JP2000314726A - Liquid chromatograph combined mass spectrometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize ion molecule reaction of a sample and a solvent to attain liquid chromatograph combined mass spectrometry of high sensitivity by eccentrically arranging the center axis of a communicating path for mist flow from liquid chromatograph and the center of a pore. SOLUTION: A sample solution is poured from a pouring port 3, fed to an analysis column 5 by a moving phase 1, separated component by component, eluted and fed to an atomizer 6. Mist from the atomizer 6 passes through a vaporizer 8 and enters an atmospheric pressure ion source part 11. Since the center axis 12 of a communicating path for making mist flow pass through, and the center of a pore 14 are eccentrically arranged, an ion sampling axis 13 is near mist peripheral flow. Fine mist is thereby ionized to efficiently desorb added molecules from a solvent. Bare ion desorbed from the solvent by an intermediate pressure part 15 enters a mass analysis part 18 from a pore 16 and is subjected to mass dispersion and detected by a detector 19 to provide mass spectrum by a data processor 21 via a DC amplifier 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid chromatograph-coupled mass spectrometer for mass spectrometric analysis of an effluent from a liquid chromatograph.

[0002]

2. Description of the Related Art Mass spectrometers (hereinafter abbreviated as MS) are high-sensitivity analyzers that provide information on the molecular weight and structure of organic compounds. for that reason,
It is an indispensable analyzer in fields such as organic chemistry, pharmacy, and biochemistry. However, MS was unable to separate and identify the components of the mixture, and it was difficult to analyze the mixture when the mixture was to be analyzed. Therefore, using a liquid chromatograph (Liquid Chromatograph, hereinafter abbreviated as LC) which is excellent in separation and identification of a mixture,
A liquid chromatograph that combines and analyzes non-volatile substances, heat-labile substances, inorganic compounds, organic compounds, low-molecular substances, and high-molecular substances if they are soluble in a solvent. Direct mass spectrometer (hereinafter LC / M
Abbreviated as S. ) Was devised.

[0003] LC is an apparatus for dissolving a sample to be analyzed in a solvent and separating the components of this solution under atmospheric pressure.
On the other hand, MS is an apparatus for analyzing a sample ionized under high vacuum. Therefore, to combine them,
The solvent must be removed from the LC effluent (desolvation) and the sample left after desolvation must be ionized and fed to a mass spectrometer under high vacuum. A technique for coupling LC and MS is described in, for example, Japanese Patent Publication No. 58-43692. According to this technique, the effluent from the LC is atomized, the mist is desolvated and ionized, and the ionized sample (desolvated effluent) is subjected to mass spectrometry.

[0004]

When the effluent from the liquid chromatograph is atomized, the jet flow spreads like a spray, but relatively large droplets of mist gather near this center. In addition, relatively small droplets of fog gather around the periphery. As these fogs move, large droplets near the center have a large mass and a large kinetic energy, and are not significantly affected by air or the like. Therefore, it does not vaporize much, and the droplet diameter does not become so small. On the other hand, the mist of small droplets in the vicinity of the periphery has a small mass and a small kinetic energy, and is therefore directly affected by air and the like. Therefore, the diameter of the droplet is gradually reduced by repeating the collision with the fluid resistance and other droplets. When the droplet diameter becomes small in this way, it is greatly affected by air and the like,
Since the movement speed is slow, the time affected is long. As a result, small droplets near the periphery are increasingly vaporized and reduce the droplet size.

As described above, when the effluent from the liquid chromatograph is atomized, the mist of large droplets near the center does not change the diameter of the droplets so much as it moves, while small droplets near the periphery. Droplet fog increasingly reduces droplet size. Therefore, the dispersion of the droplet diameter becomes larger as a whole.

There is also known a technique for further miniaturizing an effluent (a sample, a solvent, and a mixed liquid) from an atomized chromatograph and removing the solvent therefrom. A heating method having a simple structure is often used for miniaturization of droplets. That is,
The droplet is heated by a vaporizer. The vaporizer is made of a metal block or the like having a built-in heater so that it can be heated substantially uniformly. For example, a vaporizer is such that a heater wire is wound around a quartz tube. The ejected spray flow (effluent from the chromatograph) is heated by radiant heat from the vaporizer while passing through the vaporization space surrounded by the vaporizer. The peripheral flow of the spray flow has a slower moving speed due to friction with the wall surface than the central flow, and can receive more heat because it is closer to the vaporizer wall surface. That is, the droplets in the peripheral part absorb infrared rays emitted from the surrounding wall,
The vaporization of the liquid from the surface of the droplet is greatly promoted, and the miniaturization of the droplet is promoted. Most of the infrared rays are consumed by the atomization of the mist in the peripheral stream and do not reach the center of the mist, and the droplets in the center cannot be heated sufficiently. For this reason, the diameter of the droplets in the peripheral portion is originally small due to spraying and diffusion, and the diameter of the droplets in the peripheral portion decreases rapidly due to absorption of more radiant heat. Conversely, droplets having a larger diameter are concentrated at the center. For this reason, the distribution width of the droplet diameter in the spray flow becomes larger during the movement in the vaporization space from the time of generation of the mist. In other words, even in the case where the size is reduced by the heating method, fine fog gathers in the peripheral portion, and more fog having a large diameter exists in the center portion.

Here, from the point of view of the breadth of application and the stability in the LC / MS interface, among the atmospheric pressure ionizations, particularly, the atmospheric pressure chemical ionization (Atmospheric Pressu).
reChemical Ionization, hereinafter abbreviated as APCI. ) Has attracted attention and has become widely used. For APCI, for example, Analytical Chemistry (An
alytical Chemistry), Vol.62, No.13 (199
0) P713A-P725A and Journal of Chromatogr Science
aphic Science). Vol.29 (1891) P357-3
66. In APCI, an effluent (mixture of a sample and a solvent) from a liquid chromatograph is atomized under atmospheric pressure, and the mist is subjected to a corona discharge (corona discharge needle electrode) at a high voltage of about 3 to 5 kV. And to expose. Thereby, first, the solvent molecules are ionized. The generated ions then repeat the ion molecule reaction with the sample molecules,
Finally, the sample molecules are ionized. The ionized sample is guided to a mass spectrometer under a high vacuum and subjected to mass analysis.

The effluent from the liquid chromatograph is atomized and supplied to the vicinity of the corona discharge needle electrode. As described above, if there is a large variation in the droplet diameter of the mist, a complicated flow is created. Due to this, the flow of fog around the corona discharge needle electrode constantly changes. As a result, the ion molecule reaction becomes unstable and the ionized sample cannot be stably supplied to the mass spectrometer.

