JPWO2019049271A1 - Ionization probe and ion analyzer - Google Patents

Abstract

The pipeline holding part (221) holding the PEEK relay pipe (25) connected to the capillary (23) is fastened to the rotation hooking part (222), and the rotation hooking part (222) is connected to the probe body (221). ) Is movable in the axial direction of the capillary (23), while the rotation around the axis is restricted. The female thread (223a) of the nut (223), which rotates in conjunction with the operation of the adjustment knob (228) via the gears (225, 226), is screwed with the male thread (222b) of the rotation retaining part (222). are doing. Since the rotation of the rotation retaining portion (222) is restricted, when the nut (223) rotates, the screwing portion of the female screw portion (223a) and the male screw portion (222b) moves in the axial direction. The rotation hook (222) moves in the axial direction. Thereby, the capillary (23) moves in the axial direction without rotating around the axis, and the protrusion amount of the capillary (23) with respect to the gas ejection port is adjusted.

Description

  The present invention provides an ionization probe that sprays a liquid sample to perform ionization by 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 spectrometer or an ion mobility analyzer for performing ionization using the ionization probe.

  In a liquid chromatograph mass spectrometer (hereinafter abbreviated as “LC-MS” as appropriate) combining a liquid chromatograph and a mass spectrometer, an eluate containing various components separated in a time direction by a column of the liquid chromatograph is used. After being introduced into the mass spectrometer and ionized by the ion source of the mass spectrometer, 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 an ESI method, an APCI method, or an APPI method is used to ionize components in a liquid sample.

  In recent years, particularly in the fields of biochemistry, medicine, drug development, etc., the amount of a sample to be analyzed is often very small or the sample is valuable or expensive. Analysis is required. In order to respond to such demands, liquid chromatography employs a method of using a small-diameter column and reducing the flow rate of a mobile phase supplied to the column. In response to this, the ion source of the mass spectrometer employs a technique called nano-ESI or micro-ESI for efficiently ionizing the components in the eluate while suppressing the flow rate of the eluate introduced into the ionization probe. Have been.

  In general LC-MS, an eluate containing components separated by a column of a liquid chromatograph is transported from a column outlet through a pipe of an appropriate length to an ionization probe of a mass spectrometer. The longer the pipe, the greater the diffusion (spreading in the time direction) of each component during the liquid feeding, and the lower the sensitivity of component detection in the mass spectrometer. Such a decrease in detection sensitivity due to the diffusion of components is particularly problematic 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 by the column, it is desirable to shorten the piping of the eluate from the end of the column to the ionization probe as much as possible and to reduce the inner diameter thereof. For example, Patent Literature 1 discloses an apparatus 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 is directly connected to the inlet end of the capillary of the ionization probe, or if the outlet end of the column is connected to the inlet end of the capillary of the ionization probe 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 and the like).

  The probe main body 41 attached to the wall surface 21a of the ionization chamber 21, which is in a substantially atmospheric pressure atmosphere, has a substantially conical nozzle 41a at the tip, and the tip of the nozzle 41a is opened to form an ejection 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 jet port 41b into the ionization chamber 21 through the nebulizing gas flow channel 41c. I do. At an end of the probe main body 41 opposite to the nozzle 41a in the axial direction, a joint receiving port 41d having a female screw portion on an inner peripheral surface is formed. The joint 42 connecting the external pipe 45 to the outlet end of the column (not shown) and the capillary 44 has a substantially columnar shape, and has an external thread 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 end thereof is opened at the bottom of the external pipe insertion hole 42a. By screwing this joint 42 into the joint receiving port 41d of the probe main 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 42a of the joint 42, the external pipe 45 and the capillary 44 communicate with each other.

  During ionization by the ESI method, a high voltage is applied to the tip of the metal capillary 44 (or a cylindrical metal tube surrounding the outside of the tip of the glass capillary) from a high voltage source (not shown). When the liquid sample supplied to the capillary 44 through the external pipe 45 reaches the tip 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. With the help, they are sprayed as charged droplets. The charged droplet collides with the air in the ionization chamber 21 to be miniaturized. Further, in a process in which the solvent evaporates from the droplet and the miniaturization proceeds, the sample component jumps out of the droplet as gas ions. Thus, ions derived from the sample components are generated.

