nebulizer

Abstract

To provide a nebulizer with high coaxial property of a pipe through which liquid flows and a pipe through which gas flows.SOLUTION: A nebulizer AA has: an inner pipe 10 having an inner pipe flow path 12 into which liquid is introduced; an outer pipe 20 into which the inner pipe 10 is inserted, and which forms an outer pipe flow path 22 into which gas is introduced between itself and the inner pipe 10; and a spray unit 30 that is shorter in an axial direction than the inner pipe 10 and the outer pipe 20. The spray unit 30 is fixed to the tip part of the inner pipe 10 and the tip part of the outer pipe 20, and causes gas having passed through the outer pipe flow path 22 to collide with liquid having passed through the inner pipe flow path 12, to spray liquid droplets. Even when there is a positional or angular deviation at a connection part between a base part of the inner pipe 10 and the base of the outer pipe 20, the spray unit 30 can be positioned in a correct position.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to nebulizers, and more particularly, to nebulizers that atomize liquid samples for introduction into analytical devices. [Background technology]

[0002] Known atomic spectrometry methods include plasma emission spectrometry, atomic absorption spectrometry, and atomic fluorescence spectrometry. Known mass spectrometry methods include plasma mass spectrometry and liquid chromatography mass spectrometry. Furthermore, liquid chromatography using a light scattering detector is also known. In the analytical devices used for these analytical methods, a liquid sample is atomized by a nebulizer, and the resulting sample droplets are introduced into the excitation / ionization source of the analytical device.

[0003] There are various types of nebulizers, but the most widely used in the field of analysis is the coaxial nebulizer. As shown in FIG. 28, a typical coaxial nebulizer 100 has two tubes (the inner tube is called the inner tube 110 and the outer tube is called the outer tube 120) arranged coaxially, and has a structure in which the gap between the inner tube 110 and the outer tube 120 is narrowed at the tip (for example, FIG. 3 of Patent Document 1). A liquid sample is flowed inside the inner tube 110, and gas is flowed between the outer tube 120 and the inner tube 110. A high-speed gas flow collides with the liquid sample discharged from the outlet of the inner tube 110, and the liquid sample is turned into fine droplets by the shear force and sprayed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 61-6760 [Patent Document 2] Japanese Patent Application Publication No. 9-239298 [Non-patent literature]

[0005] [Non-Patent Document 1] A Direct Injection High-Efficiency Nebulizer for Inductively Coupled Plasma Mass Spectrometry, John A. McLean, Hao Zhang, and Akbar Montaser, Analytical Chemistry, Vol. 70, No. 5, pp.1012-1020, 1998 Summary of the Invention [Problem to be solved by the invention]

[0006] The spray characteristics of a coaxial nebulizer include the number of droplets generated, the size distribution, the direction of ejection, and the speed of ejection. Important parameters that determine these spray characteristics include the inner diameter of the inner tube, the thickness of the inner tube wall, the annular cross-sectional area of ​​the gap between the outer and inner tubes, the coaxiality of the inner and outer tubes, and the axial distance between the inner and outer tube outlets. For example, the size of the droplets depends on the efficiency of transmitting the shear energy of the high-speed gas flow to the liquid sample. To reduce the size of the droplets, there are several methods, such as reducing the inner diameter of the inner tube, thinning the inner tube wall to increase the contact efficiency between the liquid sample and the gas, and reducing the annular cross-sectional area of ​​the gap between the outer and inner tubes to increase the gas flow rate. In addition, the droplets are sprayed in a cone shape, and in order to distribute the droplets uniformly around the central axis of the inner and outer tubes, it is necessary to increase the coaxiality of the inner and outer tube outlets. In addition, when spraying a sample with a high salt concentration such as seawater, there is a risk that salt will precipitate at the spray nozzle, causing the spray to stop. To prevent this, it is said to be effective to set the inner tube outlet back about 0.5 to 1 mm from the outer tube outlet.

[0007] Coaxial nebulizers have the following problems: (1) In general nebulizers, which use a long, thin capillary tube made by melting and stretching a glass tube as the inner tube, the tip of the inner tube vibrates due to the high-speed gas flow and is prone to breakage. (2) It is difficult to reproducibly process and manufacture the important parameters that determine the spray characteristics, so the analytical sensitivity differs for each nebulizer. Alternatively, the optimal gas flow rate differs for each nebulizer, and for example, in the case of an ICP analyzer, the operating conditions (output, gas flow rate, observation position, etc.) must be adjusted for each nebulizer.

[0008] These problems are believed to be due to the structure itself, which combines a long inner tube and a long outer tube coaxially and flows gas through the gap at their tips. That is, conventional nebulizers have a structure in which the inner tube and the outer tube, which are long and thin structures, are connected at their bases, and even a slight misalignment in position or angle at the connection part significantly changes the positional relationship at the tip. As a result, the coaxiality of the inner tube and the outer tube at the tip is low, and the axial distance between the inner tube outlet and the outer tube outlet also varies.

[0009] It is thought that the above problem can be solved by shortening the length of the inner and outer tubes. However, nebulizers are generally installed in a spray chamber that removes droplets with a large particle size (Patent Document 2), and the nebulizer needs to have a certain length to be installed in a general spray chamber. In addition, a method is known in which a nebulizer is directly inserted into the plasma torch of an ICP analyzer without using a spray chamber to introduce droplets into the plasma (Non-Patent Document 1). When this method is adopted, a longer nebulizer is required.

[0010] In view of the above circumstances, the present invention aims to provide a nebulizer that has an overall elongated shape while suppressing damage caused by high-speed gas flows, has high coaxiality between the tube for flowing liquid and the tube for flowing gas, and has a small manufacturing error in the axial distance at the outlets of both tubes. [Means for solving the problem]

