Ionization device and mass spectrometer

Abstract

The present invention relates to an ionization device comprising: an ionization chamber (2); a sample nozzle (60) for allowing a liquid sample to flow into the ionization chamber (2); an auxiliary gas flow path (61) for supplying an auxiliary gas for promoting desolvation of the liquid sample into the ionization chamber (2); a heater (62) disposed inside the auxiliary gas flow path (61); and a heat transfer component (64) disposed inside the auxiliary gas flow path (61) in contact with the heater (62). The heat transfer component (64) can be disposed inside the heater (62) formed by spirally winding a heating wire, and between the heater (62) and the inner wall surface of the auxiliary gas flow path (61).

Description

Technical Field

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

[0002] Liquid chromatographs are one type of device used to analyze substances contained in liquid samples. In a liquid chromatograph, the liquid sample is introduced into the chromatographic column of the liquid chromatograph along with the flow of a mobile phase. Within the column, the target substance is separated from other substances. The target substance exiting the column is ionized by the ionization source of the mass spectrometer, separated, and measured based on its mass-to-charge ratio.

[0003] As the ion source of the mass spectrometer, for example, an electrospray ionization (ESI) source is used. The ESI source introduces a liquid sample into a nozzle (ESI nozzle) having a double-tube structure, charges the sample, and sprays the sample into an ionization chamber. The ESI source comprises a first flow path for introducing the liquid sample, and a second flow path formed on the periphery of the first flow path and for introducing an atomizing gas. In the ESI source, a predetermined voltage (ESI voltage) is applied to the first flow path to charge the liquid sample, and an atomizing gas is blown onto the charged droplets of the liquid sample flowing out of the front end of the first flow path and sprayed into the ionization chamber. The charged droplets sprayed into the ionization chamber are ionized by the fragmentation caused by the charge repulsion inside the droplets and the vaporization (desolvation) of the mobile phase.

[0004] Patent Documents 1 and 2 describe an ESI source equipped with a mechanism for supplying assist gas to promote desolvation of charged droplets of a liquid sample. The assist gas supply mechanism comprises a third flow channel for supplying assist gas, and an assist gas nozzle for supplying assist gas supplied from the third flow channel to the periphery of the jet of liquid sample from the ESI nozzle. A heater is disposed within the third flow channel, and the assist gas heated by the heater is supplied to the charged droplets of the liquid sample, thereby promoting desolvation.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-113832

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2015-049077 Summary of the Invention

[0009] Technical problem to be solved by the invention

[0010] In recent years, a wide variety of substances have been analyzed in liquid chromatography mass analysis, and the analysis conditions have also varied. The optimal temperature of the auxiliary gas varies depending on the characteristics of the target substance and the analysis conditions. Patent Documents 1 and 2 describe blowing an auxiliary gas heated to 400-500°C onto the charged droplets. However, when analyzing substances that are difficult to vaporize or when the mobile phase is supplied at a high flow rate, desolvation is not always sufficient, and a higher temperature auxiliary gas is required to promote desolvation of the charged droplets.

[0011] Patent Document 2 describes the use of a micro-sheath heater as a heater for heating assist gas. Micro-sheath heaters have a high heat resistance of approximately 600°C. However, due to the thin wires in micro-sheath heaters, even a slight increase in the supplied power can cause the heater to burn out. Furthermore, using a highly heat-resistant heater to prevent this would increase costs.

[0012] Here, the technical problems of the prior art are described by taking the auxiliary gas in the ESI source as an example. The same problems as above also exist in other ionization sources (such as APCI source).

[0013] The technical problem to be solved by the present invention is to provide a technology that can promote the desolvation of a liquid sample by using a low-cost auxiliary gas with a higher temperature than before.

[0014] Solutions for solving the above technical problems

[0015] The ionization device of the present invention, which has been developed to solve the above-mentioned technical problems, comprises:

[0016] ionization chamber;

[0017] a sample nozzle, for allowing the liquid sample to flow into the ionization chamber;

[0018] an auxiliary gas flow path for supplying an auxiliary gas for promoting desolvation of the liquid sample to the ionization chamber;

[0019] a heater, disposed inside the auxiliary gas flow path;

[0020] The heat transfer member is arranged inside the assist gas flow path in contact with the heater.

