JP6747601B2 - Ionization probe and ion analyzer - Google Patents

Description

The present invention is an ionization probe for spraying a liquid sample for ionization by an ionization method such as an electrospray ionization (ESI) method, an atmospheric pressure chemical ionization (APCI) method, or an atmospheric pressure photoionization method (APPI), and The present invention relates to an ion analyzer such as a mass analyzer or an ion mobility analyzer that performs ionization using the ionization probe.

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.

In general LC-MS, an eluate containing components separated by a column of a liquid chromatograph is transported from a column outlet to an ionization probe of a mass spectrometer through a pipe having an appropriate length. The longer this pipe is, the larger the diffusion (spreading in the time direction) of each component during the liquid feeding becomes, and the sensitivity of component detection in the mass spectrometer decreases. Such a decrease in detection sensitivity due to the diffusion of components becomes a problem particularly when a small amount of sample is measured at a low flow rate as described above. In order to suppress the diffusion of the components separated in the column, it is desirable to make the pipe of the eluate from the column end to the ionization probe as short as possible and make its inner diameter small. For example, Patent Document 1 discloses a device in which an outlet end of a column is directly connected to an inlet end of a capillary which is a sample flow path of an ionization probe.

However, if the outlet end of the column and the inlet end of the capillary of the ionization probe are directly connected in this way, or if the outlet end of the column and the inlet end of the capillary of the ionization probe are connected by a very short relay pipe, There is such a problem.
FIG. 4A is a schematic cross-sectional configuration diagram of a conventional general ionization probe 40 (see Patent Document 2, etc.).

The probe main body 41 mounted on the wall surface 21a of the ionization chamber 21, which has a substantially atmospheric pressure atmosphere, has a substantially conical nozzle 41a at its tip, and the tip of the nozzle 41a is opened to serve as a jet port 41b. A nebulizing gas flow channel 41c is formed inside the probe main body 41, and the nebulizing gas supplied from the outside to the probe main body 41 through the nebulizing gas pipe 43 is ejected from the ejection port 41b into the ionization chamber 21 through the nebulizing gas flow channel 41c. To do. At the end of the probe main body 41 on the side opposite to the nozzle 41a in the axial direction, a joint receiving port 41d having an internal thread portion on the inner peripheral surface is formed. The joint 42 for connecting the capillary 44 and the external pipe 45 to the outlet end of the column (not shown) has a substantially columnar shape, and a male screw portion is formed on the outer periphery thereof. The joint 42 has an external pipe insertion hole 42a, and the capillary 44 is held by the joint 42 in a state where the inlet side end of the capillary 44 is open to the bottom of the external pipe insertion hole 42a. By screwing this joint 42 into the joint receiving opening 41d of the probe body 41, the capillary 44 is held near the central axis of the nebulized gas flow channel 41c. Then, as shown in FIG. 4B, by inserting the external pipe 45 into the external pipe insertion hole 42 a of the joint 42, the external pipe 45 and the capillary 44 communicate with each other.

At the time of ionization by the ESI method, a high voltage is applied from a high voltage source (not shown) to the tip of the metal capillary 44 (or a cylindrical metal tube surrounding the tip of the glass capillary). When the liquid sample supplied to the capillary 44 through the external pipe 45 reaches the tip portion of the capillary 44, the liquid sample is charged by the action of the electric field, and the nebulized gas ejected from the ejection port 41b in substantially the same direction as the axial direction of the capillary 44 is discharged. Aided droplets are sprayed with help. The charged droplets collide with the air in the ionization chamber 21 to be atomized, and the solvent evaporates from the droplets, and in the process of atomization, the sample components fly out from the droplets as gas ions. Thus, the ions derived from the sample components are generated.

As shown in FIG. 4A, the outlet end of the capillary 44 projects a predetermined length (hereinafter, this length is referred to as a "projection amount") d from the nebulized gas ejection port 41b. The size of droplets to be sprayed and the like change depending on the protrusion amount d, and the ionization efficiency changes. Therefore, in order to achieve high detection sensitivity, it is necessary to appropriately adjust the protrusion amount d according to the flow rate of the liquid sample flowing through the capillary 44, the type of solvent (mobile phase in LC-MS), and the like. Particularly in the above-described low flow rate measurement, the influence of the protrusion amount d on the detection sensitivity is significant, and the adjustment of the protrusion amount d is even more important.