[0011] The nebulizer of the first embodiment comprises an inner tube having an inner tube flow path through which a liquid is introduced, an outer tube into which the inner tube is inserted and which forms an outer tube flow path through which a gas is introduced between the inner tube and the outer tube, and a spray unit that is shorter in the axial direction than the inner tube and the outer tube, and is characterized in that the spray unit is fixed to the tip of the inner tube and the tip of the outer tube and is configured to cause the gas that has passed through the outer tube flow path to collide with the liquid that has passed through the inner tube flow path to spray liquid droplets. The nebulizer of the second embodiment is characterized in that, in the first embodiment, the spray unit has a liquid flow path that connects a liquid inlet opening at the base end face and a liquid outlet opening at the tip face, a cylindrical flow path surrounding the liquid flow path and a gas flow path that runs from an intermediate position between the base end face and the tip face to an annular gas outlet opening at the tip face, and a gas introduction path that connects a gas inlet opening at a side face to the gas flow path, and the spray unit is fixed to the tip portion of the inner tube and the tip portion of the outer tube so that the inner tube flow path is connected to the liquid inlet and the outer tube flow path is connected to the gas inlet. A third aspect of the nebulizer is the second aspect, wherein the spray unit comprises a capillary tip and a capillary storage section connected to the capillary tip, the capillary tip having a capillary having the liquid flow path, and a flange provided at the base end of the capillary, the flange having a flange rear surface and a flange front surface constituting the base end surface, the capillary storage section having a capillary insertion hole communicating between the flange receiving surface and the storage section front surface constituting the tip surface, and the gas introduction path connecting to the capillary insertion hole, the capillary is inserted into the capillary insertion hole, forming the gas flow path between the outer peripheral surface of the capillary and the inner peripheral surface of the capillary insertion hole, and the flange front surface abutting the flange receiving surface. A fourth aspect of the nebulizer is characterized in that, in the third aspect, the capillary accommodating portion is provided on the flange receiving surface and has a cylindrical flange accommodating wall that accommodates the flange therein, and the inner diameter of the flange accommodating wall is equal to the outer diameter of the flange. A fifth aspect of the nebulizer is the third aspect, characterized in that the capillary has a large diameter portion adjacent to the flange, the large diameter portion having an outer diameter larger than other portions, and the outer diameter of the large diameter portion is equal to the inner diameter of the capillary insertion hole. A sixth aspect of the nebulizer is the third aspect, wherein the capillary insertion hole has a small diameter portion adjacent to the flange receiving surface, the small diameter portion having an inner diameter smaller than other portions, and the inner diameter of the small diameter portion is equal to the outer diameter of the capillary. A seventh aspect of the nebulizer is characterized in that, in the third aspect, the capillary storage portion has a plurality of ribs formed along the axial direction on the inner surface of the capillary insertion hole, and the apexes of the ribs contact the outer surface of the capillary. The nebulizer of the eighth aspect is characterized in that, in the third aspect, the capillary tip has a plurality of ribs formed along the axial direction on the outer peripheral surface of the capillary, and the apexes of the ribs contact the inner peripheral surface of the capillary insertion hole. A ninth aspect of the nebulizer is the nebulizer of any one of the third to eighth aspects, characterized in that the spray unit has a spacer plate sandwiched between the flange front surface and the flange receiving surface. A tenth aspect of the nebulizer is characterized in that in any one of the third to ninth aspects, the capillary insertion hole has a shape in which the inner diameter decreases continuously or stepwise toward the gas outlet. An eleventh aspect of the nebulizer is characterized in that in any one of the third to tenth aspects, the capillary has a shape in which the inner diameter of the tip portion increases continuously or stepwise toward the liquid outlet. The nebulizer of the 12th aspect is characterized in that, in any of the 3rd to 11th aspects, the capillary tip is provided on the rear surface of the flange, has an internal junction flow path that connects to the liquid flow path, has a junction that is inserted into the tip of the inner tube, and the outer diameter of the junction is equal to the inner diameter of the inner tube. A 13th aspect of the nebulizer is characterized in that, in the first aspect, the spray unit has an inner tube insertion hole which is a hole connecting the base end surface and the tip surface, and which forms a gas flow path between the inserted inner tube and the inner tube from an intermediate position between the base end surface and the tip surface to an annular gas outlet opening into the tip surface, and a gas introduction path which connects a gas inlet opening into a side surface to the gas flow path, and the spray unit is fixed to the tip portion of the inner tube by inserting the inner tube into the inner tube insertion hole, and is fixed to the tip portion of the outer tube so that the outer tube flow path and the gas inlet are connected. A nebulizer of a fourteenth aspect is characterized in that, in any one of the first to thirteenth aspects, the outer tube is a torch inner tube of a plasma torch of an ICP analyzer. The nebulizer of a 15th aspect is characterized in that, in any one of the 1st to 13th aspects, the outer tube is inserted into a torch inner tube of a plasma torch of an ICP analyzer, forming a sheath gas flow path between the outer tube and the torch inner tube through which a sheath gas is introduced. Effect of the Invention

[0012] According to the first aspect, the inner tube and the outer tube are arranged coaxially in an elongated shape, so that it is easy to install in a general spray chamber. In addition, since the spray unit is a short member, damage caused by a high-speed gas flow can be suppressed. And, since the spray unit is fixed to the tip of the inner tube and the tip of the outer tube, even if there is a positional or angular deviation at the joint between the inner tube base and the outer tube base, the spray unit can be arranged in the correct position. Moreover, since the spray unit is a short member, the manufacturing error of the positional relationship between the tube for flowing the liquid and the tube for flowing the gas is small. Therefore, the tube for flowing the liquid and the tube for flowing the gas are highly coaxial, and the error in the axial distance at the outlets of both tubes is small. According to the second aspect, since the spray unit is a short member, the manufacturing error in the positional relationship between the liquid flow path and the gas flow path is small, so that the liquid flow path and the gas flow path are highly coaxial and the manufacturing error in the axial distance at the outlets of both flow paths is small. According to the third aspect, the spray unit has a simple configuration consisting of a capillary tip and a capillary containing portion, and therefore can be manufactured with high reproducibility. According to the fourth aspect, the flange is fitted inside the flange receiving wall, so that the capillary tip is positioned in the radial direction relative to the capillary receiving portion, thereby improving the coaxiality between the capillary and the capillary insertion hole. According to the fifth aspect, the large diameter portion of the capillary fits into the capillary insertion hole, so that the capillary is positioned in the radial direction relative to the capillary insertion hole, thereby improving the coaxiality between the capillary and the capillary insertion hole. According to the sixth aspect, the capillary is fitted into the small diameter portion of the capillary insertion hole, so that the capillary is positioned in the radial direction relative to the capillary insertion hole, thereby improving the coaxiality between the capillary and the capillary insertion hole. According to the seventh aspect, the capillary is supported by the ribs on the inner peripheral surface of the capillary insertion hole, so that the capillary is positioned in the radial direction relative to the capillary insertion hole, thereby improving the coaxiality between the capillary and the capillary insertion hole. According to the eighth aspect, the rib on the outer peripheral surface of the capillary contacts the inner peripheral surface of the capillary insertion hole, thereby determining the radial position of the capillary relative to the capillary insertion hole, thereby improving the coaxiality between the capillary and the capillary insertion hole. According to the ninth aspect, the axial distance between the liquid outlet and the gas outlet can be adjusted by changing the thickness or the number of the spacer plates. According to the tenth aspect, the cross-sectional area of ​​the gas outlet can be made small, so that the gas flow rate increases and droplets with small diameters can be generated. According to the eleventh aspect, since the tip of the capillary is thin, the contact efficiency between the liquid and the gas is increased, and the particle size of the droplets can be reduced. According to the twelfth aspect, the inner tube and the capillary tip can be joined liquid-tightly, so that leakage of liquid can be suppressed. According to the thirteenth aspect, since the inner tube is inserted into the inner tube insertion hole of the spray unit, the manufacturing error in the positional relationship between the inner tube and the spray unit is small, so that the inner tube flow path and the gas flow path at the tip of the nebulizer are highly coaxial, and the error in the axial distance at the outlets of both flow paths is small. According to the fourteenth aspect, the droplets can be directly introduced into the plasma generated in the ICP analyzer. According to the fifteenth aspect, by flowing a sheath gas around the droplets sprayed from the spray unit, it is possible to prevent the droplets from being adsorbed onto the inner wall of the torch inner tube. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a longitudinal cross-sectional view of a nebulizer according to a first embodiment. [Diagram 2] Fig. (A) is an exploded perspective view of the spray unit, and Fig. (B) is a perspective view of the spray unit. [Diagram 3] FIG. 2 is an enlarged vertical cross-sectional view of the spray unit and its periphery. [Figure 4] FIG. 2 is a longitudinal cross-sectional view of a nebulizer having an outer tube as a single component. [Diagram 5] Fig. 1A is an exploded perspective view of a spray unit in which the gas introduction passage is a groove, and Fig. 1B is a perspective view of the spray unit in the same configuration. [Figure 6] 1 is an enlarged vertical cross-sectional view of the periphery of a spray unit with a part of the spray unit inserted into an inner tube. FIG. [Figure 7] FIG. 13 is an enlarged vertical cross-sectional view of the periphery of a spray unit in which the capillary receiving portion has a flange receiving wall. [Figure 8] FIG. 13 is an enlarged vertical cross-sectional view of the periphery of a spray unit in which the capillary tip has a joint. [Figure 9] Fig. 1A is a longitudinal sectional view of a spray unit having a capillary insertion hole in a continuous cone shape, and Fig. 1B is a longitudinal sectional view of a spray unit having a capillary insertion hole in a stepped cone shape. [Figure 10] FIG. 2 is a longitudinal cross-sectional view of a capillary tip in which the tip of the capillary is cone-shaped. [Figure 11] FIG. 13 is a longitudinal sectional view of a spray unit in which the capillary receiving portion has a flange receiving wall. [Figure 12] FIG. 2 is a longitudinal cross-sectional view of a spray unit in which the capillary has a large diameter portion. [Figure 13] FIG. 13 is a longitudinal sectional view of a spray unit in which a capillary insertion hole has a small diameter portion. [Figure 14] Fig. 1A is a longitudinal sectional view of a spray unit in which the capillary insertion hole has a rib, and Fig. 1B is a sectional view taken along line bb in Fig. 1A. [Figure 15] Fig. 1A is a vertical cross-sectional view of a spray unit in which the capillary has ribs, and Fig. 1B is a cross-sectional view taken along line bb in Fig. 1A. [Figure 16] FIG. 13 is a longitudinal sectional view of a spray unit having a spacer plate. [Figure 17] FIG. 2 is an enlarged vertical cross-sectional view of the periphery of a spray unit in a configuration in which the spray unit is integrated as a single member. [Figure 18] 1 is an enlarged vertical cross-sectional view of the periphery of a spray unit in which the spray unit and an inner tube are integrated into one member; FIG. [Figure 19] FIG. 1 is a longitudinal cross-sectional view of a nebulizer according to a second embodiment. [Figure 20] FIG. 2 is an enlarged vertical cross-sectional view of the spray unit and its periphery. [Figure 21] 13 is an enlarged vertical cross-sectional view of the periphery of a spray unit in which the inner diameter of the rear portion of the inner tube insertion hole is reduced. FIG. [Figure 22] Fig. 1A is a vertical cross-sectional view of a spray unit in which an inner tube insertion hole has a rib, and Fig. 1B is a cross-sectional view taken along line bb in Fig. 1A. [Figure 23] Fig. 1A is a vertical cross-sectional view of a spray unit in which the front part of the inner tube insertion hole is cone-shaped, and Fig. 1B is a cross-sectional view taken along line bb in Fig. 1A. [Figure 24] FIG. 11 is a longitudinal cross-sectional view of a nebulizer according to a third embodiment. [Diagram 25] FIG. 11 is an enlarged vertical cross-sectional view of the periphery of a spray unit of a third embodiment. [Figure 26] FIG. 13 is an enlarged vertical cross-sectional view of the periphery of a spray unit of a fourth embodiment. [Figure 27] 27 is a cross-sectional view taken along line XXVI-XXVI in FIG. 26. [Figure 28] FIG. 1 is a longitudinal cross-sectional view of a typical coaxial nebulizer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] [First embodiment] Next, an embodiment of the present invention will be described with reference to the drawings. The nebulizer according to the first embodiment of the present invention is used to atomize a liquid sample to obtain sample droplets. The sample droplets are introduced into an excitation / ionization source or the like of an analytical device and are subjected to analysis. For example, the excitation / ionization source or the like is plasma in an ICP analytical device, which is generated by a plasma torch. In addition, in liquid chromatography, the sample droplets are introduced into a light scattering detector after desolvation. Such detectors are also included in the excitation / ionization source or the like.