[0021] Effects of the Invention

[0022] In the ionization device of the present invention, an auxiliary gas that promotes the desolvation of the liquid sample flowing out of the sample nozzle is supplied. In the auxiliary gas flow path where the auxiliary gas flows, in addition to the heater, a heat transfer component connected to the heater is also provided. In the previous ionization devices, only a heater was provided in the auxiliary gas flow path, and a large amount of auxiliary gas flowing through the auxiliary gas flow path was released without contacting the heater. On the other hand, in the ionization device of the present invention, since a heat transfer component is provided in addition to the heater, the contact area between the auxiliary gas flowing through the auxiliary gas flow path and the heat source (heater and heat transfer component) becomes larger than before, and the auxiliary gas can be heated more efficiently, thereby supplying auxiliary gas at a higher temperature than before. In addition, the heater itself only needs to use the same heater as before, and the ionization device can be constructed at a low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the configuration of a mass spectrometer including an embodiment of the ionization device of the present invention.

[0024] Figure 2 This figure explains the internal structure of the tip portion of the ESI ionization probe, which is the ionization device of this embodiment.

[0025] Figure 3 It is a schematic diagram of a cross section of the tip portion of the ESI ionization probe, which is the ionization device of this embodiment.

[0026] Figure 4 It is the SUS mesh which is the heat transfer component in this embodiment.

[0027] Figure 5 This is a diagram illustrating the arrangement of the heat transfer components in this embodiment.

[0028] Figure 6 This is another diagram illustrating the arrangement of the heat transfer components in this embodiment.

[0029] Figure 7 This is a diagram illustrating the structure of the heater used in this embodiment.

[0030] Figure 8 This is another diagram illustrating the structure of the heater used in this embodiment.

[0031] Figure 9 This is another diagram illustrating the structure of the heater used in this embodiment.

[0032] Figure 10 This is another diagram illustrating the structure of the heater used in this embodiment.

[0033] Figure 11These are experimental results obtained by confirming the heating effect of the assist gas by the ionization device of this embodiment. DETAILED DESCRIPTION

[0034] An embodiment of the ionization device of the present invention will be described below with reference to the accompanying drawings. The ionization device of this embodiment is incorporated as an ionization unit of a mass spectrometer and ionizes a liquid sample containing a target substance.

[0035] Figure 1 This is a diagram of the main components of a mass spectrometer. This mass spectrometer comprises an ionization chamber 2, a first intermediate vacuum chamber 3, a second intermediate vacuum chamber 4, and an analysis chamber 5 within a chamber 1. An ESI ionization probe 60 is located within the ionization chamber 2, which ionizes components in a liquid sample. Furthermore, ion guides 11 and 13 are located within the first intermediate vacuum chamber 3 and the second intermediate vacuum chamber 4, respectively, to converge and transport ions. Furthermore, a quadrupole mass filter 15 and an ion detector 16 are located within the analysis chamber 5, which separate ions based on their mass-to-charge ratio (m / z).

[0036] The ionization chamber 2 and the first intermediate vacuum chamber 3 are connected via a thin-diameter heated capillary 10. Furthermore, the first intermediate vacuum chamber 3 and the second intermediate vacuum chamber 4 are connected via an ion passage hole formed at the top of the skive 12. Furthermore, the second intermediate vacuum chamber 4 and the analysis chamber 5 are connected via an ion passage opening 14.

[0037] The ionization chamber 2 is at a substantially atmospheric pressure. On the other hand, the analysis chamber 5 is evacuated to a pressure of, for example, 10 -3 ~10 -4 The first intermediate vacuum chamber 3 and the second intermediate vacuum chamber 4 sandwiched between the ionization chamber 2 and the analysis chamber 5 are also evacuated by vacuum pumps, forming a multi-stage differential exhaust system with gradually increasing vacuum levels.

[0038] The analysis operation in the mass spectrometer of this embodiment will be briefly described. The liquid sample to be analyzed is introduced into the liquid sample supply tube 7 of the ESI ionization probe 60. The liquid sample supply tube 7 comprises, for example, two capillaries connected by a conductive flow path connection fixture. A predetermined voltage (ESI voltage) is applied to the flow path connection fixture, thereby charging the liquid sample.

[0039] When the liquid sample flows out of the ESI ionization probe 60, a nebulizing gas (nebulization-promoting gas) is blown toward it, causing it to be sprayed as fine charged droplets into the ionization chamber 2. Furthermore, an assist gas serving as a heating gas is supplied to the charged droplets sprayed into the ionization chamber 2, thereby desolvating the mobile phase (solvent) from the charged droplets and ionizing substances in the sample.

