Esi ion source, and mass spectrometry system

Abstract

To provide a mass spectrometry system capable of stably operating a mass spectrometer.SOLUTION: The mass spectrometry system includes: an atomization unit 3 that changes a sample to be analyzed by a mass spectrometer into charged droplets and supplies the same; an ion source chamber 4 in which the charged droplets introduced from the atomization unit 3 are ionized; an ion inlet 5 that introduces the ions generated as a result of ionization of the charged droplets into the mass spectrometer; and a vortex generator 1 that generates a vortex and introduces the generated vortex into the ion source chamber 4. The axis of the ion inlet 5 and the axis of the vortex introduced into the ion source chamber 4 from the vortex generator 1 intersect at a predetermined angle.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the technology of ESI ion sources and mass spectrometry systems. [Background technology]

[0002] At sewage treatment plants and food production sites, samples to be measured are collected by people, prepared so that they can be analyzed by analytical equipment, and then the prepared samples are analyzed by the analytical equipment to carry out management.

[0003] In recent years, there has been a demand to increase the number of measurements in order to improve the accuracy of such management. However, due to a decrease in analytical experts and rising labor costs for those being measured, it has become impossible to maintain the current number of analyses. In addition, optical detectors that are less susceptible to the accumulation of dirt and other contaminants are becoming more common in devices for continuous monitoring. Continuous monitoring means that monitoring is carried out continuously.

[0004] However, when the sample to be measured is small and contains many impurities, the application of a mass spectrometer is required as a device with higher component separation and qualitative capabilities than optical analysis. However, mass spectrometers that analyze liquid samples have issues such as shorter maintenance cycles due to the accumulation of contamination on the ion source caused by the measured sample, which is a problem when maintaining high-sensitivity analysis over long periods of time.

[0005] In order to solve such problems, the techniques described in Non-Patent Documents 1 and 2 and the techniques described in Patent Documents 1 and 2 have been disclosed.

[0006] An example of a typical device using vortex flow is Non-Patent Document 1. The technology described in Non-Patent Document 1 makes it possible to atomize charged droplets released from a spray by generating a vortex flow around the periphery of the ionization region. Furthermore, the technology described in Non-Patent Document 1 generates a peripheral vortex flow, which generates a gas flow that advances in the direction of sample introduction, thereby achieving high sensitivity.

[0007] Similarly, Patent Document 1 discloses an interface component and a method for manufacturing the same, in which "the interface component combines electrostatic optics and a skimmer with an internal chamber that can be filled with gas at a predetermined pressure, and is constructed by silicon lithography, etching, and bonding."

[0008] According to the technique described in Patent Document 1, similar to the technique described in Non-Patent Document 1, ion introduction with ionized material can be achieved by collision of two flows with a vortex or other rotating mixture.

[0009] Next, Non-Patent Document 2 describes the collision of a uniform vortex flow with charged droplets and a gas flow from an ion source, and the sensitivity improvement due to the vortex flow has been realized.

[0010] Patent Document 2 discloses an impactor spray ion source, which is "an ion source comprising one or more nebulizers 1 and one or more targets 50, wherein the one or more nebulizers 1 are arranged and adapted to emit, during use, a stream consisting primarily of droplets that are caused to impact the one or more targets 50 and are thereby ionized to produce a plurality of ions, and the one or more targets 50 further comprise one or more structures 14 configured to disturb gas flowing along the surface of the one or more targets 50."

[0011] In the technology described in Patent Document 2, a vortex generating mechanism is inserted perpendicular to the sample introduction section into the spray formed by ions and gas emitted from the ion source. The collision of the formed vortex with the spray and the vortex with each other improves sensitivity and prevents contamination of the sample introduction section. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-327959 [Patent Document 2] Japanese Patent Publication No. 2020-24923 [Non-patent literature]

[0013] [Non-Patent Document 1] Analytical. Chemistry, 2020, Vol.92, p.12049-12054 [Non-patent document 2] Analytical. Chemistry, 2017 September,Vol.05; 89(17): p.8981-8987 Summary of the Invention [Problem to be solved by the invention]

[0014] The technique described in Non-Patent Document 1 has a problem in that it cannot reduce contamination of the sample introduction part caused by the neutral droplets in the center directly hitting the sample introduction part.

