JP3141511U - Liquid chromatograph mass spectrometer - Google Patents

Abstract

In a liquid chromatograph mass spectrometer having an interface portion configured such that an atmospheric pressure chamber is partitioned by a second partition wall installed in parallel with a vacuum partition wall, the workability of metal capillary removal work is improved.
A gas flow path fixed on a vacuum partition 16 and having a close contact surface close to a peripheral surface of a through hole 17a that passes through a second partition wall 17 and communicates with a dry gas nozzle 13 and has one end of a gas flow path penetrating through the inside. The dry gas pipe 15 is connected through a flow path block 18 that opens to a position communicating with the through hole 17a on the close contact surface. As a result, if the second partition wall 17 is removed for maintenance, the connection of the dry gas is also disconnected at the back of the second partition wall 17, so that it is not necessary to remove the piping and workability is improved.
[Selection] Figure 1

Description

  The present invention relates to a liquid chromatograph mass spectrometer (hereinafter referred to as LC / MS) having an atmospheric pressure ionization interface, and more particularly to the structure of a dry gas introduction section in an interface section.

  In LC / MS combining a liquid chromatograph and a mass spectrometer, an interface for ionizing a liquid flowing out from the column of the liquid chromatograph is provided at the front stage of the mass spectrometer. As an ionization method in the interface, an atmospheric pressure chemical ionization method or an electrospray ionization method in which a liquid is atomized and heated under atmospheric pressure and then ionized using a corona discharge or a high electric field is widely used.

FIG. 3 shows a schematic configuration example of a conventional LC / MS, particularly focusing on the interface portion.
In the figure, a vacuum chamber 2 is formed in a housing 10, and a mass analyzer (not shown) is accommodated therein. The configuration and operation of the mass analyzer are described in detail in Patent Document 1, and description thereof is omitted here. Reference numeral 1 denotes an interface unit connected to the vacuum chamber 2, which includes an atmospheric pressure chamber 11, an ionization probe 14 inserted toward the inside thereof, and a metal thin tube 12 that guides an ionized sample to the vacuum chamber 2. Is done. The atmospheric pressure chamber 11 and the vacuum chamber 2 are separated by a vacuum partition 16, and the two chambers are communicated through a metal thin tube 12 penetrating the vacuum partition 16.

  The liquid (column eluate) containing the sample separated by the liquid chromatograph unit 3 is introduced into the ionization probe 14 via the pipe 31. Since the internal configuration and operation of the ionization probe 14 are not directly related to the present invention, a detailed description thereof will be omitted. However, the sample components in the column eluate introduced into the ionization probe 14 become charged droplets together with the solvent, and the ionization probe 14 is blown out into the atmospheric pressure chamber 11 and ionized as the solvent evaporates. The sample ions are led to the vacuum chamber 2 through the metal thin tube 12 and are subjected to mass spectrometry. At this time, the solvent component is vaporized and removed in the heated metal thin tube 12, but further promotes desolvation. Then, a dry gas (also referred to as a solvent removal gas or a drying gas) is blown out from the dry gas nozzle 13 into the atmospheric pressure chamber 11. The dry gas is also described in Patent Document 1.

FIG. 4 is a diagram showing the configuration of the interface unit 1 shown in FIG. 3 in more detail. In the figure, the same components as those in FIG.
In FIG. 4, the atmospheric pressure chamber 11 includes an atmospheric pressure ionization chamber 11 a in which an ionization probe 14 is inserted, and the atmospheric pressure ionization chamber 11 a and the vacuum chamber 2, by a second partition wall 17 installed in parallel with the vacuum partition wall 16. And an atmospheric pressure rear chamber 11b interposed between the two. A dry gas nozzle 13 protrudes from a wall surface of the second partition wall 17 facing the atmospheric pressure ionization chamber 11 a, and a metal thin tube 12 that passes through the vacuum partition wall 16 and the second partition wall 17 is held at the axis of the dry gas nozzle 13. Has been. A plurality of dry gas outlets 13 a are opened at the top of the dry gas nozzle 13 so as to surround the end of the metal thin tube 12, and from here, parallel to the axis of the metal thin tube 12 and to the axis of the ionization probe 14. Dry gas is blown out in the orthogonal direction.
A heater (not shown) is embedded in the dry gas nozzle 13, thereby heating the metal thin tube 12 and the dry gas to promote the vaporization of the solvent.

  The drying gas passes through a drying gas pipe 15 from a nitrogen gas cylinder or the like (not shown), and further passes through a passage block 18 having a through passage formed therein and a through hole 17a formed in the second partition wall 17. It is supplied to the gas nozzle 13. The flow path block 18 is fixed to the surface of the second partition wall 17 on the atmospheric pressure rear chamber 11b side with the through hole 17a aligned with the hole position, and is detachably connected by the dry gas pipe 15 and the joint 15a. In the atmospheric pressure rear chamber 11b, in addition to the connection of the dry gas, an electrical wiring (not shown) is also connected. The second partition wall 17 isolates these connections from the solvent mist sprayed from the ionization probe 14 and the like. Also plays a role in preventing contamination.

JP 2003-322639 A

In the above configuration, the metal thin tube is contaminated with a sample residue or the like inside, so that maintenance such as periodic removal and cleaning or replacement is necessary. In order to remove the metal thin tube, it is necessary to open the lid (not shown) provided on the front (left side in FIG. 4) and remove the second partition wall equipped with the dry gas nozzle and the channel block forward from the housing. Since the dry gas piping is connected to the back surface of the second partition wall, it is necessary to pull out the second partition wall to a certain extent, and then to insert the hand from the front side to disconnect the joint. Very bad was the problem.
The present invention has been made in view of such circumstances, and in an LC / MS having an interface portion configured such that an atmospheric pressure chamber is partitioned by a second partition wall installed in parallel with a vacuum partition wall, The purpose is to improve the workability of the work for removing the thin tubes.