  As shown in FIG. 4A, the outlet end of the capillary 44 protrudes by a predetermined length d (hereinafter, this length is referred to as “projection amount”) d from the nebulizing gas outlet 41b. The size and the like of the droplet to be sprayed change according to the amount of protrusion d, and the ionization efficiency changes. Therefore, in order to achieve high detection sensitivity, it is necessary to appropriately adjust the protrusion amount d in accordance with the flow rate of the liquid sample flowing through the capillary 44 and the type of the solvent (mobile phase in LC-MS). In particular, in the measurement of the low flow rate described above, the influence of the protrusion amount d on the detection sensitivity is remarkable, 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, by changing the length of screwing the joint 42 into the joint receiving port 41d, the protrusion amount d of the capillary 44 can be adjusted. That is, as shown in FIG. 4B, when the joint 42 is rotated so that the joint 42 is screwed deeper into the joint receiving port 41d, the entire capillary 44 advances forward (downward in FIG. 4), and the protrusion amount thereof d increases.

  In this configuration, since the joint 42 is rotated when adjusting the protrusion amount d of the capillary 44, the end 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. Therefore, even if the end portion is rotated around the axis, the rotation is not caused by the external pipe. It is absorbed by the twist in the middle of 45. However, when the outlet end of the column is directly connected to the inlet end of the capillary, the rotation around the axis as described above cannot be absorbed. Even when the outlet end of the column and the inlet end of the capillary are connected via a very short relay pipe, such a short relay pipe cannot sufficiently absorb the rotation around the axis as described above. Usually, since the column is fixed to the column oven, if the capillary 44 is forcibly rotated, the relay pipe may be damaged. For this reason, 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 is not connected. There is a problem that the above-described conventional mechanism for adjusting the amount of protrusion cannot be adopted.

  Also, 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 by a very short relay pipe, the column oven and the ionization probe are not connected. Since the space between the two is narrowed, the operation itself of rotating the joint 42 is very difficult.

U.S. Patent No. JP 2008-21455 A

  The present invention has been made in order to solve the above-described problems, and has an object to directly connect an outlet end of a column of a liquid chromatograph to an inlet end of a capillary of an ionization probe. Even when the outlet end of the column and the inlet end of the capillary of the ionization probe are connected with a very short relay pipe, the amount of protrusion of the capillary is accurately adjusted without rotating the column around the axis. It is an object of the present invention to provide an ionization probe capable of performing the above-mentioned steps and an ion analyzer using the ionization probe.

Means for Solving the Problems The present invention made to solve the above problems includes a capillary through which a liquid sample flows, and a probe main body having a nozzle provided at a distal end side with an ejection port for ejecting a nebulizing gas in the axial direction of the capillary. An ionization probe for spraying a liquid sample to ionize a component contained in the liquid sample, comprising an adjustment mechanism for adjusting an axial position of the capillary with respect to the ejection port, the adjustment mechanism comprising:
a) holding the capillary or a straight pipe connected coaxially thereto at the inlet end of the capillary and restricting the rotation of the capillary around the axis with respect to the probe body, while allowing the capillary to move in the axial direction; A first movable portion which is attached to the probe main body and has a thread portion formed on a part of the outer peripheral surface which is substantially cylindrical;
b) having a substantially cylindrical inner peripheral surface formed with a screw portion to be screwed with the screw portion of the first movable portion, while restricting axial movement of the capillary with respect to the probe main body, A second movable portion attached to the probe main 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 is typically one in which a liquid sample is sprayed into an ionization chamber that is substantially at atmospheric pressure in order to perform 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 around the axis of the capillary is restricted. On the other hand, the movement of the second movable portion in the axial direction of the capillary with respect to the probe main body is restricted, but the second movable portion is rotatable around the axis of the capillary capillary. For example, when the second movable part is rotated directly or indirectly by a user operation, the first movable part is screwed into the first movable part by screwing the screw part of the second movable part and the screw part of the first movable part. Power is transmitted, but 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 screwing 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 is restricted in the axial direction of the capillary, the first movable portion moves in the axial direction relatively to the second movable portion by an amount corresponding to the 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 main body. Accordingly, the capillary held in the first movable portion or the straight pipe integrated 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 capillary nor the straight tubular pipe rotates around the axis, but simply moves straight in the axial direction.