[0040] The ions generated in the ionization chamber 2 are introduced into the heated capillary 10 by the pressure difference between the ionization chamber 2 and the first intermediate vacuum chamber 3. Ions passing through the heated capillary 10 further advance desolvation, thereby promoting the occurrence of ionization.

[0041] Ions introduced into the first intermediate vacuum chamber 3 via the heated capillary 10 are converged by the electric field generated by the ion guide 11 and then introduced into the second intermediate vacuum chamber 4 via the ion passage hole at the top of the skimmer 12. Within the second intermediate vacuum chamber 4, these ions are converged by the electric field generated by the ion guide 13 and transported to the analysis chamber 5 through the ion passage opening 14. In the analysis chamber 5, only ions with a specific mass-to-charge ratio pass through the longitudinal space of the quadrupole mass filter 15 and reach the ion detector 16 for detection. The mass-to-charge ratio of ions passing through the quadrupole mass filter 15 depends on the DC voltage and high-frequency voltage applied to the filter 15. Therefore, by, for example, sweeping these applied voltages, the mass-to-charge ratio of ions incident on the ion detector 16 can be swept within a predetermined range.

[0042] Next, the configuration of the ESI ionization probe 60 of this embodiment will be described. Figure 2 It shows Figure 1 FIG. 2 is a schematic diagram of a cross section of the internal structure of the tip portion of the ESI ionization probe 60 shown. Figure 3 Schematic diagram of a cross section (a cross section perpendicular to the direction of flow of the liquid sample) of the front end portion of the ESI ionization probe 60. Figure 2 In FIG. 6 , the heat transfer member 64 is omitted in order to illustrate the assist gas flow path 61 for easier understanding.

[0043] In the ESI ionization probe 60, the nozzle 65 for spraying the liquid sample includes a capillary 66 through which the liquid sample flows and an atomizing gas pipe 67 coaxially provided on the outer periphery of the capillary 66. The space between the outer periphery of the capillary 66 and the inner periphery of the atomizing gas pipe 67 serves as an atomizing gas flow path through which the atomizing gas flows. Figure 2 A conductive member (not shown) is disposed on the upstream side of the capillary 66 shown in FIG. 1 , and an ESI voltage is applied to the conductive member to impart electric charge to the liquid sample.

[0044] An assist gas nozzle 63 is provided outside the atomizing gas tube 67, coaxially with the capillary tube 66 and the atomizing gas tube 67. The distal end of the assist gas nozzle 63 is machined into a tapered shape. Assist gas is supplied from an assist gas discharge hole 631, which opens into a circular ring, so as to surround the outside of the jet of charged droplets of the liquid sample ejected from the nozzle 65.

[0045] An annular housing 68 is provided around the assist gas nozzle 63. An assist gas flow path 61 is formed within the housing 68. A gas inlet 611 is formed at one location of the assist gas flow path 61. A gas outlet 612 is formed on the opposite side of the center O of the housing 68 and communicates with the assist gas nozzle 63.

[0046] A substantially annular heater 62 and a heat transfer member 64 are disposed on the auxiliary gas flow path 61 to cover almost the entire circumference thereof. In this embodiment, the heat transfer member 64 is as follows: Figure 4 As shown, a stainless steel (SUS) mesh formed into a shape matching the space between the assist gas flow path 61 and the heater 62 or the space inside the heater 62 is used. Figure 4 The upper left is a top view of the heat transfer component 64 disposed inside the heater 62, and the lower left is a side view of the heat transfer component 64. Figure 4 The heat transfer member 64 shown on the right side of FIG. 1 is a perspective view of the heat transfer member 64 disposed between the inner wall surface of the assist gas flow path 61 and the heater 62 .

