A method and device for backflushing a small-hole gas assembly of a mass spectrometer

Abstract

The present invention relates to a method and device for backflushing a small orifice gas assembly of a mass spectrometer. The device includes: a first solenoid valve and a second solenoid valve. The inlet of the first solenoid valve is connected to a gas cylinder. The first outlet of the first solenoid valve is connected to a throttle valve. The throttle valve is connected to a collision gas control valve group. The collision gas control valve group is connected to the second solenoid valve. The second solenoid valve is connected to a collision cell. The second outlet of the first solenoid valve is connected between the collision gas control valve group and the second solenoid valve. A mechanical pump is connected between a one-way throttle valve and the collision gas control valve group. The implementation method of the present invention is simple, ensuring the stable and reliable inlet gas flow of the instrument; by switching between forward and reverse flushing, the cleaning requirements of the small orifice gas assembly are met; and the disassembly and maintenance cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of mass spectrometers, and in particular to a backflushing method and device for a small-hole gas component of a mass spectrometer. Background Art

[0002] The application of mass spectrometer involves medicine, environment, food, materials, energy, military and other fields. Mass spectrometry is an analytical method that analyzes by measuring the mass-to-charge ratio of the sample ions. The sample to be analyzed must first be ionized, and then the ions are separated according to the mass-to-charge ratio (m / z) by using the different motion behaviors of different ions in the electric field or magnetic field to obtain a mass spectrum. The qualitative and quantitative results of the sample can be obtained through the mass spectrum and related information of the sample.

[0003] The classification of mass spectrometers includes organic mass spectrometer, inorganic mass spectrometer, isotope mass spectrometer, gas analysis mass spectrometer, etc.; a typical mass spectrometer is generally composed of an injection system, an ion source, a mass analyzer, a detector, a vacuum system, and a control and data processing system.

[0004] like Figure 1 As shown in the figure, during mass spectrometry analysis, collision gas and source gas are important components of the experimental process. In order to meet the quality control requirements of the ion source and collision cell gas flow, a gas control valve group is used to achieve optimal gas supply. Taking the collision cell gas supply as an example, the collision cell body is generally a semi-enclosed cavity, and the entrance lens and exit lens are used to introduce and extract the ion beam. Collision gas or reaction gas, such as high-purity nitrogen, argon, hydrogen, and ammonia, is introduced through the gas path. Accurately controlling the gas flow can regulate the fragment ion yield.

[0005] The gas source gas and collision gas flow rate of the mass spectrometer are generally small, such as Figure 2 As shown, taking collision gas as an example, it is generally several hundred microliters to several milliliters per minute. The control of collision gas requires stability and cannot have large fluctuations. In the process of realizing gas flow control, there is an important part, the small hole gas component, with an aperture ranging from 0.1mm to 0.54mm. The gas volume is controlled by combining small hole gas components with different apertures. However, due to the small inner diameter of the small hole gas component, dust and impurities can easily cause blockage in the hole. The blockage of the small hole gas component will cause changes in the intake volume, resulting in reduced ionization and changes in the vacuum degree of the cavity, which will ultimately reduce the sample detection intensity. Summary of the invention

[0006] In order to achieve the above-mentioned purpose and other advantages according to the present invention, the first object of the present invention is to provide a method for backflushing a small-hole gas assembly of a mass spectrometer, comprising the following steps:

[0007] Start taking in air;

[0008] Read the cavity vacuum signal;

[0009] Determine whether the vacuum degree error is greater than or equal to the preset error value;

[0010] Otherwise, neither the first solenoid valve nor the second solenoid valve operates, and the collision cell intake mode is executed;

[0011] If yes, change the channel of the first solenoid valve, disconnect the second solenoid valve, and execute the backflush cleaning mode;

[0012] Determine whether the backflush time is greater than or equal to the preset time;

[0013] If yes, jump to the step of reading the signal;

[0014] Otherwise, jump to the step of executing the backflush cleaning mode.

[0015] Further, the preset error value is ±5% to ±15%.

[0016] Further, the preset time is 30s to 90s.

[0017] Further, if the vacuum degree error is less than the preset error value, open the first air outlet of the first solenoid valve, close the second air outlet of the first solenoid valve, open the second solenoid valve, and execute the collision cell intake mode.

[0018] Further, if the vacuum degree error is greater than or equal to the preset error value, close the first air outlet of the first solenoid valve, open the second air outlet of the first solenoid valve, disconnect the second solenoid valve, and execute the backflush cleaning mode.

[0019] The second object of the present invention is to provide a backflush device for a small hole gas assembly of a mass spectrometer, including: a first solenoid valve and a second solenoid valve. The intake port of the first solenoid valve is connected to an air tank, the first air outlet of the first solenoid valve is connected to a throttle valve, the throttle valve is connected to a collision gas control valve group, the collision gas control valve group is connected to the second solenoid valve, the second solenoid valve is connected to a collision cell, the second air outlet of the first solenoid valve is connected between the collision gas control valve group and the second solenoid valve, and a mechanical pump is connected between the one-way throttle valve and the collision gas control valve group.

