Ionization device and mass spectrum detection equipment

Abstract

The invention discloses an ionization device and mass spectrum detection equipment, the ionization device comprises a first chamber, a second chamber, a first ionization part, a first deflection part and a second ionization part, and the first chamber is communicated with the second chamber. The first chamber is provided with an inlet, a fluid to be measured enters the first chamber through the inlet, the first ionization part ionizes other components except a preset gas in the fluid to be measured, the first deflection part separates ions generated by ionization of the first ionization part from the preset gas and discharges the ions from the first chamber, and the preset gas enters the second chamber; the second ionization part ionizes the preset gas entering the second chamber. The ionization device is provided with two stages of chambers, other components except the preset gas in the fluid to be detected are ionized and discharged in the first chamber and prevented from entering the second chamber, when the ionization device is applied to mass spectrum detection equipment, impurity gas entering a multiplier can be reduced, and the detection accuracy and sensitivity requirements are met while the detection efficiency is improved. The service life of the multiplier can be prevented from being greatly shortened.

Description

Technical Field

[0001] This invention relates to the field of mass spectrometry analysis, and in particular to an ionization device and a mass spectrometry detection device. Background Technology

[0002] Helium is the known element with the lowest boiling point in nature and belongs to the rare (inert) gas category. Due to its chemical inertness, rare gas elements and their isotopic composition are ideal tracers for studying various physical processes in geological bodies. Accurately evaluating the helium resource potential or quantity in basin areas or typical helium-bearing oil and gas reservoirs provides crucial data for decision-making in helium-related industries and is also a key parameter for selecting favorable distribution areas.

[0003] Currently, the thermal conductivity detector is mainly used for helium detection in the logging industry. The thermal conductivity detector is a general-purpose detector with the following two main characteristics: 1. Various gases such as hydrogen and alkanes in natural gas samples have a strong interfering effect on its testing. In particular, the presence of alkanes affects the stability of subsequent mass spectrometry detection of helium content. Traditional methods use separation columns in gas chromatography, but this separation is not thorough enough; 2. The sensitivity of the thermal conductivity detector is insufficient, with a minimum detection limit of 50 ppm. Since the helium concentration in ambient air is generally around 5 ppm, this does not meet the requirements for on-site testing.

[0004] Alternatively, mass spectrometry can be used to test helium, which employs a multiplier, offering high sensitivity. However, multipliers have two drawbacks: 1. A large influx of ionized ions into the system leads to severe degradation of the multiplier; although the gain can be adjusted by voltage, its lifespan is significantly reduced; 2. Removing impurities from the gas using pretreatment methods results in variations in helium concentration, failing to accurately reflect concentration changes in formation gas. Summary of the Invention

[0005] The purpose of this invention is to provide an ionization device and a mass spectrometry detection equipment that can reduce the amount of impurity gas other than the preset gas entering the multiplier, thereby meeting the accuracy and sensitivity requirements for the preset gas detection while avoiding a significant reduction in the lifespan of the multiplier.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An ionization device includes a first chamber, a second chamber, a first ionization section, a first deflection section, and a second ionization section, wherein the first chamber and the second chamber are connected.

[0008] The first chamber is provided with an inlet for allowing the fluid to be tested to enter the first chamber. The first ionization unit and the first deflection unit are disposed in the first chamber. The first ionization unit is used to ionize other components in the fluid to be tested, except for a preset gas. The first deflection unit is used to separate the ions generated by the ionization of the first ionization unit from the preset gas and discharge them from the first chamber, allowing the preset gas to enter the second chamber. The second ionization unit is disposed in the second chamber and is used to ionize the preset gas entering the second chamber.

[0009] Optionally, the first deflection section includes a first electrode and a second electrode, which are arranged opposite to each other so that an electric field can be formed between the first electrode and the second electrode, and the ions generated by the ionization of the first ionization section pass through the space between the first electrode and the second electrode.

