A three-dimensional ion trap particle mass spectrometer teaching instrument

Abstract

The utility model relates to a three -dimensional ion trap particle mass spectrum teaching instrument belongs to mass spectrum analysis technical field, include: vacuum cavity, three -dimensional ion trap, optical detection device, laser source, three -dimensional ion trap sets up in the inside vacuum cavity, provides vacuum environment for three -dimensional ion trap by vacuum cavity, three -dimensional ion trap is equipped with from top to bottom order insulation setting's first cover electrode, ring electrode, second cover electrode, first cover electrode, ring electrode, second cover electrode inside encircles and forms ion trap area, the side of ring electrode is equipped with the laser entrance window and sample inlet of vertical setting, and the laser entrance window is passed through optical path intercommunication with laser source, and the sample inlet is connected with outside ion source, first cover electrode and the detection light path intercommunication of optical detection device. Solveed the present equipment volume big, cost is high, the operating condition is harsh and complex and is difficult for mass spectrum principle teaching, difficult to directly show its structure principle and particle running track problem.

Description

Technical Field

[0001] This utility model relates to the field of mass spectrometry analysis technology, and in particular to a three-dimensional ion trap particle mass spectrometry teaching instrument. Background Technology

[0002] Ion trap mass spectrometry, as an important instrument in the field of mass spectrometry, has been widely used in the analysis of large-mass particulate matter; ion trap mass spectrometry mainly consists of the following parts:

[0003] Particle ionization source:

[0004] A pulsed laser can be used to introduce and ionize the sample particles deposited on a glass slide, thus obtaining ions; alternatively, a discontinuous atmospheric pressure interface can be used for direct sample introduction. In this method, the sample enters the ion trap cavity with the gas flow and undergoes corona discharge near the ring electrode, which is subjected to a high voltage. Furthermore, the corona discharge can cause the particles to acquire multiple charges.

[0005] Ion beam transport region:

[0006] The particles are directly introduced into the ion trap through the stainless steel capillary along with the gas flow.

[0007] Ion trap mass analyzer standard settings:

[0008] The ion trap mass analyzer is a "potential energy bowl" that combines "ion storage" and "mass analysis" into one. It consists of upper and lower cover electrodes and a ring electrode 23 forming a small three-dimensional electric field for capturing and confining ions.

[0009] The upper and lower cover electrodes are hyperboloidal in shape and are located at the upper and lower ends of the ring electrode 23;

[0010] There are small holes in the center of the electrodes on the top and bottom covers, which allow ions to leave the ion trap for charge detection and allow scattered light to be emitted.

[0011] The ring electrode 23 is located between the upper and lower cover electrodes and is in the shape of a ring;

[0012] By changing the voltage or frequency of the cap electrode, ions can be drawn out from the stable region and brought into the detector.

[0013] By adjusting the frequency of the radio frequency voltage on the ring electrode 23, particle ions with different mass-to-charge ratios can be trapped; under the action of the radio frequency voltage, the ring electrode 23 can store a certain number of ions for subsequent operations.

[0014] By gradually reducing the frequency of the radio frequency voltage on the ring electrode 23, ions with different mass-to-charge ratios leave the ion trap in sequence. The ions are first trapped in a vacuum by the radio frequency voltage, and then the frequency is linearly reduced to eject the ions one by one to the detector according to their mass-to-charge ratio (m / z), thereby obtaining a mass spectrum and realizing mass analysis.

[0015] Existing mass spectrometry teaching instruments are in a "black box" state, which not only makes it difficult to intuitively display their structural principles, but also fails to present the ion movement trajectory. As a result, ion trap mass spectrometry lacks intuitiveness and is difficult to use for teaching the principles of mass spectrometry. Utility Model Content

[0016] Based on the above analysis, this utility model aims to provide a three-dimensional ion trap particle mass spectrometry teaching instrument and demonstration method, which at least solves one of the following technical problems of the prior art: large size, high cost, harsh and complex operating conditions that make it difficult to use for teaching mass spectrometry principles, difficulty in intuitively displaying its structural principles, inability to present ion motion trajectories, and lack of intuitiveness in ion trap mass spectrometry that makes it difficult to use for teaching mass spectrometry principles.