[0020] Further, it further includes a filter. One end of the filter is connected between the one-way throttle valve and the collision gas control valve group, and the other end of the filter is connected to the intake port of the mechanical pump.

[0021] Further, the first solenoid valve is a two-way solenoid valve.

[0022] Further, the second solenoid valve is a on-off solenoid valve.

[0023] Further, the throttle valve is a one-way throttle valve.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] The present invention provides a method and device for backwashing a small-hole gas assembly of a mass spectrometer. The collision gas changes the gas flow direction through a two-way solenoid valve from a gas source, thereby realizing the switching between the collision cell intake and the backwashing cleaning mode. The solenoid valve near the collision cell is an on-off solenoid valve, which is opened during normal intake and closed during backwashing cleaning. A filter is added to the mechanical pump suction port, which plays a role in filtering impurities during normal exhaust and backwashing cleaning. The implementation method of the present invention is simple, ensuring the stable and reliable intake flow of the instrument; by switching between normal and backwashing, the cleaning requirements of the small-hole gas assembly are met; the disassembly and maintenance cost is reduced.

[0026] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly and to be implemented in accordance with the content of the description, the following describes the preferred embodiments of the present invention in detail in conjunction with the accompanying drawings. The specific implementation manners of the present invention are given in detail by the following embodiments and their accompanying drawings. Brief Description of the Drawings

[0027] The drawings described herein are used to provide a further understanding of the present invention and form a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 It is a schematic diagram of the collision gas intake system;

[0029] Figure 2 It is a schematic diagram of the collision cell intake process;

[0030] Figure 3 It is a schematic diagram of the backwashing device for the small-hole gas assembly of the mass spectrometer in Embodiment 1;

[0031] Figure 4 It is a schematic diagram of the relationship between the small-hole opening and the vacuum degree in Embodiment 2;

[0032] Figure 5 It is a flowchart of the method for backwashing the small-hole gas assembly of the mass spectrometer in Embodiment 2;

[0033] Figure 6 It is a schematic diagram of the collision cell intake mode in Embodiment 2;

[0034] Figure 7 It is a schematic diagram of the backwashing cleaning mode in Embodiment 2. Detailed Description of the Preferred Embodiments

[0035] Next, in combination with the accompanying drawings and specific implementation manners, the present invention will be further described. It should be noted that, on the premise of no conflict, any combination of the following-described embodiments or technical features can form a new embodiment.

[0036] Example 1

[0037] A backflush device for a small-hole gas assembly of a mass spectrometer, as Figure 3 shown, includes: a first solenoid valve and a second solenoid valve. The inlet of the first solenoid valve is connected to a gas tank. The first outlet of the first solenoid valve is connected to a throttle valve. The throttle valve is connected to a collision gas control valve group. The collision gas control valve group is connected to the second solenoid valve. The second solenoid valve is connected to a collision cell. The second outlet of the first solenoid valve is connected between the collision gas control valve group and the second solenoid valve. A mechanical pump is connected between a one-way throttle valve and the collision gas control valve group.

[0038] Preferably, the first solenoid valve is a two-way solenoid valve, the second solenoid valve is an on-off solenoid valve, and the throttle valve is a one-way throttle valve. The collision gas changes the gas flow direction through the two-way solenoid valve from the gas tank, thereby realizing the switching between the collision cell inlet and the backflush cleaning mode. The second solenoid valve near the collision cell is an on-off solenoid valve, which is opened during normal blowing and closed during backflush cleaning.

[0039] Preferably, it further includes a filter. One end of the filter is connected between the one-way throttle valve and the collision gas control valve group, and the other end of the filter is connected to the inlet of the mechanical pump. By adding a filter at the suction port of the mechanical pump, it plays a role in filtering impurities during normal blowing exhaust and backflush cleaning.

[0040] Example 2

[0041] It can be known from experimental data that the inlet of different small-hole gas assemblies will result in different chamber vacuum degrees. By monitoring the change of the vacuum degree, it is judged whether the small-hole assembly is blocked, and then the on-off of the solenoid valve is determined. As Figure 4 shown, it can be known from experimental data that the inlet methods with different opening sizes of different small-hole gas assemblies will result in different chamber vacuum degrees. The data of the middle line are the standard values measured in the experiment, and the data of the bottom line and the top line are the ±10% error lines.

[0042] A backflush method for a small-hole gas assembly of a mass spectrometer, as Figure 5 shown, includes the following steps:

[0043] Start inletting gas;

[0044] Read the chamber vacuum degree signal;

[0045] Judge whether the vacuum degree error is greater than or equal to a preset error value. The preset error value is ±5% to ±15%, such as setting the preset error value to ±10%.

