JP6747602B2 - Ion source and ion analyzer - Google Patents

Description

The present invention relates to an ion source for ionizing components in a liquid sample, and an ion analyzer such as a mass spectrometer or an ion mobility spectrometer equipped with the ion source, and more specifically, an electrospray ionization (ESI) method, An ion source having an ionization probe for spraying a liquid sample for performing ionization by an ionization method such as an atmospheric pressure chemical ionization (APCI) method or an atmospheric pressure photoionization (APPI) method, and an ion analysis including the ion source Regarding the device.

A liquid chromatograph mass spectrometer combined with a liquid chromatograph and a mass spectrometer (hereinafter, appropriately abbreviated as “LC-MS”) uses an eluate containing various components separated in a time direction by a column of the liquid chromatograph. After being introduced into the mass spectrometer and ionized by the ion source of the mass spectrometer, the ions derived from the sample components are separated and detected according to the mass-to-charge ratio m/z by a mass separator such as a quadrupole mass filter. In a mass spectrometer used for LC-MS, an atmospheric pressure ionization method such as ESI method, APCI method, and APPI method is used to ionize components in a liquid sample.

In recent years, especially in the fields of biochemistry, medical care, drug development, etc., the amount of sample to be analyzed is often very small, or the sample is rare or expensive. It is required that the analysis can be performed. In order to meet such demands, liquid chromatographs employ a method of using a column having a small diameter and reducing the flow rate of the mobile phase supplied to the column. In response to this, the ion source of the mass spectrometer employs, for example, a technique called nano ESI or micro ESI, which efficiently ionizes the components in the eluent while suppressing the flow rate of the eluate introduced into the ionization probe. Has been.

As disclosed in Patent Document 1, in LC-MS, ions derived from a sample component generated from a spray flow from an ionization probe have a gas pressure from an ionization chamber, which is a substantially atmospheric pressure atmosphere, through a desolvation tube having a small diameter. It is sent to the intermediate vacuum chamber of the next lower stage. Therefore, in order to improve the analysis sensitivity, it is necessary to efficiently feed the ions generated in the ionization chamber into the desolvation tube. When the ionization probe is moved in the axial direction, the distance between the capillary end of the ionization probe and the ion introduction port of the desolvation tube and the angle formed by both axes change, and the transport of ions through the desolvation tube is changed. Efficiency changes. Therefore, there is conventionally known an ion source in which the position of the ionization probe in the axial direction can be adjusted so that the analysis sensitivity can be adjusted.

FIG. 4 is a schematic cross-sectional view of an example of a conventional atmospheric pressure ion source capable of adjusting the position of the ionization probe in the axial direction.
The ionization probe 22 includes a probe main body 220 having a nebulizing gas flow passage therein, and a small-diameter capillary 221 through which a liquid sample supplied from the outside flows. The probe main body 220 has a substantially columnar nozzle 220a having a substantially conical shape at its tip, and the distal end 221a of the capillary 221 slightly projects from the tip of this nozzle 220a. The probe main body 220 is held by a probe holding portion 23 having a substantially annular shape, which is mounted on a wall surface 21a of the ionization chamber 21 having a substantially atmospheric pressure atmosphere. The inner peripheral surface of the probe holding portion 23 has an appropriate slidability, and by pushing the probe body 220 from the outside of the ionization chamber 21 toward the inside of the ionization chamber 21 or pulling it out in the opposite direction, the ionization probe 22 The axial position can be adjusted.

An arm 43 protruding in a direction orthogonal to the axial direction of the capillary 221 is fixed to the probe body 220 in order to push in and pull out the probe body 220, and an adjusting screw 42 is attached to an end of the arm 43. It is supported. On the outside of the wall surface 21a of the ionization chamber 21, a screw receiving portion 41 having a screw hole formed on its inner peripheral side is attached, and the screw thread portion of the adjusting screw 42 is screwed into the screw hole of the screw receiving portion 41. .. The screwing direction of the adjusting screw 42 coincides with the axial direction of the probe main body 220. When the head portion of the adjusting screw 42 is rotated to screw the threaded portion into the screw hole of the screw receiving portion 41, the arm 43 having one end fixed to the adjusting screw 42 moves substantially in the axial direction accordingly. .. As a result, the probe body 220 fixed to the other end of the arm 43 is pushed into the ionization chamber 21 as indicated by the arrow B in FIG.