[0009] Also in APCI, heating and atomizing the mist of the effluent of the liquid chromatograph is effective in promoting the subsequent ion molecule reaction. However, in this case, as described above, a large difference in density (variation in diameter of droplets) and a difference in temperature occur in the spray flow. When the jet flow having this temperature difference is supplied near the corona discharge needle electrode,
The temperature around the corona discharge needle electrode constantly changes, and again the ion molecule reaction becomes unstable. For this reason, the ionized sample cannot be stably supplied to the mass spectrometer, and high-sensitivity analysis becomes impossible.

An object of the present invention is to stabilize the mist of an effluent supplied from a liquid chromatograph to a corona discharge needle electrode,
Accordingly, it is an object of the present invention to stabilize the ion-molecule reaction between a sample and a solvent and to enable high-sensitivity LC / MS measurement.

[0011]

In order to achieve the above object, according to the present invention, an effluent from a liquid chromatograph is sprayed, the spray stream is heated and ionized, and the stream is guided through pores. In mass spectrometry, droplets around the spray flow were configured to be ionized.

[0012]

According to the above arrangement, the peripheral flow of the high-temperature spray flow having a high ratio of fine droplets can be selectively taken into the atmospheric pressure ion source and ionized. Further, generated ions (including cluster ions) are taken into the intermediate pressure portion, and desolvation is efficiently performed by accelerated collision dissociation due to an ion drift voltage.

A slight increase in temperature alleviates cooling due to adiabatic expansion and makes desolvation effective. As a result, chemical noise derived from cluster ions can be significantly reduced, and a high sensitivity distribution can be achieved. Even if the composition of the solvent changes momentarily by gradient analysis or the like, only the peripheral portion where the solution has been miniaturized is ionized and taken in, so that desolvation in the intermediate pressure chamber is efficiently performed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. 1 shows an LC / M according to an embodiment of the present invention.
It is explanatory drawing which shows S (including interface). FIG. 2 is an enlarged view of the nebulizer and the vaporizer. 1 and 2, reference numeral 1 denotes a mobile phase for separating sample components;
Is a pump, 3 is a sample inlet for injecting a sample solution, 4 is an analysis column, 6 is a sprayer, 7 is a spray space at atmospheric pressure, 8 is a vaporizer, 81 is a heater, 82 is a spiral insertion rod, and 9 is a vaporizer. Space 10 is a needle electrode for corona discharge to which high voltage is applied, 1
1 is an atmospheric pressure chemical ion source, 14 is a first pore for ion sampling, 15 is an intermediate pressure section, 16 is a second pore, 17 is a vacuum pump for exhausting the intermediate pressure section, 18 is a mass spectrometer. , 19 is a detector, 20 is a DC amplifier, 21 is a data processing unit, 22 is a vacuum pump for evacuating the mass analysis unit,
Numeral 30 indicates a central axis of the spray flow, and numeral 31 indicates a peripheral flow of the spray flow.

In FIG. 1, a mobile phase 1 (solvent) stored in a mobile phase tank is sent out by a pump 2. The sample solution is injected from the sample injection port 3 with a micro syringe or the like,
It is sent to the analytical column 4 by the continuously flowing mobile phase 1. The sent sample is separated and eluted for each component in the analysis column 4. The eluted components are sent to the atomizer 6 via a pipe.

There are various types of nebulizers. FIG. 2A shows an example of thermal spraying. The sprayer 6 includes a metal capillary 61 having an inner diameter of about 0.1 mm, a heat block 62 surrounding the metal capillary 61, a heater 63, a temperature sensor 64, and the like. The metal capillary 61 of the sprayer 6 is
The heating is performed through the heat block 62 controlled by the temperature sensor 64 and the temperature sensor 64. The eluate is sent to the metal capillary 61 and heated at a stretch to about 200 ° C., and is ejected from the tip of the metal capillary 61 into the spray space 7 at atmospheric pressure as a mist. This spray flow enters the heated vaporizing space 9 of the vaporizer 8 while gradually diffusing through the spraying space 7. At the time of this diffusion, the peripheral portion 3 is heated by the surroundings.
In FIG. 1, fine droplets are collected, and more droplets having a large diameter are present in the central portion 30. The details of this phenomenon will be described later. Returning to FIG. 1 again, the mist that has passed through the vaporizer 8 enters the atmospheric pressure ion source unit 11. Here 3 to 5k
The solvent molecules are first ionized by corona discharge generated from the tip of the corona discharge needle electrode to which a high voltage of about V is applied. The generated ions then repeat the ion-molecule reaction with the sample, eventually ionizing the sample molecules. Ions are introduced from the first pores 14 into the intermediate pressure section 15. At this time, the pressure changes from atmospheric pressure to medium vacuum, the ions are cooled, and cluster ions are generated. Here the first partition 1
The cluster ions are accelerated by the drift voltage V applied to 41 and the second partition 161 and collide with neutral molecules.
This collision is repeated many times, and a part of the energy of this collision is taken in, and the ions are heated and desorb the added molecules (desolvation by collision dissociation). Here, uniform and fine droplets (cluster ions) are efficiently desolvated. The deionized bare ions enter the mass spectrometer 18 through the second pores 16. Here, the mass dispersion is detected by the detector 19 and passed through the DC amplifier 20 to give a mass spectrum by the data processor 21.

Here, the basic configuration of the LC / MS interface of the APCI will be described.

