thickness of the resin layer 44 can be set to 1 mm or less or 1 mm or less. The resin layer 44 can be integrated with the large diameter component 36 by adhesion, fusion, or the like, or can be fixed by press-fitting or riveting of the fitting portion or the like.

[0117] Figure 8 A structure of the capillary 12 of the modification example of Example 2 is shown. In order to make the flow of the solution at the portion of the hole 45 smooth, such a structure can be formed. Figure 8 The hole 45 of the resin layer 44 is characterized in that the upstream side opening portion 46 is larger than the downstream side opening portion 47. Thereby, smooth flow can be achieved.

[0118] Figure 8 In the structure of the present example, the deviation of the center axes of the pipe 11 and the capillary 12 can also be absorbed as in Figure 7 Furthermore, according to the structure of the present example, the resin layer 44 can be easily removed by heating, so that the capillary 12 can be easily replaced. Figure 8The structure allows for a smooth connection of the inner circumferences of the pipe 11 when its inner diameter is larger than that of the capillary tube 12. Conversely, when the inner diameter of the pipe 11 is smaller than that of the capillary tube 12, the opening 46 on the upstream side can be smaller than the opening 47 on the downstream side.

[0119] Figure 9 The structure of the piping 11 is shown in a modified example of Example 2. In this way, the downstream end face 34 of the piping 11 can also be formed by a resin layer 48 having holes 49.

[0120] also, Figure 9 Piping 11 can be connected with Figure 7 capillary tube 12 or Figure 8 It can be used together with the capillary 12 of Example 1. That is, it can be configured such that at least one of the upstream end face 37 of the large-diameter component 36 and the downstream end face 34 of the pipe 11 has a resin layer.

[0121] In the structure of Embodiment 2 as described above, the sealing surface has a resin layer, thus enabling the sealing performance unique to resin, and also enabling an ion source and mass analyzer that can absorb central axis deviation.

[0122] Figure 10 Use of expression Figure 7 The results of pressure resistance evaluation of the capillary 12 structure shown and the piping 11 structure of Example 1 are presented. Regarding the structure of piping 11, the downstream end face 34 is made of stainless steel, and the contact portion with the capillary 12 is annular with an outer diameter of 1.6 mm and an inner diameter of 0.3 mm. The capillary 12 has a structure with a PEEK resin layer 44 on the upstream end face 37, and its inner diameter is sealed to allow for pressure increase.

[0123] Figure 10 This represents the result of plotting a curve based on the pressure of the compression spring 31 (sealing force) when a solution (water:methanol = 1:1) is supplied to pipe 11 at a flow rate of 0.1 mL / min under these conditions. The horizontal axis represents time. Because the inner diameter is sealed, the pressure increases over time. When the internal pressure exceeds the sealing force, leakage occurs, and the curve deviates from the linear relationship between time and pressure.

[0124] Figure 11 This shows the result of plotting a curve relating the point (pressure) just before release to the load on the compression spring 31. Based on this result, it can be seen that... Figure 7 The structure, when used as a general ion source, can achieve a sufficient withstand voltage of 40 MPa. Furthermore, in Figure 10 In the diagram, some data has been omitted for ease of illustration. Figure 10 Data and Figure 11The data do not correspond one-to-one.

[0125] (Example 3)

[0126] Example 3 is an ion source and mass spectrometer in which the capillary holding portion has an anti-rotation pin. The description will be centered on the points of difference from Example 1 for ease of explanation.

[0127] Figure 12 is a structural diagram of the ion generating portion 5 of Example 3. The ion generating portion 5 of Example 3 has the feature that the capillary holding portion 28 has an anti-rotation pin 50. The anti-rotation pin 50 is fixed to the capillary holding portion 28 or formed integrally with the capillary holding portion 28, and is configured in a cylindrical shape that extends, for example, in parallel with the axis of the capillary 12. Figure 12 Two anti-rotation pins 50 are shown.