U.S. Pat.No. 9254497

However, in the ion source having the above configuration, when the adjusting screw 42 is screwed in, a force in the direction of rotating the arm 43 and the probe main body 220 acts as indicated by an arrow A in FIG. Therefore, the probe main body 220 does not move straight in the axial direction, but moves in the axial direction as a whole while swinging about the axis. Therefore, not only does the accurate position adjustment of the ionization probe 22 be hindered, but a large load is applied to the probe holding portion 23, which causes deterioration due to wear or the like. In order to smoothly move the probe main body 220 in the axial direction while restricting the movement of the probe main body 220 in a direction other than the axial direction, it is desirable to increase the axial length of the probe holding portion 23. However, the axial length of the probe holder 23 is restricted by the axial length of the probe body 220. In the above-mentioned ionization probe for low flow rate ESI called nano ESI or micro ESI, the decrease in sensitivity due to the diffusion of the sample components due to the length of the pipe is a particular problem. Therefore, at such a low flow velocity ESI, the extension of the capillary 221 accompanying the lengthening of the probe main body 220 in the axial direction is not preferable in terms of sensitivity reduction.

Further, in the ion source having the above configuration, in order to reduce the force acting on the arm 45 and the probe main body 220 other than the axial direction when the adjusting screw 42 is screwed in, the length of the arm 43 is shortened, that is, the adjusting screw 42. Also, the screw receiving portion 41 may be provided at a position close to the probe main body 220. However, when the adjusting screw 42 and the screw receiving portion 41 are close to the probe main body 220, the capillary 221 is replaced or the inlet end of the capillary 221 and the outlet end of the column of the liquid chromatograph (or the end of the pipe connected thereto). ) It becomes difficult to perform work such as connection with.

Particularly, in the above low flow rate ESI, it is common to make the pipe length from the column outlet end to the ionization probe as short as possible, and to arrange the column and the capillary of the ionization probe coaxially. The space between the column (and the column oven in which it is placed) and the ionization probe body is very small. When the adjusting screw 42 is arranged in such a narrow space, the operator needs to operate the adjusting screw 42 in the narrow space, resulting in extremely poor workability. Therefore, the adjusting screw 42 and the screw receiving portion 41 must be arranged at a position separated from the probe main body 220 to some extent, and also in that point, the force acting on the arm 45 and the probe main body 220 other than the axial direction should be reduced. It is difficult.

The present invention has been made to solve the above problems, and an object of the present invention is to adjust the axial position of an ionization probe by operating the ionization probe at a position some distance from the installation position of the ionization probe. It is an object of the present invention to provide an ion source capable of performing smoothly and accurately, and an ion analyzer using the ion source.

The present invention made to solve the above problems has an ionization chamber and a nozzle for spraying a liquid sample into the ionization chamber, and an opening formed in a wall surface of the ionization chamber movably in the axial direction thereof. An ionization probe that is held in a state of being inserted, and an ion source that ionizes a component contained in a liquid sample sprayed into the ionization chamber by the ionization probe,
a) an adjusting operation unit arranged outside the ionization chamber at a position apart from the ionization probe, and movable in the same direction as the axial direction of the ionization probe according to an operation from the outside,
b) an arm shaft support portion arranged outside the ionization chamber at a position opposite to the adjustment operation portion with the ionization probe interposed therebetween,
c) The arm shaft support part has a rod-shaped part whose one end is axially supported, and the other end is movably and rotatably attached to the adjustment operation part in a predetermined range in the extending direction of the rod-shaped part, An arm portion attached to the ionization probe so as to be movable and rotatable in a predetermined range in the extending direction at an intermediate position of the rod-shaped portion;
It is characterized by having.

The ion source according to the present invention typically performs ionization by the ESI method, the APCI method, or the APPI method. Note that, for example, in the case of an ion source by the ESI method, it is not necessary to provide an appropriate component according to the type of the ionization method, such as an electric field forming unit for charging the liquid sample immediately before being sprayed from the ionization probe. Of course.