[0015] As shown in Fig. 1, the nebulizer AA of this embodiment has an inner tube 10 and an outer tube 20. Although not particularly limited, both the inner tube 10 and the outer tube 20 are circular tubes with a circular cross section. The outer diameter of the inner tube 10 is smaller than the inner diameter of the outer tube 20. The inner tube 10 is inserted inside the outer tube 20. Therefore, the inner tube 10 and the outer tube 20 form a double tube.

[0016] The base end opening of the inner tube 10 is a liquid supply port 11. A supply source of liquid, such as a liquid sample, is connected to the liquid supply port 11. The internal space of the inner tube 10 is referred to as the inner tube flow path 12. Liquid is introduced into the inner tube flow path 12. The outer tube 20 has a gas supply port 21. A supply source of gas, such as nebulizer gas, is connected to the gas supply port 21. The space formed between the inner circumferential surface of the outer tube 20 and the outer circumferential surface of the inner tube 10 is referred to as the outer tube flow path 22. Gas is introduced into the outer tube flow path 22.

[0017] 1, the outer tube 20 is made up of a distal tube 23 and a proximal tube 24. The distal tube 23 and the proximal tube 24 are joined by a method such as threaded joining. It is preferable to fit an O-ring 25 into the joint between the distal tube 23 and the proximal tube 24 to prevent gas leakage.

[0018] A ferrule 13 is provided at the base of the inner tube 10. The inner tube 10 is joined to the outer tube 20 by screwing a cap 14 onto the rear of a proximal tube 24 and pressing the ferrule 13 against the proximal tube 24. In this manner, the inner tube 10 and the outer tube 20 are joined at their bases.

[0019] A spray unit 30 is inserted into the tip of the inner tube 10. The spray unit 30 is a cylindrical member that is shorter in the axial direction than the inner tube 10 and the outer tube 20. The tip of the inner tube 10 is inserted into and fixed to a hole formed in the tip of the outer tube 20. Therefore, the spray unit 30 is fixed to the tip of the inner tube 10, and is also fixed to the tip of the outer tube 20 via the inner tube 10.

[0020] The nebulizer AA has an inner tube 10 and an outer tube 20 arranged coaxially, and has an elongated shape similar to a typical coaxial nebulizer. Therefore, the nebulizer AA is easy to install in a typical spray chamber. Although not particularly limited, the axial length of the nebulizer AA is 50 to 80 mm, and the outer diameter of the outer tube 20 is 6 to 10 mm.

[0021] The spray unit 30 is configured to collide the gas passing through the outer pipe flow path 22 with the liquid passing through the inner pipe flow path 12, and spray the generated droplets. For example, as shown in FIG. 2(A), the spray unit 30 may be configured with a capillary tip 40 and a capillary receiving portion 50.

[0022] The capillary tip 40 has a cylindrical capillary 41. A flange 42 is provided at the base end of the capillary 41. An opening on the base end side of the capillary 41 is referred to as a liquid inlet 43, and an opening on the tip end side is referred to as a liquid outlet 44. An internal space of the capillary 41 that communicates with the liquid inlet 43 and the liquid outlet 44 is referred to as a liquid flow path 45. Of the front and back surfaces of the flange 42, the surface on the base end side of the capillary 41 is referred to as a flange rear surface 46, and the surface on the tip end side is referred to as a flange front surface 47.

[0023] The capillary receiving part 50 is a cylindrical member. One of both end faces of the capillary receiving part 50 is called a flange receiving surface 51, and the other face is called a receiving part front surface 52. The capillary receiving part 50 has a capillary insertion hole 53 formed along the central axis, which communicates with the flange receiving surface 51 and the receiving part front surface 52. In addition, a gas introduction path 54 is formed along the radial direction in the middle of the capillary receiving part 50. One end of the gas introduction path 54 is connected to the capillary insertion hole 53, and the other end opens to the side surface of the capillary receiving part 50. This opening on the side surface is called a gas inlet 55. There may be one or more gas introduction paths 54. In the example shown in FIG. 2(A), four gas introduction paths 54 are formed radially at equal angular intervals from the capillary insertion hole 53.

