WO2018100621A1

WO2018100621A1 - Ionizer and mass spectrometer

Info

Publication number: WO2018100621A1
Application number: PCT/JP2016/085353
Authority: WO
Inventors: 学上田
Original assignee: 株式会社島津製作所
Priority date: 2016-11-29
Filing date: 2016-11-29
Publication date: 2018-06-07

Abstract

Provided are an ionizer and a mass spectrometer in which a standard sample supply unit (21) for introducing a standard sample into an ionizing chamber in which the atmosphere is at approximately atmospheric pressure comprises: a sample container (213) in which a standard sample is accommodated; a gas flow path (212); a sample flow path (214) having one end connected to an intermediate location in the gas flow path (212) and the other end connected to the sample container (213); and a gas supply unit (211) that supplies a gas within the gas flow path (212). When gas is supplied within the gas flow path (212) from the gas supply unit (211), the sample within the sample container (213) is aspirated via the sample flow path (214) by the Venturi effect, mixed with the flow of gas, and introduced into the ionizing chamber. Solvent molecule ions are generated in the ionizing chamber by the ESI method or the like and sample component molecules are ionized by an ion-molecule reaction. As a result, components derived from a standard sample are stably introduced into the ionizing chamber by a route differing from that of an ionizing probe and it is possible to ionize the components.

Description

Ionizer and mass spectrometer

The present invention relates to an ionizer that ionizes components in a sample and a mass spectrometer equipped with the ionizer, and more specifically, an ionizer suitable for an ion source such as a mass spectrometer and an ion mobility meter, and the ionizer. The present invention relates to a mass spectrometer provided.

In a liquid chromatograph mass spectrometer (LC-MS) using a mass spectrometer as a detector of a liquid chromatograph (LC), electrospray ionization is used to ionize a liquid sample containing components separated by an LC column. An atmospheric pressure ion source using an (ESI) method, an atmospheric pressure chemical ionization (APCI) method, an atmospheric pressure photoionization (APPI) method or the like is used. When performing normal analysis in LC-MS, the eluate from the LC column is introduced into the mass spectrometer. When tuning or calibrating each part of the mass spectrometer, A standard sample of known type and concentration is introduced directly into the mass spectrometer.

As a method for introducing a standard sample into an atmospheric pressure ion source of a mass spectrometer, a pressurized liquid feeding method described in Patent Document 1 is conventionally known. In the pressurized liquid feeding method, an inert gas (for example, nitrogen gas) having a predetermined pressure is introduced through a pressure tube into the inner space of the container above the liquid level of the sealed container containing the standard sample solution. On the other hand, the other end of the liquid feeding tube having one end inserted below the liquid surface of the standard sample solution is connected to an ionization probe of the mass spectrometer. The pressurized gas introduced into the internal space of the sealed container pushes down the liquid level of the standard sample solution, whereby the standard sample solution is fed to the ionization probe through the liquid feeding tube.

In the pressurized liquid feeding method, the standard sample solution is fed in a state where the pressurized inert gas is sealed in a sealed container. For this reason, as the gas pressure in the container decreases as the liquid level decreases, the amount of liquid fed gradually decreases, and the standard sample solution cannot be fed to the ionization probe at a constant flow rate. In addition, when the liquid feeding is continued for a certain long time, for example, every time the liquid level is lowered by a predetermined height, the operator needs to introduce an inert gas into the container. there were.

Further, in the pressurized liquid feeding method, when the standard sample solution is fed, the standard sample solution does not reach the ionization probe until the flow path in the liquid feeding tube is filled with the standard sample solution. Therefore, even if the standard sample solution starts to be fed, it is necessary to wait for a certain amount of time (for example, 1 minute) until the standard sample solution is introduced into the ionization probe and the components in the sample are ionized. Inefficient.

In addition, in the conventional standard sample introduction method, since a standard sample solution is introduced into an ionization probe to ionize components in the sample, an elution with one end connected to the LC column outlet is performed when tuning is performed. It was necessary for the operator to change the piping so that the liquid feeding pipe having one end connected to the standard sample container was connected to the ionization probe instead of the liquid piping. Further, in order to eliminate such reconnection work, it is necessary to provide a valve for switching the flow path in the pipe between the LC column outlet and the ionization probe.
Such pipe reconnection is very troublesome and reduces the efficiency of analysis work. On the other hand, if a flow path switching valve is provided, the cost of the apparatus increases. In addition, a standard sample and a liquid chromatograph are used for the piping inside the ionization probe and the piping connecting the ionization probe and the flow path switching valve. There is also a problem of contamination because the eluate from

Furthermore, in the conventional standard sample introduction method, only a liquid standard sample can be introduced into the ion source. For example, a gaseous standard sample volatilized from a solid standard sample cannot be introduced into the ion source. could not.