[0015] Furthermore, in the technology described in Patent Document 1, the vortex or rotational mixing of the two flows that may be generated is not uniform. Collisions between the non-uniform flows and charged droplets cause sensitivity fluctuations, making it difficult to adopt this method for continuous monitoring.

[0016] In the technology described in Non-Patent Document 2, the vortex generating mechanism and the sample inlet are arranged coaxially, so that neutral droplets caught in the vortex are constantly supplied to the sample inlet. This causes dirt to adhere to the sample inlet, making it difficult to perform continuous monitoring for long periods of time.

[0017] In the technology described in Patent Document 2, the collision of the spray with the vortex generated by the inserted vortex generating mechanism causes dirt to accumulate on the vortex generating mechanism. Unless this accumulation of dirt is eliminated, stable performance cannot be maintained for a long period of time.

[0018] In the above-mentioned Patent Documents 1 and 2 and Non-Patent Documents 1 and 2, various measures using eddy currents are taken to improve sensitivity, but the compatibility with the long-term stability required for continuous monitoring is not considered an issue.

[0019] The present invention has been made in view of the above background, and an object of the present invention is to operate a mass spectrometer stably. [Means for solving the problem]

[0020] In order to solve the above-mentioned problems, the present invention comprises an atomization device that supplies a sample to be analyzed by a mass spectrometer as charged droplets, an ion source chamber in which the charged droplets introduced from the atomization device are ionized, an ion inlet that introduces ions resulting from the ionization of the charged droplets into the mass spectrometer, and a vortex generator that generates a vortex and introduces the generated vortex into the ion source chamber, wherein the axis of the ion inlet and the axis of the vortex introduced from the vortex generator into the ion source chamber intersect at a predetermined angle. Other solutions will be described as appropriate in the embodiments. [Effects of the Invention]

[0021] According to the present invention, the mass spectrometer can be operated stably. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a diagram showing the configuration of an ESI ion source (part 1). [Figure 2] FIG. 2 is a diagram showing the configuration of an ESI ion source (part 2). [Figure 3] FIG. 2 is a cross-sectional view of the ion source chamber. [Figure 4] FIG. 2 is a diagram showing a detailed configuration of a vortex generator. [Figure 5] 1 is a diagram showing the configuration of a mass spectrometry system according to an embodiment of the present invention. [Figure 6] FIG. 2 is a diagram illustrating a configuration of a control device according to the present embodiment. [Figure 7] FIG. 10 is a diagram showing the behavior of vortex gas in an internal cross section of the ion source chamber as viewed from the vortex generator side. [Figure 8] FIG. 1 shows the behavior of vortex gases in a perspective view of a vortex generator and an ion source chamber. [Figure 9A] 10A and 10B are diagrams showing the behavior of vortex gas when the vortex generator and the ion source chamber are viewed from the atomizer side. [Figure 9B] FIG. 10 is a diagram showing the behavior of vortex gas when the vortex generator and the ion source chamber are viewed from the side. [Figure 10] FIG. 1 illustrates the behavior of charged droplets inside the ion source chamber. DETAILED DESCRIPTION OF THE INVENTION

[0023] Next, a mode for carrying out the present invention (referred to as an "embodiment") will be described in detail with reference to the drawings as appropriate.

[0024] (Configuration of ESI ion source Z) 1 and 2 are diagrams showing the configuration of the ESI ion source Z. Fig. 1 shows an overall external view, and Fig. 2 shows a perspective cross-sectional view. Fig. 2 is a perspective cross-sectional view taken along the arrow in Fig. 1.

[0025] 1 and 2, an ESI (electrospray ionization) ion source Z includes a vortex generator 1, a heater 2, an atomizer 3, an ion source chamber 4, and an ion inlet 5. A mass spectrometer 8 (see FIG. 5) is connected to the ion inlet 5. Incidentally, the "introduction" in the ion inlet 5 means introduction into the mass spectrometer 8. That is, ions are emitted from the ion inlet 5 toward the inside of the mass spectrometer 8.