[0024] As shown in FIG. 2(B), the capillary tip 40 and the capillary storage section 50 are joined to form the spray unit 30. The spray unit 30 is a cylindrical member overall, and has a base end surface 31, a tip surface 32, and a side surface 33. All or a part of the base end surface 31 of the spray unit 30 is formed by the flange rear surface 46 of the capillary tip 40. All or a part of the tip surface 32 of the spray unit 30 is formed by the storage section front surface 52 of the capillary storage section 50. All or a part of the side surface 33 of the spray unit 30 is formed by the side surface of the flange 42 and the side surface of the capillary storage section 50.

[0025] 3, the capillary 41 of the capillary tip 40 is inserted into the capillary insertion hole 53 of the capillary storage part 50, and the flange front surface 47 abuts against the flange receiving surface 51. The outer diameter of the capillary 41 is smaller than the inner diameter of the capillary insertion hole 53. Therefore, a gas flow path 56 is formed between the outer peripheral surface of the capillary 41 and the inner peripheral surface of the capillary insertion hole 53.

[0026] The spray unit 30 has a liquid inlet 43 opening on the base end face 31 and a liquid outlet 44 opening on the tip face 32. The spray unit 30 has a liquid flow path 45 that communicates the liquid inlet 43 and the liquid outlet 44. The spray unit 30 has a gas flow path 56 that extends from the middle position between the base end face 31 and the tip face 32 to the tip face 32. The gas flow path 56 is a cylindrical flow path that surrounds the liquid flow path 45. The opening of the gas flow path 56 at the tip face 32 is called a gas outlet 57. The gas outlet 57 is an annular opening that surrounds the liquid outlet 44. The spray unit 30 has a gas introduction path 54 that communicates the gas inlet 55 opening on the side face 33 and the gas flow path 56. In this way, the spray unit 30 has a configuration similar to that of a double pipe.

[0027] Although not particularly limited, the outer diameter of the spray unit 30 is 1 to 4 mm, and the length in the axial direction is 3 to 7 mm. The inner diameter of the capillary 41 is 30 to 500 μm, and the wall thickness is 5 to 60 μm. The length of the part of the capillary 41 other than the flange 42 is 2 to 8 mm. The inner diameter of the capillary insertion hole 53 is 10 to 60 μm larger than the outer diameter of the capillary 41. Therefore, the thickness of the gas flow path 56 is 5 to 30 μm. The capillary insertion hole 53 is 0.5 to 1 mm longer than the part of the capillary 41 other than the flange 42. Therefore, the liquid outlet 44 is retracted 0.5 to 1 mm from the tip surface 32. The capillary insertion hole 53 may be 0.5 to 1 mm shorter than the part of the capillary 41 other than the flange 42. In this case, the liquid outlet 44 protrudes 0.5 to 1 mm from the tip surface 32.

[0028] The spray unit 30 is inserted into the inner tube 10 from the base end side. Therefore, the inner tube flow path 12 of the inner tube 10 and the liquid inlet 43 of the spray unit 30 are connected. The liquid introduced into the inner tube flow path 12 flows through the liquid flow path 45. The outer diameter of the spray unit 30 is equal to the inner diameter of the inner tube 10. Therefore, the outer peripheral surface of the spray unit 30 and the inner peripheral surface of the inner tube 10 are in liquid-tight contact with each other, so that the liquid does not leak between them.

[0029] The outer diameter of the spray unit 30 and the inner diameter of the inner tube 10 do not need to be strictly equal, but only need to be equal to the extent that liquid does not leak. The outer diameter of the spray unit 30 may be slightly smaller than the inner diameter of the inner tube 10 so that the spray unit 30 can be easily inserted into the inner tube 10. Also, the outer diameter of the spray unit 30 may be slightly larger than the inner diameter of the inner tube 10 to improve liquid tightness. In this specification, the outer diameter of the inserting member and the inner diameter of the inserted member are not limited to being strictly equal, and also include cases where they are different to the extent that the purpose is achieved.

[0030] 3, the entire spray unit 30 is inserted inside the inner tube 10. A through hole 15 is formed at a position corresponding to the gas inlet 55 of the inner tube 10 so that the gas inlet 55 of the spray unit 30 is not blocked by the inner tube 10. The outer tube flow path 22 and the gas inlet 55 are connected via this through hole 15. Therefore, the gas introduced into the outer tube flow path 22 flows through the gas introduction path 54 and the gas flow path 56. Note that a portion of the inner tube 10 on the tip side of the through hole 15 is fixed to the tip of the outer tube 20.

[0031] A cylindrical fixture 61 may be inserted inside the inner tube 10. The fixture 61 abuts against the base end surface 31 of the spray unit 30, and fixes the position of the spray unit 30 relative to the inner tube 10.

[0032] 1, the liquid supplied to the liquid supply port 11 flows through the inner pipe flow path 12 and the liquid flow path 45 in this order, and is discharged from the liquid outlet 44. Meanwhile, the gas supplied to the gas supply port 21 flows through the outer pipe flow path 22, the gas introduction path 54, and the gas flow path 56 in this order, and is discharged from the gas outlet 57. Then, at the tip surface 32 of the spray unit 30, the high-speed gas flow discharged from the gas outlet 57 collides with the liquid discharged from the liquid outlet 44, and the liquid becomes fine droplets due to the shear force, and is sprayed.

[0033] The spray unit 30 is fixed to the tip of the inner tube 10 and the tip of the outer tube 20. Therefore, even if there is a positional or angular misalignment at the joint between the base of the inner tube 10 and the base of the outer tube 20, the inner tube 10 bends to absorb the misalignment, and the spray unit 30 is positioned correctly. Moreover, since the spray unit 30 is a short member, the manufacturing error of the positional relationship between the liquid flow path 45 and the gas flow path 56 is small. In other words, the liquid flow path 45 and the gas flow path 56 are highly coaxial, and the manufacturing error of the axial distance at the outlets of both flow paths is small. Therefore, it is possible to suppress damage to the tip of the inner tube, variation in spray characteristics, and the like, which are considered to be problems of conventional coaxial nebulizers.

[0034] In this specification, "coaxiality" refers to the degree to which the central axes of multiple members coincide with each other. High coaxiality means that the difference between the central axes of multiple members is small. Low coaxiality means that the difference between the central axes of multiple members is large.

[0035] Furthermore, if the spray unit 30 is configured to include the capillary tip 40 and the capillary receiving portion 50, the configuration is simple and can be manufactured with high reproducibility.

[0036] In the example shown in FIG. 1, the outer tube 20 is composed of two members, a tip tube 23 and a base tube 24. Alternatively, as shown in FIG. 4, the outer tube 20 may be a single member. Also, a tip cap 26 may be provided at the tip of the outer tube 20. With this configuration, the inner tube 10 is inserted into the outer tube 20, and the tip cap 26 is fixed to the tip of the outer tube 20 by fitting, screwing, bonding, or the like, to complete the nebulizer AA. In particular, the task of fixing the tip of the inner tube 10 to the tip of the outer tube 20 becomes easier.

[0037] As shown in Fig. 5(A), the gas introduction path 54 may be a groove formed in the flange receiving surface 51 of the capillary receiving part 50. As shown in Fig. 5(B), when the capillary chip 40 and the capillary receiving part 50 are joined, the flange front surface 47 and the flange receiving surface 51 come into contact with each other. As a result, the groove-shaped gas introduction path 54 becomes a tubular flow path.

[0038] As shown in Fig. 6, only a portion of the base end side of the spray unit 30 may be inserted inside the inner tube 10. In the example shown in Fig. 6, the outer diameter of the portion of the spray unit 30 on the base end side from the gas introduction path 54 is equal to the inner diameter of the inner tube 10, and the outer diameter of the remaining tip side portion is approximately the same as the outer diameter of the inner tube 10. Only the base end side portion of the spray unit 30 is inserted inside the inner tube 10, and the tip side portion is exposed to the outside from the tip of the inner tube 10. In addition, the tip portion of the spray unit 30 is directly fixed to the tip portion of the outer tube 20.