International Publication No. 2009/141847 Pamphlet

The present invention has been made in view of the above problems, and the main purpose thereof is a component in a standard sample introduced at a stable flow rate over a long period of time without performing complicated work such as additional introduction of gas. By providing an ionizer that can quickly ionize components in the sample by introducing the standard sample when it is desired to use the standard sample for tuning the mass spectrometer, etc. is there.

An ionization apparatus according to the present invention, which has been made to solve the above problems,
a) a sample container containing a liquid sample or gas sample;
b) a gas flow path through which gas flows, a sample flow path having one end connected in the middle of the gas flow path and the other end connected to the sample container, and a gas supply for feeding gas into the gas flow path A liquid sample or a gas sample in the sample container through the sample channel by the venturi effect by the gas fed from the gas supply unit into the gas channel and mixed with the gas flow A sampling part to perform,
c) an ionization unit that introduces at least a part of a gas mixed with a liquid sample or a gas sample in the sample collection unit and ionizes components in the gas;
It is characterized by having.

Here, although the gas sample itself can be stored in the sample container, a solid sample or a liquid sample can be put in the sample container, and a component volatilized from these samples can be used as the gas sample.

In the ionization apparatus according to the present invention, when, for example, a component in a liquid sample contained in a sample container is ionized, a gas is supplied at a predetermined flow rate from the gas supply unit to the gas flow path in the sample collection unit. This gas is preferably an inert gas such as nitrogen. The gas flows in the gas flow path, but a sample flow path communicating with the sample container is connected in the middle of the gas flow path, and the connection portion is in a decompressed state in accordance with Bernoulli's law of conservation of energy. As a result, a venturi effect occurs, and the liquid sample in the sample container is sucked to the gas channel side through the sample channel and mixed with the gas flowing in the gas channel. In this way, the gas mixed with the liquid sample is introduced into the ionization unit, and components in the liquid sample are ionized in the ionization unit. The same applies when a gas sample is stored in the sample container. Note that the gas mixed with the sample in the sample collection unit may be entirely introduced into the ionization unit, or only part of the gas may be branched and introduced into the ionization unit.

In the ionization apparatus according to the present invention, the gas flow rate fed from the gas supply unit into the gas flow path is controlled to be substantially constant, whereby a substantially constant amount of sample is introduced into the ionization unit, and the components in the sample are removed. It can be ionized. Moreover, since the sample is mixed with the gas flow and introduced into the ionization section regardless of the liquid or gas, the sample-derived ions can be generated with almost no delay from the start of gas supply.

As an aspect of the ionization apparatus according to the present invention, the ionization unit includes a reaction ion generation unit that ionizes a predetermined liquid or gas to generate a reaction ion, and in the gas in which the liquid sample or the gas sample is mixed The component in the gas in which the liquid sample or the gas sample is mixed can be ionized by an ion-molecule reaction between the component and the reaction ion generated in the reaction ion generation unit.

For example, the reactive ion generation unit is configured to generate reactive ions by one or more of an electrospray ionization (ESI) method, an atmospheric pressure chemical ionization (APCI) method, or an atmospheric pressure photoionization (APPI) method. be able to.
Specifically, as these configurations, a dedicated ionization probe for the ESI method, APCI method, or APPI method conventionally used, or ionization and APCI by the ESI method as disclosed in Non-Patent Document 1 are used. An ionization probe that can simultaneously perform ionization by the method may be used.

As described above, such an ionization probe ionizes components in an externally supplied liquid sample such as an LC column. However, by supplying a liquid sample containing only a solvent or a mobile phase, the solvent or mobile phase is used. The reaction ion derived from can be produced | generated. In the ionization apparatus having such a configuration, when analyzing a target liquid sample, the gas supply from the gas supply unit in the sample collection unit is stopped and the sample is stored in the sample container. Is stopped and components in the liquid sample supplied to the ionization probe may be ionized. On the other hand, when tuning a device using a standard sample, a liquid sample of only a solvent or only a mobile phase is supplied to the ionization probe, and gas from the gas supply unit in the sample collection unit to the gas channel is supplied. What is necessary is just to ionize the component in this sample by implementing supply and introducing the standard sample accommodated in the sample container into the ionization part.