In the conventional ionization probe 40 shown in FIG. 4, the inlet end of the capillary 44 is fixed to the joint 42. Therefore, the protrusion amount d of the capillary 44 can be adjusted by changing the length of screwing the joint 42 into the joint receiving opening 41d. That is, as shown in FIG. 4(b), when the joint 42 is rotated so that the joint 42 is screwed deeper into the joint receiving opening 41d, the entire capillary 44 advances forward (downward in FIG. 4) and its protrusion amount. d becomes large.

In this configuration, since the joint 42 is rotated when the protrusion amount d of the capillary 44 is adjusted, the end portion of the external pipe 45 connected to the joint 42 also rotates around the axis. Usually, the external pipe 45 is a resin tube having flexibility and flexibility, and has a certain length, so that even if the end portion of the external pipe 45 is rotated around the axis, the rotation of the external pipe 45 is prevented. It is absorbed by the twist in the middle of 45. However, when the outlet end of the column and the inlet end of the capillary are directly connected, the rotation around the axis as described above cannot be absorbed. Further, even when the outlet end of the column and the inlet end of the capillary are connected via a very short relay pipe, such short relay pipe cannot sufficiently absorb the rotation around the axis as described above. Normally, the column is fixed to the column oven, and therefore, forcibly rotating the capillary 44 may damage the relay pipe. Therefore, when the outlet end of the column is directly connected to the inlet end of the capillary of the ionization probe, or when the outlet end of the column is connected to the inlet end of the capillary of the ionization probe with a very short relay pipe, the capillary There is a problem that the conventional mechanism as described above cannot be adopted to adjust the protrusion amount.

In addition, when the outlet end of the column is directly connected to the inlet end of the capillary of the ionization probe, or when the outlet end of the column is connected to the inlet end of the capillary of the ionization probe with a very short relay pipe, the column oven and the ionization probe Since the space between them becomes narrow, the work itself of rotating the joint 42 is very difficult.

U.S. Patent No. 9095791 Japanese Patent Laid-Open No. 2008-21455

The present invention has been made to solve the above problems, and its object is to directly connect the outlet side end of the column of the liquid chromatograph and the inlet side end of the capillary of the ionization probe or , Even when connecting the outlet end of the column and the inlet end of the capillary of the ionization probe with a very short relay pipe, the protrusion amount of the capillary can be adjusted accurately without rotating the column around the axis. (EN) Provided are an ionization probe and an ion analyzer using the ionization probe.

The present invention made to solve the above-mentioned problems comprises a capillary through which a liquid sample flows, and a probe main body having a nozzle provided with a nozzle for ejecting a nebulizing gas in the axial direction of the capillary on the tip side. Then, an ionization probe for spraying a liquid sample to ionize the components contained in the liquid sample, comprising an adjusting mechanism for adjusting the axial position of the capillary with respect to the ejection port, the adjusting mechanism comprising:
a) A capillary or a straight pipe connected coaxially to the capillary is held at the inlet end of the capillary, and rotation of the capillary around the axis is restricted with respect to the probe main body, while the capillary is movable in the axial direction. A first movable part that is attached to the probe main body and has a screw part formed on a part of the outer peripheral surface that is substantially cylindrical;
b) has a substantially cylindrical inner peripheral surface having a threaded portion that is screwed into the threaded portion of the first movable portion, and restricts axial movement of the capillary with respect to the probe main body, A second movable part mounted on the probe body so as to be rotatable around the axis of the capillary;
It is characterized by including.

The ionization probe according to the present invention typically sprays a liquid sample into an ionization chamber under an atmospheric pressure atmosphere for ionization by the ESI method, the APCI method, or the APPI method.

In the ionization probe according to the present invention, the first movable portion is movable in the axial direction of the capillary with respect to the probe main body, but the rotation of the capillary about the axis is restricted. On the other hand, the movement of the second movable portion with respect to the probe main body in the axial direction is restricted, but the second movable portion is rotatable about the axis of the capillary. For example, when the second movable portion is directly or indirectly rotated by a user's operation, the first movable portion is screwed by the screw portion of the second movable portion and the screw portion of the first movable portion. Although the power is transmitted, the rotation of the first movable portion is restricted. On the other hand, the first movable portion is movable in the axial direction of the capillary. Therefore, when the second movable portion is rotated, the screwed portion of the screw portion of the second movable portion and the screw portion of the first movable portion moves in the axial direction. Since the movement of the second movable portion in the axial direction of the capillary is restricted, the first movable portion moves in the axial direction relative to the second movable portion by the amount of movement of the screwed portion in the axial direction. ..