[0017] This utility model provides a three-dimensional ion trap particle mass spectrometry teaching instrument, including:

[0018] Vacuum chamber, three-dimensional ion trap, optical detection device, laser source;

[0019] The three-dimensional ion trap is disposed inside a vacuum chamber, which provides a vacuum environment for the three-dimensional ion trap.

[0020] The three-dimensional ion trap is provided with a first cover electrode, a ring electrode, and a second cover electrode arranged in an insulated manner from top to bottom; the first cover electrode, the ring electrode, and the second cover electrode surround each other to form an ion trap region;

[0021] The ring electrode has a vertically arranged laser inlet and a sample inlet on its side. The laser inlet is connected to the laser source through an optical path, and the sample inlet is connected to an external ion source.

[0022] The first cover electrode is connected to the detection optical path of the optical detection device.

[0023] Preferably, the vacuum chamber is fixed to the base by screws;

[0024] The first cover electrode is insulated from the ring electrode by a first ceramic ring; the second cover electrode is insulated from the ring electrode by a second ceramic ring.

[0025] Preferably, the first cap electrode, the second cap electrode, and the ring electrode are conductive structures; the first cap electrode and the second cap electrode have holes as particle outlets; and the ring electrode is connected to a radio frequency high voltage.

[0026] Preferably, the ring electrode has 2 to 4 openings on its side, with adjacent openings perpendicular to each other and relative openings centrally symmetrically distributed. A set of mutually perpendicular openings is selected as the sample inlet and the laser inlet.

[0027] Preferably, a z-axis window is provided at the connection between the top of the vacuum cavity and the optical detection device, and the hole at the center of the first cover electrode is coaxially arranged with the z-axis window, so that the optical detection device can detect the internal particle movement through the z-axis window;

[0028] A laser incident window and a y-axis window are provided on the side of the vacuum chamber and at the corresponding positions on the side of the ring electrode.

[0029] Preferably, the optical detection device can be a monitor, which is a CMOS sensor and has shooting and video recording functions;

[0030] An external ion source provides charged particles with a particle size in the micrometer range.

[0031] Preferably, the laser source is a 532nm green dot laser generator.

[0032] Preferably, a miniature electromagnetic valve is provided at the sample inlet of the vacuum chamber.

[0033] Preferably, a diaphragm pump and a molecular pump connected in series are provided on one side of the vacuum cavity;

[0034] The diaphragm pump is fixed to the base by a diaphragm pump fixing component; the inlet of the diaphragm pump is connected to the vacuum chamber through a connector, and the outlet of the diaphragm pump is connected to the molecular pump, forming a series two-stage vacuum system.

[0035] Preferably, the mass spectrometry teaching instrument further includes a charge detector;

[0036] The charge detector is connected to the central region of the second cap electrode. By reducing the frequency of the radio frequency voltage on the ring electrode, the electric field of the ion trap is adjusted so that the particles lose stability in order of their mass-to-charge ratio. The charged particles that leave the ion trap enter the charge detector through the particle outlet, thus realizing the detection of charged particles.

[0037] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0038] 1. This invention directs the laser beam from the side of the ring electrode in a direction parallel to the plane of particle movement, which avoids interference with the detection of scattered light during head-on irradiation, simplifies the optical path and volume, and improves imaging quality.

[0039] 2. The present invention adopts an injection port that allows the sample to enter from the side of the ring electrode in a direction parallel to the particle running plane, which simplifies the injection system, improves the ion transmission efficiency, and reduces ion loss.

[0040] 3. This invention employs a z-axis viewing window above a vacuum chamber, connected to a CMOS sensor-type monitor, which greatly simplifies the optical path. Furthermore, it uses relatively large charged particles as monitoring particles, thus enabling the acquisition of particle-scattered light using a less demanding CMOS sensor, meeting the weak light acquisition requirements of this application scenario. Compared to existing technologies, it significantly reduces size, cost, and operational difficulty, while also providing a clear view of ion movement trajectories and facilitating the teaching of mass spectrometry principles.