[0128] The pipe fixing portion 29 has a hole or groove corresponding to the anti-rotation pin 50, and the anti-rotation pin 50 is engaged in this hole or groove, so movement of the anti-rotation pin 50 in a direction that is not parallel with the axis is restricted. In this way, the anti-rotation pin 50 functions as an anti-rotation mechanism that prevents relative rotation of the pipe 11 and the capillary 12 (for example, relative rotation around the axis of the capillary 12). The anti-rotation pin 50 is a guide, so it is possible to prevent relative rotation of the pipe 11 with respect to the capillary 12 as a result of the rotational action of the nut portion 30.

[0129] Furthermore, if the pipe 11 is relatively rotated with respect to the capillary 12, the downstream end face 34 and the upstream side end face 37, which are sealing surfaces, rotate while contacting each other, so there is a concern that the deterioration of both sealing surfaces will be accelerated. In contrast, according to the ion generating portion 5 of the present embodiment, in the case of, for example, more frequent replacement of the capillary 12, it is possible to extend the life of the pipe 11 by preventing friction of the anti-rotation pin 50.

[0130] In the present embodiment, the structure in which the capillary holding portion 28 is provided with the anti-rotation pin 50 is described, but it is also possible to provide the anti-rotation pin 50 to the pipe fixing portion 29, and it is also possible to provide a hole or groove corresponding to this to the capillary holding portion 28.

[0131] In addition, in the present embodiment, the anti-rotation mechanism is configured by the anti-rotation pin 50, but the anti-rotation mechanism can also be configured by other configurations or components, and it is also possible to use various anti-rotation mechanisms such as keys and key grooves, protrusions and guide grooves, and the like.

[0132] In the structure of Example 3 described above, it is possible to realize an ion source and mass spectrometer with long component life by the anti-rotation pin.

[0133] (Example 4)

[0134] Example 4 is an ion source and mass spectrometer in which the center axes of the tubing and capillary are more easily aligned (axle integration). For convenience, the description will focus on the differences from Example 1.

[0135] Figure 13 is a structural diagram of the ion generation section 5 of Example 4. Figure 13 The ion generation section 5 of has the following feature: the tubing fixing section 29 has a fitting section 51 on the inner periphery, and the large diameter section 36 of the capillary 12 is guided by the fitting section 51.

[0136] The outer diameter of the tubing 11 of the tubing fixing section 29 is also guided, so the center axes of the capillary 12 and the tubing 11 are more easily aligned. It is preferable to have a tapered section 52 in the tubing fixing section 29 in a manner that makes it easy to insert and remove the capillary 12 relative to the tubing fixing section 29. The tapered section 52 can be a simple chamfer or the like. It is also possible to apply a tapered section, chamfer (in this case, an outer tapered shape with a sharp upstream side) to the large diameter section 36 of the capillary 12.

[0137] In this embodiment, the alignment structure based on the fitting section 51 is described, but in addition to this, various alignment structures such as pins, grooves, and slits can also be used.

[0138] In the structure of Example 4 described above, an ion source and mass spectrometer in which the tubing and capillary are more easily aligned can be realized.

[0139] (Example 5)

[0140] Example 5 is an ion source and mass spectrometer in which the capillary holding section has a stylus. For simplicity, the description will focus on the differences from Example 1.

[0141] Figure 14 is a structural diagram of the ion generation section 5 of Example 5. Figure 14 The ion generation section 5 of has the following feature: the capillary holding section 28 has a stylus 53. The stylus 53 is an electrically conductive body, for example, composed of a metal such as copper or stainless steel.

[0142] In the ion generation section 5 of this embodiment, the capillary 12 and the capillary holding section 28 are also composed of an electrically conductive body (for example, a metal), and can be used with a voltage applied between the capillary 12 and the inlet electrode 7. In this embodiment, the tubing fixing section 29 and the nut section 30 of the tubing holding section 27 are also composed of an electrically conductive body (for example, a metal). In this way, in this embodiment, both the tubing holding section 27 and the capillary holding section 28 have electrically conductive sections. This usage is generally used for ESI ion sources.

[0143] In Figure 14In the structure, a voltage is applied to the capillary 12 via the capillary holding section 28 as well. The voltage is applied to the capillary holding section 28 from the power supply 54 via the wiring 55. The capillary 12 contacts the capillary holding section 28, and thus a voltage is applied to the capillary 12 as well.