That is, the first movable portion moves in the axial direction of the capillary with respect to the probe body. As a result, the capillary held in the first movable portion or the straight pipe arranged integrally with the capillary moves in the axial direction, and the position of the capillary in the axial direction with respect to the ejection port changes. At this time, neither the capillaries nor the straight pipes rotate around the axis, but simply move straight in the axial direction.

As an aspect of the ionization probe according to the present invention, the first movable part is a substantially columnar conduit holding part that holds the capillary or the straight tubular pipe along a central axis thereof, and the conduit holding part. Is a substantially annular body fixed to the periphery of the probe, has a threaded portion formed on the outer peripheral surface thereof, and has a regulation pin inserted into a pin hole formed in the axial direction of the capillary in the probe main body. A stop portion can be included.

In addition, in this configuration, the pipe line holding portion may be integrated by press-fitting the pipe line holding portion inside the rotation holding portion, but the screw portion formed on the outer peripheral surface of the pipe line holding portion and the rotation holding portion may be integrated. Both may be integrated by screwing with a screw portion formed on the inner peripheral surface. Thereby, the pipe line holding portion can be removed from the rotation retaining portion while the rotation retaining portion is attached to the second movable portion, and the capillary and the straight pipe can be pulled out from the probe main body. In particular, when the inner diameter of the capillary is small, there is a problem that the liquid sample is likely to be clogged, but the above configuration improves the maintainability of the capillary.

Further, in the ionization probe according to the present invention, preferably, an adjusting knob installed at a position deviated from a rotation axis of the second movable section, and a rotational driving force of the adjusting knob is transmitted to the second movable section. It is preferable to further include a transmission mechanism section that rotates the second movable section.

As the transmission mechanism portion, an appropriate one such as a gear, a combination of a pulley and a belt, and a combination of a sprocket and a roller chain can be used. Further, the rotary shaft of the adjusting knob and the rotary shaft of the second movable portion may be parallel to each other, but the direction of the rotary shaft may be changed by using a bevel gear or the like.

With this configuration, the adjustment knob operated by the user can be arranged at a position appropriately separated from the rotation axis of the second movable portion. As a result, it is not necessary to provide an adjusting knob near the inlet side end of the capillary, and it is not necessary to secure a space in which the user can operate. Therefore, for example, it becomes easy to connect the inlet end of the capillary or the straight pipe to the outlet end of the column of the liquid chromatograph.

Further, in the ionization probe having the above-described preferable configuration, the transmission mechanism section may have a configuration in which a gear ratio between the adjustment knob and the second movable section is 1 or more.

According to this configuration, the amount of movement of the capillary with respect to the amount of rotation of the adjustment knob is small, so that fine adjustment of the position of the capillary is easy. This makes it easier to obtain high detection sensitivity by adjusting the amount of protrusion of the capillaries.

The ion analyzer according to the present invention is characterized by including an ion source using the ionization probe 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 capillary or the straight pipe is connected to the inlet-side end of the pipe.

As described above, when connecting the outlet side end of a liquid chromatograph column to the inlet side end of a capillary or a very short relay pipe, it is difficult to rotate the capillary around its axial direction. With the ionization probe according to the invention, the amount of protrusion of the capillary can be easily and accurately adjusted without rotating the capillary or the relay pipe itself around its axial direction. Therefore, the ionization probe according to the present invention has a configuration in which the outlet side end of the column of the liquid chromatograph and the inlet side end of the capillary are directly connected, or the outlet side end of the column and the inlet side end of the capillary are very short. It is suitable for a configuration in which connection is made via a relay pipe. Thus, by directly connecting the outlet side end of the column and the inlet side end of the capillary, or by connecting the outlet side end of the column and the inlet side end of the capillary with a very short relay pipe, Diffusion of the components separated by the column is suppressed, and highly sensitive analysis can be performed.

According to the ionization probe of the present invention, the amount of protrusion of the capillary can be adjusted accurately without rotating the capillary about its axis. Thereby, by using the ionization probe according to the present invention, the outlet side end of the column of the liquid chromatograph of the preceding stage and the inlet side end of the capillary of the ionization probe are directly connected, or the outlet side end of the column is ionized. The probe can be connected to the inlet side end of the capillary with a very short relay pipe, and highly sensitive analysis can be performed while suppressing the diffusion of the components separated in the column.