[0026] The atomization device 3 is provided above the ion source chamber 4. Above the ion source chamber 4 means the side opposite to the ground side of the ion source chamber 4. The atomization device 3 atomizes samples that are continuously introduced into the main body of the atomization device 3 from a sample inlet 301. The samples are to be analyzed by a mass spectrometer 8. As shown in FIG. 2, the atomization device 3 is equipped with an ion source spray unit 311 that is a capillary. The sample introduced into the main body of the atomization device 3 from the sample inlet 301 is sprayed into the inside of the ion source chamber 4 from the ion source spray unit 311 as charged droplets.

[0027] In this way, the atomization device 3 continuously supplies the sample to be analyzed by the mass spectrometer 8 as charged droplets.

[0028] The vortex generator 1 generates a vortex flow from the gas, and introduces the vortex gas from the vortex generator 1 into the ion source chamber 4. Hereinafter, the gas that becomes a vortex gas is referred to as a vortex gas (vortex). In this way, the vortex generator 1 generates a vortex flow and introduces the generated vortex flow into the ion source chamber 4.

[0029] Inside the ion source chamber 4, the charged droplets sprayed from the ion source spray unit 311 are mixed with the vortex gas introduced from the vortex generator 1. This causes the charged droplets to dry and become smaller. Then, ions are desorbed from the smaller charged droplets. In this way, inside the ion source chamber 4, the charged droplets introduced from the atomizer 3 are ionized.

[0030] The heating device 2 is coaxial with the vortex generator 1 and faces the ion source chamber 4 across it. A heating gas (arrow A2 in FIG. 2 ) is introduced into the heating device 2 from a gas inlet 201. The introduced heating gas is heated by the heating device 2 and then introduced into the ion source chamber 4. That is, the heating device 2 heats the heating gas flowing through the heating device 2, and the heated gas is introduced into the ion source chamber 4 as a gas for heating and drying the sample (charged droplets). This dries the charged droplets introduced into the ion source chamber 4 from the vortex generator 1. As a result, the charged droplets become smaller, and the excess charge due to the size reduction is detached from the charged droplets by Coulomb repulsion, resulting in ionization.

[0031] In this way, the heating device 2 dries the charged droplets introduced from the atomization device 3. This makes it possible to accelerate the desorption process by the heating gas.

[0032] Although the installation of the heating device 2 is not essential, it is desirable to install it since it can promote desorption.

[0033] Thereafter, the ions are introduced into the mass spectrometer 8 through the aperture 501 provided in the ion inlet 5 in accordance with the voltage applied to the ion inlet 5. In this way, the ion inlet 5 introduces the ions generated as a result of ionization of the charged droplets into the mass spectrometer 8.

[0034] Inside the ion source chamber 4, the axis of the ion inlet 5 and the axis of the vortex (vortex gas) introduced into the ion source chamber 4 from the vortex generator 1 intersect at a predetermined angle. Preferably, the predetermined angle formed by the axis of the ion inlet 5 and the axis of the vortex is approximately 90°. In other words, the axis of the vortex gas intersects with the axis of the ion inlet 5, and preferably, the axis of the vortex gas and the axis of the ion inlet 5 are approximately perpendicular to each other. In addition, the axis of the vortex gas and the axis of the ion spray also intersect, preferably, are approximately perpendicular to each other.

[0035] Incidentally, the axis of the ion inlet 5 is the traveling direction of ions emerging from the orifice 501, i.e., the direction perpendicular to the opening surface of the orifice 501. The axis of the vortex is the traveling direction of the vortex. Furthermore, "approximately 90°" refers to an angle that can be regarded as 90° and 90°. Note that the angle may be deviated from 90° as long as the effect of the present invention is not impaired.

[0036] 2, an exhaust section 401 is provided at the bottom of the ion source chamber 4. The exhaust section 401 is in communication with the atmosphere. By providing such an exhaust section 401, the internal pressure of the ion source chamber 4 can be maintained at atmospheric pressure.