In this way, the liquid sample introduction path and the standard sample introduction path, which are the purpose of analysis into the ionization section, can be separated, and there is no need to reconnect the pipes between them or to switch the flow path using a valve. In addition, contamination of both samples can be avoided.

As another aspect of the ionization apparatus according to the present invention,
The ionization unit includes a thermoelectron generation unit that generates thermoelectrons, and the thermoelectrons generated by the thermoelectron generation unit are brought into contact with components in the gas in which the liquid sample or gas sample is mixed. May be ionized by an electron ionization (EI) method.

However, ionization by ion-molecule reaction using ions generated by the above ESI method, APCI method or the like is possible in an atmospheric pressure atmosphere, but ionization by the EI method using thermoelectrons is performed in a vacuum atmosphere. There is a need. Therefore, a vacuum that is communicated with the chamber through a small-diameter opening or channel and not evacuated by a vacuum pump, rather than in a chamber at approximately atmospheric pressure to which a gas mixed with a sample is supplied through the gas channel. A thermoelectron generator may be provided indoors. In this configuration, since ionization is performed by the EI method, fragment ions (product ions) are easily generated instead of molecular ions. For example, even when a standard sample containing one kind of known component is used, the mass-to-charge ratio derived from the component is different. Multiple types of fragment ions can be obtained. Thereby, when tuning a mass spectrometer etc. using the ion derived from a standard sample, it is possible to perform tuning at a plurality of different mass-to-charge ratio values.

The ionization apparatus according to the present invention may further include an ion dissociation unit that dissociates ions derived from the sample components ionized by the ionization unit.

As an ion dissociation method in the ion dissociation part, for example, collision induced dissociation (CID), in-source CID, electron transfer dissociation (ETD), electron capture dissociation (ECD), or the like can be used. These ion dissociations may be performed not in a chamber at approximately atmospheric pressure but in a vacuum chamber evacuated as described above. Even with this configuration, multiple types of product ions with different mass-to-charge ratios can be obtained from one type of component. Therefore, when tuning a mass spectrometer or the like using ions derived from a standard sample as described above. Tuning at a plurality of different mass-to-charge ratio values can be performed.

In the ionization apparatus according to the present invention, it is preferable that the gas supplied into the gas flow channel at the outlet end of the gas flow channel for introducing the gas mixed with the liquid sample or the gas sample into the ionization unit. A valve body may be provided that is pushed by the flow to open the outlet end and closes the outlet end in a state where the gas flow is stopped.

According to this configuration, when the sample contained in the sample container is not introduced into the ionization unit, the gas flow path and the ionization unit can be blocked by the valve body. Therefore, when components in the liquid sample to be analyzed are ionized in the ionization section, it is possible to prevent molecules of the components and ions derived from the components from entering the gas flow path. Thereby, when ionizing the component in the standard sample accommodated in the sample container, the contamination by the component in the liquid sample to be analyzed can be avoided.

The mass spectrometer according to the present invention is characterized in that any of the above-described ionizers according to the present invention is provided as an ion source. That is, the mass spectrometer according to the present invention is an atmospheric pressure ionization mass spectrometer that ionizes components in a liquid sample at approximately atmospheric pressure and performs mass analysis. For example, a liquid chromatograph mass spectrometer combined with a liquid chromatograph Can be configured.

According to the ionization apparatus and the mass spectrometer according to the present invention, a stable flow rate can be obtained over a long period of time without performing complicated work such as additional introduction of gas required in the conventional pressurized liquid feeding method. A sample such as a standard sample can be introduced into the ionization section, and components in the sample can be ionized. Regardless of whether the sample is liquid or gas, the sample is mixed with the gas flow and introduced into the ionization unit. Therefore, a standard sample can be quickly introduced into the ionization unit during device tuning. Components in the sample can be ionized and subjected to analysis. Thereby, operations such as device tuning can be performed efficiently.

The block diagram of the principal part of the mass spectrometer which is one Example of this invention. The schematic block diagram of the standard sample supply part in the mass spectrometer of a present Example. The schematic block diagram of the modification of a standard sample supply part. The schematic block diagram of the other modification of a standard sample supply part. The block diagram of the principal part of the mass spectrometer which is another Example of this invention. The partial block diagram of the principal part of the mass spectrometer which is another Example of this invention.