[0039] With the spray unit 30 configured as described above, the gas inlet 55 is exposed to the outside of the inner tube 10, so there is no need to form a through hole 15 in the inner tube 10. This makes it easy to manufacture the inner tube 10. In addition, there is no need to align the gas inlet 55 of the spray unit 30 with the through hole 15 of the inner tube 10, so that the nebulizer AA can be easily assembled.

[0040] As shown in FIG. 7, the capillary receiving portion 50 may have a cylindrical flange receiving wall 58 provided on the outer periphery of the flange receiving surface 51. The flange 42 of the capillary tip 40 is received inside the flange receiving wall 58. The tip of the inner tube 10 may be inserted inside the flange receiving wall 58. The spray unit 30 may be fixed to the tip of the inner tube 10 by inserting the spray unit 30 into the inner tube 10 as in the example shown in FIG. 3, or by inserting the inner tube 10 into the spray unit 30 as in the example shown in FIG. 7. In the latter example, it is preferable that the inner diameter of the flange receiving wall 58 is equal to the outer diameter of the inner tube 10 to such an extent that the outer peripheral surface of the inner tube 10 and the inner peripheral surface of the flange receiving wall 58 are in close contact with each other liquid-tightly and air-tightly.

[0041] As shown in Fig. 8, the capillary chip 40 may have a cylindrical joint 48 provided at the center of the flange rear surface 46. The internal space of the joint 48 is a joint flow path 49 that connects to the liquid flow path 45. The joint 48 is inserted into the inside of the tip of the inner tube 10. It is preferable that the outer diameter of the joint 48 is equal to the inner diameter of the inner tube 10 to such an extent that the outer peripheral surface of the joint 48 and the inner peripheral surface of the inner tube 10 are in liquid-tight contact with each other. With this configuration, the inner tube 10 and the capillary chip 40 can be joined liquid-tightly, thereby suppressing liquid leakage.

[0042] Furthermore, if the spray unit 30 has both the flange housing wall 58 and the joint 48, the tip of the inner pipe 10 can be sandwiched from both the inside and the outside. The inner pipe 10 and the spray unit 30 are more firmly attached to each other, improving the liquid-tightness and air-tightness.

[0043] The inner diameter of the capillary insertion hole 53 may be uniform throughout, or as shown in Figures 9(A) and 9(B), it may be cone-shaped with the inner diameter decreasing continuously or stepwise toward the gas outlet 57. In this way, the cross-sectional area of ​​the gas outlet 57 can be reduced, increasing the gas flow rate and generating droplets with a small particle size.

[0044] As shown in Fig. 10, the tip of the capillary 41 may be cone-shaped with an inner diameter that increases continuously or stepwise toward the liquid outlet 44. Since the tip of the capillary 41 is thin, the contact efficiency between the liquid and the gas increases, and the particle size of the droplets can be reduced. In addition, by making only the tip of the capillary 41 thin and leaving the other parts with a certain degree of thickness, the rigidity of the capillary 41 can be maintained. Furthermore, salts contained in the liquid sample are less likely to precipitate at the tip of the capillary 41, making it suitable for spraying samples with high salt concentrations.

[0045] To thin the tip of the capillary 41, the outer diameter of the capillary 41 may be made smaller toward the liquid outlet 44. In this case, however, the gas flow will deviate from a straight line to an oblique direction. Also, the annular cross-sectional area of ​​the gas outlet 57 will be larger, so the gas flow rate will decrease and the shear force will be weaker. On the other hand, if the inner diameter of the capillary 41 is made larger toward the liquid outlet 44, such problems will not occur.

[0046] 11, when the capillary receiving portion 50 has a flange receiving wall 58, it is preferable that the outer diameter of the flange 42 of the capillary chip 40 is equal to the inner diameter of the flange receiving wall 58. In this configuration, the flange 42 fits inside the flange receiving wall 58, thereby determining the radial position of the capillary chip 40 relative to the capillary receiving portion 50. This can improve the coaxiality between the capillary 41 and the capillary insertion hole 53.

[0047] However, the central axis of the capillary 41 does not necessarily coincide with the central axis of the flange 42. There is a possibility that some misalignment occurs due to manufacturing errors. In this case, even if the flange 42 is positioned, the coaxiality between the capillary 41 and the capillary insertion hole 53 decreases by the amount of the manufacturing error.

[0048] Therefore, as shown in FIG. 12, the capillary 41 may have a large diameter portion 41a. The large diameter portion 41a is a portion of the capillary 41 close to the flange 42, and has a larger outer diameter than the other portions. The capillary 41, including the large diameter portion 41a, is inserted into the capillary insertion hole 53. The outer diameter of the large diameter portion 41a is equal to the inner diameter of the capillary insertion hole 53. Therefore, the large diameter portion 41a of the capillary 41 fits into the capillary insertion hole 53, and the radial position of the capillary 41 is determined relative to the capillary insertion hole 53. This can improve the coaxiality between the capillary 41 and the capillary insertion hole 53 even if the central axis O1 of the capillary 41 and the central axis O2 of the flange 42 do not coincide with each other.

[0049] The large diameter portion 41a can be formed by, for example, electroforming technology. Alternatively, the large diameter portion 41a may be formed by inserting a heat shrink tube into the capillary 41. By providing the large diameter portion 41a in the capillary 41, the strength of the capillary 41 can be increased.

[0050] As shown in FIG. 13, the capillary insertion hole 53 may have a small diameter portion 53a. The small diameter portion 53a is a portion of the capillary insertion hole 53 close to the flange receiving surface 51, and has a smaller inner diameter than other portions. The capillary 41 is passed through the small diameter portion 53a. The inner diameter of the small diameter portion 53a is equal to the outer diameter of the capillary 41. Therefore, the capillary 41 fits into the small diameter portion 53a of the capillary insertion hole 53, and the radial position of the capillary 41 relative to the capillary insertion hole 53 is determined. This can improve the coaxiality between the capillary 41 and the capillary insertion hole 53 even if the central axis O1 of the capillary 41 does not coincide with the central axis O2 of the flange 42.

[0051] As shown in Figures 14(A) and 14(B), the capillary receiving section 50 may have a plurality of ribs 53b formed along the axial direction on the inner peripheral surface of the capillary insertion hole 53. The ribs 53b may be formed over the entire length of the capillary insertion hole 53, or may be formed on only a part of it. It is preferable that three or more ribs 53b are provided at equal angular intervals in the circumferential direction on the inner peripheral surface of the capillary insertion hole 53. In addition, it is preferable that the height of the ribs 53b is equal to 1 / 2 the difference between the inner diameter of the capillary insertion hole 53 and the outer diameter of the capillary 41.

[0052] When the capillary 41 is inserted into the capillary insertion hole 53, the apexes of the multiple ribs 53b come into contact with the outer circumferential surface of the capillary 41. Therefore, the capillary 41 is supported by the ribs 53b, and the radial position of the capillary 41 is determined relative to the capillary insertion hole 53. This makes it possible to improve the coaxiality between the capillary 41 and the capillary insertion hole 53 even if the central axis O1 of the capillary 41 and the central axis O2 of the flange 42 do not coincide with each other.

[0053] As shown in Figures 15(A) and 15(B), the capillary tip 40 may have multiple ribs 41b formed along the axial direction on the outer circumferential surface of the capillary 41. The ribs 41b may be formed over the entire length of the capillary 41, or may be formed on only a part of it. It is preferable that three or more ribs 41b are provided at equal angular intervals in the circumferential direction on the outer circumferential surface of the capillary 41. In addition, it is preferable that the height of the ribs 41b is equal to 1 / 2 the difference between the inner diameter of the capillary insertion hole 53 and the outer diameter of the capillary 41.