  As one mode of the ionization probe according to the present invention, the first movable section includes a substantially cylindrical pipe holding section that holds the capillary or the straight pipe along a central axis thereof, and the pipe holding section. A rotation ring having a threaded portion formed on the outer peripheral surface thereof and a restriction pin inserted into a pin hole formed in the probe body in an axial direction of the capillary. And a stop portion.

  In this configuration, the two may be integrated by press-fitting the conduit holding portion inside the rotation retaining portion, but the screw portion formed on the outer peripheral surface of the conduit retaining portion and the rotation retaining portion may be integrated. Both may be integrated by screwing with a threaded portion formed on the inner peripheral surface. Thus, the capillary and the straight pipe can be pulled out from the probe body by removing the conduit holding portion from the rotation holding portion while the rotation holding portion is attached to the second movable portion. In particular, when the inner diameter of the capillary is small, there is a problem that the liquid sample is easily clogged. However, according to the above configuration, the maintainability of the capillary is improved.

  Further, in the ionization probe according to the present invention, preferably, an adjustment knob installed at a position deviated from a rotation axis of the second movable portion, and a rotational driving force of the adjustment knob is transmitted to the second movable portion. And a transmission mechanism for rotating the second movable portion.

  As the transmission mechanism, any suitable 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. The rotation axis of the adjustment knob may be parallel to the rotation axis of the second movable portion, but the direction of the rotation axis may be changed by using a bevel gear or the like.

  According to 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. This eliminates the need to provide an adjustment knob near the entrance end of the capillary, and eliminates the need to secure a space near the capillary that can be operated by the user. 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 preferred configuration, the transmission mechanism section may have a configuration in which a speed ratio between the adjustment knob and the second movable section is 1 or more.

  According to this configuration, since the amount of movement of the capillary relative to the amount of rotation of the adjustment knob is small, fine adjustment of the position of the capillary is easy. This makes it easy to obtain high detection sensitivity by adjusting the amount of projection of the capillary.

  Further, an ion analyzer according to the present invention includes an ion source using the ionization probe according to the present invention.

  The ion analyzer according to the present invention is generally a mass analyzer that separates and detects ions generated in the ion source or ions derived from the ions according to the mass-to-charge ratio, or ions generated in the ion source. Alternatively, the ion mobility analyzer is 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 in accordance with the mass-to-charge ratio after separating them in accordance with the ion mobility can also 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 of the column and It is preferable that the capillary or the straight tubular pipe be connected to the inlet end.

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

  ADVANTAGE OF THE INVENTION According to the ionization probe which concerns on this invention, the protrusion amount can be adjusted with high precision, without rotating a capillary around an axis. Thereby, by using the ionization probe according to the present invention, the outlet end of the column of the preceding liquid chromatograph is directly connected to the inlet end of the capillary of the ionization probe, or the outlet end of the column is ionized with the ionization probe. The probe can be connected to the inlet end of the capillary with a very short relay pipe, and high-sensitivity analysis can be performed while suppressing the diffusion of components separated by the column.

FIG. 1 is a schematic sectional view of a main part of an ionization probe according to one embodiment of the present invention. FIG. 5 is an operation explanatory diagram when adjusting the amount of capillary protrusion in the ionization probe of the present embodiment. FIG. 2 is a schematic configuration diagram of LC-MS using the ionization probe of the present embodiment. The schematic sectional drawing of the conventional general ionization probe.

Hereinafter, an ionization probe according to an embodiment of the present invention and LC-MS using the same will be described with reference to the accompanying drawings.
FIG. 1 is a schematic sectional view of a main part of the ionization probe according to the present embodiment. FIG. 2 is an operation explanatory diagram for adjusting the amount of capillary protrusion in the ionization probe of the present embodiment. FIG. 3 is a schematic configuration diagram of one embodiment of the LC-MS using the ionization probe of the present embodiment.

First, with reference to FIG. 3, the configuration of the LC-MS of this embodiment and a schematic analysis operation will be described.
This LC-MS roughly includes a liquid chromatograph 1 and a mass spectrometer 2. The liquid chromatograph 1 includes a mobile phase container 10, a liquid sending 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. The column 14 is accommodated in the oven chamber. The column oven 13 is arranged such that the outlet end 14a of the column 14 disposed therein is aligned with a relay pipe 25 of the ionization probe 22, which will be described later.