The APCI LC / MS interface is mainly composed of (1) atomizing means, (2) atomizing means, (3)
Ionization means, (4) desolvation means for cluster ions,
(5) It is constituted by means for taking ions into the MS part. (1) Spray The solution (mixture of effluent / sample from the chromatograph and the solvent) is sprayed in the sprayer 6 into the spray space 7 at atmospheric pressure with the aid of gas flow, heating and ultrasonic vibration. Spraying is a good means to stably transfer many thermally labile substances present in a liquid to the gas phase. Fog is a mixture of gas and liquid. Even if the fog is heated, the temperature of the fog does not rise because heat is consumed by the heat of vaporization of the solvent until the fog completely vaporizes and turns into a gas. Therefore, there is an advantage that the thermally unstable substance can be stably transferred to the gas phase. Analysis column 4
The eluate from is sent to the metal capillary 61 and
It is heated to about 00 ° C. and is ejected from the tip of the metal capillary 61 into the spray space 7 at atmospheric pressure as a mist. The mist enters the heated vaporization space 9 of the vaporizer 8 while gradually diffusing through the spray space 7. Generally, the droplet diameter of the mist ejected from the metal capillary 61 is widely distributed from 100 μm to 1 μm. Since the diffusion speed of vaporized molecules and microdroplets is higher than that of relatively large droplets, as a result, these microdroplets are more present in the peripheral portion 31 of the spray flow. Conversely, large droplets exist near the center 30 of the spray flow. This situation is shown in FIG. (2) Fine atomization A huge droplet of about 100 μm prevents ionization and causes chemical noise in the subsequent process.
Therefore, large droplets need to be sufficiently miniaturized before ionization. For miniaturization of droplets, for example, a heating method having a simple structure is often used. Further, this heating has an effect of reducing the degree of cooling due to adiabatic expansion in the intermediate pressure chamber 15. As shown in FIG. 2, the vaporizer 8 is made of a metal block or the like containing a heater 81,
For example, the vaporizing space 9 formed with a diameter of about 5 mm and a length of about 50 mm can be heated substantially uniformly. Further, as shown in FIG. 3, the vaporizer 8 may be such that a heater wire 49 is wound around a quartz tube 50 having a length of about 50 mm and an inner diameter of about 5 mm. The vaporization space 9 is formed linearly so that the mist can smoothly reach the atmospheric pressure ion source 11. The spray flow ejected from the metal capillary 61 is heated by radiant heat from the vaporizer 8 while passing through the vaporization space 9. Here, the peripheral flow 31 of the spray flow
The moving speed is slower than the central flow 30 due to friction with the wall surface, and more heat is supplied because the moving speed is closer to the wall surface of the vaporizer 9. That is, the droplets in the peripheral portion 31 absorb the infrared rays emitted from the surrounding wall surface, and the vaporization of the liquid from the surface of the droplets is promoted to promote the miniaturization of the droplets. On the other hand, with respect to the central portion 30, most of the infrared rays are consumed by the miniaturization of the mist of the peripheral flow, and do not reach the central portion of the mist.
Are not sufficiently heated.

As described above, the diameter of the droplets in the peripheral portion is originally small due to the spraying and the diffusion, and the diameter of the droplets in the peripheral portion 31 is rapidly reduced by absorbing more radiant heat.
Conversely, droplets having a larger diameter are concentrated on the central portion 30.
Therefore, the distribution width (variation) of the droplet diameter in the spray flow is
It becomes larger as it moves through the vaporization space 9 from the time of fog generation. That is, the peripheral portion 31 has a high temperature and fine mist is collected, and the central portion 30 has a low temperature and more mist having a large diameter is present. This situation is shown in FIGS. 2A and 2B. (3) Ionization The fine mist passing through the vaporizer 8 and the vaporized solvent molecules enter the atmospheric pressure ion source unit 11 in a mixed state.
Here, the solvent molecules are first ionized by corona discharge generated from the tip of the corona discharge needle electrode 10 to which a high voltage of 3 to 5 kV is applied. The generated ions then repeat the ion molecule reaction with the sample molecules, eventually ionizing the sample molecules. (4) Desolvation of cluster ions Generated ions are
The intermediate pressure portion 1 evacuated by the vacuum pump 17 from the first fine hole 14 which constitutes one wall surface of the atmospheric pressure ion source 11 and is opened near the center of the partition wall 141 provided on the opposite surface of the vaporizer 8.
5 is introduced. The introduced ions are rapidly cooled by adiabatic expansion due to a sudden decrease in pressure, and form cluster ions to which polar molecules such as water are added. The cluster ions are accelerated by the ion drift voltage V applied between the partition walls 141 and 161 and repeatedly collide with neutral molecules. Part of the energy of this collision is taken into the inside, the cluster ions are heated, and the added molecules are removed. This is called desolvation by collisional dissociation. The small molecular weight molecules that have entered the intermediate pressure chamber 15 diffuse and are exhausted by the vacuum pump 17. (5) Incorporation of ions into the MS part The desorbed ions are then transferred to the second pore 1 near the center of the partition 161.
6 and enters the mass spectrometer 18. Here, the mass dispersion is detected by the detector 19 and passed through the DC amplifier 20 to give a mass spectrum by the data processor 21.

Next, cluster ions and chemical noise will be described.

On the mass spectrum, chemical noise may appear in addition to the ions based on the sample. FIG. 4 shows an example of chemical noise appearing on the mass spectrum. Generally, the horizontal axis of the mass spectrum is the mass-to-charge ratio (m / z),
The vertical axis is the ion current value. Peaks appearing at equal intervals from P1 to P6 on the mass spectrum are cluster ions. When the composition of P1 of ions is assumed to have also added water and M, cluster ions from P2 P6 is represented by (M + nH ₂ O). When water is used for the mobile phase M
Is H ₃ O m / z19. For this reason, a large number of cluster ions of water may appear at a high intensity every m / z 18 as in 19, 37, 55, 73 on the mass spectrum. Water molecules are also added to the molecular ions Pm1 of the sample and Pm1
2, Pm3 may appear.

In this case, since one ion species Pm1 is dispersed into several ion species, the original molecular ion Pm1 is dispersed.
Has a low ion current value. In addition to these ions, ions are detected continuously over a wide mass range. This is considered to be cluster ions that arrived at the detector without being subjected to accurate mass analysis due to evaporation of additional molecules and the like while the cluster ions were flying in the intermediate pressure chamber 15, the mass spectrometer 18, and the like. With the exception of the molecular ions Pm1 in the sample, these ions have a negative effect on the analysis and prevent the identification of the molecular ions Pm1. These are collectively called chemical noise.

In order to suppress the appearance of these cluster ions, it is sufficient to thoroughly heat the mist before ionization to completely vaporize the sample and the solvent, or to heat the entire interface. However, in atomization means such as gas atomization, heating atomization, and ultrasonic atomization currently used for atmospheric pressure chemical ionization and the like, the diameter of the mist droplet is widely distributed, for example, from about 100 μm to about 1 μm. Therefore, if it is attempted to vaporize even a large diameter droplet by heating at all, the small diameter droplet will continue to receive heat for a long time after vaporization. This excessive heating leads to thermal decomposition of the sample molecules, and the molecular weight and structural information of the sample are all lost, so that analysis as LC / MS is practically impossible.