In the ion source according to the present invention, when adjusting the position of the ionization probe in the axial direction, for example, an operator manually operates the adjustment operation part and moves the adjustment operation part by an appropriate amount. One end of the rod-shaped part of the arm is attached to this adjustment operation part, and the other end is pivotally supported by the arm shaft support part.Therefore, when the adjustment operation part moves linearly, the rod-shaped part is pivotally supported. Rotate with the position being used as the fulcrum. Since the adjustment operation part moves linearly, the distance between the attachment position (the force point to which the force is applied) and the fulcrum of the rod-shaped part in the adjustment operation part changes with the rotation of the arm part. Since the position can be moved within a predetermined range in the extending direction of the rod-shaped portion, the change in the distance is absorbed thereby. On the other hand, as the arm part rotates about the fulcrum, a force for rotating the ionization probe acts via the attachment position (action point) between the rod-shaped part and the ionization probe. However, since the attachment position between the rod-shaped portion and the ionization probe can also be moved within a predetermined range in the extending direction of the rod-shaped portion, the attachment position also moves with the rotation of the arm portion, which causes the ionization probe to It will move linearly in the axial direction.

Thus, in the ion source according to the present invention, the ionization probe can be smoothly moved in the axial direction. Further, in the ion source according to the present invention, since the movement amount of the ionization probe is smaller than the movement amount (adjustment amount) of the adjustment operation unit, it is easy to adjust the fine position of the ionization probe.

In addition, as described above, although the attachment position of the rod-shaped portion and the ionization probe moves in the extending direction of the rod-shaped portion when the arm portion rotates, the action direction of the force on the ionization probe is not the axial direction. However, by setting the fulcrum that pivotally supports the rod-shaped portion as far as possible from the point of action in the ionization probe, the direction of the force acting on the ionization probe can be made closer to the axial direction. Thereby, the oscillation of the ionization probe can be effectively suppressed.

In the ion source according to the present invention, the adjusting operation part includes a screw receiving part whose position is fixed with respect to a wall surface of the ionization chamber, and an adjusting screw having a screw part screwed into the screw receiving part. It can be configured to include.

In this configuration, for example, the operator manually turns the head of the adjusting screw to adjust the screwing depth of the screw portion into the screw receiving portion, thereby adjusting the axial position of the ionization probe. That is, the axial position of the ionization probe can be finely adjusted by the number of times the head of the adjusting screw is turned and its angle. Thereby, for example, in the mass spectrometer equipped with the ion source according to the present invention, the axial position of the ionization probe can be easily adjusted so as to obtain high analysis sensitivity.

Further, in the ion source according to the present invention, preferably, the arm portion is a U-shaped member in a top view including two linear rod-shaped portions arranged in parallel with the ionization probe interposed therebetween. ..

According to this configuration, when the arm portion rotates, the ionization probe receives a force from the rod-shaped portions on both sides thereof in the substantially axial direction via the action points. Therefore, even when the probe holding portion that holds the ionization probe in the opening formed in the wall surface of the ionization chamber is relatively short in the axial direction, the ionization probe moves smoothly in the axial direction, and the accurate position Can be adjusted.

The ion analyzer according to the present invention is characterized by including the ion source according to the present invention.

The ion analyzer according to the present invention is usually a mass analyzer for separating and detecting ions generated in an ion source or ions derived from the ions according to a mass-to-charge ratio, or ions generated in an ion source. Alternatively, it is either an ion mobility analyzer that separates and detects ions derived from the ions according to the ion mobility. Of course, an ion mobility-mass spectrometer that separates ions according to their ion mobility and then according to their mass-to-charge ratio can be used.

In such an ion analyzer according to the present invention, preferably, an eluate containing components separated by a column of a liquid chromatograph is introduced into an ion source of the ion analyzer, and an outlet side end portion of the column is used. It is preferable that the ionization probe is directly connected to the inlet side end of the capillary, which is the sample channel.
Here, the configuration of "directly connecting the outlet side end of the column and the inlet side end of the capillary which is the sample flow path in the ionization probe" means that the both are connected via a very short relay pipe. Including a configuration that is substantially directly connected. Further, "extremely short" is a state in which the column and the capillary are connected so that the column oven and the ionization probe housed in the column are arranged with no or almost no gap.

When the outlet side end of the column of the liquid chromatograph and the inlet side end of the capillary are substantially directly connected, the column oven in which the column is housed is arranged in the vicinity of the ionization probe. On the other hand, in the ion source according to the present invention, since it is possible to adjust the position in the axial direction of the ionization probe by operating the adjustment operation unit provided at a position distant from the ionization probe, in the ion analyzer according to the present invention, It is not necessary to arrange the adjustment operation unit in the space between the ionization probe and the column oven. This allows the column oven to be placed in close proximity to the ionization probe. Further, in the ion analyzer according to the present invention, by substantially directly connecting the outlet side end portion of the column and the inlet side end portion of the capillary in this manner, diffusion of the components separated in the column is suppressed, and high sensitivity is obtained. Can be analyzed. Therefore, the ion source according to the present invention is particularly suitable for low flow rate ESI called nano ESI or micro ESI.