[0037] (Cross section of ion source chamber 4) Fig. 3 is a cross-sectional view of the ion source chamber 4. Fig. 3 shows a cross section taken along the arrow in Fig. 1. Figs. 1 and 2 will be referenced as appropriate. In Fig. 3, the mass spectrometer 8 is at the back of the paper.

[0038] As described above, the atomization device 3, which continuously supplies the sample, includes the ion source spray unit 311, which sprays the liquid sample into the ion source chamber 4. The sample is then sprayed from the ion source spray unit 311 as a spray of charged droplets. The sprayed charged droplets collide with the vortex gas supplied by the vortex generator 14, which is installed so that its axis intersects with the ion inlet 5. As described above, the heating device 2 is disposed at a position opposite the vortex generator 1 with respect to the ion source spray unit 311 to promote desolvation from the charged droplets.

[0039] (Vortex generator 1) FIG. 4 is a diagram showing the detailed configuration of the vortex generator 1. As shown in FIG.

[0040] 4 is a diagram showing a cross section of the vortex generator 1. In FIG. 4, the ion source chamber 4 is in the direction of the right side.

[0041] The vortex generator 1 is composed of a vortex guide 110, a vortex gas inlet 111, and a vortex generator 120. The vortex guide 110 forms a vortex and supports the introduction of the vortex into the ion source chamber 4. A vortex gas, which is a gas for forming a vortex, is introduced into the vortex gas inlet 111. Then, a vortex is generated in the vortex generator 120.

[0042] A spiral notch 121 is formed on the periphery of the vortex generating unit 120. The spiral notch 121 and the vortex guide 110 form a flow path 131 for the vortex gas. The vortex gas introduced from the vortex gas inlet 111 moves along the flow path 131, causing the vortex gas to form a vortex. As shown in FIG. 4 , the vortex generating unit 120 is installed partway along the vortex guide 110, and beyond that is a hollow portion 132. The vortex gas that has formed a vortex by moving along the flow path 131 maintains its vortex state even inside the hollow portion 132. The vortex gas is then introduced into the ion source chamber 4 as a vortex.

[0043] Further, inside the vortex gas inlet 111, an energizing gas flow passage 141 communicating with the cavity 132 is provided to introduce the energizing gas into the cavity 132. The vortex gas generated by the energizing gas introduced from the energizing gas flow passage 141 is energized. Note that it is desirable that the vortex gas and the energizing gas are similar gases.

[0044] (system configuration diagram) FIG. 5 is a diagram showing the configuration of a mass spectrometry system Y according to this embodiment.

[0045] The mass spectrometry system Y includes an ESI ion source Z, a control device 6, a mass spectrometer 8, a vortex gas storage tank 701, a vortex gas delivery pump 702, a heating gas storage tank 711, and a heating gas delivery pump 712.

[0046] The mass spectrometer 8 analyzes the ions generated by the ESI ion source Z.

[0047] A vortex gas storage tank 701 in which vortex gas is stored is connected to a vortex gas delivery pump 702 via a pipe 731. The vortex generator 1 is connected to the vortex gas delivery pump 702 via a pipe 732. A valve 721 is provided on the pipe 732 connecting the vortex gas delivery pump 702 to the vortex generator 1.

[0048] A heating gas storage tank 711 in which heating gas is stored and a heating gas delivery pump 712 are connected via a pipe 741. Furthermore, the heating device 2 and the heating gas delivery pump 712 are connected via a pipe 742. Furthermore, a valve 722 is provided on the pipe 742 connecting the heating gas delivery pump 712 and the heating device 2.

[0049] The vortex gas delivery pump 702, the heating gas delivery pump 712, and the valves 721 and 722 can be controlled by the control device 6. With this configuration, the flow rate and flow velocity of the vortex gas and the flow rate and flow velocity of the heating gas can be controlled by the control device 6. The control device 6 can also control the temperature of the heating device 2.

[0050] (Control device 6) 6 is a diagram showing the configuration of the control device 6 in this embodiment, with reference to FIG. 5 as needed.

