A mass spectrometer sample introduction system employing an acoustic orifice

Abstract

A mass spectrometer sampling system with a sound speed small hole. It includes a sample gas inlet, a sampling module, a low pressure vacuum pump, the sample gas inlet is connected with the sampling module through an eighth pipe, the sampling module includes a first two-way interface, a second three-way interface, one end of the first two-way interface is connected with the eighth pipe through a precision filter, the other end of the first two-way interface is connected with a primary capillary through a sound speed small hole, one end of the second three-way interface is connected with the primary capillary, the other end is connected with a vacuum cavity through a secondary capillary, the third end of the second three-way interface is connected with the low pressure vacuum pump, and the eighth pipe of the sample gas inlet is provided with electric heating. The sound speed small hole is arranged in front of the primary capillary of the sampling module to quantitatively control the sampling gas, the whole sampling flow path can be heated to above 100 DEG C, the stable sampling of the mass spectrometer during analysis can be ensured, the measurement is more stable and accurate, and the stable and accurate measurement of the measured gas with high water content can be realized.

Description

Technical Field

[0001] This utility model relates to the field of mass spectrometry technology, and in particular to a mass spectrometer sample introduction system using a sonic pinhole. Background Technology

[0002] A mass spectrometer is a precision measuring instrument for quantitative analysis of sample substances. During measurement, in order to ensure the stability and accuracy of the measurement results, it is necessary to stably control the injection flow rate of the sample substance and ensure that the injection volume is within the rated range.

[0003] Existing sample introduction systems use ordinary electronic flow meters to control the flow rate, but these flow meters cannot be heated, and the sample gas cannot be electrically heated to high temperatures. For example... Figure 1 The diagram shows the structure of an existing sample introduction system. This system has a sample control flow meter 2' installed at the inlet 1' and a bypass control flow meter 4' installed at the bypass outlet 3'. The sample flow rate is controlled by the two flow meters. The drawback of this structure is that the sample flow rate measured by the mass spectrometer is mainly determined by the sample flow rate entering the primary capillary 5' and the secondary capillary 6'. This structure can accurately control the sample flow rate entering the eighth-thickness tube 7', but since the flow meter cannot be heated, the electric heating 8' can only be placed after the flow meter. The sample gas after electric heating enters the primary and secondary capillary tubes. In this way, the flow meter cannot accurately control the sample flow rate entering the primary and secondary capillary tubes, that is, it cannot accurately quantitatively control the measured gas, thus failing to guarantee the stability and accuracy of the measurement results. This is especially noticeable when measuring complex mixed sample gases. In addition, it is also difficult to achieve stable and accurate measurements when measuring gases with high water content. Utility Model Content

[0004] The purpose of this invention is to solve the above-mentioned technical problems and provide a mass spectrometer sample introduction system using a sonic orifice. This sample introduction system sets a sonic orifice before the first-stage capillary of the sample introduction module to quantitatively control the introduced gas. The entire sample introduction flow path can be heated to above 100°C, which can ensure stable sample introduction during mass spectrometer analysis, making the measurement more stable and accurate. Stable and accurate measurement can also be achieved for analytes with high water content.

[0005] To solve the aforementioned problems in the prior art, the technical solution of this utility model is as follows:

[0006] This utility model discloses a mass spectrometer sample introduction system using a sonic aperture, comprising a sample gas inlet, a sample introduction module, and a low-pressure vacuum pump. The sample gas inlet is connected to the sample introduction module via an eighth-stage tube. The sample introduction module includes a first two-way interface and a second three-way interface. One end of the first two-way interface is connected to the eighth-stage tube via a fine filter, and the other end of the first two-way interface is connected to a primary capillary via a sonic aperture. One end of the second three-way interface is connected to the primary capillary, and the other end is connected to the vacuum chamber via a secondary capillary. The third end of the second three-way interface is connected to the low-pressure vacuum pump. An electric heat tracing device is installed on the eighth-stage tube of the sample gas inlet.

[0007] The sample gas of this mass spectrometer's sample introduction system sequentially passes through an eighth-stage tube, a fine filter, a sonic orifice, a primary capillary, and a secondary capillary before entering the vacuum chamber for detection. The flow rate of the sample gas is controlled by a sonic orifice located before the primary capillary of the sample introduction module. Due to the use of a sonic orifice, electric heating can be installed at the eighth-stage tube at the sample gas inlet, and the entire sample introduction flow path can be heated to over 100°C. The flow rate of the heated sample gas entering the primary capillary is directly controlled through the sonic orifice, ensuring stable sample introduction during mass spectrometry analysis.

[0008] Furthermore, the low-pressure vacuum pump is connected to an exhaust pipe through an exhaust port for venting.