According to the ion source of the present invention, the axial position of the ionization probe can be adjusted smoothly and accurately by operating the ionization probe at a position some distance from the installation position of the ionization probe. In addition, since the ionization probe is less likely to swing when adjusting the position of the ionization probe in the axial direction, it is difficult to apply an unreasonable force to the probe holding portion holding the ionization probe on the wall surface of the ionization chamber, and to prevent deterioration of the ionization probe. Damage can be suppressed. In addition, since the position adjustment of the ionization probe is highly accurate, the ion analyzer including the ion source according to the present invention can realize high analysis sensitivity.

The top view of the important section of the ionization probe which is one example of the present invention. FIG. 3 is a partial cross-sectional schematic configuration diagram of a main part of the ionization probe of the present embodiment. The schematic block diagram of LC-MS using the ionization probe of a present Example. The schematic sectional drawing of the conventional general ionization probe.

Hereinafter, an ion source according to an embodiment of the present invention and an LC-MS using the same will be described with reference to the accompanying drawings.
FIG. 1 is a plan view of a main part of an ion source according to the present embodiment, and FIG. 2 is a partial sectional schematic configuration diagram of the ion source according to the present embodiment. Further, FIG. 3 is a schematic configuration diagram of one embodiment of LC-MS using the ion source of the present embodiment. For convenience of explanation, in FIG. 3, the X axis, the Y axis, and the Z axis which are orthogonal to each other are defined as illustrated. In this LC-MS, the Z-axis direction is the lateral direction, the X-axis direction is the height direction, and the Y-axis is the depth direction.

First, the configuration and schematic analysis operation of the LC-MS of this embodiment will be described with reference to FIG.
The LC-MS is roughly divided into a liquid chromatograph 1 and a mass spectrometer 2. The liquid chromatograph 1 includes a mobile phase container 10, a liquid feed pump 11, an injector 12, a column 14, and a column oven 13.
The column oven 13 includes an oven chamber (not shown) in which a heater and a cooler are arranged and the periphery thereof is covered with a heat insulating material, and the column 14 is accommodated in the oven chamber. The column oven 13 is arranged such that the outlet side end portion 14a of the column 14 arranged therein is positioned in line with a relay pipe 223 of the ionization probe 22 described later.

The mass spectrometer 2 includes an ion source 20 and an analysis unit 200. The ion source 20 and the analysis unit 200 are housed in a horizontally long casing (not shown) together with a vacuum pump (not shown) and the like. As shown in FIG. 3, the mass spectrometer 2 is a triple quadrupole mass spectrometer. The ion source 20 is an ESI ion source, and includes an ionization probe 22 that sprays charged droplets into an ionization chamber 21 that is maintained at an atmospheric pressure atmosphere. The ionization probe 22 has a capillary 221 through which a liquid sample having a low flow rate flows, and an inlet side end of the capillary 221 is connected to a relay pipe 223 by a joint 222, and an inlet side end of the relay pipe 223 is substantially formed. It is taken out of the housing horizontally. The inlet side end of the relay pipe 223 is inserted into the column oven 13 of the liquid chromatograph 1 and connected to the outlet side end 14 a of the column 14. The relay pipe 223 is made of a resin such as PEEK (polyether ether ketone) resin, for example, and the metal capillary 221 is not exposed to the outside of the ionization probe 22, so high safety can be secured.

The entire analysis unit 200 is housed in the vacuum chamber 201. The inside of the vacuum chamber 201 is partitioned into a first intermediate vacuum chamber 202, a second intermediate vacuum chamber 203, and a high vacuum chamber 204 from the side close to the ionization chamber 21. Each of the chambers 202 to 204 is evacuated by a vacuum pump to form a differential evacuation system in which the degree of vacuum gradually increases from the ionization chamber 21 to the high vacuum chamber 204.