[0010] Optionally, the first ionization section is disposed on the side of the first electrode and the second electrode near the inlet.

[0011] Optionally, a first channel communicating with the first chamber is connected to the side wall of the first chamber, and the first channel is used to output ions discharged from the first chamber.

[0012] Optionally, it also includes a quadrupole assembly disposed in the second chamber, the quadrupole assembly including a first pole, a second pole, a third pole and a fourth pole.

[0013] Optionally, a second channel communicating with the second chamber is connected to the side wall of the second chamber, and a vacuum pump is connected to the second channel. The vacuum pump is used to create a vacuum environment in the second chamber and the first chamber.

[0014] Optionally, a first channel communicating with the first chamber is connected to the side wall of the first chamber. The first channel is used to output ions discharged from the first chamber, and the first channel is communicating with the second channel.

[0015] Optionally, the ionization energy generated by the first ionization section is less than the minimum ionization energy of the preset gas, and the difference between the minimum ionization energy of the preset gas and the ionization energy generated by the first ionization section is 2eV to 3eV.

[0016] Optionally, the ionization energy generated by the second ionization section is greater than the maximum ionization energy of the preset gas.

[0017] A mass spectrometry detection device, comprising:

[0018] The ionization device described in any of the above items;

[0019] The multiplier is connected to the second chamber of the ionization device.

[0020] As can be seen from the above technical solution, the ionization device provided by the present invention includes a first chamber, a second chamber, a first ionization section, a first deflection section, and a second ionization section, wherein the first chamber and the second chamber are connected. The first chamber is provided with an inlet, through which the fluid to be tested enters the first chamber. The first ionization section and the first deflection section are disposed in the first chamber. The first ionization section ionizes the components in the fluid to be tested other than a preset gas. The first deflection section is used to separate the ions generated by the ionization of the first ionization section from the preset gas and discharge them from the first chamber, allowing the preset gas to enter the second chamber. The second ionization section is disposed in the second chamber, and the second ionization section ionizes the preset gas entering the second chamber. The ionization device of this invention is provided with two chambers. In the first chamber, components other than the preset gas in the fluid to be tested are ionized, so that these impurity components are separated from the preset gas and prevented from entering the second chamber. This ionization device can be applied to mass spectrometry detection equipment. The second chamber can be connected to the multiplier of the mass spectrometry detection equipment. By using this ionization device, the entry of impurity gases other than the preset gas into the multiplier can be reduced. While meeting the accuracy and sensitivity requirements for the detection of the preset gas, the lifespan of the multiplier can be avoided from being greatly reduced.

[0021] The mass spectrometry detection device provided by this invention can achieve the above-mentioned beneficial effects. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is an internal schematic diagram of an ionization device provided in an embodiment of the present invention;

[0024] Figure 2 A structural diagram of an ionization device provided in an embodiment of the present invention;

[0025] Figure 3 A top view of an ionization device provided in an embodiment of the present invention;

[0026] Figure 4 A perspective view of an ionization device provided in an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of the principle of a quadrupole assembly of an ionization device provided in an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the stable region when three ions with masses m1, m2 and m3 pass through a quadrupole in one embodiment of the present invention.

[0029] Figure 7 This is a schematic diagram illustrating the principle of ion movement in the electric field between the first and second electrodes according to an embodiment of the present invention.

[0030] The reference numerals in the accompanying drawings include:

[0031] 101-First chamber, 102-Second chamber, 103-Inlet, 104-First ionization section, 105-First electrode plate, 106-Second electrode plate, 107-Second ionization section, 108-Quadrupole assembly, 201-First pole, 202-Second pole, 203-Third pole, 204-Fourth pole;

[0032] 109 - Multiplier, 110 - First channel, 111 - Second channel, 112 - Third channel, 113 - Vacuum gauge, 114 - Molecular pump, 115 - First flange, 116 - Second flange, 117 - Third flange, 118 - Fourth flange. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0034] This embodiment provides an ionization device, including a first chamber, a second chamber, a first ionization section, a first deflection section, and a second ionization section, wherein the first chamber and the second chamber are connected.