An embodiment of a mass spectrometer equipped with an ionization apparatus according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a configuration diagram of a main part of the mass spectrometer of the present embodiment, and FIG. 2 is a schematic configuration diagram of a standard sample supply unit 21 in the mass spectrometer of the present embodiment.

As shown in FIG. 1, in the mass spectrometer of the present embodiment, an ionization chamber 11 having a substantially atmospheric pressure atmosphere and an analysis chamber 14 maintained in a high vacuum atmosphere by a high performance vacuum pump (not shown) are provided in the housing 10. And the 1st intermediate | middle vacuum chamber 12 and the 2nd intermediate | middle vacuum chamber 13 which are between these ionization chambers 11 and the analysis chambers 14, and whose vacuum degree is increasing in steps are formed. That is, the mass spectrometer of this embodiment has a multistage differential exhaust system configuration. An ionization probe 20 is provided as an ion source in the ionization chamber 11, and the ionization chamber 11 and the first intermediate vacuum chamber 12 communicate with each other through a small-sized desolvation tube 23.

In the first intermediate vacuum chamber 12 and the second intermediate vacuum chamber 13, ion guides 24 and 26 are provided for transporting ions to the subsequent stage while converging ions, respectively. The chamber 13 is separated by a skimmer 25 having a small hole at the top. Also, in the analysis chamber 14, there are a quadrupole mass filter 27 that separates ions according to the mass-to-charge ratio m / z, and an ion detector 28 that detects ions that have passed through the quadrupole mass filter 27. Has been placed. The configuration of each part can be changed as appropriate, such as replacing the quadrupole mass filter 27 with an orthogonal acceleration time-of-flight mass analyzer.

Next, a typical mass spectrometry operation in the mass spectrometer of the present embodiment will be described. An eluate eluted from a column of a liquid chromatograph (LC) (not shown) is introduced into the ionization probe 20 of the mass spectrometer of the present embodiment. This eluate contains various components separated in the time direction by the LC column. This component is a sample for analysis in the mass spectrometer of this example.

The ionization probe 20 ionizes components contained in a liquid sample supplied from the outside by the ESI method. In other words, the eluate that has reached the ionization probe 20 is sprayed into the ionization chamber 11, which is an atmosphere at substantially atmospheric pressure, with the help of the nebulizing gas as charged droplets having a biased charge. The charged droplet ejected from the ionization probe 20 is miniaturized by contacting with the surrounding gas, and the vaporization of the solvent in the droplet is promoted. The sample components contained in the charged droplets are ionized in the process of making the charged droplets finer and removing the solvent. A standard sample is supplied from a standard sample supply unit 21 via a sample introduction tube 22 to a region where charged droplets are sprayed from the ionization probe 20, that is, an ionization region in the ionization chamber 11. When the components in the eluate are analyzed as described above, the introduction of the standard sample into the ionization chamber 11 is stopped.

The generated ions derived from the sample components are sucked into the desolvation tube 23 by the air flow generated mainly by the pressure difference between the ionization chamber 11 and the first intermediate vacuum chamber 12, and then flowed into the first intermediate vacuum chamber 12. Sent. The desolvation tube 23 is heated by a heater (not shown), and the desolvation of the charged droplets is promoted inside the desolvation tube 23 to generate ions derived from the sample components. In the first intermediate vacuum chamber 12, the ions are converged by the ion guide 24, sent to the second intermediate vacuum chamber 13 through a small hole at the top of the skimmer 25, and further converged by the ion guide 26 and sent to the analysis chamber 14.

A predetermined voltage is applied to the four rod electrodes constituting the quadrupole mass filter 27 from a power source (not shown), and only ions having a mass-to-charge ratio corresponding to the voltage pass through the quadrupole mass filter 27 and are ionized. The light enters the detector 28. The ion detector 28 outputs a detection signal corresponding to the amount of incident ions. Therefore, for example, when the voltage applied to the rod electrode constituting the quadrupole mass filter 27 is scanned within a predetermined range, the mass-to-charge ratio of ions that can pass through the quadrupole mass filter 27 is scanned within the predetermined mass-charge ratio range. Is done. A data processor (not shown) can obtain a mass spectrum indicating the signal intensity of ions over a predetermined mass-to-charge ratio range based on the detection signals sequentially obtained at this time.