[0144] The sample solution introduced into the capillary 12 is ionized by the voltage applied from the power supply 54, and is ejected from the downstream end 13 in a mist form (electrospray). The timing of voltage application and the voltage value of the power supply 54 are controlled by the control section 10. The value of the voltage applied to the capillary 12 is in the range of, for example, 1 kV to 10 kV in absolute value, to the introduction electrode 7.

[0145] Further, in the case of generating positive ions, a voltage of +1 kV to +10 kV is applied to the introduction electrode 7 from the capillary 12. In the case of generating negative ions, a voltage of -1 kV to -10 kV is applied to the introduction electrode 7 from the capillary 12. The flow rate of the sample solution is set in the range of, for example, 1 nL / min to 1 mL / min, depending on the inner diameter of the capillary 12.

[0146] Here, for comparison, a structure in which the stylus 53 is omitted is assumed in Figure 14 The pipe fixing section 29 and the capillary 12 do not directly contact each other, and thus in such a structure, problems can occur due to potential floating. For example, in the case where the pipe fixing section 29 and the compression spring 31 are made of metal, and the pipe 11 and the nut section 30 are made of an insulating material, there is a concern that the potential of the pipe fixing section 29 and the compression spring 31 will float with respect to the potential of the capillary holding section 28 and the capillary 12. If there are components that thus float in potential, there is a possibility that analysis will become unstable.

[0147] In contrast, in the present embodiment, the stylus 53 contacts both the pipe fixing section 29 and the capillary holding section 28, and thus the pipe fixing section 29 and the capillary holding section 28 are in conduction and are at the same potential, and there are no components that float.

[0148] Thus, the stylus 53 functions as a unit for equalizing the potentials of the conductive components of the pipe holding section 27 and the capillary holding section 28 with respect to each other.

[0149] The stylus 53 can have a spring (not shown) or the like inside, and can be configured so that the floating probe section 56 is caused to enter and exit in the longitudinal direction by the action of the spring. When the pipe holding section 27 is attached, the probe section 56 is pressed against the pipe fixing section 29 by the action of the internal spring, and thus the pipe holding section 27 and the capillary holding section 28 are at the same potential.

[0150] In the present embodiment, the structure in which the capillary holding section 28 has the stylus 53 is described, but the structure in which the pipe fixing section 29 has the stylus 53 can also be adopted. In addition to the stylus 53, various structures that enable the two to be at the same potential, such as a plug-in type socket, a leaf spring, and the like, can also be used.

[0151] In the structure of Embodiment 5 described above, the ion source and the mass spectrometer in which the components that do not float in potential can be realized by the stylus.

[0152] (Embodiment 6)

[0153] Embodiment 6 is an ion source and a mass spectrometer in which the capillary holding section has a gas spray pipe. In order to facilitate the description, the description is centered on the points of difference from Embodiment 1.

[0154] Figure 15 is a structure diagram of the ion generating section 5 of the present embodiment. The ion generating section 5 of the present embodiment has the following feature: the capillary holding section 28 has a gas spray pipe 57. The gas introduced from the gas introduction port 58 is sprayed in mist form from the opening portion 59 of the gas spray pipe 57 disposed on the outside of the small-diameter section 35 of the capillary 12. Figure 15 In the present embodiment, the structure in which the capillary holding section 28 and the gas spray pipe 57 are integrated is described, but they can also be different structural components.

[0155] In an ESI ion source, depending on the flow conditions of the sample solution, a spray gas is sometimes used. In the process of the ion generation principle of the ESI method, the droplets of the sample solution repeatedly split, and finally become very fine droplets and ionize. The droplets that do not become sufficiently fine through the ionization process have neutral droplets, charged droplets, and the like. By gasifying or evaporating them, the ionization efficiency can be improved. For this purpose, a spray gas based on the gas spray pipe 57 can be used.

[0156] The flow rate of the spray gas can use an inert gas such as nitrogen, argon, or the like in the range of, for example, 0.5 to 10 L / min. Further, in the case of intensifying the gasification of the droplets, a method (not shown) in which a heated gas (for example, around 800°C or less than 800°C) is sprayed in mist form from the outside is sometimes further used. The flow rate of the heated gas can likewise use an inert gas such as nitrogen, argon, or the like in the range of, for example, 0.5 to 50 L / min.