[0054] When the capillary 41 is inserted into the capillary insertion hole 53, the apexes of the multiple ribs 41b come into contact with the inner peripheral surface of the capillary insertion hole 53. Therefore, the radial position of the capillary 41 is determined relative to the capillary insertion hole 53. This makes it possible to improve the coaxiality between the capillary 41 and the capillary insertion hole 53 even if the central axis O1 of the capillary 41 and the central axis O2 of the flange 42 do not coincide with each other.

[0055] 12 to 15, when the capillary receiving portion 50 has the flange receiving wall 58, it is preferable that the outer diameter of the flange 42 of the capillary chip 40 is smaller than the inner diameter of the flange receiving wall 58. With this configuration, there is a play between the outer peripheral surface of the flange 42 and the inner peripheral surface of the flange receiving wall 58. Therefore, even if the central axis O1 of the capillary 41 and the central axis O2 of the flange 42 do not coincide with each other, the flange 42 can be received inside the flange receiving wall 58 without any difficulty.

[0056] 16, a spacer plate 34 may be sandwiched between the flange front surface 47 of the capillary chip 40 and the flange receiving surface 51 of the capillary storage part 50. The spacer plate 34 is an annular plate having a hole at a position corresponding to the capillary insertion hole 53. By changing the thickness or number of the spacer plates 34, the axial distance between the liquid outlet 44 and the gas outlet 57 can be adjusted.

[0057] A flexible sheet such as a silicone sheet or a rubber sheet can be used as the spacer plate 34. If a flexible sheet is used as the spacer plate 34, the gap between the flange front surface 47 and the flange receiving surface 51 is eliminated, improving the liquid-tightness and air-tightness.

[0058] As shown in Fig. 17, the spray unit 30 may be one member. In other words, the capillary chip 40 and the capillary container 50 may be combined into one member. The spray unit 30 may have therein a liquid flow path 45, a gas introduction path 54, and a gas flow path 56. Such a spray unit 30 may be formed by injection molding, a 3D printer, or the like.

[0059] Furthermore, the spray unit 30 and the inner tube 10 may be formed as an integral member as shown in Fig. 18. Such a member can also be formed by injection molding, a 3D printer, or the like.

[0060] The materials of the various parts constituting the nebulizer AA are preferably chemically stable and resistant to acids and organic solvents, and have mechanical strength that allows for micromachining. Examples include resins, glass, ceramics, carbon, and metals. Examples of resins include PEEK (polyether ether ketone), PPS (polyphenylene sulfide), PFA (perfluoroalkoxyalkane), PTFE (polytetrafluoroethylene), and polyimide. Materials with slightly poor acid resistance, such as PDMS (polydimethylsiloxane) and acrylic, can also be used depending on the type of liquid sample. Examples of metals include chemically resistant metals such as gold, platinum, and iridium. In addition, a base made of a non-chemically resistant metal may be coated with resin, glass, ceramics, carbon, chemically resistant metal, and the like. For example, a base made of nickel coated with gold may be used.

[0061] Second Embodiment Next, a nebulizer BB according to a second embodiment will be described. 19, like the nebulizer AA of the first embodiment, the nebulizer BB of this embodiment has an inner tube 10, an outer tube 20, and a spray unit 30. The inner tube 10 and the outer tube 20 form a double tube.

[0062] In this embodiment, a tube with a relatively small diameter is used as the inner tube 10. For example, a tube having an inner diameter and an outer diameter similar to those of the capillary 41 in the first embodiment can be used as the inner tube 10. Although not particularly limited, a quartz glass tube or a polyimide-coated quartz glass tube with an outer diameter of 350 μm and an inner diameter of 250 μm can be used as the inner tube 10. Also, a PFA tube or a PEEK tube with an outer diameter of 3 mm and an inner diameter of 2 mm can be used as the outer tube 20.

[0063] 20, the spray unit 30 is a cylindrical member as a whole. Although not particularly limited, the spray unit 30 has an outer diameter of 1.6 mm and a length of 6 mm. In addition, examples of materials for the spray unit 30 include PFA, PEEK, and quartz glass.

[0064] The spray unit 30 has a base end surface 31, a tip surface 32, and a side surface 33. An inner pipe insertion hole 35 that communicates with the base end surface 31 and the tip surface 32 is formed in the spray unit 30 along the central axis. A gas introduction passage 54 is formed in the middle of the spray unit 30 along the radial direction. One end of the gas introduction passage 54 is connected to the inner pipe insertion hole 35, and the other end opens to the side surface 33 of the spray unit 30. This opening in the side surface 33 is referred to as a gas inlet 55. There may be one gas introduction passage 54, or there may be multiple gas introduction passages 54.

[0065] The tip of the inner tube 10 is inserted into the inner tube insertion hole 35 of the spray unit 30. The inner diameter of the inner tube insertion hole 35 is larger than the outer diameter of the inner tube 10. For example, the inner diameter of the inner tube insertion hole 35 is 400 μm, and the outer diameter of the inner tube 10 is 350 μm. Therefore, a gap is generated between the outer peripheral surface of the inner tube 10 and the inner peripheral surface of the inner tube insertion hole 35. In order to fill this gap, an adapter tube 36 is fitted into a part of the inner tube 10, and the outer diameter of that part of the inner tube 10 is substantially enlarged. The adapter tube 36 may be fused to the inner tube 10 or may be bonded by an adhesive. The inner diameter of the adapter tube 36 is equal to the outer diameter of the inner tube 10, and the outer diameter of the adapter tube 36 is equal to the inner diameter of the inner tube insertion hole 35. For example, the inner diameter of the adapter tube 36 is 350 μm, and the outer diameter is 400 μm. The adapter pipe is disposed in a rear portion 35r of the inner pipe insertion hole 35 relative to the gas introduction passage 54. Therefore, the gap in the rear portion 35r of the inner pipe insertion hole 35 is closed by the adapter pipe .

[0066] In the portion 35f of the inner pipe insertion hole 35 forward of the gas introduction passage 54, a gap is secured between the outer peripheral surface of the inner pipe 10 and the inner peripheral surface of the inner pipe insertion hole 35. This gap is called a gas flow passage 56. The gas flow passage 56 is a flow passage from an intermediate position between the base end face 31 and the tip face 32 of the spray unit 30 to an annular gas outlet 57 opening at the tip face 32. The gas flow passage 56 is a cylindrical flow passage surrounding the inner pipe 10. The gas outlet 57 is an annular opening surrounding the liquid outlet 44 (the opening at the tip side of the inner pipe 10). The gas introduction passage 54 connects the gas inlet 55 and the gas flow passage 56. In this way, the inner pipe 10 and the spray unit 30 form a double pipe.

[0067] The spray unit 30 is fixed to the tip of the inner tube 10 by inserting the inner tube 10 into the inner tube insertion hole 35. The spray unit 30 is fixed to the inner tube 10, for example, by bonding the adapter tube 36 to the inner circumferential surface of the inner tube insertion hole 35 with an adhesive. Alternatively or in addition to this, the spray unit 30 may be fixed to the inner tube 10 by filling a recess formed in the base end surface 31 of the spray unit 30 with adhesive 37 and bonding it.

[0068] The tip of the spray unit 30 before the gas inlet 55 is fixed to the tip of the outer tube 20. Therefore, the outer tube flow path 22 and the gas inlet 55 are connected.