In the mass spectrometer of the present embodiment, for example, prior to the execution of the analysis as described above, tuning for optimizing the voltage applied to each part such as the ion guides 24 and 26 is performed. In that case, not the component in the liquid sample supplied to the ionization probe 20 but the component in the standard sample introduced through the sample introduction tube 22 is utilized.
As shown in FIG. 2, the standard sample supply unit 21 includes a sample container 213 in which a standard sample solution is stored, a gas flow channel 212, one end immersed in the standard sample solution in the sample container 213, and the other end gas. A sample channel 214 connected in the middle of the channel 212 and a gas feeding unit 211 that feeds gas at a predetermined flow rate into the gas channel 212 are included. The end (the right end in FIG. 2) of the gas flow path 212 opposite to where the gas is introduced is connected to the sample introduction tube 22 opened in the ionization chamber 11.

The standard sample supply unit 21 sucks and feeds the standard sample solution in the sample container 213 using the venturi effect caused by the gas flowing in the gas flow path 212.
The commonly known Bernoulli equation expresses the law of conservation of energy per unit mass of fluid, and is expressed by the following equation (1).
(1/2) v ² + (P / ρ) = constant (1)
Here, v is the velocity of the fluid, P is the pressure of the fluid, and ρ is the density of the fluid. From this equation, it can be seen that the pressure decreases as the fluid velocity increases.

Now, in the standard sample supply unit 21 shown in FIG. 2, an inert gas such as nitrogen is allowed to flow from the gas supply unit 211 into the gas flow path 212. At this time, if the pressure at the connection portion of the sample channel 214 to the gas channel 212 is P1, and the pressure in the upper space in the sample container 213 is P2, P1 <P2 from Bernoulli's energy conservation law. That is, a pressure difference P 1 -P 2 occurs at both ends of the sample channel 214, and the standard sample solution stored in the sample container 213 is sucked up by this pressure difference, and the standard sample solution passes through the sample channel 214. It is introduced into the gas flow path 212. The standard sample solution is mixed with the gas flowing in the gas channel 212 and introduced into the ionization chamber 11. The gas supplied from the gas supply unit 211 is preferably a high-temperature dry gas. When the sucked standard sample solution is mixed with such dry gas, the solvent in the solution is easily vaporized, and the gas molecules of the standard sample can be introduced into the ionization chamber 11.

At this time, the ionization probe 20 is supplied with only a liquid sample containing no substantial sample component, for example, a mobile phase used in LC. This sample is electrostatically sprayed from the ionization probe 20 to generate a large amount of solvent molecular ions. That is, many solvent molecular ions exist as reaction ions in the region where the standard sample components are introduced into the ionization chamber 11 together with the gas through the sample introduction tube 22. Therefore, the component molecules derived from the standard sample come into efficient contact with the solvent molecular ions and are ionized by the ion-molecule reaction. The ions derived from the standard sample thus generated are sucked into the desolvation tube 23 on the air flow generated mainly by the pressure difference between the ionization chamber 11 and the first intermediate vacuum chamber 12, and sent to the subsequent stage for mass analysis. To be served.

As described above, when it is necessary to use a standard sample, for example, for device tuning or mass calibration, the components in the standard sample are ionized and massed in the ionization chamber 11 instead of the eluate from the LC column. Can be used for analysis. By maintaining the flow rate of the gas supplied from the gas supply unit 211 to the gas flow path 212 substantially constant, a substantially constant amount of the standard sample can be introduced into the ionization chamber 11. In addition, since the time taken for the gas delivered from the gas delivery unit 211 to pass through the gas flow path 212 and reach the ionization chamber 11 is short, it will enter the ionization chamber 11 without much time delay from the start of gas delivery. The introduction of standard samples can be started. In addition, the standard sample introduction path to the ionization chamber 11 is completely different from the path through which the eluate is sent from the LC column outlet to the ionization probe. There is no need to switch roads. In addition, contamination caused by the sample remaining in the channel can be avoided.

In the above embodiment, the ionization probe 20 performs ionization by the ESI method. However, it should be understood that the ionization probe 20 may perform ionization by the APCI method or the APPI method. Further, like the DUIS probe described in Non-Patent Document 1, ionization by a plurality of mechanisms may be performed simultaneously. In any case, any solvent molecular ion that can be used for the ion-molecule reaction may be supplied to the ionization chamber 11.