[0041] 4. This invention employs an optimized laser source and a laser incident path that is directly parallel to the particle's orbital plane via a y-axis window, enabling rapid calibration of the laser's optical path. Compared to existing technologies, this greatly simplifies operation and facilitates teaching.

[0042] 5. This utility model uses a glass y-axis viewing window, which can intuitively display the internal structure of the ion trap, facilitating intuitive teaching of mass spectrometry principles.

[0043] 6. This utility model greatly simplifies the sample injection path, reduces the number of components and sample loss by using a miniature solenoid valve to control the sample injection, and is easier to miniaturize than conventional equipment.

[0044] 7. This utility model can effectively utilize the high efficiency of diaphragm pumps to save energy, while protecting molecular pumps, extending their service life, and achieving a high vacuum environment.

[0045] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages will become apparent from the description or be learned by practicing the invention. The objectives and other advantages of this invention can be realized and obtained from the description and accompanying drawings, which are particularly pointed out. Attached Figure Description

[0046] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0047] Figure 1 This is a schematic diagram showing a charged particle rotating along a specific trajectory within the annular plane of the ring electrode in one embodiment of this utility model.

[0048] Figure 2 A three-dimensional structural diagram of a three-dimensional ion trap particle mass spectrometry teaching instrument from one perspective;

[0049] Figure 3 A schematic diagram of the three-dimensional structure of a three-dimensional ion trap particle mass spectrometry teaching instrument from another perspective;

[0050] Figure 4 This is a schematic diagram of the ion trap structure inside the vacuum chamber;

[0051] Figure 5 for Figure 4 Sectional view of plane AA.

[0052] Figure label:

[0053] 0-Base; 1-24V DC power supply; 2-Z-axis viewing window; 3-Laser incident viewing window; 4-Laser source; 5-Vacuum cavity;

[0054] 10-Miniature solenoid valve; 11-Monitor; 12-Vacuum gauge; 13-Connector; 14-Inlet; 15-Molecular pump; 16-Diaphragm pump fixture; 17-Diaphragm pump; 18-Data acquisition card; 19-Y-axis window; 20-Ion trap fixture;

[0055] 21-First cover electrode; 22-First ceramic ring; 23-Ring electrode; 24-Second ceramic ring; 25-Second cover electrode; 26-Detector copper cover; 27-Charge detector;

[0056] 28 - High voltage amplifier; 29 - High voltage amplifier mounting hardware. Detailed Implementation

[0057] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0058] This invention provides a three-dimensional ion trap particle mass spectrometry teaching instrument, such as... Figures 1 to 4 As shown, it includes: a vacuum chamber 5, a three-dimensional ion trap, an optical detection device, and a laser source 4;

[0059] The three-dimensional ion trap is set inside the vacuum chamber 5, and the vacuum chamber 5 provides a vacuum environment for the three-dimensional ion trap;

[0060] The three-dimensional ion trap is provided with a first cover electrode 21, a ring electrode 23, and a second cover electrode 25 arranged in an insulated manner from top to bottom; the first cover electrode 21, the ring electrode 23, and the second cover electrode 25 surround each other to form an ion trap region;

[0061] The ring electrode 23 has a vertically arranged laser inlet and a sample inlet 14 on its side. The laser inlet is connected to the laser source 4 through an optical path, and the sample inlet 14 is connected to an external ion source.

[0062] The first cover electrode 21 is connected to the detection optical path of the optical detection device.

[0063] In practice, the mass spectrometry teaching instrument can be selected in a confinement mode, which keeps the particles in the ion trap in a stable trajectory for easy teaching observation. The introduced charged particles enter the three-dimensional electric field formed by the first cap electrode 21, the ring electrode 23, and the second cap electrode 25 within the three-dimensional ion trap. By adjusting the electric field, the charged particles are confined and exhibit a periodic, stable trajectory. For example, it could be... Figure 1 The charged particles rotate in a specific trajectory within the annular plane of the ring electrode 23; simultaneously, under laser irradiation, the charged particles are scattered and can be detected by an optical detection device, thus visually presenting the periodic and stable trajectory of the charged particles in the three-dimensional ion trap.