The ionization chamber 21 and the first intermediate vacuum chamber 202 communicate with each other through a small-diameter desolvation tube 24. In the first intermediate vacuum chamber 202, a plurality of electrode plates arranged so as to surround the ion optical axis C are formed. The ion guide 205 is installed. The first intermediate vacuum chamber 202 and the second intermediate vacuum chamber 203 communicate with each other through a small hole at the top of the skimmer 206, and the second intermediate vacuum chamber 203 is composed of a plurality of rod electrodes surrounding the ion optical axis C. An ion guide 207 is installed. In the high vacuum chamber 204, a front quadrupole mass filter 208 and a rear quadrupole mass filter 211 are arranged with a collision cell 209 in which an ion guide 210 is arranged inside, and an ion detector 212. It is provided.

In the liquid chromatograph 1, the liquid feed pump 11 sucks and feeds the mobile phase stored in the mobile phase container 10. When a fixed amount of the sample solution is injected from the injector 12 into the mobile phase, the sample solution is introduced into the column 14 along with the flow of the mobile phase. Then, while the sample liquid passes through the column 14 whose temperature is controlled by the column oven 13, various components contained in the sample liquid are separated in the time direction and reach the outlet side end 14 a of the column 14. When the eluate containing the components separated in the column 14 is introduced into the capillary 221 via the relay pipe 223 of the ionization probe 22, charged droplets derived from the eluate are sprayed into the ionization chamber 21 from the end of the capillary 221. To be done. The charged droplets collide with the atmosphere to be atomized, and the sample components become gas ions in the process of evaporation of the solvent. The generated ions are carried by the gas flow formed by the pressure difference between both ends of the desolvation tube 24, sucked into the desolvation tube 24, and introduced into the first intermediate vacuum chamber 202.

As described above, the ions derived from the sample components introduced into the first intermediate vacuum chamber 202 are converged by the ion guide 205 and sent to the second intermediate vacuum chamber 203 through the small holes of the skimmer 206. The ions are converged by the ion guide 207, sent to the high vacuum chamber 204, and introduced into the front quadrupole mass filter 208. Among the ions derived from the sample components introduced, only ions having a specific mass-to-charge ratio corresponding to the voltage applied to the front quadrupole mass filter 208 pass through the front quadrupole mass filter 208, and the precursor ions Then, the collision cell 209 is entered. A CID (collision-induced dissociation) gas is continuously or intermittently introduced into the collision cell 209, and the precursor ions are dissociated by contacting the CID gas to generate various product ions. The product ions are introduced into the rear quadrupole mass filter 211, and only the product ions having a specific mass-to-charge ratio corresponding to the voltage applied to the rear quadrupole mass filter 211 pass through the rear quadrupole mass filter 211. It passes through and reaches the ion detector 212. The ion detector 212 generates a detection signal according to the amount of ions that have arrived.

In order to achieve high analytical sensitivity in the LC-MS, the axial direction (Z-axis direction) of the ionization probe 22 is determined according to the flow rate (liquid feeding speed) of the mobile phase in the liquid chromatograph 1 and the type of the mobile phase. It is desirable to adjust the position of. In order to perform such position adjustment, the ion source 20 of this embodiment includes a position adjusting mechanism 40 having the following characteristic configuration. The position adjusting mechanism 40 will be described in detail with reference to FIGS.

1 is a plan view of the ionization probe 22 mounted in the ionization chamber 21 as viewed from the left side. Further, FIG. 2 is a partial cross-sectional schematic configuration diagram in which only some of the constituent elements are shown in cross-sections (but not in the same plane) for easy understanding. 1 and 2, the same components as those in the conventional ion source shown in FIG. 4 are designated by the same reference numerals to clarify the correspondence.

In the ion source 20 of the present embodiment, the probe main body 220 of the ionization probe 22 has a substantially cylindrical shape as in the conventional case, and is held in a state of being inserted into the central opening of the probe holding portion 23 having a substantially annular shape. Outside the wall surface 21a of the ionization chamber 21, a screw receiving portion 41 having a screw hole formed on its inner peripheral side is fixed at a position separated from the ionization probe 22 by a predetermined distance. A shaft base 46 is fixed to the outside of the wall surface 21a of the ionization chamber 21 on the opposite side of the screw receiving portion 41 with the axis of the ionization probe 22 interposed therebetween on the X axis. There is. A shaft 46a extending in the Y-axis direction is attached to the shaft base 46.