In the above embodiment, the standard sample solution was accommodated in the sample container 213. As the standard sample solution, PEG (polyethylene glycol), PFTBA (perfluorotributylamine) or the like dissolved in water or methanol can be used. Alternatively, a volatile solid sample may be accommodated in the sample container 213, and a sample component that volatilizes from the solid sample, that is, a gas sample may be mixed into a gas flow and introduced into the ionization chamber 11. As such a solid sample, vacuum grease or the like can be used. Further, a sample component that volatilizes from a volatile liquid sample stored in the sample container 213 may be introduced into the ionization chamber 11 in a gas flow. When a gas sample volatilized from a solid sample or a liquid sample is sucked up using the venturi effect, one end of the sample channel 214 may be simply connected to the upper portion of the sample container 213.

When such a volatile solid sample or liquid sample is used, the amount of evaporation from the solid sample or liquid sample and the gas flow in the gas channel 212 based on the vapor pressure and pressure difference (P2-P1) of the solid sample. The amount of sample mixed in can be adjusted. The sample mixing amount can also be adjusted by changing to a solid sample having a different vapor pressure, changing the inner diameter of the gas flow path 212, changing the gas flow rate, or the like.

In addition, it is more effective for the sample suction due to the above-mentioned venturi effect to have a larger pressure difference (P2-P1). For this purpose, it is necessary to reduce the pressure P1 in the vicinity of the connection between the gas channel 212 and the sample channel 214. There is. In order to lower the pressure P1, the gas flow rate at the connection is preferably increased. FIG. 3 is a schematic configuration diagram of a modified example of the standard sample supply unit 21. In this example, the inner diameter of the gas channel 212 is made smaller in the vicinity of the connecting portion of the sample channel 214 than on both sides thereof. Thereby, the flow velocity of the gas passing through the vicinity of the connection portion is increased, and the pressure is decreased, so that the sample is easily sucked up.

Further, the gas flow path 212 does not need to be continuous in the gas flow direction. FIG. 4 is a schematic configuration diagram of another modification of the standard sample supply unit 21. In this example, the gas flow channel 212 is divided into a first gas flow channel 212A and a second gas flow channel 212B, and the opposing ends of the two

flow channels

212A and 212B are both tapered nozzles. It is formed in a shape. The sample channel 214 is connected to a sealed connection chamber 212c provided so as to surround the facing portions of the two

channels

212A and 212B. As a result, the flow rate of the gas passing through the two

flow paths

212A and 212B is increased, and the pressure in the connection chamber 212c is reduced, so that the sample is easily sucked up.

In the mass spectrometer of the above embodiment, the component derived from the sample is basically ionized in the ionization chamber 11 which is an atmospheric pressure atmosphere. However, the gaseous sample component generated by desolvation in the ionization chamber 11 is used. It may be introduced into the first intermediate vacuum chamber 12 and ionized in the first intermediate vacuum chamber. In this case, an ionization method different from the atmospheric pressure ionization method can be used.

FIG. 5 is a configuration diagram of a main part of a mass spectrometer which is another embodiment of the present invention. The same components as those in the embodiment shown in FIG.
In this mass spectrometer, a thermoelectron generator 30 including a filament that generates thermoelectrons by supplying a heating current from the outside into the first intermediate vacuum chamber 12, and thermoelectrons emitted from the thermoelectron generator 30. The trap electrode 31 for receiving is disposed in pairs. When the thermoelectrons emitted from the thermoelectron generator 30 come into contact with the sample component molecules introduced into the first intermediate vacuum chamber 12, the component molecules are ionized by an electron ionization (EI) method.

Generally, at the time of device tuning and mass calibration, optimization and mass calibration are performed for each of a plurality of different mass-to-charge ratio values. Since fragmentation is likely to occur in ionization by the EI method, fragment ions having various mass-to-charge ratios are generated even if there is only one sample component. For example, by collecting the information by adjusting the voltage applied to, for example, an ion guide so that the detection signal is maximized for each fragment ion having different mass-to-charge ratio values thus generated, one or Tuning with high accuracy is possible by using a standard sample containing only a small number of components. The same applies to mass calibration using a standard sample.