  The mass spectrometer 2 includes an ion source 20 and an analyzer 200. The ion source 20 and the analyzer 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 for spraying a charged droplet into an ionization chamber 21 maintained at a substantially atmospheric pressure atmosphere. The ionization probe 22 has a capillary 23 through which a liquid sample with a low flow rate flows. The 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 It is taken out of the housing horizontally. The inlet end of the relay pipe 25 is inserted into the column oven 13 of the liquid chromatograph 1, and connected to the outlet end 14a of the column 14. The relay pipe 25 is made of, for example, a resin such as PEEK (polyetheretherketone) resin. Since the capillary 23 made of metal is not exposed outside the ionization probe 22, high safety can be secured.

  The analysis section 200 is entirely housed in a 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 near the ionization chamber 21. Each of the chambers 202 to 204 is evacuated by a vacuum pump, and has a differential exhaust system in which the degree of vacuum increases stepwise 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 26. In the first intermediate vacuum chamber 202, a plurality of electrode plates arranged so as to surround the ion optical axis C are provided. Is provided. 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. The second intermediate vacuum chamber 203 includes a plurality of rod electrodes surrounding the ion optical axis C. An ion guide 207 is provided. In the high vacuum chamber 204, a front-stage quadrupole mass filter 208 and a rear-stage 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 is further provided. Is provided.

  In the liquid chromatograph 1, a liquid sending pump 11 sucks and sends a mobile phase stored in a mobile phase container 10. When a certain amount of the sample solution is injected into the mobile phase from the injector 12, the sample solution is introduced into the column 14 along with the flow of the mobile phase. While the sample solution passes through the column 14 whose temperature is controlled by the column oven 13, various components contained in the sample solution are separated in the time direction and reach the outlet end 14 a of the column 14. When the eluate containing the components separated in the column 14 is introduced into the capillary 23 via the relay pipe 25 of the ionization probe 22, charged droplets derived from the eluate are sprayed from the end of the capillary 23 into the ionization chamber 21. You. The charged droplet collides with the atmosphere and is miniaturized, and the sample component becomes gas ions in the process of evaporating the solvent. The generated ions are sucked into the desolvation tube 26 on the gas flow formed by the pressure difference between both ends of the desolvation tube 26, and are 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. These ions are converged by the ion guide 207, sent to the high vacuum chamber 204, and introduced into the pre-stage quadrupole mass filter 208. Of the ions derived from the introduced sample components, only ions having a specific mass-to-charge ratio corresponding to the voltage applied to the pre-quadrupole mass filter 208 pass through the pre-quadrupole mass filter 208, and And enters the collision cell 209. A CID (collision-induced dissociation) gas is introduced into the collision cell 209 continuously or intermittently, and the precursor ions come into contact with the CID gas and dissociate to generate various product ions. This product ion is introduced into the latter-stage quadrupole mass filter 211, and only the product ion having a specific mass-to-charge ratio corresponding to the voltage applied to the latter-stage quadrupole mass filter 211 passes through the latter-stage quadrupole mass filter 211. It passes through and reaches the ion detector 212. The ion detector 212 generates a detection signal corresponding to the amount of the arrived ions.

  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 projection of the capillary 23 cannot be adjusted by rotating the capillary 23 around its axis as in the related art. Therefore, the ionization probe 22 of the present embodiment has the following characteristic adjustment mechanism.

  FIGS. 1 and 2 show the ionization probe 22 according to the present embodiment in the vicinity of the base of a probe main body 220 located outside the ionization chamber 21 and holding a relay pipe 25 integrated with the capillary 23 (B in FIG. 4). FIG. The conduit holding portion 221 corresponding to the joint 42 in the conventional ionization probe shown in FIG. 4 is configured such that the inlet side 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 part 221a is formed on a part of the substantially cylindrical outer peripheral surface of the conduit holding part 221. On the other hand, on the inner peripheral surface of the through-hole of the substantially annular rotation hooking part 222, a female screw part 222 a to be screwed with the male screw part 221 a of the pipeline holding part 221 is formed. The conduit holding portion 221 is strongly screwed into the rotation hooking portion 222 such that the male screw portion 221a of the pipe holding portion 221 is screwed into the female screw portion 222a of the rotation hooking portion 222, and both are substantially integrated. ing. The pipeline holding part 221 and the rotation retaining part 222 correspond to a first movable part in the present invention.