FIG. 3 is a schematic cross-sectional view of a main part of an ionization probe that is an embodiment of the present invention. FIG. 8 is an operation explanatory view when adjusting the amount of capillary projection in 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 ionization probe 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 schematic cross-sectional view of the main part of the ionization probe of this embodiment. FIG. 2 is an operation explanatory diagram when adjusting the amount of capillary projection in the ionization probe of the present embodiment. FIG. 3 is a schematic configuration diagram of one embodiment of LC-MS using the ionization probe of this embodiment.

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 is provided with a heater and a cooler, and has an oven chamber (not shown) whose periphery 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 aligned with the relay pipe 25 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 23 through which a liquid sample having a low flow rate flows, and an inlet side end of the capillary 23 is connected to a relay pipe 25 by a joint 24, and the inlet side end of the relay pipe 25 is substantially formed. It is taken out of the housing horizontally. The inlet side end of the relay pipe 25 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 25 is made of a resin such as PEEK (polyetheretherketone) resin, and the metal capillary 23 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 are communicated with each other through a small-diameter desolvation pipe 26, and a plurality of electrode plates arranged so as to surround the ion optical axis C are provided in the first intermediate vacuum chamber 202. 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 23 through the relay pipe 25 of the ionization probe 22, charged droplets derived from the eluate are sprayed into the ionization chamber 21 from the end of the capillary 23. It 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 produced ions are carried by the gas flow formed by the pressure difference between the both ends of the desolvation tube 26, sucked into the desolvation tube 26, 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 this LC-MS, the outlet end 14a of the column 14 and the inlet end of the capillary 23 are connected via a very short PEEK relay pipe 25. Therefore, the amount of protrusion of the capillary 23 cannot be adjusted by rotating the capillary 23 around its axis as in the conventional case. Therefore, the ionization probe 22 of this embodiment is equipped with the following characteristic adjusting mechanism.

1 and 2, in the ionization probe 22 of the present embodiment, the vicinity of the base of the probe main body 220 located outside the ionization chamber 21 (B in FIG. 4) that holds the relay pipe 25 that is integral with the capillary 23. FIG. 3 is a schematic cross-sectional view of a portion indicated by. In the conduit holding portion 221 corresponding to the joint 42 in the conventional ionization probe shown in FIG. 4, the inlet end of the relay pipe 25 connected to the capillary 23 by the joint 24 extends outside the ionization chamber 21. The outer peripheral surface of the relay pipe 25 is held. In FIG. 3, the left-right direction is the axial direction of the capillary 23 (that is, the axial direction of the relay pipe 25), but in FIGS. 1 and 2, the vertical direction is the axial direction of the capillary 23. A male screw portion 221a is formed on a part of the outer peripheral surface of the conduit holding portion 221 which is substantially cylindrical. On the other hand, a female screw portion 222a that is screwed with the male screw portion 221a of the conduit holding portion 221 is formed on the inner peripheral surface of the through hole of the rotation stopping portion 222 that is substantially annular. The pipe line holding portion 221 is strongly tightened into the rotation hooking portion 222 so that the male screw portion 221a of the pipe line holding portion 221 is screwed into the female screw portion 222a of the rotation hooking portion 222, and the both are substantially integrated. ing. The conduit holding portion 221 and the rotation stopping portion 222 correspond to the first movable portion in the present invention.

A plurality of hooking pins 222c are erected on a plane of the rotation hooking portion 222 facing the probe body 220 so as to extend in the axial direction of the capillary 23. On the other hand, a plurality of pin holes 220a are formed in the probe main body 220 so as to extend in the axial direction of the capillary 23, and the conduit holding portion 221 and the rotation hooking portion 222 have a plurality of hooking pins 222c, respectively. It is attached to the probe main body 220 while being inserted into the hole 220a. A male screw portion 222b is also formed on the outer peripheral surface of the rotation hooking portion 222 having a substantially cylindrical shape, and a nut 223 in which a female screw portion 223a screwed to the male screw portion 222b is formed on the inner peripheral surface is a rotation hooking portion. It is attached to the outside so as to cover 222. The flange 223b protruding outward from the peripheral edge of the nut 223 is pressed against the probe main body 220 with some play by a fixing plate 224 fixed to the probe main body 220. As a result, the nut 223 is rotatable about its axis, but the movement of the capillary 23 in the axial direction is restricted. The nut 223 corresponds to the second movable portion in the present invention.