[0046] Otherwise, neither the first solenoid valve nor the second solenoid valve operates. According to the connection relationship between the components in Example 1, at this time, the first outlet of the first solenoid valve is opened, the second outlet of the first solenoid valve is closed, and the second solenoid valve is opened to execute the collision cell inlet mode.

[0047] As Figure 6 shown, the intake mode of the collision cell is as follows: The gas passes through the gas tank, two-way solenoid valve, one-way throttle valve, and the excess gas is pumped away by the mechanical pump. The pressure at the intake port of the mechanical pump is maintained constant, and the collision gas control valve group controls the gas to enter the collision cell through the second solenoid valve.

[0048] If so, change the channel of the first solenoid valve. Specifically, close the first outlet of the first solenoid valve, open the second outlet of the first solenoid valve, disconnect the second solenoid valve, and execute the backflush cleaning mode.

[0049] As Figure 7 shown, the backflush cleaning mode is as follows: When a small hole component is blocked, the two-way solenoid valve changes the channel. The gas passes through the gas tank and the two-way solenoid valve and enters the right side of the collision gas control valve group. The second solenoid valve is disconnected, and the gas flows backward through the small hole component to blow away dust and impurities. After the gas passes through the filter, it is pumped away by the mechanical pump.

[0050] Judge whether the backflush time is greater than or equal to the preset time. The preset time is 30s - 90s. For example, the preset time is set to 60s;

[0051] If so, jump to the step of reading the signal;

[0052] Otherwise, jump to execute the backflush cleaning mode.

[0053] It should also be noted that the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent in such process, method, commodity or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, commodity or device including the element.

[0054] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and the key points of each embodiment are the differences from other embodiments.

[0055] The above is only for the embodiments of this specification and is not intended to limit one or more embodiments of this specification. For those skilled in the art, one or more embodiments of this specification may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of one or more embodiments of this specification shall be included within the scope of the claims of one or more embodiments of this specification. One or more embodiments of this specification, one or more embodiments of this specification, one or more embodiments of this specification, one or more embodiments of this specification.

Claims

1. A method for backflushing a small-hole gas assembly of a mass spectrometer, characterized in that, it includes the following steps: Start admitting gas; Read the cavity vacuum signal; Judge whether the vacuum error is greater than or equal to a preset error value; Otherwise, neither the first solenoid valve nor the second solenoid valve operates, and the collision cell gas admission mode is executed; If yes, change the channel of the first solenoid valve, disconnect the second solenoid valve, and execute the backflushing and cleaning mode; Judge whether the backflushing time is greater than or equal to a preset time; If yes, jump to the step of reading the cavity vacuum signal; Otherwise, jump to the step of executing the backflushing and cleaning mode.

2. The method for backflushing a small-hole gas assembly of a mass spectrometer according to claim 1, characterized in that: The preset error value is ±5% to ±15%.

3. The method for backflushing a small-hole gas assembly of a mass spectrometer according to claim 1, characterized in that: The preset time is 30s to 90s.

4. The method for backflushing a small-hole gas assembly of a mass spectrometer according to claim 1, characterized in that: If the vacuum error is less than the preset error value, open the first gas outlet of the first solenoid valve, close the second gas outlet of the first solenoid valve, open the second solenoid valve, and execute the collision cell gas admission mode.

5. The method for backflushing a small-hole gas assembly of a mass spectrometer according to claim 4, characterized in that: If the vacuum error is greater than or equal to the preset error value, close the first gas outlet of the first solenoid valve, open the second gas outlet of the first solenoid valve, disconnect the second solenoid valve, and execute the backflushing and cleaning mode.

6. A backflushing device for a small-hole gas assembly of a mass spectrometer, which applies the method according to any one of claims 1 to 5, characterized in that, it includes: A first solenoid valve and a second solenoid valve. The gas inlet of the first solenoid valve is connected to a gas tank. The first gas outlet of the first solenoid valve is connected to a throttle valve. The throttle valve is connected to a collision gas control valve group. The collision gas control valve group is connected to the second solenoid valve. The second solenoid valve is connected to a collision cell. The second gas outlet of the first solenoid valve is connected between the collision gas control valve group and the second solenoid valve. A mechanical pump is connected between the throttle valve and the collision gas control valve group.

7. The backflushing device for a small-hole gas assembly of a mass spectrometer according to claim 6, characterized in that: It further includes a filter. One end of the filter is connected between the throttle valve and the collision gas control valve group, and the other end of the filter is connected to the gas inlet of the mechanical pump.

8. The backflushing device for a small-hole gas assembly of a mass spectrometer according to claim 6, characterized in that: The first solenoid valve is a two-way solenoid valve.

9. The backflushing device for a small-hole gas assembly of a mass spectrometer according to claim 6, characterized in that: The second solenoid valve is an on-off solenoid valve.

10. The backflushing device for a small-hole gas assembly of a mass spectrometer according to claim 6, characterized in that: The throttle valve is a one-way throttle valve.

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