[0064] It should be noted that when the laser is incident parallel to the ion trap direction, the excitation of ions in the laser field mainly occurs on a plane perpendicular to the laser propagation direction. This excitation method causes the ions to emit scattered light perpendicular to the laser direction, thus allowing for efficient collection. In this configuration, the laser path is relatively simple, eliminating the need for complex mirror or lens systems to adjust the laser direction. Furthermore, the laser incident parallel to the ion trap direction ensures that the laser is uniformly distributed on a plane perpendicular to the ion trap axis, thereby improving the imaging quality.

[0065] Compared with the prior art, in this invention, the laser is incident from the side of the ring electrode 23 in a direction parallel to the particle running plane, which can improve the scattered light collection efficiency, simplify the optical path and volume, and improve the imaging quality.

[0066] Compared with the prior art, the sample inlet 14 of this invention enters the sample system from the side of the ring electrode 23 in a direction parallel to the particle running plane, which can simplify the sample introduction system, improve the ion transmission efficiency, and reduce ion loss.

[0067] Specifically, the vacuum chamber 5 is fixed to the base 0 by the ion trap fixing member 20; the first cover electrode 21 is insulated from the ring electrode 23 by the first ceramic ring 22; and the second cover electrode 25 is insulated from the ring electrode 23 by the second ceramic ring 24.

[0068] Specifically, the first and second ceramic rings are insulating structures, and the height of the ceramic rings is 5mm-15mm.

[0069] Specifically, the first cover electrode 21, the second cover electrode 25, and the ring electrode 23 are conductive structures; the first cover electrode 21 and the second cover electrode 25 have holes as particle outlets with a radius of 1mm-3mm.

[0070] Specifically, the first cover electrode 21 and the second cover electrode 25 are grounded, and the ring electrode 23 is connected to the radio frequency high voltage.

[0071] Specifically, the ring electrode 23 has at least two and at most four openings on its side. Adjacent openings are perpendicular to each other, and the relative openings are centrally symmetrically distributed. A set of mutually perpendicular openings is selected as the sample inlet and the laser inlet.

[0072] Specifically, the optical detection device may be a monitor 11;

[0073] A z-axis window 2 is provided at the connection between the top of the vacuum chamber 5 and the optical detection device. The hole in the center of the first cover electrode 21 is coaxially arranged with the z-axis window 2, so that the optical detection device can detect the internal particle movement through the z-axis window 2.

[0074] A laser incident window 3 and a y-axis window 19 are provided on the side of the vacuum chamber 5 at positions corresponding to the side of the ring electrode 23.

[0075] During implementation, the sample inlet on the opposite side of the y-axis window 19 passes through the vacuum chamber 5 and is sealed to the vacuum chamber 5; the laser source 4 is aligned with the center of the ring electrode 23 from the side of the vacuum chamber 5; and the monitor 11 is aligned with the center of the first cover electrode 21 from the vertical direction.

[0076] Specifically, the monitor 11 can achieve continuous magnification from 1 to 1200 times, and has two functions: video recording mode and photo taking mode. It is fixed to the z-axis viewing window 2 above the vacuum cavity 5 by a monitor 11 clamp.

[0077] Preferably, the monitor 11 can be a CMOS sensor, and the external ion source can provide charged particles with a particle size in the micrometer range.

[0078] In the existing technology, the overall size of the instrument is too large. Particle observation in the ion trap requires the use of an expensive weak signal camera (such as COOKE QE) that requires a cooling system because the monitor 11 is too far away from the trapped particle. At the same time, the weak signal camera has extremely high requirements for the coupling of the optical system and strict requirements for operation and optical path adjustment, which makes it unsuitable for use as a teaching instrument.