[0035] The first chamber is provided with an inlet for allowing the fluid to be tested to enter the first chamber. The first ionization unit and the first deflection unit are disposed in the first chamber. The first ionization unit is used to ionize other components in the fluid to be tested, except for a preset gas. The first deflection unit is used to separate the ions generated by the ionization of the first ionization unit from the preset gas and discharge them from the first chamber, allowing the preset gas to enter the second chamber. The second ionization unit is disposed in the second chamber and is used to ionize the preset gas entering the second chamber.

[0036] The fluid to be tested enters the first chamber through the inlet. The first ionization unit ionizes all components in the fluid except for the preset gas. The first deflection unit separates the ions generated by the ionization from the preset gas, causing the ions to exit the first chamber and the preset gas to enter the second chamber. In the second chamber, the second ionization unit ionizes the preset gas entering the second chamber, further enabling detection of the preset gas based on the ions generated by its ionization.

[0037] The ionization device in this embodiment has two chambers. In the first chamber, components other than the preset gas in the fluid to be tested are ionized, separating these impurities from the preset gas and preventing them from entering the second chamber. This ionization device can be applied to mass spectrometry detection equipment. The second chamber can be connected to the multiplier of the mass spectrometry detection equipment. Applying this ionization device can reduce the entry of impurities other than the preset gas into the multiplier. While meeting the accuracy and sensitivity requirements for the detection of the preset gas, it can also prevent a significant reduction in the lifespan of the multiplier.

[0038] In some embodiments, the inlet may be located at one end of the first chamber, and the other end of the first chamber may communicate with the second chamber. In this embodiment, the structure of the first ionization section is not limited, and the first ionization section may be, but is not limited to, an ionizing filament.

[0039] In some embodiments, the first deflection section may include a first electrode and a second electrode, which are disposed opposite to each other such that an electric field can be formed between them. Ions generated by ionization by the first ionization section pass through the space between the first electrode and the second electrode. As the ions pass through the space between the first electrode and the second electrode, they are deflected by the electric field force between them, separating them from the preset gas and preventing them from entering the second chamber.

[0040] In some embodiments, the first ionization section may be disposed on the side of the first and second electrodes near the inlet, such that the fluid to be tested entering from the inlet is first ionized by the first ionization section, and the generated ions continue to enter the space between the first and second electrodes, where they are deflected under the influence of the electric field. For example, see [reference needed]. Figure 1 , Figure 1This is a schematic diagram of the internal structure of an ionization device provided in this embodiment. As shown in the figure, an inlet 103 is provided at one end of a first chamber 101, and the other end of the first chamber 101 is connected to a second chamber 102. A first ionization unit 104, a first electrode plate 105, and a second electrode plate 106 are disposed within the first chamber 101. The first electrode plate 105 and the second electrode plate 106 are arranged opposite each other with a space between them. Ions generated by ionization by the first ionization unit 104 pass through the space between the first electrode plate 105 and the second electrode plate 106. An electric field can be formed between the first electrode plate 105 and the second electrode plate 106 by applying a voltage.

[0041] In some embodiments, a first channel communicating with the first chamber 101 is connected to the side wall of the first chamber 101. The first channel is used to allow ions discharged from the first chamber 101 to exit. Ions generated by ionization in the first chamber 101 via the first ionization unit 104 can be discharged through the first channel. See exemplary embodiments. Figure 2 , Figure 3 and Figure 4 , Figure 2 This is a structural diagram of an ionization device provided in this embodiment. Figure 3 This is a top view of an ionization device provided in this embodiment. Figure 4 The figure shows a perspective view of an ionization device provided in this embodiment. A first channel 110 is connected to the outer wall of the first chamber 101, and the first channel 110 communicates with the first chamber 101. A first flange 115 may be provided at the inlet of the first chamber 101, and a second flange 116 may be provided at the outlet of the second chamber 102.