As described above, the cluster ions hinder the analysis of the molecular weight and increase the chemical noise. However, on the other hand, a large number of molecules such as water added to the molecules or ions have the effect of preventing the influence of heat from the surroundings from being directly transmitted to the molecules or ions and preventing thermal decomposition. Further, the applied heat is consumed for evaporating the cluster ions and the additional molecules from the droplets, thereby preventing the temperature rise of the molecules or ions and preventing thermal decomposition. Fog is a mixture of droplets and gas. Therefore, even if the fog is heated, the heat is consumed for vaporizing the solvent from the droplet surface, and the fog temperature does not rise. Thereby, the thermally unstable substance sent from the LC can be stably sent to the atmospheric pressure ion source in a mist state. For this reason too much heating of the fog is not possible.

In order to reduce chemical noise due to cluster ions and prevent thermal decomposition of sample molecules, precise temperature control of the heating section has been attempted. This will significantly increase the annoyance. Various methods are used in liquid chromatography, and the solvent used is, for example, 100% water.
From 100% to 100% of organic solvent. Also, it is frequently performed to add a salt or an acid to a solvent or to use a buffer solution for a mobile phase. In such a case, it is difficult to control the temperature of the vaporizer for each mobile phase and for each composition of the mobile phase, which greatly limits the application of LC / MS.

Incidentally, in order to homogenize the mist, the direction of the spray flow is mechanically changed, and a high-temperature peripheral flow and a relatively low-temperature central flow are mixed to promote the vaporization of the droplets. By mechanically changing the direction of the spray flow, the central flow and the peripheral flow are switched, so that the infrared rays emitted from the vaporization space wall surface can reach the inside of the spray flow. This will be described later in detail.

Next, details of the vaporizer 8 will be described.

In FIG. 1, a spiral insertion rod 82 serving as a fluid guide is inserted into a vaporizing space 9 on a cylinder formed in the center of a vaporizer 8. Thereby, the vaporization space 9 is formed in a spiral shape. First, the mist sprayed from the sprayer 6 (the effluent from the chromatograph) enters the heated spiral vaporizing space 9. The fog constantly changes its direction of flow along the insertion rod on the helix. The flow of the mist is no longer laminar, but the flow constituting the mist is constantly approaching and heating the heated wall. Further, since the mist is constantly stirred and mixed, the droplets of the mist are miniaturized. As described above, since the heating is sufficiently performed, the set temperature of the vaporizer 8 can be lowered. Thereby, the thermal decomposition of the thermally unstable substance can be prevented.

The use of the spiral vaporizing space 9 makes it possible to produce uniform and finer mist. By introducing the fine ionization mist into the mass spectrometer through the first pores 14 and the second pores 16 as described above, desolvation of additional molecules can be efficiently performed by accelerated collision of ions in the intermediate pressure chamber. Often done. In addition, since a droplet having a large diameter can be prevented from being introduced into the mass spectrometric unit, chemical noise can be significantly reduced. As a result, a mass spectrum can be obtained as shown in FIG. As can be easily understood from this figure, cluster ions (P1 to P6 in FIG. 4) and chemical noise derived from a mobile phase such as water disappear. On the other hand, as for the molecular ion, since the desolvation of the cluster ion proceeds, the ion current value can be increased by stripping off the additional molecule. That is, the ion current values from the peaks Pm1 to Pm3 in FIG. 4 can be collected into the peak Pm1. As a result, molecular ions can be identified with high sensitivity.

The heating space 9 can be formed by processing a stainless steel heat block 8 with a drill or the like. A stainless steel spiral insertion rod may be inserted into this. The helix may be single, double or more. Instead of a spiral rod, a round rod slightly smaller than the inner circumference of the vaporizing space 9 may be used as an insertion rod. The insert bar is preferably made of a thermally conductive material to prevent the fog from condensing. Further, if a small heater is built in the insertion rod, the fog can be heated from the inside, and the finer fog is accelerated. In addition, contamination can be prevented beforehand by freely taking out and cleaning. [Embodiment 2] Next, LC / M according to another embodiment of the present invention.
S will be described.

FIGS. 6A and 6B are explanatory views of the vaporizer 8 of the LC / MS according to this embodiment. The other parts are the same as in the second embodiment, and the description is omitted. Hereinafter, the description of the same parts in other embodiments will be omitted. In this embodiment, the sample solution is sprayed and vaporized.
The introduction into the MS section 18 after the ionization in the atmospheric pressure chemical ion source 11 and the introduction into the MS section 18 are the same as those in the above embodiment.
FIG. 6A is a sectional view of the vaporizer 8. In Example 1, a spiral insertion rod was inserted into the entire vaporization space 9 to guide the spray flow. In the present embodiment, a fluid guide placed in a part of the vaporizing space 9 as shown in FIG. In this figure, a fluid guide 83 is placed in a vaporizing space 9 created in the center of the vaporizer 8. The fluid guide 83 is made up of a plurality of fins 85 in the form of a propeller twisted with each other and a cylinder 84 for fixing them. The mist sprayed from the spray 6 is fin 8
5 creates a spiral flow in the vaporization space 9. Thereby, uniform heating and finer fog are performed. Two or more fluid guides 83 can be placed in the vaporization space 9. Embodiment 3 Next, LC / M according to another embodiment of the present invention.
S will be described.

FIGS. 7A and 7B are explanatory diagrams of the vaporizer 8 of the LC / MS according to this embodiment. FIG. 7 (a)
Is a sectional view of the vaporizer 8. In this embodiment, the sample solution is sprayed and introduced into the vaporizer 8 and the atmospheric pressure chemical ion source 11
After the ionization in step (a), the introduction into the MS section 18 is the same as in the above-described embodiment. As shown in FIG. 7B, a mixer 86 is placed in the vaporizing space 9. The mixer 86 is provided with a hole in the mixing section 88 at the center thereof. A plurality of introduction holes 87 lead from the outer periphery of the mixer to the holes of the mixing section 88. The mist sprayed from the spray 6 enters the vaporization space 9 and is heated. The outer periphery of the well-heated mist immediately reaches the mixing section 88 through the introduction hole 87 formed in the outer periphery of the mixer 86. The central flow of the mist moves along the wall surface of the mixer 86 and reaches the mixing section 88 through the introduction hole 87. In this way, the central flow can move slowly through the vicinity of the inner periphery of the vaporizer 8 and be heated. Further, the mixing in the mixer 88 promotes uniform heating and finer mist. The structure of the mixer 86 can be freely made other than this figure. Other shapes may be used as long as the peripheral flow and the central flow are separately taken and mixed at one place.

If the mixer 86 can be inserted into and removed from the vaporizing space 9 from the outside, cleaning can be simplified. Embodiment 4 Next, LC / M according to another embodiment of the present invention.
S will be described.