The shaft body 46a rotatably supports the ends of the pair of flat plate rod-shaped portions of the arm 45 having a substantially U-shape including a pair of flat plate rod-shaped portions that are parallel to each other and extend linearly. The distance between the pair of flat plate rod-shaped portions of the arm 45 is larger than the outer diameter of the probe main body 220 of the ionization probe 22, and the length of the flat plate rod-shaped portion is about the same as the distance between the screw receiving portion 41 and the shaft base 46 or that. Is slightly longer than. The adjusting screw 42, which is screwed into the screw hole of the screw receiving portion 41, is provided with a connecting portion 48 having substantially cylindrical protrusions 48a on both sides thereof. The connecting portion 48 is attached to the adjusting screw 42 such that it does not interlock with the rotation of the adjusting screw 42 but interlocks with its advance/retreat in the Y axis direction. At the ends of the pair of flat plate rod-shaped portions of the arm 45 on the opposite side to the supporting position by the shaft body 46a, elongated slots 45a are formed in the extending direction of the flat plate rod-shaped portions, and the pair of flat portions of the connecting portion 48 are formed. The protrusion 48a is loosely fitted in the elongated hole 45a.

Further, the probe main body 220 is also provided with a pair of substantially cylindrical protrusions 47 extending in the Y-axis direction, and the pair of protrusions 47 is provided in the middle of the pair of flat plate rods of the arm 45 in the extending direction. It is loosely fitted into the long hole 45 b formed. That is, the arm 45 is rotatably supported by the shaft body 46a, is connected to the adjusting screw 42 at a position opposite to the rotation shaft, and is further moved in the Y-axis direction at the intermediate portion of the pair of flat plate rod-shaped portions. Is connected to the probe body 220. The position adjusting mechanism 40 having the arm 45 as a center uses the principle of leverage, and the pivotal support position by the shaft body 46a is a fulcrum, the connecting position by the protrusion 48a is a force point to which an external force is applied, and the protrusion The connecting position by the portion 47 can be regarded as the point of action.

When the operator rotates the head of the adjusting screw 42 to screw the adjusting screw 42 into the screw receiving portion 41, the connecting portion 48 moves in the Z-axis direction. Then, a force for rotating the arm 45 in the direction indicated by the arrow a in FIG. 2 is applied via the protrusion 48a, that is, from the force point. Thus, as the arm 45 rotates and approaches the X-axis direction, the protrusion 48a moves in the elongated hole 45a in the longitudinal direction. Thereby, the arm 45 can be smoothly rotated while linearly moving the adjusting screw 42 in the Z-axis direction.

When the arm 45 rotates in this way, a force is applied to the probe main body 220 via the elongated hole 45b and the protrusion 47. If the protrusion 47 is connected to the arm 45 through a round hole having no play, the rotation of the arm 45 is directly transmitted to the probe main body 220, and therefore the direction of the force applied to the probe main body 220 is not the axial direction. On the other hand, in the position adjusting mechanism 40, since the protrusion 47 is connected to the arm 45 through the elongated hole 45b, the protrusion 47 moves in the elongated hole 45b in the longitudinal direction as the arm 45 rotates. Move to. As a result, a force substantially along the axial direction (in the Z-axis direction) is applied to the probe main body 220 from the protrusion 47, that is, the point of action, and the ionization probe 22 moves smoothly in the Z-axis direction.

As described above, the operator can easily adjust the axial position of the ionization probe 22 by operating the adjustment screw 42. In this position adjusting mechanism 40, since the headstock 46, the adjusting screw 42 and the screw receiving portion 41 are arranged on both sides of the ionizing probe 22 with the ionizing probe 22 interposed therebetween, the ionizing probe 22 is ionized compared to the amount of movement of the adjusting screw 42 in the Z-axis direction. The amount of movement of the probe 22 in the Z-axis direction is small. Therefore, it is possible to easily perform fine position adjustment of the ionization probe 22 in the axial direction.

As the distance between the fulcrum and the action point decreases, the direction of the force applied to the action point inclines with respect to the Z-axis direction. Therefore, it is desirable that the distance between the fulcrum and the action point is long, and it is preferable that the headstock 46 is separated from the probe body 220 as much as possible. Further, the distance between the adjusting screw 42 and the screw receiving portion 41 and the ionization probe 22 should be long enough that the adjusting screw 42 and the screw receiving portion 41 do not hinder the maintenance of the ionization probe 22 and the installation of the column oven 13. Good.