[0157] In the structure in which the spray gas is used, in order to seal the gas, a seal 60 is disposed on the large-diameter section 36 of the capillary 12. The seal 60 can use various structures such as an O-ring, a gasket, and the like. In the present embodiment, the structure in which the seal 60 is disposed on the large-diameter section 36 is described, but the structure in which the seal 60 is disposed on the capillary holding section 28 can also be adopted.

[0158] In the present embodiment, as in Embodiment 1, the position Z1 of the downstream end 13 of the capillary 12 is not only positioned at the position Z1 of the capillary 12 in the state where the capillary 12 is not inserted into the capillary holding portion 28 (see FIG. 1) but also positioned at the position Z1 of the capillary 12 in the state where the capillary 12 is inserted into the capillary holding portion 28 (see FIG. 2). Figure 4 ), the protruding amount Z2 of the capillary 12 from the front end of the gas jetting tube 57 is also high in reproducibility.

[0159] In the structure of Embodiment 6 described above, a gas jetting tube is used, and a high ionization efficiency of a sample solution can be achieved in an ion source and a mass spectrometer.

[0160] Figure 16 is a structure diagram of a modification example of Embodiment 6. In this example, a fitting portion 61 is formed in the inner periphery of the capillary holding portion 28, and a part of the outer periphery of the large-diameter portion 36 of the capillary 12 is fitted into the fitting portion 61.

[0161] Figure 15 In Embodiment 6, the seal 60 is disposed at the position where the face is sealed in the large-diameter portion 36, but in Figure 16 In Embodiment 6, the seal 60 is disposed at the position where the face is sealed in the large-diameter portion 36, but in Figure 16 In Embodiment 6, the seal 60 is disposed at the position where the face is sealed in the large-diameter portion 36, but in

[0162] Figure 15 In Embodiment 6, the seal 60 is disposed at the position where the face is sealed in the large-diameter portion 36, but in Figure 16 In Embodiment 6, the seal 60 is disposed at the position where the face is sealed in the large-diameter portion 36, but in Figure 15 In Embodiment 6, the seal 60 is disposed at the position where the face is sealed in the large-diameter portion 36, but in

[0163] In the case where such a shaft seal method is used, the seal 60 can be disposed in the capillary holding portion 28 instead of the large-diameter portion 36. However, in such a structure, the seal 60 is present at the insertion site of the capillary 12, and thus becomes a cause of hooking when the capillary 12 is inserted. Therefore, it is more preferable that the seal 60 be disposed in the capillary 12.

[0164] As shown in Figure 16 , the coordinate axis in the longitudinal direction (axial direction) of the capillary 12 is defined as the Z axis, and the coordinate axes in the directions orthogonal to the Z axis and in the orthogonal relationship with each other are defined as the X axis and the Y axis, respectively. In particular, the direction of the lower side of the paper of Figure 16 is set as the positive direction of the Z axis, the direction of the front side of the paper is set as the positive direction of the Y axis, and the direction of the right side of the paper is set as the positive direction of the Z axis. The direction in which ions travel from the downstream end 13 of the capillary 12 toward the inlet electrode 7 is a direction substantially along the X axis.

[0165] By doing so, as shown in Figure 16That has the fitting portion 61, can limit the position in the X axis direction and the Y axis direction, therefore the mounting position's reproducibility is improved.

[0166] Next, the importance of the reproducibility of the protruding amount Z2 of the capillary 12 from the front end of the gas spraying tube 57 is described. Experiments of current detection based on the protruding amount Z2 were performed using the structure shown in FIG. 6. Figure 17 The center of the hole 8 of the lead-in electrode 7 (the inlet position) was defined as the origin (X, Y, Z) = (0, 0, 0). The Z-axis direction distance Z from the origin to the front end of the gas spraying tube 57 was set to 10 mm, and the X-axis direction distance X from the origin to the axis of the capillary 12 was set to 5 mm. In addition, the Y-axis direction distance from the origin to the axis of the capillary 12 was set to 0 mm (not particularly shown).