FIG. 8 is an explanatory view of the vaporizer 8 of the LC / MS according to this embodiment. In this embodiment, the spraying of the sample solution and the introduction into the vaporizer 8 and the introduction into the MS section 18 after the ionization in the atmospheric pressure chemical ion source 11 are the same as those in the previous embodiment. FIG. 8 is a sectional view of the vaporizer 8. In this embodiment, a vaporized space 9 having a curved flow path is formed inside the vaporizer 8. The mist sprayed from the sprayer 6 enters the heated vaporization space 9. The fog changes its direction of flow along the curved vaporization space 9. The mist receives a force in a direction different from the traveling direction, and the peripheral flow and the central flow constituting the mist are switched, approaching the heated wall surface and heated. Thereby, the mist can be uniformly heated, and the mist can be made finer.

In FIG. 8, the vaporization space is drawn at 90 °, but other angles may be used. As shown in FIG. 9, a vaporization space 9 orthogonal to the vaporizer 8 may be formed and used. Also, a plurality of curved vaporization spaces may be combined. The curved vaporizing space 9 can also be formed by bending a metal tube as shown in FIG. 10, inserting the curved tube into a hole formed in a block of the vaporizer 8, and then welding with a silver wax 92 or the like.

As shown in FIG. 11, two holes having different axes may be formed in the carburetor 8 and connected to each other in the carburetor block. Also, two or more perforated vaporizer blocks can be assembled by assembling such that the axes of the holes are shifted. Embodiment 5 FIG. 12 shows an LC / M according to an embodiment of the present invention.
It is explanatory drawing which shows S (including interface). FIG.
Indicates a turbulence generating plate. In this embodiment, the spraying of the sample solution, introduction into the vaporizer 8 and introduction into the MS section 18 after ionization in the atmospheric pressure chemical ion source 11 are the same as in the previous embodiment.

First, the basic function of the turbulence generating plate will be described. As shown in FIG. 14, placing an object 46 in a fluid creates a negative pressure behind the object 46. To compensate for this, the fluid wraps around and creates a vortex 33. Vortices 33 are created one after the other on both sides behind the object 46. This is known as the "Kalman vortex". The vortex can be used to mix and refine the fog.

That is, the turbulence generating plate 40 is placed in the vaporizing space 9 as shown in FIGS. The turbulence generating plate 40 has a structure as shown in FIG. A plurality of small through holes are provided on a circumference from a center point 42 of the heating space 9. The turbulence generating plate 40 may be made of a disk of stainless steel or the like having a thickness of about 1 to 5 mm. When the turbulence generating plate 40 is installed, for example, as shown in FIG. 15, the mist is obstructed by the turbulence generating plate 40 installed in the heating space 9,
A turbulence 33 is formed downstream through the plurality of through holes. The flow rate of the solution supplied to the atomizer 6 is, for example, about 1 ml / min, and when vaporized, becomes, for example, 1000 ml / min. Gas (mist) with such a large flow rate, for example, several meters inside diameter
Since the liquid drops pass through the vaporizing space 9 having a length of about 50 mm and a length of about 50 mm, the fine droplets ride on the flow of the vaporized solvent and pass through the through holes 41 without colliding with the turbulence generating plate 40. The flow passing through the through hole 41 forms a turbulent flow (vortex) 33 downstream of the turbulent flow generating plate 40. The turbulent flow 33 mechanically agitates the peripheral flow 31 in which fine droplets having a high temperature are collected and the central flow 30 in which large droplets having a lower temperature are collected. Thereby, the temperature of the spray flow can be made uniform, and the vaporization of large droplets is promoted. In addition, large droplets are mechanically torn by a complicated gas flow, and miniaturization is promoted. As described above, the mist is made fine and uniform at a stretch by passing through the turbulence generating plate 40. Further, the fine mist passing through the vaporizer 8 enters the atmospheric pressure ion source unit 11 and is ionized.

The heating space 9 can be easily formed by drilling a round hole having a diameter of about 5 mm and a length of about 50 mm in a heat block 8 made of stainless steel. The turbulence generating plate 40 is provided in the heating space 9.
It may be provided at a position of about 40 mm from the entrance. In order to prevent contamination, the turbulence generating plate 40 is made of a material having a good thermal conductivity so that the temperature thereof can be kept substantially the same as that of the vaporizer 8. Further, the turbulence generating plate 40 may be fixed to the carburetor 8 with fixing screws 43 as shown in FIG. Embodiment 6 Next, an LC / M according to another embodiment of the present invention will be described.
S will be described.

FIG. 16 shows an LC / LC according to another embodiment of the present invention.
It is explanatory drawing of the vaporizer 8 part of MS. In this embodiment, the spraying of the sample solution, introduction into the vaporizer 8 and introduction into the ionization MS section in the atmospheric pressure chemical ion source 11 are the same as those in the above embodiment.

In this embodiment, a hole is made in the vaporizer 8 downstream of the vaporizing space 9 and a screw 48 is inserted. The screw 48 is long enough to reach the wall below the vaporization space 9. Further, the diameter of the screw 43 is smaller than the diameter of the vaporization space 9 so that a sufficient gap can be formed in the vaporization space 9 even when the screw 43 is completely tightened. The mist enters the vaporizing space 9 and is heated by infrared rays from the wall of the vaporizer 8. The fog bypasses the screw 48 and creates a turbulent flow (vortex) downstream of the screw 48. The principle of turbulence formation is shown in FIG. This makes it possible to achieve finer and more uniform fog as in the fifth embodiment.
The screw 48 is made of a material having good heat conductivity so as to prevent the solvent and the sample from condensing. Further, the screw 48 can be easily positioned by a driver or the like from the outside, and the flow of fog can be freely controlled. As a result, it is possible to easily find the point at which the finer fog proceeds. When the screw 48 becomes dirty, it can be easily removed and cleaned. [Embodiment 7] Next, LC / M according to another embodiment of the present invention.
S will be described.

FIG. 17 shows a LC / LC according to another embodiment of the present invention.
It is explanatory drawing of the vaporizer 8 part of MS. In this embodiment, the spraying of the sample solution, introduction into the vaporizer 8 and introduction into the ionization MS section in the atmospheric pressure chemical ion source 11 are the same as those in the first embodiment.