  A plurality of locking pins 222c are provided upright on the plane of the rotation locking 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 a plurality of locking pins 222c are respectively formed in the pipeline holding portion 221 and the rotation locking portion 222. It is attached to the probe main body 220 while being inserted into the hole 220a. A male screw part 222b is also formed on the substantially cylindrical outer peripheral surface of the rotation hook part 222, and a nut 223 formed on the inner peripheral surface with a female screw part 223a screwed to the male screw part 222b is attached to the rotation hook part. It is mounted on the outside so as to cover 222. The flange 223 b projecting outward from the peripheral edge of the nut 223 is pressed against the probe main body 220 with a certain play by a fixing plate 224 fixed to the probe main body 220. Thus, although the nut 223 is rotatable about its axis, the axial movement of the capillary 23 is restricted. This nut 223 corresponds to the second movable portion in the present invention.

  A large gear 226 is fitted around the outer periphery of the nut 223. A small gear 225 meshing with the large gear 226 is rotatably arranged around a shaft 227 erected on a fixed plate 224. I have. An adjustment knob 228 for a user to operate is attached to an end of the shaft 227. Naturally, the number of teeth of the large gear 226 is far greater than the number of teeth of the small gear 225, and the speed change ratio of the power transmission mechanism including the small gear 225 and the large gear 226 is a value sufficiently larger than 1. It is.

  In the adjustment mechanism of the ionization probe 22, the capillary 23, the relay pipe 25, the pipeline holding section 221, and the rotation retaining section 222 are substantially integrated. On the other hand, the large gear 226 and the nut 223 are also substantially integrated. The female screw portion 223a of the nut 223 and the male screw portion 222b of the rotation retaining portion 222 are in a screwed state. In this state, as shown in FIG. 2, when the adjustment gear 228 is rotated to rotate the small gear 225 about the shaft 227, the large gear 226 meshing with the small gear 225 is moved in the opposite direction. Rotate. Accordingly, 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 simply rotates at that position. On the other hand, the female thread 223a of the nut 223 and the male thread 222b of the rotation hook 222 are screwed together, and the rotation hook 222 cannot rotate due to the engagement between the hook pin 222c and the pin hole 220a. Therefore, when the nut 223 rotates, the screwing position between the female screw portion 223a and the male screw portion 222b moves in the axial direction of the capillary 23. Since the rotation locking portion 222 is movable within a predetermined range in the axial direction of the capillary 23, when the nut 223 rotates and the screwing position moves, the rotation locking portion 222 itself moves in the axial direction of the capillary 23. I do. Thereby, the relay pipe 25 held by the pipe holding part 221 and the capillary 23 connected thereto move integrally in the axial direction. FIG. 2 shows a state in which the rotation hooking part 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 motion in the axial direction of the capillary 23, and the relay pipe 25 and the capillary 23 move in the axial direction. Thereby, the protrusion amount d of the capillary 23 from the nebulized gas ejection port 41b can be adjusted. Even during the adjustment, the relay pipe 25 and the capillary 23 do not rotate around the axis. Therefore, as a matter of course, as shown in FIG. Also does not rotate about its axis. Further, since the length of the relay pipe 25 itself is short in order to prevent the diffusion of components in the relay pipe 25, the root of the ionization probe 22 and the column oven 13 are close to each other, and the gap therebetween is considerably narrowed. On the other hand, the user can adjust the protrusion amount d by turning the adjustment knob 228 provided at a position sufficiently long distance A away from the position of the capillary 23 which is the center of rotation of the large gear 226. In addition, the column oven 13 is unlikely to hinder 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 driven to rotate 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. Thus, for example, when the user rotates the adjustment knob 228 by 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 as to achieve high detection sensitivity.

  In the above-described embodiment, the rotation of the adjustment knob 228 is transmitted to the nut 223 by the small gear 225 and the large gear 226. Instead of the gear, for example, a combination of a pulley and a belt, a sprocket and a roller chain An appropriate power transmission mechanism such as a combination can be used. In the above-described embodiment, the rotation axis of the small gear 225 and the rotation axis of the large gear 226 are parallel. However, for example, a configuration may be employed in which both rotation axes are obliquely formed by using a bevel gear or the like. Further, the conduit holding part 221 and the rotation retaining part 222 may be one member from the beginning instead of being separate members. 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. In addition, the shape of each member can be appropriately changed.

  Further, the above embodiment is merely an example of the present invention, and it is obvious that any change, modification, or addition within the spirit of the present invention is included in the scope of the claims of the present application.