[0167] The experiments were performed in a state where no sample solution was supplied and no gas was sprayed. Figure 18 The results of detection of the current value flowing between the gas spraying tube 57 and the capillary 12 and the lead-in electrode 7 using the ammeter when a voltage of 5 kV was applied to the lead-in electrode 7 in the gas spraying tube 57 and the capillary 12 under this condition are shown.

[0168] As a result, as shown in FIG. 7, the detected current value had a large difference depending on the protruding amount Z2. The current value is related to the strength of the electric field, that is, the analysis sensitivity, and thus it was shown that, in order to obtain high analysis reproducibility, the assembly in which the protruding amount Z2 is high in reproducibility is required. Figure 18 Next, the results of pressure resistance evaluation performed by the structure of FIG. 8 are described. The structure of the pipe 11 was such that the downstream end surface 34 was composed of PEEK resin, the contact portion with the capillary 12 was provided in a ring shape, the outer diameter of the ring shape was 1.6 mm, and the inner diameter was 0.8 mm.

[0169] Figure 16 On the other hand, the structure of the capillary 12 was such that the upstream side end surface 37 was composed of stainless steel, and the inner diameter of the capillary 12 was closed in order to increase the pressure.

[0170] The results of drawing a graph of the relationship between the pressure resistance and the load of the compression spring 31 when the solution (water:methanol = 1:1) was delivered to the pipe 11 at a flow rate of 0.1 mL / min under this condition are shown. Figure 19

[0171] The comparison was made by the presence or absence of the seal 60. In the experimental results of the structure having the seal 60 ("with O-ring"), and in the experimental results of the structure not having the seal 60 ("without O-ring"), a high pressure resistance was obtained by a small load. According to this structure, it was judged that, as described above, the elastic force was lost due to the force required to crush the seal 60. Figure 19 ​​

[0172] In this experiment, the seal 60 used an O-ring (inner diameter 3 mm, wire diameter 1 mm), the angle of the tapered portion 40 was 30 degrees, and the compression amount of the O-ring was 15% (i.e., the depth of the groove for arranging the O-ring was set to 85% of the wire diameter of the O-ring). In the case of face sealing with the same compression amount Figure 15 , the force for crushing the O-ring is required in the oblique direction, and thus a compression force of, for example, about four times is required, and thus the elastic force is further lost.

[0173] Figure 20 shows a graph of the results of plotting the average pressure generated by the flow rate of the solution (water:methanol = 1:1) actually flowing when the inner diameter of the capillary 12 was not sealed in the same experimental structure as the "with O-ring" of Figure 19

[0174] This experiment was performed under the condition that the length of the capillary 12 was set to 168 mm and the inner diameter was set to 0.1 mm. A graph was plotted based on the ratio of the actually measured liquid amount of the solution actually flowing from the downstream end 13 of the capillary 12 to the theoretical value (calculated liquid amount) of the solution amount calculated from the set flow rate and the liquid passage time (actual measured liquid amount / calculated liquid amount). As shown in Figure 20 , the linearity of the flow rate and the pressure was good. In addition, the actually measured value and the theoretical value of the solution amount maintained a value very close to 1, and it could be confirmed that there was no leakage of the solution.

[0175] (Example 7)

[0176] Example 7 is an ion source and a mass spectrometer in which the capillary holding portion is composed of a double structure. For convenience of explanation, the description will be centered on the differences from Example 1.

[0177] Figure 21 is a structural view of the ion generating portion of Example 7. In this embodiment, the capillary holding portion 28 of the ion generating portion 5 is characterized in that it is a double structure inside. For example, the capillary holding portion 28 is provided with an outer member 28a and an inner member 28b. By the inner member 28b, a configuration in which the insertion path from the capillary 12 cannot directly see the gas introduction port 58 can be achieved. That is, by the inner member 28b, the hole 39 and the gas introduction port 58 are separated, and the capillary 12 does not contact the gas introduction port 58 or its periphery when inserted.