Further, a large gear 226 is fitted on the outer periphery of the nut 223, and a small gear 225 meshing with the large gear 226 is rotatably arranged around a shaft body 227 erected on the fixed plate 224. There is. Then, an adjustment knob 228 for a user to operate is attached to an end portion of the shaft body 227. As a matter of course, the number of teeth of the large gear 226 is much larger than that of the small gear 225, and the gear ratio of the power transmission mechanism including the small gear 225 and the large gear 226 is a value sufficiently larger than 1. Is.

In the adjusting mechanism of the ionization probe 22, the capillary 23, the relay pipe 25, the conduit holding portion 221 and the rotation stopping portion 222 are substantially integrated. On the other hand, the large gear 226 and the nut 223 are also substantially integrated. Then, the female screw portion 223a of the nut 223 and the male screw portion 222b of the rotation stopper 222 are screwed together. In this state, as shown in FIG. 2, when the adjustment knob 228 is rotated to rotate the small gear 225 about the shaft body 227, the large gear 226 meshed with the small gear 225 moves in the opposite direction. Rotate. Along with this, the nut 223 also rotates in the same direction as the large gear 226. However, since the movement of the nut 223 in the axial direction of the capillary 23 is restricted, the nut 223 only rotates at that position. On the other hand, the female screw portion 223a of the nut 223 and the male screw portion 222b of the rotation locking portion 222 are screwed together, and the rotation locking portion 222 cannot rotate due to the locking pin 222c and the pin hole 220a being locked. Therefore, when the nut 223 rotates, the screwing position of the female screw portion 223a and the male screw portion 222b moves in the axial direction of the capillary 23. Since the rotation stopping portion 222 is movable in a predetermined range in the axial direction of the capillary 23, when the nut 223 rotates and the screwing position moves, the rotation stopping portion 222 itself moves in the axial direction of the capillary 23. To do. As a result, the relay pipe 25 held by the pipe holding portion 221 and the capillary 23 connected thereto move integrally in the axial direction. FIG. 2 shows a state in which the rotation stopper 222 has moved in the axial direction of the capillary 23 to a position closest to the probe main body 220.

That is, when the user rotates the adjustment knob 228, the rotational driving force is converted into a linear movement of the capillary 23 in the axial direction, and the relay pipe 25 and the capillary 23 move in the axial direction. Thereby, the amount of protrusion d of the capillary 23 from the ejection port 41b of the nebulizing gas can be adjusted. Even during the adjustment, the relay pipe 25 and the capillary 23 do not rotate around the axis, and, as a matter of course, as shown in FIG. 3, the column 14 connected to the inlet end of the relay pipe 25 is used. The outlet end 14a of the does not rotate about its axis. Further, since the length of the relay pipe 25 itself is short in order to prevent the components from diffusing in the relay pipe 25, the root of the ionization probe 22 and the column oven 13 come close to each other, and the gap between them becomes considerably narrow. On the other hand, the user can adjust the protrusion amount d by rotating the adjusting knob 228 provided at a position sufficiently long distance A away from the position of the capillary 23, which is the rotation center of the large gear 226. The column oven 13 is less likely to interfere with the operation of the adjustment knob 228. Therefore, high operability and workability can be realized.

Further, since the gear ratio of the small gear 225 and the large gear 226, which are rotationally driven by the adjustment knob 228, is sufficiently larger than 1, the rotation angle of the nut 223 is considerably smaller than the rotation angle of the adjustment knob 228. Thereby, for example, when the user rotates the adjustment knob 228 one rotation, the distance that the capillary 23 moves in the axial direction is small. Therefore, it is easy to finely adjust the protrusion amount d, and the protrusion amount d can be finely adjusted so that high detection sensitivity is achieved.

In the embodiment described above, the rotation of the adjusting knob 228 is transmitted to the nut 223 by the small gear 225 and the large gear 226. However, instead of the gear, for example, a combination of a pulley and a belt, a sprocket and a roller chain are used. An appropriate power transmission mechanism such as a combination can be used. Further, in the above-described embodiment, the rotary shaft of the small gear 225 and the rotary shaft of the large gear 226 are parallel to each other. However, a bevel gear or the like may be used to obliquely intersect both rotary shafts. Further, the conduit holding portion 221 and the rotation stopping portion 222 may not be separate members, but may be a single member from the beginning. Alternatively, the capillary 23 may be held by the conduit holding portion 221 without using the relay pipe 25, and the inlet end of the capillary 23 may be directly connected to the outlet end of the column 14. Further, the shape of each member can be changed appropriately.