[0069] The liquid introduced into the inner pipe flow passage 12 flows through the inner pipe flow passage 12 and is discharged from the liquid outlet 44. Meanwhile, the gas introduced into the outer pipe flow passage 22 flows through the outer pipe flow passage 22, the gas introduction passage 54, and the gas flow passage 56 in this order, and is discharged from the gas outlet 57. Then, at the tip surface 32 of the spray unit 30, the high-speed gas flow discharged from the gas outlet 57 collides with the liquid discharged from the liquid outlet 44, and the shear force causes the liquid to become fine droplets and are sprayed.

[0070] The spray unit 30 is fixed to the tip of the inner tube 10 and the tip of the outer tube 20. Therefore, even if there is a positional or angular misalignment at the joint between the base of the inner tube 10 and the base of the outer tube 20, the inner tube 10 bends, etc., to absorb the misalignment, and the spray unit 30 is positioned correctly. In addition, since the inner tube 10 is inserted into the inner tube insertion hole 35 of the spray unit 30, the manufacturing error in the positional relationship between the inner tube 10 and the spray unit 30 is small. Therefore, the inner tube flow path 12 and the gas flow path 56 at the tip of the nebulizer BB are highly coaxial, and the error in the axial distance at the outlets of both flow paths is small.

[0071] As shown in Fig. 21, the inner diameter of the rear portion 35r of the inner pipe insertion hole 35 may be made smaller and equal to the outer diameter of the inner pipe 10. With such a configuration, it is not necessary to provide an adapter pipe 36 to the inner pipe 10. On the other hand, the inner diameter of the front portion 35f of the inner pipe insertion hole 35 is larger than the outer diameter of the inner pipe 10. This forms a gas flow path 56 between the inner pipe 10 and the inner pipe insertion hole 35. For example, if the outer diameter of the inner pipe 10 is 350 µm, the inner diameter of the rear portion 35r of the inner pipe insertion hole 35 may be set to 350 µm, and the inner diameter of the front portion 35f may be set to 400 µm.

[0072] The spray unit 30 can be fixed to the inner tube 10 by adhering the inner tube 10 to the inner surface of the inner tube insertion hole 35 with an adhesive, or by filling a recess formed in the base end face 31 of the spray unit 30 with adhesive 37 and adhering it.

[0073] As shown in Figures 22(A) and 22(B), the spray unit 30 may have a plurality of ribs 35b formed along the axial direction on the inner peripheral surface of the inner pipe insertion hole 35. The ribs 35b may be formed over the entire length of the inner pipe insertion hole 35, or may be formed only on a part of the inner pipe insertion hole 35. For example, the ribs 35b may be formed on a part of the inner pipe insertion hole 35 other than the tip part. Also, the ribs 35b may be formed only on the rear part 35r of the inner pipe insertion hole 35.

[0074] It is preferable that three or more ribs 35b are provided at equal angular intervals in the circumferential direction of the inner circumferential surface of the inner pipe insertion hole 35. It is also preferable that the height of the ribs 35b is equal to half the difference between the inner diameter of the inner pipe insertion hole 35 and the outer diameter of the inner pipe 10. For example, if the inner diameter of the inner pipe insertion hole 35 is 400 μm and the outer diameter of the inner pipe 10 is 350 μm, the height of the ribs 35b may be set to 25 μm.

[0075] When the inner pipe 10 is inserted into the inner pipe insertion hole 35, the apexes of the multiple ribs 35b come into contact with the outer circumferential surface of the inner pipe 10. Therefore, the inner pipe 10 is supported by the ribs 35b, and the radial position of the inner pipe 10 is determined relative to the inner pipe insertion hole 35. This makes it possible to improve the coaxiality between the inner pipe 10 and the inner pipe insertion hole 35.

[0076] The inner pipe 10 may be bonded to the inner circumferential surface of the inner pipe insertion hole 35 with an adhesive, or the inner pipe 10 may be bonded by filling a recess formed in the base end face 31 of the spray unit 30 with adhesive 37. The adhesive 37 can also prevent gas from flowing into the gas flow passage 56 from the base end face 31.

[0077] As shown in Figures 23(A) and 23(B), the front portion 35f of the inner pipe insertion hole 35 may be formed in a cone shape with the inner diameter gradually decreasing toward the gas outlet 57. In addition, a plurality of ribs 35b are formed on the inner peripheral surface of the cone-shaped portion of the inner pipe insertion hole 35. When inserting the inner pipe 10 into the inner pipe insertion hole 35, the inner pipe 10 is inserted until the tip of the inner pipe 10 abuts against the ribs 35b and stops. This makes it possible to fix the position of the tip of the inner pipe 10.

[0078] Third Embodiment Next, a nebulizer CC according to a third embodiment will be described. As shown in Fig. 24, the nebulizer CC of this embodiment is provided in a plasma torch 70 of an ICP analyzer. The ICP analyzer has a plasma torch 70 that generates plasma P. The plasma torch 70 has a triple tube structure consisting of a torch outer tube 71, a torch middle tube 72, and a torch inner tube 73. In general, a plasma gas is passed through an outer flow passage formed between the torch outer tube 71 and the torch middle tube 72. An auxiliary gas is passed through an intermediate flow passage formed between the torch middle tube 72 and the torch inner tube 73. A carrier gas is passed through an inner flow passage inside the torch inner tube 73.

[0079] The nebulizer CC of this embodiment is built into the torch inner tube 73. Specifically, as shown in FIG. 25, the inner tube 10 and the spray unit 30 of the nebulizer CC are inserted into the inside of the torch inner tube 73. The spray unit 30 can have the same configuration as that of the first embodiment. In the illustrated example, the spray unit 30 is entirely disposed inside the inner tube 10, and the tip of the inner tube 10 is inserted into a gas seal 74 having a circular tube shape. The inner diameter of the gas seal 74 is equal to the outer diameter of the inner tube 10, and the outer diameter of the gas seal 74 is equal to the inner diameter of the torch inner tube 73. Therefore, the tip of the inner tube 10 is fixed to the torch inner tube 73 via the gas seal 74.

[0080] Alternatively, only the base end of the spray unit 30 may be inserted into the inner tube 10, and the tip end may be inserted into the gas seal device 74. The inner tube 10 may be inserted into the spray unit 30, and the spray unit 30 may be inserted into the gas seal device 74. The spray unit 30 and the inner tube 10 may be integrated, and the spray unit 30 may be inserted into the gas seal device 74. In these cases, the spray unit 30 is fixed to the torch inner tube 73 via the gas seal device 74.

[0081] The spray unit 30 may be configured similarly to the second embodiment. In this case, a tube with a relatively small diameter can be used as the inner tube 10. The inner diameter of the torch inner tube 73 is usually about 4 mm. If an inner tube 10 with a small diameter is used, it is easy to insert the inner tube 10 into the torch inner tube 73.

[0082] In this embodiment, the torch inner tube 73 functions as the outer tube 20 of the nebulizer CC. Therefore, gas flows through the outer tube flow passage 22 between the inner tube 10 and the torch inner tube 73.

[0083] In this embodiment as well, droplets are sprayed from the tip surface 32 of the spray unit 30. The sprayed droplets are directly introduced into the plasma P generated in the ICP analyzer without passing through a spray chamber.

[0084] When attempting to incorporate a nebulizer into the torch inner tube 73 as in this embodiment, it is necessary to prepare a nebulizer that is longer than a typical coaxial nebulizer. Therefore, if there is a positional or angular misalignment at the joint between the base of the nebulizer's inner tube and the base of the torch inner tube 73, the misalignment at the tip will be large. However, in this embodiment, the spray unit 30 is fixed to the tip of the inner tube 10 and the tip of the torch inner tube 73, and the spray unit 30 is positioned in the correct position. Therefore, damage to the tip of the inner tube and variations in spray characteristics can be suppressed.