Further, the above embodiment is merely one example of the present invention, and it is needless to say that appropriate changes, modifications and additions are made within the scope of the claims of the present invention within the scope of the present invention.

For example, although the ion source of the above-mentioned embodiment performs ionization by the ESI method, it may perform ionization by the APCI method or APPI method. In the ion source by the APCI method, a needle electrode that causes a corona discharge is arranged in front of a spray flow of sample droplets, and the corona discharge generated by the high voltage applied to the needle electrode causes the buffer gas introduced into the ionization chamber. Alternatively, the solvent gas vaporized from the liquid sample is ionized. Then, by chemically reacting the gas ions with the vaporized sample component, the sample component may be ionized. Further, in the ion source by the APPI method, the spray flow of the sample droplets may be irradiated with light of a predetermined wavelength (ultraviolet light), and the vaporized sample components may be ionized by the light energy.

Further, the example shown in FIG. 3 is an example in which the ion source according to the present invention is applied to LC-MS, but ions derived from sample components generated by the ESI method or the like are separated according to ion mobility and detected. The ion source according to the present invention is applied to an ion mobility spectrometer and an ion mobility-mass spectrometer that separates ions derived from a generated sample component according to ion mobility and then further separates according to mass-to-charge ratio. It is also clear that it is applicable.

DESCRIPTION OF SYMBOLS 1... Liquid chromatograph 10... Mobile phase container 11... Liquid feed pump 12... Injector 13... Column oven 14... Column 14a... Exit side end 15... Joint 2... Mass spectrometer 20... Ion source 200... Analysis part 201... Vacuum Chamber 202... First intermediate vacuum chamber 203... Second intermediate vacuum chamber 204... High vacuum chambers 205, 207, 210... Ion guide 206... Skimmer 208... Pre-quadrupole mass filter 209... Collision cell 211... Post-quadrupole mass Filter 212... Ion detector 21... Ionization chamber 21a... Wall surface 22... Ionization probe 220... Probe body 220a... Nozzle 221, Capillary 222... Joint 223... Relay pipe 23... Probe holding part 24... Desolvation pipe 40... Position adjustment mechanism 45 ... Arms 45a, 45b... Long holes 46... Shaft base 46a... Shaft bodies 47, 48a... Projection portion 48... Connecting portion

Claims (7)

An ionization chamber; and an ionization probe that has a nozzle for spraying a liquid sample into the ionization chamber and is held in a state of being inserted into an opening formed in a wall surface of the ionization chamber so as to be movable in the axial direction thereof. Then, in the ion source for ionizing the components contained in the liquid sample sprayed into the ionization chamber by the ionization probe,
a) an adjusting operation unit arranged outside the ionization chamber at a position apart from the ionization probe, and movable in the same direction as the axial direction of the ionization probe according to an operation from the outside,
b) an arm shaft support portion arranged outside the ionization chamber at a position opposite to the adjustment operation portion with the ionization probe interposed therebetween,
c) The arm shaft support part has a rod-shaped part whose one end is axially supported, and the other end is movably and rotatably attached to the adjustment operation part in a predetermined range in the extending direction of the rod-shaped part, An arm portion attached to the ionization probe so as to be movable and rotatable in a predetermined range in the extending direction at an intermediate position of the rod-shaped portion;
An ion source comprising: The ion source according to claim 1, wherein
The ion source characterized in that the adjusting operation part includes a screw receiving part whose position is fixed to a wall surface of the ionization chamber, and an adjusting screw having a screw part screwed into the screw receiving part. .. The ion source according to claim 1, wherein
The ion source, wherein the arm portion is a U-shaped member in a top view including two linear rod portions arranged in parallel with the ionization probe interposed therebetween. An ion analyzer comprising the ion source according to claim 1. The ion analyzer according to claim 4, wherein
An eluate containing components separated by a column of a liquid chromatograph is introduced into the ion source of the ion analyzer, and the outlet side end of the column and the inlet side of a capillary which is a sample flow path in the ionization probe. An ion analyzer characterized by being directly connected to the end. The ion analyzer according to claim 5, wherein
An ion analyzer, wherein the ions generated by the ion source or the ions derived from the ions are separated and detected according to the mass-to-charge ratio. The ion analyzer according to claim 5, wherein
An ion analyzer, wherein ions generated by the ion source or ions derived from the ions are separated and detected according to ion mobility.

Images