  For example, the ionization probe of the above embodiment performs ionization by the ESI method, but may perform ionization by the APCI method or the APPI method. When changing to the ionization probe by the APCI method, a needle electrode for generating a corona discharge is disposed in front of the spray flow of the sample droplet, and the corona discharge generated by the high voltage applied to the needle electrode causes the ionization chamber to be changed. The buffer gas introduced into the sample or the solvent gas vaporized from the liquid sample is ionized. Then, the sample component may be ionized by chemically reacting the gas ion with the vaporized sample component. In the case of changing to an ionization probe by the APPI method, light of a predetermined wavelength (ultraviolet light) may be irradiated to the spray flow of the sample droplet, and the vaporized sample component may be ionized by the light energy.

  Although the embodiment shown in FIG. 3 is an example in which the ionization probe according to the present invention is applied to LC-MS, ions generated by spraying a liquid sample into an 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 ions according to the present invention, and an ion mobility-mass spectrometer that separates ions derived from a sample component according to the ion mobility and then further separates according to the mass-to-charge ratio. It is also clear that ionization probes can be applied.

DESCRIPTION OF SYMBOLS 1 ... Liquid chromatograph 10 ... Mobile phase container 11 ... Liquid sending pump 12 ... Injector 13 ... Column oven 14 ... Column 14a ... Outlet end 2 ... Mass spectrometer 20 ... Ion source 21 ... Ionization chamber 21a ... Wall surface 22 ... Ionization Probe 220 ... Probe body 220a ... Pin hole 221 ... Pipe holding part 221a ... Male screw part 222 ... Rotation hook part 222a ... Female screw part 222b ... Male screw part 222c ... Hook pin 223 ... Nut 223a ... Female screw part 223b ... Flange 224 ... Fixed plate 225 ... Small gear 226 ... Large gear 227 ... Shaft 228 ... Adjustment knob 23 ... Capillary 24 ... Joint 25 ... Relay piping 26 ... Desolvation tube 200 ... Analysis unit 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 ... subsequent quadrupole mass filter 212 ... ion detector

Claims (8)

A capillary through which the liquid sample flows, and a probe main body having a nozzle provided at a tip end thereof with an ejection port for ejecting a nebulizing gas in the axial direction of the capillary, and spraying the liquid sample to be included in the liquid sample An ionization probe for ionizing a component, comprising an adjustment mechanism for adjusting an axial position of the capillary with respect to the ejection port, the adjustment mechanism comprising:
a) holding the capillary or a straight pipe connected coaxially thereto at the inlet end of the capillary and restricting the rotation of the capillary around the axis with respect to the probe body, while allowing the capillary to move in the axial direction; A first movable portion which is attached to the probe main body and has a thread portion formed on a part of the outer peripheral surface which is substantially cylindrical;
b) a substantially cylindrical inner peripheral surface formed with a threaded portion to be screwed into the threaded portion of the first movable portion, and a second portion attached to the probe 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 part includes a substantially cylindrical pipe holding part that holds the capillary or the straight pipe along a central axis thereof, and a substantially annular body fixed around the pipe holding part. A threaded portion is formed on the outer peripheral surface, and the probe main body further includes a rotation retaining portion having a regulating pin inserted into a pin hole formed in an axial direction of the capillary. Ionization probe. The ionization probe according to claim 1, wherein
An adjustment knob installed at a position off the rotation axis of the second movable portion, and a transmission mechanism for transmitting a rotational driving force of the adjustment knob to the second movable portion to rotate the second movable portion; An ionization probe, further comprising: The ionization probe according to claim 3, wherein
The transmission mechanism section has a gear ratio between the adjustment knob and the second movable section of 1 or more.   An ion analyzer provided with an ion source using the ionization probe according to claim 1. The ion analyzer according to claim 5, wherein
An eluate containing components separated by a liquid chromatography column is introduced into an ion source of the ion analyzer, and an outlet end of the column and an inlet end of the capillary or the straight tubular pipe. And an ion analyzer connected to the ion analyzer. The ion analyzer according to claim 6,
An ion analyzer characterized in that ions generated by the ion source or ions derived from the ions are separated and detected according to a mass-to-charge ratio. The ion analyzer according to claim 6,
An ion analyzer characterized in that ions generated by the ion source or ions derived from the ions are separated and detected according to ion mobility.

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