[0178] By this, it is possible to prevent the capillary 12 from hanging on the gas introduction port 58 when inserted into the hole 39. Such a double structure communicates the inside hollow of the gas introduction port 58 and the gas spray pipe 57 via the space 63 of the outer periphery of the inner member 28b, and thus a configuration in which the gas flows can be achieved.

[0179] ​The hole 39 is separated from the inner diameter of the gas jet tube 57 by the space 63, but by providing the tapered portion 65 having a larger opening portion 64 than the hole 39 at the upstream side entrance of the inner diameter of the gas jet tube 57, the capillary 12 can be smoothly inserted.

[0180] In the present embodiment, the structure of Figure 21 is described, but as long as the structure from which the gas introduction port 58 cannot be directly seen from the insertion path of the capillary 12 (i.e., the structure which does not contact the gas introduction port 58 or its periphery when the capillary 12 is inserted), the specific structure is not limited to Figure 21 .

[0181] By the structure of Embodiment 7 described above, an ion source and a mass spectrometer which can smoothly insert a capillary can be realized.

[0182] (Embodiment 8)

[0183] Embodiment 8 is an ion source and a mass spectrometer in which the installation surface of the capillary holding portion is composed of a tapered surface. For convenience of explanation, the description is centered on the difference from Embodiment 1.

[0184] Figure 22 is a structural view of the ion generating portion 5 of Embodiment 8. Figure 22 (A) indicates a state in which the capillary 12 is installed in the capillary holding portion 28, Figure 22 (B) indicates the structure of the capillary 12, Figure 22 (C) indicates the structure of the capillary holding portion 28.

[0185] As shown in Figure 22 , the ion generating portion 5 of the present embodiment is characterized in that the installation surface 41 of the capillary holding portion 28 is composed of a tapered portion 40. Correspondingly, the downstream side surface 38 of the capillary 12 also becomes a tapered shape.

[0186] As shown in Figure 22 (A), by the installation of the tapered surfaces to each other, the position in the Z-axis direction of the capillary 12 can also be restricted, and thus the same effect as Embodiment 1 can be obtained (in addition, the definition of the coordinate system is the same as Figure 16 ). Further, by the fitting of the tapered surfaces to each other, the positions in the X-axis direction and the Y-axis direction can also be restricted (i.e., the axes can be made coincident), and as a result, the positions in all of the XYZ axes can be restricted, and thus the component shape can be simplified.

[0187] In the structure of Embodiment 8 described above, by the positioning of the tapered surfaces, an ion source and a mass spectrometer in which the component shape can be simplified can be realized.

[0188] (Embodiment 9)

[0189] Example 9 is an ion source and mass spectrometer in which the capillary holding portion has a spring. The description will be centered on the points of difference from Example 1 for ease of explanation.

[0190] Figure 23 is a structural view of the ion generating portion of Example 7. Figure 23 The ion generating portion 5 of is characterized in that the capillary holding portion 28 is composed of two members (for example, an outer member 67 and an inner member 68) that are assembled via a compression spring 66.

[0191] Figure 23 The capillary holding portion 28 of is composed of the outer member 67 and the inner member 68 via the compression spring 66. Thus, as in Example 1, when the pipe holding portion 27 and the capillary holding portion 28 are assembled by rotating the nut portion 30, a sealing force can be applied between the downstream end surface 34 of the pipe 11 and the upstream side end surface 37 of the capillary 12 by the action of the compression spring 66.

[0192] The capillary holding portion 28 is divided into the outer member 67 and the inner member 68, so in this example, the face 69 that receives the inner peripheral lower end surface 30a of the nut portion 30 and the setting face 41 that receives the downstream side surface 38 of the large diameter member 36 of the capillary 12 are different.

[0193] It is preferable to provide a stopper 70 in the outer member 67 in such a way that the inner member 68 does not fly out to the upstream side due to the elastic force of the compression spring 66. As the stopper 70, in addition to Figure 23 a step, various mechanisms such as a stop ring, a pin, and the like can be used.

[0194] If the positional relationship Z3 in the Z-axis direction of the inner peripheral lower end surface 30a of the nut portion 30 and the downstream end surface 34 of the pipe 11 is constant, the position Z1 of the downstream end 13 of the capillary 12 (see Figure 4 ) is also a constant position.