[0042] In some embodiments, the ionization device may further include a capillary tube communicating with inlet 103 for introducing the fluid to be measured into inlet 103.

[0043] In this embodiment, the structure of the second ionization section 107 is not limited, and it may be, but is not limited to, an ionization filament.

[0044] In some embodiments, the ionization device may further include a quadrupole assembly 108 disposed in the second chamber 102. The quadrupole assembly 108 is used to perform ion selection and molecular weight measurement on ions generated by ionization via the second ionization section 107. The quadrupole assembly 108 includes a first pole 201, a second pole 202, a third pole 203, and a fourth pole 204, which are arranged side by side. Ions generated by ionization via the second ionization section 107 pass along the length of each pole. The second ionization section 107 may be disposed on the side of the quadrupole assembly 108 near the first chamber 101.

[0045] Exemplarily, reference can be made to Figure 5 , Figure 5 which is a schematic diagram of the principle of a quadrupole assembly of an ionization device provided in this embodiment. As shown in the figure, the relatively arranged first pole 201 and third pole 203 are connected and are of the same polarity; the relatively arranged second pole 202 and fourth pole 204 are connected and are of the same polarity. Then a DC voltage (U) and a radio frequency voltage (V, which can be understood as an alternating current) are applied respectively. When ions enter the quadrupole, their movement direction is along the z-axis and they are alternately affected by the DC and AC voltages in the x-axis and y-axis directions, resulting in offsets in the x and y-axis directions. If the offset amplitude is within a certain range, the ions can move in a certain orbit in the quadrupole. Therefore, there is a stable region for each ion in the quadrupole, and the stable region is related to the mass-to-charge ratio of the ions. The calculation steps are described as follows:

[0046] Φ = +(U - Vcosωt), -Φ = -(U - Vcosωt);

[0047] where U represents the DC voltage, V represents the amplitude of the radio frequency voltage, and ω represents the angular frequency of the radio frequency voltage. By differentiating and transforming the above equations, the Paul equation is obtained as follows:

[0048] , ;

[0049] where u, x, and y represent the positions of the ions, a u and q u respectively represent the stable regions (the movement ranges in the x-axis and y-axis) of the ions under the influence of the DC voltage and the AC voltage (i.e., the radio frequency voltage). It can be obtained from the equations that the stable region is only related to two variables, the mass m and the charge e of the ions, and other parameters are constants. By comparing the above two formulas, it can be seen that the stable region of the ions has a linear relationship with U and V. The stable regions are represented by U and V as Figure 6 shown, where m1 < m2 < m3. The dotted lines below each ion respectively define their respective stable regions. By drawing a straight line between U and V, in this proportion, m1, m2, and m3 can be successively separated. The greater the slope of this line, the higher the resolution.

[0050] In some embodiments, a second channel 111 communicating with the second chamber 102 is connected to the side wall of the second chamber 102, and a vacuum pump is connected to the second channel 111. The vacuum pump is used to create a vacuum environment in the second chamber 102 and the first chamber 101. In this embodiment, the structure of the vacuum pump is not limited; it can be selected according to the required vacuum level in the chambers during practical applications. The vacuum pump may include a backing pump, which is used to create a first vacuum level in the second chamber 102 and the first chamber 101, thus creating a low-vacuum environment. Alternatively, the vacuum pump may include a molecular pump, which is used to create a second vacuum level in the second chamber 102 and the first chamber 101, where the second vacuum level is greater than the first vacuum level. In this case, the molecular pump can create a high-vacuum environment in the second chamber 102 and the first chamber 101. See also, for an example, [reference needed]. Figure 3 and Figure 4 As shown, molecular pump 114 is connected to second channel 111, and the port of second channel 111 is connected to molecular pump 114 via third flange 117 and fourth flange 118. In some embodiments, a first channel 110 communicating with the first chamber 101 is connected to the side wall of the first chamber 101, and the first channel 110 is used to output ions discharged from the first chamber 101. A second channel 111 communicating with the second chamber 102 is connected to the side wall of the second chamber 102. A vacuum pump is connected to the second channel 111, and the first channel 110 communicates with the second channel 111.

