JP3135952U - Atmospheric pressure ionization mass spectrometer - Google Patents

Abstract

An atmospheric pressure ionization mass spectrometer that is easy to maintain and can be reduced in cost is provided.
A vacuum vessel 2 that accommodates a mass spectrometer is provided with an extending portion 22 whose outer wall extends in the direction of an atmospheric pressure ionization chamber 15 and an ionization probe 14 is attached to the extending portion 22 and an atmospheric pressure ionization chamber. 15 is configured to be surrounded by the extending portion 22 and the partition wall 16 between the vacuum chamber 21 and the lid 18 detachably attached to the extending portion 22. As a result, the interface part is also housed in a part of the vacuum vessel 2, so that the number of parts that require precision machining is reduced, and there is no connection of piping / wiring to the lid 18 that is removed during maintenance. Moreover, since the lid 18 is lightweight, it can be easily removed.
[Selection] Figure 1

Description

  The present invention relates to an atmospheric pressure ionization mass spectrometer suitable for use as a liquid chromatograph mass spectrometer (hereinafter abbreviated as LC / MS) in combination with a liquid chromatograph.

  LC / MS is a composite analyzer that conducts mass analysis by introducing the sample separated in the liquid chromatograph part to the mass analyzer part. The mass spectrometer used for this is sent from the liquid chromatograph part. An interface is needed to ionize incoming samples. In recent years, an interface type that ionizes at atmospheric pressure is used as an interface, and a mass spectrometer equipped with the interface is an atmospheric pressure ionization mass spectrometer.

  FIG. 3 is a cross-sectional view showing a configuration of a conventional atmospheric pressure ionization mass spectrometer, particularly focusing on the interface portion. Since the overall configuration of the atmospheric pressure ionization mass spectrometer is described in detail as background art in, for example, Patent Document 1, detailed description is omitted here, and only an outline of the structure will be described below with reference to FIG.

  In FIG. 3, 2 is a vacuum vessel incorporating a mass analyzer (not shown), and 1 is an atmospheric pressure ionization interface connected thereto. The atmospheric pressure ionization interface 1 includes an ionization chamber housing 11 that is detachably attached to the vacuum vessel 2, an ionization probe 14 attached thereto, an ion introduction unit 12 that introduces an ionized sample into the mass analysis unit, and the like. Consists of. An atmospheric pressure ionization chamber 15 that is a space covered with the ionization chamber housing 11 and a vacuum chamber 21 that is an internal space of the vacuum vessel 2 are separated by a partition wall 16, and a narrow tube 12 a of an ion introduction portion 12 provided in the partition wall 16. The two rooms communicate with each other.

The sample separated by the liquid chromatograph (not shown) is guided to the ionization probe 14 through the piping system 13, sprayed and ionized there, introduced into the vacuum chamber 21 through the thin tube 12 a, and mass spectrometry. To be served.
The piping system 13 includes a plurality of pipes such as an atomizing gas supply pipe for atomizing the sample, in addition to the connecting pipe connected to the liquid chromatograph unit. Reference numeral 17 denotes a discharge port for discharging a drain of a solvent or the like.

As described above, in the conventional LC / MS, the ionization chamber housing 11 that accommodates the atmospheric pressure ionization interface 1 is provided separately from the vacuum vessel 2 that accommodates the mass analysis unit, and both are connected by bolts or the like. A similar structure can also be seen in Patent Document 2, for example. That is, FIG. 6 and FIG. 7 of the same document show a configuration in which a container or housing for accommodating an atmospheric pressure ionization unit is mounted on a vacuum partition that forms a vacuum chamber.
JP 2006-170689 A JP 2002-236110 A

  The vacuum vessel and ionization chamber housing configured as described above require rigidity to maintain the accuracy of the built-in device and pressure resistance to ensure a high vacuum, so after being cast with a metal such as aluminum, cutting However, since each of them is processed separately, the processing man-hours increase and this increases the manufacturing cost.

  Also, since the inside of the atmospheric pressure ionization interface is easily contaminated with sample residues, it is necessary to clean it from time to time. In order to perform cleaning and other maintenance, it is necessary to remove the ionization chamber housing from the vacuum vessel. This removal work is not only due to the weight of the metal casting, but also the connection of the piping system and electrical wiring (not shown). Adding to the annoyance that had to be removed, it was never an easy task.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an atmospheric pressure ionization mass spectrometer that can be easily maintained and can be reduced in cost.