In this embodiment, a plurality of projections 45 are provided on the wall surface of a cylindrical vaporizing space 9 formed at the center of the vaporizer 8. The fog bypassing the projection 45 generates a number of turbulent flows (vortices) after the projection 45. This turbulent flow can make the fog fine and uniform. Instead of forming the projection 45 directly on the wall surface of the cylindrical vaporization space 9, another cylindrical tube 44 that can be inserted into the vaporization space 9 may be prepared, and the projection 45 may be formed in the cylindrical tube 44. If the cylindrical tube 44 becomes dirty, it can be removed and washed. As described above, according to the first to seventh embodiments,
The mist is made finer and uniform in the vaporization space, preventing the mist with irregular droplet diameters from being randomly introduced into the atmospheric pressure ion source, and ionizing fine droplets of uniform diameter. The solvent can be efficiently transferred to the MS section to remove the solvent.
Thereby, chemical noise can be minimized and high-sensitivity analysis can be achieved. It also allows the introduction of solvents of a wide range of compositions. Embodiment 8 Next, an LC / MS according to another embodiment will be described.

In order to homogenize the mist, the spray flow is mechanically divided and the spray flow is made thinner so that the infrared rays emitted from the wall of the vaporizing space reach the inside of the spray flow. As shown in FIG. 18, a plurality of vaporization spaces 9 such as a plurality of thin tubes 182 are provided within the range of the mist from the center of the vaporizer 8. The mist is divided and passes separately through the plurality of heated thin tubes 182. Of course, the diameter of the fog is limited to less than the diameter of the capillary 182. As the surface area of the capillary increases, the infrared radiation emitted from the wall of the capillary 182 increases and is easily heated to the center of each mist. This promotes finer fog. Further, when the diameter of the flow velocity of the mist is large, the heat does not easily reach the center, and the temperature of the vaporizer 8 must be set high to heat the center of the mist. In the case of this embodiment, Since the heating is performed sufficiently, the set temperature of the vaporizer 8 can be lowered. Thereby, the thermal decomposition of the thermally unstable substance can be prevented. The mist that has passed through the plurality of thin tubes 182 enters the atmospheric pressure ion source unit 11, where solvent molecules are first ionized by corona discharge generated from the tip of the corona discharge needle electrode to which a high voltage of 3 to 5 kV is applied. You. The generated ions then repeat the ion-molecule reaction, eventually ionizing the sample molecules. Ions are introduced from the first pores 14 into the intermediate pressure section 15. This is the same as in the previous embodiment.

As described above, a fine mist can be formed by employing the plurality of vaporization spaces 9, and ionized, and ions are introduced into the mass analyzer 18 through the first pores 14 and the second pores 16. Can be. As a result, the fine droplets are subjected to accelerated collision of ions in the intermediate pressure chamber, and the desolvation of the added molecules is efficiently performed. Further, since it is possible to prevent large diameter droplets and cluster ions from being introduced into the mass spectrometer, chemical noise can be significantly reduced. Further, cluster ions and chemical noise derived from a mobile phase such as water can be suppressed low. On the other hand, molecular ions can increase the ion current value by stripping off additional molecules. As a result, molecular ions can be identified with high sensitivity.
The heating space 9 can be formed by processing a stainless steel heat block 8 with a drill or the like. Embodiment 9 Next, an LC / M according to another embodiment of the present invention will be described.
S will be described.

FIG. 20 shows an LC / LC according to another embodiment of the present invention.
It is explanatory drawing of the vaporizer 8 part of MS. In this embodiment, the spraying of the sample solution, the introduction of the vaporizer 8 and the introduction into the MS section 18 after the ionization in the atmospheric pressure chemical ion source 11 are the same as those in the previous embodiment. FIG. 20 is a sectional view of the vaporizer 8. A hole having a diameter of about 5 mm and a length of about 50 mm is formed in the center of the vaporizer 8, and a rod-shaped partition plate 183 is inserted into the hole. FIG.
In the case of 0, a cross-shaped partition plate is shown, but the shape of the partition plate 83 can be freely selected. The vaporization space 9 may be separated into a plurality of vaporization spaces by inserting the partition plate, and the mist may be moved in each vaporization space. According to this embodiment,
As in the eighth embodiment, the mist flux is subdivided and the number of heated wall surfaces is increased. As a result, the vaporization of the mist droplets is promoted, and the mist is made finer. The partition plate 183 is made of a material having good heat conductivity, so that the mist can be heated well and condensation of the sample can be prevented. Furthermore, if a small heater is built in the partition plate 183, the fog can be heated from the inside, and the miniaturization of the fog is accelerated. If the partition plate 183 can be taken out, cleaning can be easily performed. [Embodiment 10] Next, the LC / LC according to another embodiment of the present invention is described.
MS will be described.

FIG. 21 shows an LC / LC according to another embodiment of the present invention.
It is explanatory drawing of the vaporizer 8 part of MS. In this embodiment, the spraying of the sample solution, the introduction of the vaporizer 8 and the introduction into the MS section 18 after the ionization in the atmospheric pressure chemical ion source 11 are the same as those in the previous embodiment. FIG. 21 is a sectional view of the vaporizer 8. A hole having a diameter of, for example, about 5 mm and a length of about 50 mm is formed in the center of the vaporizer 8, and an insertion rod 185 having a plurality of projections 184 attached to the outer periphery is inserted into the hole. Thereby, the vaporization space 9 is formed in a gap between the outer circumference of the insertion rod 185 and the inner circumference of the hole of the vaporizer 8. The thickness of the vaporizing space 9 can be freely selected depending on the diameter of the insertion rod. If the vaporization space 9 is made as thin as about 1 mm, the fog can be sufficiently heated. If the insertion rod 185 can be taken out, cleaning can be easily performed. Further, if a small heater 186 is sealed in the insertion rod 185 and the fog is heated from the inside, the finer fog is further promoted. [Embodiment 11] Next, LC /
MS will be described.

FIG. 22 shows an LC / LC according to another embodiment of the present invention.
It is explanatory drawing of the vaporizer 8 part of MS. In this embodiment, the spraying of the sample solution, the introduction of the vaporizer 8 and the introduction into the MS section 18 after the ionization in the atmospheric pressure chemical ion source 11 are the same as those in the previous embodiment. FIG. 22 is a cross-sectional view of the vaporizer 8 along the spray direction. At the center of the vaporizer 8, for example, 5m in diameter
A hole having a length of about 50 mm and a length of about 50 mm is formed. A filling 187 such as quartz wool or stainless steel wool is placed in the vaporization space 9. The mist that has flowed into the vaporizing space 9 comes to a filling 187 such as quartz wool or stainless steel wool, and becomes a plurality of flows, and the vaporizer 9
Heated from the wall. This further promotes finer fog.