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 ionization probe of the above-mentioned embodiment performs ionization by the ESI method, it may perform ionization by the APCI method or the APPI method. When changing to an ionization probe by the APCI method, a needle electrode that causes a corona discharge is arranged in front of the spray flow of sample droplets, and the corona discharge generated by the high voltage applied to this needle electrode causes the ionization chamber to move. The solvent gas vaporized from the buffer gas or the liquid sample introduced into the column is ionized. Then, by chemically reacting the gas ions with the vaporized sample component, the sample component may be ionized. Further, in the case of changing to an ionization probe by the APPI method, the spray flow of 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 embodiment shown in FIG. 3 is an example in which the ionization probe according to the present invention is applied to LC-MS, but the ions generated by spraying the liquid sample into the ionization chamber by the ionization probe are changed according to the ion mobility. The present invention relates to an ion mobility spectrometer that separates and detects a sample and an ion mobility-mass spectrometer that separates ions derived from a sample component according to ion mobility and then further separates according to mass-to-charge ratio. It is also clear that an ionization probe can be applied.

DESCRIPTION OF SYMBOLS 1... Liquid chromatograph 10... Mobile phase container 11... Liquid feed pump 12... Injector 13... Column oven 14... Column 14a... Outlet side end 2... Mass spectrometer 20... Ion source 21... Ionization chamber 21a... Wall surface 22... Ionization Probe 220... Probe body 220a... Pin hole 221... Pipe line holding part 221a... Male screw part 222... Rotation stop part 222a... Female screw part 222b... Male screw part 222c... Locking pin 223... Nut 223a... Female screw part 223b... Flange 224... Fixed plate 225... Small gear 226... Large gear 227... Shaft body 228... Adjustment knob 23... Capillary 24... Joint 25... Relay pipe 26... Desolvation pipe 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... Front quadrupole mass filter 209... Collision cell 211... Rear quadrupole mass filter 212... Ion detector

Claims (8)

A liquid sample is included in the liquid sample by spraying the liquid sample and a probe main body having a nozzle provided on the tip side with a nozzle for ejecting nebulizing gas in the axial direction of the capillary. An ionization probe for ionizing a component, comprising an adjustment mechanism for adjusting the axial position of the capillary with respect to the ejection port, the adjustment mechanism comprising:
a) A capillary or a straight pipe connected coaxially to the capillary is held at the inlet end of the capillary, and rotation of the capillary around the axis is restricted with respect to the probe main body, while the capillary is movable in the axial direction. A first movable part that is attached to the probe main body and has a screw part formed on a part of the outer peripheral surface that is substantially cylindrical;
b) has a substantially cylindrical inner peripheral surface having a threaded portion screwed into the threaded portion of the first movable portion, and is attached to the probe main body so as to be rotatable around the axis of the capillary. 2 movable parts,
An ionization probe comprising: The ionization probe according to claim 1, wherein
The first movable portion is a substantially columnar conduit holding portion that holds the capillary or the straight tubular pipe along a central axis thereof, and a substantially annular body fixed around the conduit holding portion. And a rotation locking portion having a restriction pin inserted into a pin hole formed in the axial direction of the capillary in the probe main body, with a threaded portion formed on the outer peripheral surface thereof. Ionization probe. The ionization probe according to claim 1, wherein
An adjusting knob installed at a position off the rotation axis of the second movable section, and a transmission mechanism section for transmitting the rotational driving force of the adjusting knob to the second movable section to rotate the second movable section. An ionization probe, further comprising: The ionization probe according to claim 3, wherein
The ionization probe, wherein the transmission mechanism section has a gear ratio of 1 or more between the adjusting knob and the second movable section. An ion analyzer equipped with an ion source using the ionization probe according to claim 1. The ion analyzer according to claim 5, wherein
Introducing an eluate containing components separated by a column of a liquid chromatograph into the ion source of the ion analyzer, the outlet side end of the column and the capillary or the inlet side end of the straight pipe. An ion analyzer characterized by being connected to. The ion analyzer according to claim 6, 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 6, 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.

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