[0051] The control device 6 is configured as a PC (Personal Computer), a tablet terminal, a smartphone, or the like. The control device 6 is equipped with a memory 610 configured as a RAM (Random Access Memory), etc. The control device 6 is also equipped with a calculation device 601 configured as a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), etc. The control device 6 is also equipped with a storage device 602 configured as a HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. The control device 6 is also equipped with an input device 603 configured as a keyboard, a mouse, a touch panel display, etc., and a display device 604 configured as a monitor, a touch panel display, etc. The control device 6 is also equipped with a vortex gas delivery pump 702, a heating gas delivery pump 712, and a communication device 605 that transmits and receives information to and from the heating device 2.

[0052] Then, the program stored in the storage device 602 is loaded into the memory 610, and the loaded program is executed by the arithmetic device 601. As a result, a vortex gas flow rate control unit 611, a heating gas flow rate control unit 612, and a temperature control unit 613 are realized.

[0053] The vortex gas flow rate control unit 611 controls the vortex gas delivery pump 702 to control the flow rate and flow velocity of the vortex gas introduced from the vortex gas delivery pump 702 to the vortex generating device 1 .

[0054] The heating gas flow rate control unit 612 controls the heating gas delivery pump 713 to control the flow rate and flow velocity of the heating gas introduced from the heating gas delivery pump 713 to the heating device 2 .

[0055] The temperature control unit 613 controls the temperature of the heating device 2 .

[0056] In this way, the control device 6 can control the flow rate and flow velocity of the vortex gas (vortex flow). The control device 6 can also control the flow rate and flow velocity of the heating gas. Furthermore, the control device 6 can control the temperature of the heating device 2.

[0057] (Vortex gas behavior) Next, the behavior of the vortex gas will be explained with reference to Figures 7 to 9B. Figures 1 and 2 will also be referenced as appropriate. In Figures 7 to 9B, the length of the arrows indicates the flow velocity. That is, the longer the arrow, the faster the flow velocity. Also, Figures 7 to 9B show the case where no heating gas is introduced into the ion source chamber 4 from the heating device 2.

[0058] Fig. 7 is a diagram showing the behavior of the vortex gas in the internal cross section of the ion source chamber 4 as viewed from the side of the vortex generator 1. Fig. 8 is a perspective view showing the behavior of the vortex gas of the vortex generator 1 and the ion source chamber 4. Fig. 9A is a diagram showing the behavior of the vortex gas when the vortex generator 1 and the ion source chamber 4 are viewed from the side of the atomization device 3. Fig. 9B is a diagram showing the behavior of the vortex gas when the vortex generator 1 and the ion source chamber 4 are viewed from the side.

[0059] The vortex (vortex gas) generated by the configuration of the vortex generator 1 shown in Fig. 4 is introduced into the ion source chamber 4 while maintaining the vortex state, as shown in the vortex diagram in Fig. 8. In reality, a vortex-like flow velocity distribution is maintained at the position of the ion source spray section 311, as shown in the vortex behavior upon gas introduction shown in Fig. 7. Note that the symbol C in Fig. 7 indicates the center of the vortex.

[0060] As described above with reference to FIG. 2, part of the airflow inside the ion source chamber 4 is exhausted from the exhaust unit 401 provided in the lower part of the ion source chamber 4.

[0061] 9A and 9B, the flow velocity of the vortex gas (reference symbol A1) flowing through the flow passage 131 formed in the vortex generator 1 is maintained substantially constant as it is introduced into the ion source chamber 4. As described above in FIG. 4, an energizing gas (reference symbol A3), which is a gas for energizing a vortex, is introduced from outside the vortex generator 1 into the energizing gas flow passage 141 formed in the vortex generating unit 120 of the vortex generator 1. The energizing gas introduced from outside the vortex generator 1 flows through the energizing gas flow passage 141 and is then discharged into the cavity 132. A portion of the discharged energizing gas mixes with the vortex of the vortex gas, thereby energizing the vortex.

[0062] (Behavior of charged droplets inside the ion source chamber 4) FIG. 10 is a diagram showing the behavior of charged droplets inside the ion source chamber 4. The right side of the paper in FIG. 10 is the side of the ion introduction port 5. In FIG. 10, the size of the circle of the charged droplet indicated by the symbol L indicates the particle diameter of the charged droplet. Note that although FIG. 10 shows four different sizes of charged droplets, in reality there are many more different sizes of charged droplets.