[0047] respectively Figure 5 、 Figure 6 Show Figure 2 The arrangement of the heat transfer member 64 inside the assist gas flow path 61 on the left side, Figure 2 The heat transfer component 64 is arranged inside the auxiliary gas flow path 61 on the right side. The heat transfer component 64 is arranged in contact with the heater 62 in such a way as to fill the space between the inner wall surface of the auxiliary gas flow path 61 and the heater 62. In addition, the heat transfer component 64 is also arranged inside the annular heater 62. In addition, a heat transfer component 64 is inserted inside the heater 62. Figure 4 The heat transfer member 64 shown on the left is a member folded and formed into a U-shape. The interior of the assist gas flow path 61 is heated by the heater 62 and the heat transfer member 64 that transfers heat from the heater 62. Figure 5 as well as Figure 6 In the embodiment, the heat transfer member 64 disposed in the space between the inner wall of the auxiliary gas flow path 61 and the heater 62 is formed as a member having an L-shaped or linear cross section, but it can also be modified appropriately by using a member having a circular cross section. Figure 5 as well as Figure 6In the embodiment, the heat transfer member 64 disposed inside the heater 62 is a member having a U-shaped cross section, but a member having a circular cross section can also be used and appropriately modified. In addition, the heat transfer member 64 only needs to have a portion in contact with the heater 62, and the configuration of the heat transfer member 64 is not limited to Figure 5 as well as Figure 6 Configuration shown.

[0048] In this embodiment, a deformable SUS mesh is used as the heat transfer member 64, allowing it to be positioned without gaps to match the shapes of the assist gas flow path 61 and the heater 62. Furthermore, since the mesh-like heat transfer member 64 has numerous holes, it does not obstruct the flow of assist gas.

[0049] Reference Figures 7 to 10 The heater 62 is a micro-sheath heater. Figure 7 The two wings of a heating wire 620 processed into a roughly Y shape are as shown. Figure 8 As shown, they are wound and formed into coils, forming Figure 9 The two heating parts 621 and 622 are shown. Figure 10 As shown, each heating portion 621, 622 is bent into a substantially semicircular ring shape, and the ends of the two heating portions 621, 622 are butted together, thereby completing the heater 62 consisting of two substantially semicircular heating portions 621, 622.

[0050] The two heating sections 621 and 622 are each made by integrating two heating wires 620 with current flowing in opposite directions, winding them into a spiral, and then coating them with insulating material. Therefore, the magnetic flux induced by the current flowing through the two tightly packed heating wires 620 is in completely opposite directions, canceling each other out. Therefore, even if heating current flows through the heating sections 621 and 622, the induced magnetic field will not affect them. Furthermore, because they are coated with insulating material, there is no concern about leakage, allowing for safe use.

[0051] The auxiliary gas is introduced into the auxiliary gas flow path 61 from the gas inlet 611. The direction of the auxiliary gas flowing from the gas inlet 611 toward the auxiliary gas flow path 61 is almost perpendicular to the auxiliary gas flow path 61. In addition, the gas flow path from the gas inlet 611 to the gas outlet 612 is substantially perpendicular to the auxiliary gas flow path 61. Figure 3 The gas flow path has two paths, an upper semicircular flow path and a lower semicircular flow path. Since the flow resistance of the two paths is almost equal, the assist gas flows in almost two halves in the upper and lower paths.

[0052] The assist gas, flowing in two separate paths, is heated by the heater 62 and the heat transfer component 64, respectively. The gas then merges in front of the gas outlet 612 and flows toward the assist gas nozzle 63. The heating sections 621 and 622 have nearly identical shapes, and the heat transfer components 64 are positioned to the same extent in both paths. The amount of assist gas flowing through the two paths is nearly equal, and the gas passing through each path is heated to a nearly identical temperature. This minimizes temperature variations in the assist gas, ensuring a stable supply of high-temperature assist gas.

[0053] As described above, the assist gas flowing into the assist gas flow path 61 from the gas inlet 611 is heated as it travels toward the gas outlet 612. Therefore, the assist gas temperature near the gas inlet 611 is lower, while the assist gas temperature near the gas outlet 612 is higher. The assist gas nozzle 63 is located farther from the gas inlet 611 and closer to the gas outlet 612. Therefore, the assist gas, heated to a high temperature by the heater 62, flows into the assist gas nozzle 63 with little cooling and is ejected from the assist gas ejection hole 631. Furthermore, the assist gas nozzle 63 is located farther from the assist gas flow path 61 near the gas inlet 611, where the cooler assist gas is present. Therefore, the assist gas nozzle 63 itself is less likely to cool. Therefore, heat from the heater 62 and the heat transfer member 64 is efficiently utilized, allowing stable, high-temperature assist gas to be ejected from the assist gas ejection hole 631.