In addition, in order to obtain the same effect as described above, sample components are ionized in the ionization chamber 11 and then dissociated in the first intermediate vacuum chamber 12 to generate product ions having various mass-to-charge ratios. You may make it do. In that case, for example, in-source CID is generated in the first intermediate vacuum chamber 12, a collision cell is disposed in the first intermediate vacuum chamber 12, and CID is generated in the collision cell, or ETD or ECD is generated. The sample component ions may be dissociated by utilizing the above.

Further, in the mass spectrometer having the above-described configuration, a part of the liquid sample electrostatically sprayed from the ionization probe 20 during normal analysis enters the inside of the sample introduction tube 22 to contaminate the inside of the pipeline and cause contamination. It may be a cause. Therefore, in order to avoid this, as shown in FIG. 6, a valve body 22 a that can be swung by a hinge or the like is provided on the end surface of the sample introduction tube 22 opened in the ionization chamber 11. When the gas is not supplied from the gas supply unit 211 into the gas flow path 212, the valve body 22a closes the end surface of the sample introduction tube 22 as shown in FIG. Thereby, the space in the gas flow path 212 and the space in the ionization chamber 11 are blocked by the valve body 22a. On the other hand, when gas is supplied from the gas supply unit 211 into the gas flow path 212, as shown in FIG. 6B, the valve body 22a is opened by the pressure of the gas, and the gas accompanying the sample is ionized. It is introduced into the chamber 11. Thus, in the mass spectrometer having this configuration, it is possible to prevent fine droplets and the like existing in the ionization chamber 11 from entering the gas flow path 212.

It should be noted that the above embodiment is merely an example of the present invention, and it is obvious that modifications, changes, additions and the like as appropriate within the scope of the present invention are included in the scope of the claims of the present application.

DESCRIPTION OF SYMBOLS 10 ... Housing 11 ... Ionization chamber 12 ... 1st intermediate | middle vacuum chamber 13 ... 2nd intermediate | middle vacuum chamber 14 ... Analysis chamber 20 ... Ionization probe 21 ... Standard sample supply part 211 ...

Gas feed part

212, 212A, 212B ... Gas flow path 213 ... Sample container 214 ... Sample flow path 22 ... Sample introduction tube 22a ... Valve body 23 ...

Desolvation tubes

24, 26 ... Ion guide 25 ... Skimmer 27 ... Quadrupole mass filter 28 ... Ion detector 30 ... Thermoelectron generator 31 ... Trap electrode

Claims

a) a sample container containing a liquid sample or gas sample;
b) a gas flow path through which gas flows, a sample flow path having one end connected in the middle of the gas flow path and the other end connected to the sample container, and a gas supply for feeding gas into the gas flow path A liquid sample or a gas sample in the sample container through the sample channel by the venturi effect by the gas fed from the gas supply unit into the gas channel and mixed with the gas flow A sampling part to perform,
c) an ionization unit that introduces at least a part of a gas mixed with a liquid sample or a gas sample in the sample collection unit and ionizes components in the gas;
An ionization apparatus comprising:
The ionization apparatus according to claim 1,
The ionization unit includes a reaction ion generation unit that ionizes a predetermined liquid or gas to generate a reaction ion, and is generated by the component in the gas mixed with the liquid sample or the gas sample and the reaction ion generation unit. An ionization apparatus characterized by ionizing a component in a gas mixed with the liquid sample or gas sample by an ion-molecule reaction with a reaction ion.
The ionization apparatus according to claim 2,
The ionization apparatus, wherein the reaction ion generation unit generates reaction ions by any one or more of an electrospray ionization method, an atmospheric pressure chemical ionization method, and an atmospheric pressure photoionization method.
The ionization apparatus according to claim 1,
The ionization unit includes a thermoelectron generation unit that generates thermoelectrons, and the thermoelectrons generated by the thermoelectron generation unit are brought into contact with components in the gas in which the liquid sample or gas sample is mixed. An ionizer characterized in that it is an electron ionizer.
The ionization apparatus according to claim 1,
An ionization apparatus further comprising: an ion dissociation unit that dissociates ions derived from the sample components ionized by the ionization unit.
The ionization apparatus according to claim 1,
The outlet end of the gas flow path for introducing the gas mixed with the liquid sample or the gas sample into the ionization section is pushed by the gas flow fed into the gas flow path to open the outlet end. The ionization apparatus further comprising: a valve body that closes the outlet end when the gas flow is stopped.
A mass spectrometer comprising the ionization apparatus according to any one of claims 1 to 6 as an ion source.