As described above, according to the eighth embodiment to the eleventh embodiment, it is possible to prevent the mist having irregular diameters of the droplets from being randomly introduced into the atmospheric pressure ion source unit 11 and to make the temperature uniform so that the fine particles can be made finer. The droplets having the uniform diameter are ionized and sent to the MS section. Therefore, the solvent can be efficiently removed by the ion drift voltage V. This minimizes chemical noise and achieves high sensitivity analysis. Further, the temperature setting of the vaporizer can be kept low, and the thermal decomposition of the thermally unstable substance can be prevented. [Embodiment 12] FIG. 23 is a block diagram showing another embodiment of the present invention.
It is explanatory drawing which shows C / MS (including interface).

In FIG. 23, the ion sampling axis 13 is set to be near the spray peripheral flow 31. As a result, the fine mist is mainly ionized and the first pores 14,
It can be introduced into the mass spectrometer 18 from the second pore 16. That is, since many fine fogs are gathered around the ejected fog, this is characteristically selected and guided to the intermediate pressure chamber 15. Further, the fine droplets repeat the accelerated collision of ions by the ion drift voltage V applied between the partition walls 141 and 161 in the intermediate pressure chamber, and the desolvation of the additional molecules is performed efficiently. In addition, since a droplet having a large diameter at the center of the spray flow can be prevented from being introduced into the mass spectrometer, chemical noise can be significantly reduced. Therefore, cluster ions and chemical noise derived from the mobile phase such as water can be suppressed. On the other hand, molecular ions can increase the ion current value by stripping off additional molecules. As a result, molecular ions can be identified with high sensitivity. [Embodiment 13] Next, an LC / LC according to another embodiment of the present invention is described.
MS will be described.

FIG. 24 shows an LC / LC according to another embodiment of the present invention.
It is explanatory drawing of MS. In the figure, the same reference numerals as those in FIG. Only new codes will be described.

In FIG. 24, 123 is a partition, 124 is a spray flow sampling hole, 25 is a first exhaust port, and 26 is a second exhaust port. This embodiment is the same as the previous embodiment up to the spraying of the sample solution and the introduction of the vaporizer 8. A partition 123 with a hole 124 is placed downstream of the vaporization space 9 and in front of the atmospheric pressure ion source 11. The vaporization space 9 and the atmospheric pressure ion source 11 are isolated by the partition 123. The fine holes 124 are provided in the vicinity of the peripheral flow 31 shifted from the central axis 30 of the spray flow. Fine mist is concentrated in the peripheral portion compared to the central portion. This allows the mist in the peripheral portion of the spray flow to be selectively introduced into the atmospheric pressure ion source portion 11 for ionization. A part of the spray flow that is not introduced into the inner atmospheric pressure ion source part 11 is discharged from the first exhaust port 25 to the outside. Further, the gas introduced into the atmospheric pressure ion source unit 11 and not involved in ionization is discharged to the outside from the second outlet 26 of the atmospheric pressure ion source unit 11. In the case of the first embodiment, there is a risk that turbulent flows in the atmospheric pressure ion source unit 11 cause droplets having different diameters to be mixed and introduced into the mass analyzer. However, according to the second embodiment, since only the mist at the peripheral portion of the spray flow is actively sampled, fine mist having a uniform particle diameter can be selectively ionized. Fine ions having a uniform particle size are subjected to accelerated collision in the intermediate pressure chamber by the ion drift voltage V, and as a result, desolvation is performed efficiently.

In this embodiment, the partition 123 with the hole 124 is fixed inside the apparatus. However, it is also possible to adjust the spray flow from outside at right angles. As a result, the spray flow can be freely sampled, and a droplet having a desired diameter can be sampled and ionized. Through external adjustment, it is possible to search for the best points such as sensitivity maximum and noise minimum.

In Examples 12 and 13, the method of sampling ions generated under the atmospheric pressure was described using the pores. It is sufficient that the generated ions can be introduced into the MS section while maintaining the pressure difference, and the ions can be replaced with pores by slits, capillaries, or the like. Further, the mass spectrometer is not limited to QMS. A magnetic field type MS, an ion trap MS, or an MS having another principle may be used.

As described above, Embodiments 12 and 13
According to the method described above, it is possible to prevent mist with irregular diameters from being randomly introduced into the atmospheric pressure ion source unit, ionize the droplets having the uniform diameter, send the droplets to the MS unit, and efficiently remove the solvent. be able to. Thereby, chemical noise can be minimized and high-sensitivity analysis can be achieved. [Experiment] The following experiment was performed to verify the effect of the present invention. (1) Apparatus An LC / MS having the configuration shown in FIG. 12 was used. However, the analytical column 4 was removed, and the sample inlet 3 and the nebulizer 6 were directly connected.
A comparison was made between when the turbulence generating plate 40 was attached and when it was removed.

As the mobile phase 1, pure water was used. Water is the most difficult to remove solvent and produces large cluster ions. The vaporizer temperature was fixed at 400 ° C., and the temperature of the atomizer 6 and the flow rate of water were changed to observe the appearance of cluster ions. Corona discharge voltage HV is 3 kV, and drift voltage V for collision dissociation is 5
0V and other parameters were fixed during the experiment. The mass spectrometer 18 was swept while changing the temperature of the atomizer 6 and the flow rate of water, and mass spectra were repeatedly collected. Cluster ions on one mass spectrum are integrated and output as a total ion current (TIC). TI
Large C indicates that a large number of cluster ions have appeared. Here, TIC and chemical noise are synonyms. (2) Results and consideration FIGS. 25 and 26 show the experimental results. FIG. 25 shows the nebulizer 6
The results of observing the appearance of cluster ions by changing the temperature and flow rate of water are shown. The horizontal axis is the temperature of the atomizer, and the vertical axis is the TIC. × and ○ indicate the TIC when the turbulence generating plate 40 was removed, and □ indicates the TIC when the turbulence generating plate 40 was mounted. The flow rate of the mobile phase was as follows: ×: 1 ml / min, ○: 0.5 ml / mi
n and □ indicate a flow rate of 1 ml / min. When the turbulence generating plate 40 is not mounted, x and o have no measurement result at 200 ° C. This is because, when the temperature of the sprayer 6 is set to 250 ° C. or lower, the cluster ions of water rapidly increase, the TIC becomes extremely unstable, and the measurement becomes impossible. If the temperature of the sprayer 6 is 2
When set to 50 ° C, TIC is 2 at a flow rate of 1 ml / min.
× 10 ⁷ . When the flow rate is halved to 0.5 ml / min, T
The IC is also reduced by half to 1 × 10 ⁷ . If the temperature of the atomizer 6 is set high, the TIC (chemical noise) decreases. But,
8 × 1 even at a flow rate of 0.5 ml / min and a temperature of the sprayer 6 of 350 ° C.
It does not ^fall below 06. Further heating is not possible to avoid thermal decomposition of the sample.