[0051] In some embodiments, a third channel 112 communicating with the second chamber 102 is connected to the side wall of the second chamber 102. A vacuum gauge 113 is connected to the third channel 112. The vacuum gauge 113 is used to measure the vacuum degree of the second chamber 102 and the first chamber 101. The real-time vacuum degree in the first chamber 101 and the second chamber 102 can be obtained based on the measurement results of the vacuum gauge 113.

[0052] The ionization energy generated by the first ionization section 104 is less than the minimum ionization energy of the preset gas, so that the preset gas will not be ionized when the fluid to be tested passes through the first chamber 101. In some embodiments, the difference between the minimum ionization energy of the preset gas and the ionization energy generated by the first ionization section 104 may be 2 eV to 3 eV. The ionization energy generated by the second ionization section 107 is greater than the maximum ionization energy of the preset gas, so that the preset gas can be completely ionized in the second chamber 102.

[0053] For example, refer to Figure 7 , Figure 7This is a schematic diagram illustrating the principle of ion movement in an electric field between a first and a second electrode, according to one embodiment. When a charged ion enters the electric field, it is influenced by the electric force and its direction of movement, gradually moving towards the electrode with the opposite charge. The deflection of the charged ion in the electric field is expressed as: Where q represents the charge of a charged ion, with one electron having a charge of 6.02 × 10⁻⁶. -19 C and U represent the electric field voltage, l represents the electric field length, m represents the mass of the charged ion, and d represents the distance between the first and second electric plates. v0 represents the initial velocity of the charged ion entering the electric field, provided by an accelerating voltage.

[0054] According to the above formula, the larger the mass of a molecule in an electric field, the smaller its deflection. In a specific example, the distance d is 0.04m, the initial velocity v0 of the charged ions is 5m / s, and the electric field is a capacitor plate with a length of 0.05m and a width of 0.04m. This ionization device is applied to a mass spectrometry detection device for detecting helium. Considering the main gas in the logging, the maximum relative mass in the logging gas is assumed to be 50 (44 for carbon dioxide). Therefore, the deflection is calculated to be y=9U. Thus, to completely deflect all ionized ions, only an electric field of 0.005V is needed; the voltage set here is 12V.

[0055] In a specific example, the vacuum level of the first chamber 101 and the second chamber 102 of the ionization device is 1*10⁻⁶. -4 Pa is connected to a 5m long capillary tube with an inner diameter of 0.04mm. Therefore, the flow rate entering the vacuum chamber is 1ml / min. The cross-sectional area of ​​the primary ion source is S0 = 1.5cm². 2 .

[0056] The ionization energy of the first ionization section 104 is set to 22 eV (the first ionization energy of helium is 24.6 eV, and helium is the substance with the highest ionization energy). At this ionization energy, all gases except helium can be ionized, producing positively charged ions that enter the deflection electric field and are directly pumped into the molecular pump. The ionization energy of the second ionization section 107 is set to be greater than or equal to 70 eV, which can be 75 eV, ensuring that helium can be completely ionized at this energy. The first ionization section 104 uses an ionization filament, which can be yttrium oxide filament, which is oxygen-resistant but ionizes incompletely; the second ionization section 107 uses an ionization filament, which is not oxygen-resistant but ionizes completely.

[0057] This embodiment also provides a mass spectrometry detection device, including:

[0058] The ionization device described in any of the above embodiments;

[0059] The multiplier 109 is connected to the second chamber 102 of the ionization device.