  In order to solve the above-mentioned problems, the present invention provides an extension part in which the outer wall of the container on the atmospheric pressure ionization chamber is extended in a vacuum container that houses the mass analysis part, and attaches the ionization probe to the extension part, and The ionization chamber is configured to be surrounded by the extending portion and a partition wall detachably attached to the extending portion and a partition wall between the vacuum chamber. As a result, the interface is housed in a part of the vacuum vessel, reducing the number of parts that require precision processing, and the lid that is removed during maintenance has no connection to piping or wiring, and is lightweight. Therefore, it can be easily removed.

  Since the present invention is configured as described above, the number of parts requiring precision machining is reduced, and the cost can be reduced. In addition, since the lid of the atmospheric pressure ionization chamber can be easily removed, maintenance is facilitated.

The atmospheric pressure ionization mass spectrometer provided by the present invention has the following characteristics. That is, the first feature is that the vacuum vessel is provided with a stretching portion and the ionization probe is attached to the stretching portion. The second feature is that the atmospheric pressure ionization chamber is formed in the stretching portion and the stretching portion. It is the point which comprised so that it might be enclosed with the partition between the lid | cover with which it was attached so that attachment or detachment was possible, and a vacuum chamber.
Therefore, the basic configuration of the best mode is an atmospheric pressure ionization mass spectrometer having the above two characteristic configurations.

FIG. 1 shows an embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 3 are the same as those in FIG.
The present embodiment is different from the conventional example shown in FIG. 3 in that the outer wall of the vacuum vessel 2 has an extending portion 22 extending in the direction of the adjacent atmospheric pressure ionization interface 1 beyond the partition wall 16. The ionization probe 14 is attached to 22, and the end of the extending portion 22 is closed with a lid 18. In other words, not only the mass analysis unit but also the atmospheric pressure ionization interface 1 is accommodated in the vacuum vessel 2, which reduces the number of cast products that require precision machining, and enables cost reduction. Become.

The lid 18 is attached to the end of the extending portion 22 with a screw or the like, and in addition, since there is no connection of piping or wiring, it can be easily removed. Moreover, since pressure resistance is not required, it can be manufactured lightly and inexpensively with sheet metal or the like.
If the lid 18 is made of a transparent material, or if a window made of a transparent material is provided on a part of the lid 18, the operation inside the atmospheric pressure ionization chamber 15 can be observed from the outside.

  The operation of the atmospheric pressure ionization interface 1 in the present embodiment configured as described above is not different from the conventional example shown in FIG.

FIG. 2 shows another embodiment of the present invention. Also in this figure, the same reference numerals as those in FIG. 1 or 3 are the same.
This embodiment is an example in which a conventionally known inclined probe is employed. This is a structure intended to suppress the suction of the droplets adhering to the narrow tube 12a by bending the inlet side tip of the narrow tube 12a of the ion introduction part 12 downward. In this case, the ionization probe 14 is also a narrow tube. It is necessary to incline according to the bending angle of 12a.
When this inclined probe is adopted in the container structure of the present invention, it can be easily realized by mounting the ionization probe 14 via the inclined washer 19 as shown in FIG.

Note that the configurations shown in FIGS. 1 and 2 are exemplifications, and the present invention is not limited to this, and various modifications are possible.
For example, here, the partition wall 16 is made of a member different from the vacuum vessel 2 for the convenience of assembling the device. However, the partition wall 16 can also be manufactured integrally with the vacuum vessel 2 by casting.

  The present invention can be used not only for LC / MS but also for ICP / MS in combination with ICP (ion coupled plasma emission spectroscopy).

It is a figure which shows one Example of this invention. It is a figure which shows the other Example of this invention. It is a figure which shows the conventional structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Atmospheric pressure ionization interface 2 Vacuum container 11 Ionization chamber housing 12 Ion introduction part 12a Narrow tube 13 Piping system 14 Ionization probe 15 Atmospheric pressure ionization room 16 Partition 17 Discharge port 18 Lid 19 Inclined washer 21 Vacuum chamber 22 Extending part

Claims (1)

  In an atmospheric pressure ionization mass spectrometer comprising a vacuum chamber that performs mass spectrometry under vacuum and an atmospheric pressure ionization chamber that includes an ionization probe that ionizes a sample under atmospheric pressure via a partition wall, the vacuum chamber includes: The vacuum container to be formed has an extension part in which the outer wall of the container on the atmospheric pressure ionization chamber is extended, the ionization probe is attached to the extension part, and the atmospheric pressure ionization chamber has the partition wall, the extension part, and The atmospheric pressure ionization mass spectrometer is formed by being surrounded by a lid that is detachably attached to the extending portion.

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