[0054] In conventional ionization devices, only the heater 62 is provided within the assist gas flow path 61. A large amount of assist gas flowing through the assist gas flow path 61 is released without contacting the heater 62. Therefore, even when using a micro-sheath heater capable of heating to approximately 600°C, the actual temperature of the supplied assist gas remains between 400°C and 500°C.

[0055] In this embodiment, a heat transfer element 64 is placed in addition to the heater 62 within the assist gas flow path 61. This increases the contact area between the assist gas flowing through the assist gas flow path 61 and the heat source (heater 62 and heat transfer element 64) compared to conventional systems. This allows for more efficient heating of the assist gas, resulting in a higher-temperature assist gas supply than conventional systems. Furthermore, the heater 62 itself can be the same as conventional systems, enabling a low-cost ionization device.

[0056] Next, we will describe an experiment conducted to confirm that the assist gas heating efficiency is improved by the ionization device of the above-described embodiment. In this experiment, assist gas (air) was introduced at a flow rate of 30 mL / min, 99 V of power was supplied to the heater 62, and the temperature change of the assist gas ejected from the assist gas ejection hole 631 was measured. Furthermore, as a comparative example, the assist gas temperature change was measured under the same conditions as above, without the heat transfer member 64.

[0057] exist Figure 11 The experimental results are shown. Figure 11 As can be seen from the graph, in the ionization device of the above embodiment, the assist gas is heated to a higher temperature more quickly (reaching a high temperature of approximately 50°C 15 minutes after the start of heating) by providing the heat transfer member 64. Based on this experiment, it is believed that although the assist gas heating temperature remains at 450°C, it can be heated to a temperature exceeding 500°C by supplying the same amount of power as in the conventional method.

[0058] The above embodiment is merely an example and can be modified as appropriate based on the main principles of the present invention. While the above embodiment describes the case where the ionization probe 60 is used in combination with ESI, it can also be used in combination with other ionization probes, such as an ionization probe for atmospheric pressure chemical ionization (APCI) or an ionization probe for atmospheric pressure photoionization (APPI). Furthermore, in a mass spectrometer plasma analyzer, when supplying gas to heat a desolvation tube (in the above embodiment, the heated capillary 10) that takes ions generated in the ionization chamber into a subsequent analysis unit, a configuration similar to the above configuration with a heat transfer component can also be used.

[0059] In the above embodiment, the heat transfer member 64 is disposed both between the assist gas flow path 61 and the heater 62 and within the heater 62. However, the heat transfer member 64 may be disposed only within one of the two locations. For example, if the outer diameter of the heater 62 is similar to the diameter of the assist gas flow path 61, even if the heat transfer member 64 is disposed only within the heater 62, sufficient heating efficiency can be achieved.

[0060] [plan]

[0061] Those skilled in the art will appreciate that the above-mentioned exemplary embodiments are specific examples of the following schemes.

[0062] (Item 1)

[0063] An ionization device according to one embodiment includes:

[0064] ionization chamber;

[0065] a sample nozzle, for allowing the liquid sample to flow into the ionization chamber;

[0066] an auxiliary gas flow path for supplying an auxiliary gas for promoting desolvation of the liquid sample to the ionization chamber;

[0067] a heater, disposed inside the auxiliary gas flow path;

[0068] The heat transfer member is arranged inside the assist gas flow path in contact with the heater.

[0069] In the ionization device described in Item 1, an auxiliary gas that promotes desolvation of the liquid sample flowing out of the sample nozzle is supplied. In the auxiliary gas flow path through which the auxiliary gas flows, in addition to the heater, a heat transfer component connected to the heater is also provided. In the previous ionization device, only a heater was provided in the auxiliary gas flow path, and a large amount of auxiliary gas flowing through the auxiliary gas flow path was released without contacting the heater. On the other hand, in the ionization device described in Item 1, since a heat transfer component is provided in addition to the heater, the contact area between the auxiliary gas flowing through the auxiliary gas flow path and the heat source (heater and heat transfer component) becomes larger than before, and the auxiliary gas can be heated more efficiently, thereby supplying auxiliary gas at a higher temperature than before. In addition, the heater itself only needs to use the same heater as before, and the ionization device can be constructed at a low cost.

[0070] (Item 2)

[0071] In the ionization device of item 1,

[0072] The sample nozzle sprays the liquid sample into the ionization chamber through an atomization-promoting gas.

[0073] The assist gas is supplied in a direction to compress a jet of the liquid sample ejected from the sample nozzle.