[0060] The mass spectrometry detection device of this embodiment includes an ionization device with two-stage chambers. In the first chamber, components other than the preset gas in the fluid to be tested are ionized, separating these impurities from the preset gas and preventing them from entering the second chamber. This also prevents them from entering the multiplier. By using this ionization device, the mass spectrometry detection device can reduce the entry of impurities other than the preset gas into the multiplier. While meeting the accuracy and sensitivity requirements for the detection of the preset gas, it can also prevent a significant reduction in the lifespan of the multiplier.

[0061] Mass spectrometry is an instrument used to detect the content of substances (quantitative analysis) and identify the categories of substances (qualitative analysis). Its main principle is to ionize the analyte in a sample into charged ions. These charged ions are then separated spatially or temporally under the influence of an electric or magnetic field. The separated charged ions are detected by a detector, resulting in a mass spectrum containing the mass-to-charge ratios and relative intensities of different charged ions. From this, the molecular weights of different components in the sample can be calculated. Qualitative analysis of the analyte can be performed using the mass spectrum or precise molecular weight measurement, while accurate quantitative analysis can be performed using the detected ion intensities.

[0062] Compared with existing technologies, the advantages of this invention are as follows: It provides a highly efficient mass spectrometry detection device that can be used to detect helium gas spectrometry for well logging. Its main features are better specificity, faster testing speed, and the ability to perform continuous and stable helium measurements. Furthermore, this mass spectrometry detection device employs a dual ionization system, overcoming the drawback of mass spectrometers having high requirements for gas sources.

[0063] The ionization device and mass spectrometry detection equipment provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An ionization device, characterized by, It includes a first chamber, a second chamber, a first ionization section, a first deflection section, and a second ionization section, wherein the first chamber and the second chamber are connected. The first chamber is provided with an inlet for allowing the fluid to be tested to enter the first chamber. The first ionization unit and the first deflection unit are disposed in the first chamber. The first ionization unit is used to ionize other components in the fluid to be tested, except for a preset gas. The first deflection unit is used to separate the ions generated by the ionization of the first ionization unit from the preset gas and discharge them from the first chamber, allowing the preset gas to enter the second chamber. The second ionization unit is disposed in the second chamber and is used to ionize the preset gas entering the second chamber.

2. The ionization device of claim 1, wherein, The first deflection section includes a first electrode plate and a second electrode plate, which are arranged opposite to each other so that an electric field can be formed between the first electrode plate and the second electrode plate, and ions generated by ionization by the first ionization section pass through the space between the first electrode plate and the second electrode plate.

3. The ionization device of claim 2, wherein, The first ionization section is disposed on the side of the first electrode plate and the second electrode plate near the inlet.

4. The ionization device of claim 1, wherein, A first channel communicating with the first chamber is connected to the side wall of the first chamber, and the first channel is used to output ions discharged from the first chamber.

5. The ionization device of claim 1, wherein, It also includes a quadrupole assembly disposed in the second chamber, the quadrupole assembly comprising a first pole, a second pole, a third pole and a fourth pole.

6. The ionization device of claim 1, wherein, A second channel communicating with the second chamber is connected to the side wall of the second chamber, and a vacuum pump is connected to the second channel. The vacuum pump is used to create a vacuum environment in the second chamber and the first chamber.

7. The ionization device of claim 6, wherein, A first channel communicating with the first chamber is connected to the side wall of the first chamber. The first channel is used to output ions discharged from the first chamber. The first channel is also connected to the second channel.

8. The ionization device of claim 1, wherein, The ionization energy generated by the first ionization section is less than the minimum ionization energy of the preset gas, and the difference between the minimum ionization energy of the preset gas and the ionization energy generated by the first ionization section is 2eV to 3eV.

9. The ionization device according to claim 1, characterized in that, The ionization energy generated by the second ionization section is greater than the maximum ionization energy of the preset gas.

10. A mass spectrometry detection device, characterized in that, include: The ionization device according to any one of claims 1 to 9; The multiplier is connected to the second chamber of the ionization device.

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