[0009] Furthermore, the sample introduction module is equipped with electric heating;

[0010] Furthermore, the sonic aperture is made of quartz glass.

[0011] This utility model discloses a mass spectrometer sample introduction system using a sonic pinhole, which has the following advantages:

[0012] 1. The injection system has a sonic orifice before the first-stage capillary of the injection module for quantitative control of the injection gas. The entire injection flow path can be heated to above 100°C, which can ensure stable injection during mass spectrometry analysis and make the measurement more stable and accurate.

[0013] 2. Stable and accurate measurements can be achieved even for gases with high water content;

[0014] 3. The original design eliminated the injection flow controller and bypass venting flow meter, resulting in a more streamlined overall structure. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an existing mass spectrometer sample introduction system;

[0016] Figure 2 This is a schematic diagram of a mass spectrometer sample introduction system using a sonic pinhole according to the present invention.

[0017] Figure 3 ,for Figure 2 The front view of the embodiment shown;

[0018] Figure 4 ,for Figure 3 DD section view in the middle;

[0019] Figure 5 This is a schematic diagram of another embodiment of a mass spectrometer sample introduction system using a sonic pinhole according to the present invention. Detailed Implementation

[0020] The present invention will be further described below with reference to embodiments:

[0021] Example 1:

[0022] like Figures 1-4 This utility model discloses a mass spectrometer sample introduction system using a sonic aperture, which includes a sample gas inlet 1, a sample introduction module 100, and a low-pressure vacuum pump 2. The sample gas inlet 1 is connected to the sample introduction module 100 through an eighth-segment tube 3. The sample introduction module includes a first two-way interface 4 and a second three-way interface 5. One end of the first two-way interface is connected to the eighth-segment tube through a fine filter 6, and the other end of the first two-way interface is connected to a primary capillary tube 8 through a sonic aperture 7. One end of the second three-way interface is connected to the primary capillary tube, and the other end is connected to a vacuum chamber 10 through a secondary capillary tube 9. The third end of the second three-way interface is connected to the low-pressure vacuum pump 2. An electric heat tracing 11 is provided on the eighth-segment tube of the sample gas inlet.

[0023] The sample gas of this mass spectrometer's sample introduction system sequentially passes through an eighth-stage tube, a fine filter, a sonic orifice, a primary capillary, and a secondary capillary before entering the vacuum chamber for detection. The flow rate of the sample gas is controlled by a sonic orifice located before the primary capillary of the sample introduction module. Due to the use of a sonic orifice, electric heating can be installed at the eighth-stage tube at the sample gas inlet, and the entire sample introduction flow path can be heated to over 100°C. The flow rate of the heated sample gas entering the primary capillary is directly controlled through the sonic orifice, ensuring stable sample introduction during mass spectrometry analysis.

[0024] The low-pressure vacuum pump 2 is connected to the exhaust pipe 22 through the exhaust port 21 for venting;

[0025] The sample injection module 100 is equipped with an electric heat tracing 12.

[0026] Example 2:

[0027] like Figure 5In this embodiment, the first two-way interface of embodiment 1 is replaced with a three-way interface 4". 100” is the sample injection module, 10” is the vacuum chamber, and 2” is the low-pressure vacuum pump. One end of the three-way interface 4” is connected to the eighth tube through a fine filter, and the other end is connected to the first-stage capillary tube through a sonic orifice. The third end of the three-way interface 4” is used to connect to the vacuum gauge. The other structures in this embodiment are the same as in embodiment 1.

[0028] The present invention has been described in detail above. The above description is only a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of this application should still fall within the scope of the present invention.

Claims

1. A mass spectrometer sample introduction system employing a sonic pinhole, characterized in that: It includes a sample gas inlet, a sample injection module, and a low-pressure vacuum pump. The sample gas inlet is connected to the sample injection module through an eighth-tier tube. The sample injection module includes a first two-way interface and a second three-way interface. One end of the first two-way interface is connected to the eighth-tier tube through a fine filter, and the other end of the first two-way interface is connected to a primary capillary tube through a sonic orifice. One end of the second three-way interface is connected to the primary capillary tube, and the other end is connected to the vacuum chamber through a secondary capillary tube. The third end of the second three-way interface is connected to the low-pressure vacuum pump. The eighth-tier tube of the sample gas inlet is equipped with electric heating.

2. The mass spectrometer sample introduction system using a sonic pinhole as described in claim 1, characterized in that, The low-pressure vacuum pump is connected to the exhaust pipe through the exhaust port for venting.

3. The mass spectrometer sample introduction system using a sonic pinhole as described in claim 1, characterized in that, The sample injection module is equipped with electric heating.

4. The mass spectrometer sample introduction system using a sonic pinhole as described in claim 1, characterized in that, The sonic aperture is made of quartz glass.

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