[0074] In the ionization device described in Item 2, desolvation of the jet of the liquid sample sprayed into the ionization chamber by the atomization promoting gas can be promoted.

[0075] (Item 3)

[0076] In the ionization device of item 1 or 2,

[0077] The heat transfer component is a mesh component.

[0078] In the ionization device of item 3, the easily deformable mesh heat transfer member is used, so it can be arranged without gaps to match the shape of the assist gas flow path. In addition, since the mesh heat transfer member has a large number of holes, it does not hinder the flow of the assist gas.

[0079] (Item 4)

[0080] The ionization device according to item 4 is the ionization device according to any one of items 1 to 3,

[0081] The heat transfer member is disposed between an inner wall of the assist gas flow path and the heater.

[0082] In the ionization device according to claim 4, the assist gas flowing between the inner wall of the assist gas flow path and the heater can be heated efficiently.

[0083] (Item 5)

[0084] The ionization device according to item 5 is the ionization device according to any one of items 1 to 4,

[0085] The heater is a component in which a heating wire is wound in a spiral shape.

[0086] In the ionization device according to item 5, the inside of the assist gas flow path can be uniformly heated by the heater.

[0087] (Item 6)

[0088] The ionization device according to item 6 is the ionization device according to item 5,

[0089] The heat transfer member is arranged inside a heater formed by winding the heating wire in the spiral shape.

[0090] In the ionization device according to item 6, the assist gas flowing inside the heater wound in a spiral shape can be heated efficiently.

[0091] (Item 7)

[0092] The ionization device described in item 7 is the ionization device described in item 5 or 6,

[0093] The heating wire is covered with an insulating material.

[0094] In the ionization device of item 7, since the heater wire is insulated, it can be used safely and the durability of the heater wire is improved.

[0095] (Item 8)

[0096] The mass analysis device in item 8 shall have:

[0097] The ionization device according to any one of items 1 to 7; and

[0098] A mass analysis unit performs mass analysis on the ions generated by the ionization device.

[0099] The ionization devices described in Items 1 to 7 can be preferably used as an ionization section of a mass spectrometer.

[0100] Description of Reference Numerals

[0101] 1 chamber

[0102] 2 Ionization chamber

[0103] 3. The first intermediate vacuum chamber

[0104] 4. Second intermediate vacuum chamber

[0105] 5 Analysis Room

[0106] 60 ESI ionization probe

[0107] 61 Auxiliary gas flow path

[0108] 611 Gas inlet

[0109] 612 Gas outlet

[0110] 62 Heater

[0111] 620 heating wire

[0112] 621, 622 Heating unit

[0113] 63 Auxiliary gas nozzle

[0114] 631 Auxiliary gas ejection hole

[0115] 64 heat transfer components

[0116] 65 nozzle

[0117] 66 capillary

[0118] 67 Atomizing gas tube

[0119] 68 shell

[0120] 7 Liquid sample supply tube.

Claims

1. An ionization device, characterized in that: have: ionization chamber; a sample nozzle, for allowing the liquid sample to flow into the ionization chamber; an auxiliary gas flow path for supplying an auxiliary gas for promoting desolvation of the liquid sample to the ionization chamber; a heater, disposed inside the auxiliary gas flow path; a heat transfer member disposed inside the assist gas flow path in contact with the heater; The assist gas flow path is a region where the assist gas flows, and the heater and the heat transfer member are arranged in the assist gas flow path so as to be in direct contact with the assist gas.

2. The ionization device according to claim 1, wherein The sample nozzle sprays the liquid sample into the ionization chamber through an atomization-promoting gas. The assist gas is supplied in a direction to compress a jet of the liquid sample ejected from the sample nozzle.

3. The ionization device according to claim 1, wherein The heat transfer component is a mesh component.

4. The ionization device according to claim 1, wherein The heat transfer member is disposed between an inner wall of the assist gas flow path and the heater.

5. The ionization device according to claim 1, wherein The heater is a component in which a heating wire is wound in a spiral shape.

6. The ionization device according to claim 5, wherein The heat transfer member is arranged inside a heater formed by winding the heating wire in the spiral shape.

7. The ionization device according to claim 5, wherein The heating wire is covered with an insulating material.

8. A mass analysis device, characterized in that have: The ionization device according to claim 1; and A mass analysis unit performs mass analysis on the ions generated by the ionization device.

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