  In order to solve the above problem, the present invention has a gas flow path that is fixed on a vacuum partition and has a close contact surface that is in close contact with a peripheral surface of a through hole that passes through the second partition and communicates with the dry gas nozzle, and penetrates the inside A dry gas pipe is connected through a flow path block that opens at a position where one end of the gas pipe communicates with the through hole on the close contact surface. Thus, if the second partition is removed for maintenance, the connection of the dry gas is also disconnected at the back of the second partition, so that the work of removing the piping is not necessary.

Since this invention is comprised as mentioned above, the workability | operativity of maintenance work, such as washing | cleaning or replacement | exchange of a metal thin tube, is improved, and work efficiency improves.
In addition, since the second partition wall becomes high temperature due to heat transfer from the heater embedded in the dry gas nozzle, the conventional structure requires heat resistance for the joint. Since it is attached to the few vacuum bulkheads, the need for heat resistance is reduced, leading to cost reduction.

The LC / MS apparatus provided by the present invention has the following characteristics. That is, the first feature is that the flow block connecting the dry gas pipe is fixed on the vacuum partition, and the second feature is that one end of the gas flow path on the flow block is The surface to be opened is configured to be in close contact with the peripheral surface of the through hole that penetrates the second partition wall and communicates with the dry gas nozzle.
Therefore, the basic configuration of the best mode is an LC / MS apparatus having the above two characteristic configurations.

  FIG. 1 shows an embodiment of the present invention. In the figure, the same components as those in FIG. 4 (including functional components) are denoted by the same reference numerals, and the description thereof is omitted. FIG. 1 shows the configuration of the interface unit 1 in comparison with FIG. 4, which is a conventional example, and the overall configuration of the LC / MS including the interface unit 1 is the same as FIG.

  This embodiment is different from the conventional example of FIG. 4 in that one end of the flow path block 18 is fixed on the vacuum partition 16 and the other end is an annular sealing material 18a made of an elastic material (for example, O And the peripheral surface of the through-hole 17a communicating with the dry gas nozzle 13 on the second partition wall 17 through a ring) while keeping airtightness. One end of the gas flow path penetrating the inside of the flow path block 18 opens to a position surrounded by the annular sealing material 18a on the surface of the flow path block 18, communicates with the through hole 17a, and passes through the inside of the flow path block 18 A dry gas pipe 15 is connected to the other end of the flow path via a joint 15a.

In the above configuration, the dry gas is supplied from the dry gas pipe 15 to the dry gas nozzle 13 through the joint 15a, the flow path block 18, and the through hole 17a in this order, and further blown out from the dry gas outlet 13a into the atmospheric pressure ionization chamber 11a. Is done.
When the second partition wall 17 is removed from the housing 10 for maintenance of the metal thin tube 12, the second partition wall 17 and the flow path block 18 are separated from each other, so that it is not necessary to disconnect the connection with the joint 15a again.

The flow path block 18 is not limited to the shape illustrated in FIG. 1, and there are several modifications. 2A and 2B show modifications thereof. In FIG. 2, only the flow path blocks 18b and 18c and their surroundings are shown, but the parts not shown are the same as in FIG.
FIG. 2A shows an example in which a flow path block 18 b having a gas flow path directly passing through is fixed to the vacuum partition 16 via a spacer 19. In this case, the drying gas pipe 15 is connected via an elbow joint 15b bent at a right angle. The advantage of this example is that the processing of the flow path block 18b is easy.
FIG. 2B is an example using a flow path block 18c made of plastic or rubber having moderate elasticity as a whole, and has an advantage that a sealing material such as an O-ring is not required. As in FIG. 2A, 15b indicates an elbow joint, and 19 indicates a spacer.

  The present invention can be used for LC / MS.

It is a figure which shows one Example of this invention. It is a figure which shows the modification Example of this invention. It is a figure which shows the conventional structure. It is detail drawing which shows the conventional structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Interface part 2 Vacuum chamber 3 Liquid chromatograph part 10 Case 11 Atmospheric pressure room 11a Atmospheric pressure ionization room 11b Atmospheric pressure rear room 12 Metal thin tube 13 Drying gas nozzle 13a Drying gas outlet 14 Ionization probe 15 Drying gas piping 15a Joint 15b Elbow Shaped joint 16 Vacuum partition wall 17 Second partition wall 17a Through hole 18 Channel block 18a Annular seal 18b Channel block 18c Channel block 19 Spacer 31 Piping

Claims (2)

  A vacuum chamber for storing the mass analysis unit and an atmospheric pressure chamber for storing the interface unit are connected via a vacuum partition, and the atmospheric pressure chamber is provided with an ionization probe by a second partition installed substantially parallel to the vacuum partition. A liquid which is divided into an atmospheric pressure ionization chamber for accommodating and an atmospheric pressure rear chamber for accommodating a drying gas pipe, and which supplies a drying gas through a through hole formed in the second partition via the drying gas pipe. In the chromatographic mass spectrometer, a position that is fixed on a wall surface facing the atmospheric pressure rear chamber of the vacuum partition, has a close contact surface that is in close contact with a peripheral surface of the through hole, and communicates with the through hole of the close contact surface A liquid chromatograph mass spectrometer, wherein the dry gas pipe is connected to a gas passage through a flow passage block having an opening at one end of a gas flow passage penetrating the inside.   2. The liquid chromatograph mass spectrometer according to claim 1, further comprising a sealing material made of a soft elastic material that is provided on the flow path block so as to surround the opening on the close contact surface.

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