[0063] As shown in FIG. 10, charged droplets with large particle sizes that are not sufficiently dried move toward the opposite side of the ion inlet 5. Conversely, charged droplets with small particle sizes move toward the ion inlet 5. Due to their size, charged droplets with large particle sizes are not sufficiently dried and contain many neutral molecules within the particles. Therefore, it is known that when charged droplets with large particle sizes are introduced into the mass spectrometer 8 through the ion inlet 5, they can cause contamination of the mass spectrometer 8. On the other hand, charged droplets with small particle sizes contain fewer neutral molecules within the particles. This reduces the effects of contamination at the ion inlet 5 and in the mass spectrometer 8 thereafter.

[0064] In commonly used mass spectrometers 8 for analyzing liquid samples, maintaining high-sensitivity analysis over long periods of time poses challenges, such as shorter maintenance intervals due to the accumulation of contamination on the ion source caused by the measurement sample.

[0065] When charged droplets that are entrained in the vortex (vortex gas) introduced into the ion source chamber 4 from the vortex generator 1 have a larger particle diameter and are heavier, they are caught in the vortex and sorted in the direction of the vortex's movement. Therefore, by forming a vortex in a direction that intersects with the axis of the ion inlet 5, it is possible to prevent charged droplets that are large in particle diameter and heavy from being introduced from inside the ion source chamber 4 into the ion inlet 5. Note that the direction of the vortex's axis (moving direction) is the direction in which the central axis of the vortex faces.

[0066] Furthermore, according to this embodiment, the collision of the charged droplets with the vortex current allows the vortex current to accelerate the drying of the charged droplets. This allows for finer charged droplets than methods that do not generate vortex currents. This reduces contamination of the ion inlet 5 and the mass spectrometer 8 with non-ionized sample and impurities in the sample. As a result, the maintenance cycle of the mass spectrometer 8, which is constantly monitored, can be extended. This allows for stable operation of the mass spectrometer with constantly monitored conditions. In other words, according to this embodiment, an ion source that is stable over a long period of time and suitable for constantly monitored conditions can be provided. As described above, constantly monitored conditions mean that monitoring is performed continuously.

[0067] In this way, the charged droplets introduced into the ion source chamber 4 from the atomizer 3 are atomized by collision with the vortex gas, thereby improving sensitivity and preventing large-sized charged droplets (ions) from being introduced into the mass spectrometer 8 through the ion source inlet 5. This reduces the accumulation of dirt in the ion inlet 5 and the mass spectrometer 8. The vortex gas introduced into the ion source chamber 4 from different axes and the generated ions are subjected to forces of the forward motion component and the rotational motion component formed by the vortex. By setting an appropriate flow rate of the vortex gas, the user can selectively move only the atomized ions to the ion inlet 5.

[0068] In particular, since the axis of the ion inlet 5 and the axis of the vortex (vortex gas) form an angle of approximately 90°, charged droplets with large particle diameters are less likely to move toward the ion inlet 5. This further reduces contamination of the ion inlet 5 and the mass spectrometer 8 by non-ionized sample and impurities in the sample.

[0069] In the ESI ion source Z of this embodiment, charged droplets sprayed by the ion source spray unit 311 included in the ESI ion source Z are dried by colliding with the vortex gas and heating gas. As a result, the drying of the charged droplets is accelerated and they are atomized. Ions generated as a result of atomization of the charged droplets move toward the ion inlet 5 due to the electric field formed between the ion source chamber 4 and the ion inlet 5. On the other hand, charged droplets that do not collide with the vortex or are not ionized do not move toward the ion inlet 5 of the mass spectrometer 8.