When the turbulence generating plate 40 is mounted, the TIC (chemical noise) becomes 1 × 10 ⁶ or less, and when the temperature of the sprayer 6 is 300 ° C. or more compared with the case where the turbulence generating plate 40 is not mounted, one digit. As described above, when the temperature of the atomizer 6 is 250 ° C. or less, the temperature is drastically reduced to two digits. Moreover, from 200 ° C to 350 ° C
There is no major change in the TIC up to now. When the turbulence generating plate 40 was not provided, 200 ° C. was too noisy to use. When the turbulence generating plate 40 is mounted, measurement becomes possible. The fact that the condition of 250 ° C. or less can be used is extremely effective because thermal decomposition of the sample can be avoided. This is the result of achieving finer and more uniform fog by the turbulence generating plate 40.

FIG. 26 shows a mass spectrum with and without the turbulence generating plate 40. The upper part of FIG. 26 shows the mass spectrum when the turbulence generating plate 40 is not provided, and the lower part shows the mass spectrum when the turbulent flow generating plate 40 is provided. The conditions for acquiring both mass spectra are the same.
The mobile phase flow rate is 1 ml / min, the temperature of the atomizer 6 is 250 ° C.,
The vaporizer temperature is 400 ° C. In the absence of the turbulence generating plate 40, ions of unknown belonging appear at an intensity of 100,000 to 50,000 over the front region from m / z 100 to 1000.
When there is a turbulence generating plate 40, the intensity is set to 10,0 from m / z200.
No peak of 00 or more appears. Many cluster ions have been eliminated by the turbulence generating plate 40.

The low noise and independence of the nebulizer temperature have the following advantages. It is not necessary to change the nebulizer temperature for mobile phases of different compositions. This is extremely effective for gradient measurement. The temperature of the nebulizer may be set to approximately 250 ° C., and the operability can be significantly improved. If the temperature of the atomizer is approximately 250 ° C., thermally unstable substances can be prevented and stable measurement can be performed.

[0060]

As described above, according to the present invention,
It is possible to improve the accuracy of mass spectrometry.

[Brief description of the drawings]

FIG. 1 is an overall view of LC / MS.

FIG. 2 is a diagram showing a thermal spray and a vaporizer.

FIG. 3 is a diagram showing details of a vaporizer.

FIG. 4 is an explanatory diagram of chemical noise in a mass spectrum.

FIG. 5 is a diagram showing a mass spectrum obtained by the present invention.

FIG. 6 is a diagram illustrating details of a vaporizer according to a second embodiment.

FIG. 7 is a diagram illustrating details of a vaporizer according to a third embodiment.

FIG. 8 is a diagram showing details of LC / MS of Example 4.

FIG. 9 is a diagram illustrating details of a vaporizer according to a fourth embodiment.

FIG. 10 is a diagram showing details of a vaporizer in a fourth embodiment.

FIG. 11 is a diagram showing details of a vaporizer in a fourth embodiment.

FIG. 12 is a diagram showing details of a vaporizer in a fifth embodiment.

FIG. 13 is a view showing details of a turbulence generating plate in the fifth embodiment.

FIG. 14 is an explanatory diagram of Karman vortex generation in the fifth embodiment.

FIG. 15 is a diagram showing details of atomization in Embodiment 6.

FIG. 16 is a diagram showing details of a vaporizer in a seventh embodiment.

FIG. 17 is a diagram illustrating details of a vaporizer according to a seventh embodiment.

FIG. 18 is an overall view of LC / MS in Example 8.

FIG. 19 is a diagram showing details of a vaporizer in an eighth embodiment.

FIG. 20 is a diagram showing details of a vaporizer in a ninth embodiment.

FIG. 21 is a diagram illustrating details of a vaporizer according to a tenth embodiment.

FIG. 22 is a diagram showing details of a vaporizer in an eleventh embodiment.

FIG. 23 is an overall view of LC / MS in Example 12.

FIG. 24 is an overall view of LC / MS in Example 13.

FIG. 25 is a diagram showing the relationship between TIC and sprayer temperature.

FIG. 26 is a mass spectrum.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Mobile phase, 4 ... Analytical column, 6 ... Nebulizer, 8 ... Vaporizer, 10 ... Needle electrode for corona discharge, 11 ... Atmospheric pressure chemical ion source part, 14 ... First pore, 16 ... Second pore, 17: vacuum pump, 18: mass spectrometer, 82: spiral insertion rod.

Claims (4)

[Claims] 1. A spraying section for spraying an effluent from a liquid chromatograph, a heating section having a communication passage for passing the spraying flow from the spraying section and performing heating, and ionizing the spraying stream from the heating section. A liquid chromatograph-coupled mass spectrometer having a mass spectrometer for conducting mass spectrometry by guiding ions generated in the ionizer through pores, wherein a central axis of the communication path and A liquid chromatograph-coupled mass spectrometer characterized in that the axes are shifted with respect to the pores. 2. A spraying section for spraying an effluent from a liquid chromatograph, a heating section having a communication passage for passing the spraying flow from the spraying section and performing heating, and a spraying section from the heating section for sensing the spraying flow from the heating section. A liquid chromatograph-coupled mass spectrometer having an ionization unit that ionizes by corona discharge of the electrode in shape and a mass analysis unit that conducts mass analysis by guiding ions generated in the ionization unit through pores, A liquid chromatograph-coupled mass spectrometer, wherein the center axis of the communication passage and the tip of the needle electrode are shifted from each other. 3. A spray section for spraying an effluent from a liquid chromatograph, a heating section having a communication passage for passing the spray flow from the spray section and performing heating, and a spray stream from the heating section for sensing a spray flow from the heating section. A liquid chromatograph-coupled mass spectrometer having an ionization unit that ionizes by corona discharge of the electrode in shape and a mass analysis unit that conducts mass analysis by guiding ions generated in the ionization unit through pores, A liquid chromatograph-coupled mass spectrometer, comprising a partition having a through-hole between the heating unit and the ionization unit, wherein the through-hole is formed at a position shifted from a central axis of the communication path. 4. The device according to claim 3, wherein the partition wall is perpendicular to a central axis of the communication path.
A liquid chromatograph-coupled mass spectrometer characterized by being adjustable from the outside.