[0085] In this embodiment, the inner tube 10 can also be arranged in a bent state. For example, various parts are arranged inside a torch box that houses a plasma torch, and these parts often become obstacles that make it difficult to arrange a nebulizer. In contrast, in this embodiment, the spray unit 30 is arranged inside the torch box, and the inner tube 10 connected to the spray unit 30 can be bent and arranged to avoid obstacles. In this way, the nebulizer can be installed even in places where there are obstacles.

[0086] [Fourth embodiment] Next, a nebulizer DD according to a fourth embodiment will be described. 26, the nebulizer DD of this embodiment is built into the torch inner tube 73 of the plasma torch 70, similar to the nebulizer CC of the third embodiment. The nebulizer DD has an inner tube 10, an outer tube 20, and a spray unit 30, and is entirely inserted inside the torch inner tube 73.

[0087] The outer tube 20 has an outer tube flange 27 at its tip. The number of outer tube flanges 27 may be one or more. The outer diameter of the outer tube flange 27 is equal to the inner diameter of the torch inner tube 73. Therefore, the outer tube flange 27 fits into the torch inner tube 73, and the nebulizer DD is fixed to the torch inner tube 73.

[0088] The space formed between the outer peripheral surface of the outer tube 20 and the inner peripheral surface of the torch inner tube 73 is called the sheath gas flow path 75. Sheath gas is introduced into the sheath gas flow path 75. As shown in FIG. 27, the outer tube flange 27 has a groove 27g that connects the front and back. The sheath gas flow path 75 is not blocked by the outer tube flange 27, and communicates via the groove 27g. Therefore, the sheath gas supplied from the base end of the outer tube 20 is released from the tip surface of the outer tube 20.

[0089] The outer pipe flange 27 may have a hole communicating the front and back instead of the groove 27g as long as it is configured to pass the sheath gas. The shape and number of the groove 27g or hole are not particularly limited. The groove 27g or hole may be oblique to the central axis of the outer pipe 20 so that the sheath gas becomes a swirling flow. The outer pipe flange 27 may be porous. As long as the outer pipe 20 can be fixed to the center of the torch inner pipe 73, multiple columnar members may be erected on the outer peripheral surface of the outer pipe 20 instead of a flange.

[0090] The nebulizer DD of this embodiment can flow a sheath gas around the droplets sprayed from the spray unit 30. This can prevent the droplets from being adsorbed to the inner wall of the torch inner tube 73. In addition, the sheath gas can desolvate the droplets, reducing the particle size of the droplets. As a result, the efficiency of excitation and ionization can be improved. [Explanation of symbols]

[0091] AA, BB, CC, DD nebulizers 10 Inner tube 11 Liquid supply port 12 Inner pipe flow path 20 outer tube 21 Gas supply port 22 Outer tube flow path 30 Spray unit 40 Capillary Tip 41 Capillary 42 Flange 43 Liquid inlet 44 Liquid outlet 45 Liquid flow path 50 Capillary storage section 53 Capillary insertion hole 54 Gas inlet 55 Gas inlet 56 Gas flow path 57 Gas outlet

Claims

1. an inner tube having an inner tube flow path into which a liquid is introduced; an outer tube into which the inner tube is inserted and which defines an outer tube flow path through which a gas is introduced between the outer tube and the inner tube; A spray unit that is shorter in an axial direction than the inner tube and the outer tube, The spray unit is fixed to a tip end of the inner tube and a tip end of the outer tube, and is configured to cause the gas that has passed through the outer tube flow path to collide with the liquid that has passed through the inner tube flow path to spray liquid droplets. A nebulizer characterized by:

2. The spray unit comprises: a liquid flow path communicating a liquid inlet opening on the base end surface with a liquid outlet opening on the tip end surface; a gas flow path that is a cylindrical flow path surrounding the liquid flow path and extends from an intermediate position between the base end surface and the tip end surface to an annular gas outlet that opens into the tip end surface; a gas inlet opening on a side surface and a gas introduction passage communicating with the gas flow passage; The spray unit is fixed to the tip of the inner tube and the tip of the outer tube so that the inner tube flow path is connected to the liquid inlet and the outer tube flow path is connected to the gas inlet.

2. The nebulizer of claim 1.

3. The spray unit comprises: A capillary tip; a capillary receiving portion coupled to the capillary tip; The capillary tip comprises: A capillary having the liquid flow path; a flange provided at a base end of the capillary and having a flange rear surface and a flange front surface constituting the base end surface; The capillary storage section is a capillary insertion hole that communicates with the flange receiving surface and the front surface of the storage portion that constitutes the tip surface; The gas introduction path is connected to the capillary insertion hole, the capillary is inserted into the capillary insertion hole, and the gas flow path is formed between an outer circumferential surface of the capillary and an inner circumferential surface of the capillary insertion hole; The front surface of the flange abuts against the flange receiving surface.

3. The nebulizer according to claim 2.

4. the capillary receiving portion is provided on the flange receiving surface and has a cylindrical flange receiving wall for receiving the flange therein; The inner diameter of the flange receiving wall is equal to the outer diameter of the flange.

4. The nebulizer according to claim 3.

5. the capillary has a large diameter portion adjacent to the flange and having an outer diameter larger than that of other portions; The outer diameter of the large diameter portion is equal to the inner diameter of the capillary insertion hole.

4. The nebulizer according to claim 3.

6. the capillary insertion hole has a small diameter portion adjacent to the flange receiving surface, the small diameter portion having an inner diameter smaller than that of other portions; The inner diameter of the narrowed portion is equal to the outer diameter of the capillary.

4. The nebulizer according to claim 3.

7. the capillary receiving portion has a plurality of ribs formed along an axial direction on an inner peripheral surface of the capillary insertion hole, The apex of the rib contacts the outer circumferential surface of the capillary.

4. The nebulizer according to claim 3.

8. The capillary tip has a plurality of ribs formed on an outer peripheral surface of the capillary along an axial direction, The apex of the rib contacts the inner circumferential surface of the capillary insertion hole.

4. The nebulizer according to claim 3.

9. The spray unit has a spacer plate sandwiched between the flange front surface and the flange receiving surface.

4. The nebulizer according to claim 3.

10. The capillary insertion hole has an inner diameter that decreases continuously or stepwise toward the gas outlet.

4. The nebulizer according to claim 3.

11. The capillary has a tip end whose inner diameter increases continuously or stepwise toward the liquid outlet.

4. The nebulizer according to claim 3.

12. the capillary tip is provided on the rear surface of the flange, has a junction flow path therein that is connected to the liquid flow path, and has a junction that is inserted into a tip end of the inner tube; The outer diameter of the joint is equal to the inner diameter of the inner tube.

4. The nebulizer according to claim 3.

13. The spray unit comprises: an inner pipe insertion hole which is a hole communicating between a base end surface and a tip surface and which forms, between the inserted inner pipe and the inner pipe, a gas flow passage from an intermediate position between the base end surface and the tip surface to an annular gas outlet opening in the tip surface; a gas inlet opening on a side surface and a gas introduction passage communicating with the gas flow passage; The spray unit is fixed to the tip end of the inner tube by inserting the inner tube into the inner tube insertion hole, and is also fixed to the tip end of the outer tube so that the outer tube flow path and the gas inlet are connected.

2. The nebulizer of claim 1.

14. The outer tube is the inner tube of the plasma torch of an ICP analyzer. A nebulizer according to any one of claims 1 to 13.

15. The outer tube is inserted into a torch inner tube of a plasma torch of an ICP analyzer, and forms a sheath gas flow path between the outer tube and the torch inner tube, through which a sheath gas is introduced. A nebulizer according to any one of claims 1 to 13.

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