[0070] The inside of the ion source chamber 4 is maintained at approximately atmospheric pressure by the exhaust unit 401. In this way, when ionization is performed at atmospheric pressure, the ion source spray unit 311 may be installed so that the collision position between the ionization region where ions are generated and the vortex flow is spaced apart from the ion inlet 5. In such a configuration, the electric field strength applied to the ions is reduced. As the electric field strength is reduced, ions with large particle diameters and heavy particles cannot be moved by the electric field. Therefore, only the finely divided ions move along the electric field and are introduced from the inside of the ion source chamber 4 into the ion inlet 5 and the mass spectrometer 8.

[0071] Furthermore, by providing the atomization device 3 above the ion source chamber 4, the charged droplets can be introduced into the ion source chamber 4 from the atomization device 3 by gravity. This allows the charged droplets to be introduced into the ion source chamber 4 from the atomization device 3 more efficiently.

[0072] It is possible to change the flow rate of the vortex (vortex gas) generated by the vortex generator 1 and the flow rate of the heating gas by the heating device 2. The flow rate of the vortex gas and the flow rate of the heating gas are changed by the control device 6 controlling the vortex gas delivery pump 702 and the heating gas delivery pump 712 as shown in FIG.

[0073] Furthermore, in the ESI ion source Z, where the measurement sample is continuously supplied, the flow rate of the solvent dissolving the sample can change. For example, in sewerage monitoring, the flow rate is several liters per hour when there are no fluctuations due to seasonal fluctuations or increases in the number of users or businesses at the treatment facility. However, seasonal fluctuations or increases in the number of users or businesses at the treatment facility can change the sample flow rate and solvent composition.

[0074] If the solvent composition changes, the particle size of the ions generated by the ESI ion source Z changes. If the particle size changes, the force that the charged droplets generated by the ion source spray unit 311 receive from the vortex changes. In this case, to perform stable measurements, the control device 6 increases the supply amount (flow rate) of the heating gas for drying the charged droplets and changes the flow rate of the vortex gas that causes the charged droplets to collide with the charged droplets in accordance with the flow rate fluctuations. In this way, it is possible to optimize the flow rate and flow rate of the vortex gas and heating gas, enabling stable analysis by the mass spectrometer 8 over a long period of time.

[0075] Another example is a change in the composition of the solvent dissolving the sample. For example, in sewer monitoring, the solvent composition when no organic solvent is mixed in is approximately 100% water. However, it is possible that a few percent to several tens of percent of organic solvent is mixed into the solvent. It is known that when the solvent composition changes in this way, the size of the ions generated by the ESI ion source Z changes. When the size of the ions changes, the velocity of the ions in the rotation direction and the velocity in the forward direction also change. In order to perform stable measurements in this case as well, stable monitoring can be achieved by having the control device 6 change the flow rate of the vortex gas that collides with the charged droplets according to the solvent composition.

[0076] In this way, the vortex generated by the vortex generator 1 plays an important role in the desolvation process and the ionization process.

[0077] 1 and 2, the heater 2 and the vortex generator 1 are disposed opposite each other with the ion source chamber 4 in between. Heated heating gas is then introduced from the heater 2 into the ion source chamber 4. This promotes the drying of the charged droplets. Note that the heating gas is introduced into the center of the vortex (reference C in FIG. 7), so it has little effect on the vortex.

[0078] The heating device 2 accelerates the drying of the charged droplets, which also accelerates the drying of the charged droplets with larger particle sizes, resulting in fewer large-sized charged droplets remaining. Furthermore, even if the amount of sample increases, the amount of unionized charged droplets can be reduced by accelerating the drying of the charged droplets. This allows the mass spectrometer 8 to achieve long-term stability.

[0079] In this way, the control device 6 can increase the heating temperature by the heater 2 according to the liquid volume, or increase the angular velocity of the vortex flow, thereby increasing the energy at the time of collision. This can also promote the miniaturization of charged droplets. In this way, the mass spectrometry system Y of this embodiment can maintain the monitoring value within a certain range even when conditions change during continuous monitoring.

[0080] In addition, if the control device 6 is equipped with a display device 604 (see Figure 6), the user can check the configuration of the ESI ion source Z and the conditions for introducing the vortex gas from the vortex generator 1 into the ion source chamber 4 using a GUI (Graphical User Interface) or the like.

[0081] The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment having all of the described configurations.