[0195] In addition, by making the diameter of the upstream side opening 72 of the hole 71 of the outer member 67 larger than the diameter of the hole 39 of the inner member 68, the capillary 12 can be smoothly inserted.

[0196] In this example, the capillary holding portion 28 has a mechanism including the compression spring 66, so it is not necessary to provide such a mechanism in the pipe holding portion 27, and the pipe holding portion 27 can be made lightweight. Thus, when the capillary 12 is replaced, the portion that is actually handled is made lightweight, and the maintainability is improved.

[0197] In the structure of Example 9 described above, by having the compression spring 66 in the capillary holding portion 28, the pipe holding portion can be made lightweight, so an ion source and mass spectrometer in which the maintainability is improved can be realized.

[0198] As for the device structure of each of the above-described embodiments, the effects of the present application can also be obtained in a device mode in which the characteristic elements of the respective device structures are combined.

[0199] Symbol explanation

[0200] 1 - mass spectrometer, 2 - ion source, 5 - ion generation section, 11 - pipe, 12 - capillary (12a - small diameter portion, 12b - large diameter portion), 13 - downstream end (capillary downstream side end surface), 27 - pipe holding section, 28 - capillary holding section, 30 - nut section (30a - inner peripheral lower end surface (positioning surface)), 31, 66 - compression spring (elastic member), 33 - internal thread section (direct drive mechanism, thread engagement mechanism), 37 - upstream side end surface (capillary upstream side end surface), 41 - setting surface (positioning surface), 42 - external thread section (direct drive mechanism, thread engagement mechanism), 44, 48 - resin layer, 50 - rotation prevention pin (rotation prevention boss), 53 - stylus (mechanism for equalizing potential), 57 - gas spray pipe.

[0201] All publications, patents, and patent applications cited in this specification are herein incorporated by reference in their entirety.

Claims

1. An ion source having: a capillary which is introduced into a sample solution to supply ions or droplets; and a pipe which supplies the sample solution to the capillary, the ion source being characterized in that the capillary has a capillary upstream end surface on an upstream side and a capillary downstream end surface on a downstream side, and the outer diameter of the capillary upstream end surface is larger than the outer diameter of the capillary downstream end surface, the capillary has a large-diameter portion which forms the capillary upstream end surface on the upstream side, and the large-diameter portion has a large-diameter portion downstream surface on the downstream side, the pipe has a pipe downstream end surface on the downstream side, the ion source has a capillary holding portion which holds the capillary, the capillary holding portion has a hole through which the capillary downstream end surface can pass and a surface on which the large-diameter portion downstream surface can be disposed, the ion source has a pipe holding portion which holds the pipe, the capillary holding portion or the pipe holding portion has an elastic member which is disposed so as to generate a sealing force between the pipe and the capillary, the capillary holding portion and the pipe holding portion are disposed so that the capillary upstream end surface and the pipe downstream end surface are in contact, so that the capillary and the pipe are sealingly connected by the sealing force generated by the elastic member, and the capillary holding portion and the pipe holding portion are positioned and fixed to each other by abutting engagement of a positioning surface of the capillary holding portion and a positioning surface of the pipe holding portion.

2. The ion source according to claim 1, characterized in that the capillary holding portion and the pipe holding portion are coupled via a direct-acting mechanism.

3. The ion source according to claim 2, characterized in that the direct-acting mechanism is a screw-coupling mechanism.

4. The ion source according to claim 1, characterized in that the elastic member is a spring.

5. The ion source according to claim 1, characterized in that at least one of the capillary upstream end surface and the pipe downstream end surface has a resin layer.

6. The ion source according to claim 1, characterized in that a rotation-preventing mechanism which prevents relative rotation of the pipe and the capillary is provided.

7. The ion source according to claim 1, characterized in that the pipe holding portion and the capillary holding portion each have an electrically conductive member, the ion source has a unit for equalizing the electric potential of the electrically conductive members of the pipe holding portion and the capillary holding portion.

8. The ion source according to claim 1, characterized in that the capillary holding portion has a gas jetting pipe.

9. A mass analyzer, comprising: The ion source according to any one of claims 1 to 8 is provided.

Images