[0082] Furthermore, the above-described configurations, functions, vortex gas flow rate control unit 611 to temperature control unit 613, storage device 602, etc. may be partly or entirely implemented in hardware by, for example, designing them as integrated circuits. Also, as shown in Fig. 6, the above-described configurations, functions, etc. may be implemented in software by a processor such as a CPU interpreting and executing a program that implements each function. Information such as the programs, tables, and files that implement each function can be stored in a memory 610, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC (Integrated Circuit) card, an SD (Secure Digital) card, or a DVD (Digital Versatile Disc). In addition, in each embodiment, the control lines and information lines shown are those that are considered necessary for explanation, and not all control lines and information lines in the product are necessarily shown. In reality, it can be considered that almost all components are interconnected. [Explanation of symbols]

[0083] 1. Vortex generator 2 Heating device 3 Atomization device 4. Ion source chamber 5 Ion introduction port 6. Control device 8 Mass spectrometer 110 Vortex Guide 111 vortex gas inlet 120 Eddy current generation section 121 Notch 131 Distribution path 132 Cavity 141 energized gas flow passage 201 Gas inlet 301 Sample inlet 311 Ion source spray section 401 Exhaust section 611 Swirl gas flow control unit 612 Heating gas flow control unit 613 Temperature control unit 701 Vortex gas storage tank 702 Vortex gas delivery pump 711 Heating gas storage tank 712 Heating gas delivery pump A1 code (vortex gas) A2 Arrow (heating gas) A3 code C code L sign (charged droplet) Y Mass Spectrometer System Z ESI ion source

Claims

1. an atomizer that supplies a sample to be analyzed by a mass spectrometer as charged droplets; an ion source chamber in which the charged droplets introduced from the atomizer are ionized; an ion inlet for introducing ions generated as a result of ionization of the charged droplets into the mass spectrometer; a vortex generator that generates a vortex and introduces the generated vortex into the ion source chamber; and The axis of the ion inlet and the axis of the vortex introduced into the ion source chamber from the vortex generator intersect at a predetermined angle. ESI ion source.

2. The predetermined angle is approximately 90°.

2. The ESI ion source of claim 1.

3. a heating device for drying the charged droplets introduced from the atomizing device into the ion source chamber; 10. The ESI ion source of claim 1, comprising:

4. the heating device heats a heating gas that is a gas flowing inside the heating device and introduces the heated heating gas into the ion source chamber, The heating device and the vortex generator are coaxially arranged and face each other across the ion source chamber.

4. The ESI ion source of claim 3.

5. The atomizer is provided on the top of the ion source chamber.

2. The ESI ion source of claim 1.

6. an ESI ion source that generates ions by ionizing a sample; a mass spectrometer for analyzing the ions produced by the ESI ion source; Equipped with The ESI ion source comprises: an atomizer that supplies a sample to be analyzed by the mass spectrometer as charged droplets; an ion source chamber in which the charged droplets introduced from the atomizer are ionized; an ion inlet for introducing ions generated as a result of ionization of the charged droplets into the mass spectrometer; a vortex generator that generates a vortex and introduces the generated vortex into the ion source chamber; Equipped with The axis of the ion inlet and the axis of the vortex introduced into the ion source chamber from the vortex generator intersect at a predetermined angle. A mass spectrometry system comprising:

7. The predetermined angle is approximately 90°.

7. The mass spectrometry system according to claim 6.

8. A control device capable of controlling the flow rate and flow velocity of the vortex flow The mass spectrometry system according to claim 6, comprising:

9. a heating device for drying the charged droplets introduced from the atomizing device into the ion source chamber; 7. The mass spectrometry system according to claim 6.

10. the heating device heats a heating gas that is a gas flowing inside the heating device and introduces the heated heating gas into the ion source chamber, The heating device and the vortex generator are coaxially arranged and face each other across the ion source chamber. The mass spectrometry system according to claim 9 .

11. a control device capable of controlling the flow rate and flow velocity of the heating gas; The mass spectrometry system according to claim 10, comprising:

12. a control device capable of controlling the temperature of the heating device; The mass spectrometry system according to claim 9, comprising:

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