[0079] Compared with existing technologies, this invention uses a z-axis viewing window 2 above the vacuum chamber 5 and connects a CMOS sensor-type monitor 11 to the z-axis viewing window 2, which greatly simplifies the optical path. At the same time, it uses charged particles with larger diameters as monitoring particles, so the relatively inexpensive CMOS sensor, which has less stringent requirements for the optical path, can collect the scattered light from the particles, meeting the weak light collection needs in this application scenario. Compared with existing technologies, it greatly reduces the size, cost, and operation difficulty, while also intuitively presenting the ion movement trajectory and being used for teaching the principles of mass spectrometry.

[0080] Specifically, the laser source 4 is a 532nm green dot laser generator, which is fixed to the laser incident window 3 on the left side of the vacuum cavity 5 by a laser universal bracket.

[0081] It should be noted that in laser optical path calibration, traditional ion trap particle mass spectrometers often require multiple mirror alignments to introduce the laser into the ion trap. This step is difficult to complete quickly and accurately for personnel without specialized training. Thanks to the miniaturized ion trap particle mass spectrometer design of this invention, the laser is introduced into the cavity in a straight line, and optical path calibration can be completed simply by adjusting the position of the laser.

[0082] Compared with the prior art, this utility model adopts an optimized laser source 4 and a laser incident path that is directly parallel to the particle running plane through the y-axis window 19, realizing rapid calibration of the laser optical path. Compared with the prior art, it greatly simplifies the operation and facilitates teaching.

[0083] Specifically, the z-axis window 2, the laser incident window 3, and the y-axis window 19 are made of glass and are fixed to the vacuum chamber 5 by fasteners. While serving as the entrance and exit of the optical path, they also ensure the sealing of the vacuum chamber 5.

[0084] Compared with the prior art, the glass y-axis window 19 of this invention can intuitively display the internal structure of the ion trap, which is convenient for intuitive teaching of mass spectrometry principles.

[0085] Preferably, a miniature solenoid valve 10 is provided at the sample inlet of the vacuum chamber. This valve not only isolates the miniature vacuum system from the outside atmosphere, but also serves as an ionization source. When a suitable pulse voltage is applied to it, the miniature solenoid valve 10 will open for a certain period of time, bringing the external sample into the ion trap to achieve pulsed sample introduction.

[0086] Compared with existing technologies, this utility model greatly simplifies the injection path, reduces the number of components and injection losses by using a miniature solenoid valve 10 to control the injection, and is easier to miniaturize than conventional equipment, making it better suited for teaching purposes.

[0087] Specifically, the central injection tube of the injection port 14 is a stainless steel capillary tube, and the stainless steel capillary tube and the injection port on the ring electrode 23 are located on the same axis, with a distance of 3mm-7mm between them.

[0088] Specifically, the vacuum chamber 5 is fixed to the base 0, and a diaphragm pump 17 and a molecular pump 15 are connected in series on one side of the vacuum chamber 5 on the base 0; the diaphragm pump 17 is fixed to the base 17 through the diaphragm pump fixing part 16; the inlet of the diaphragm pump 17 is connected to the vacuum chamber 5 through the connector 13, and the outlet of the diaphragm pump 17 is connected to the molecular pump 15, forming a series two-stage vacuum system.

[0089] Connector 13 is connected to vacuum gauge 12, which can monitor the vacuum level inside vacuum chamber 5.

[0090] During implementation, the diaphragm pump 17 acts as a backing pump, first evacuating the system to a low vacuum state (generally an ultimate vacuum of 1-0.3 mbar) to create conditions for the start-up of the molecular pump 15. The molecular pump 15 further evacuates gas on the basis of low vacuum, using high-speed rotating blades to collide with gas molecules and transport the gas molecules from the low-pressure end to the high-pressure end, thereby achieving a working pressure value of less than 1 Pa in the vacuum chamber 5.

[0091] Compared with the prior art, this utility model can effectively utilize the high efficiency of the diaphragm pump 17 to save energy, while protecting the molecular pump 15, improving its service life, and achieving a high vacuum environment.

[0092] Specifically, the mass spectrometry teaching instrument also includes a charge detector 27;

[0093] The charge detector 27 is connected to the central region of the second cover electrode 25. By adjusting the electric field of the ion trap, the particles lose stability in sequence according to their mass-to-charge ratio. The charged particles that leave the ion trap enter the charge detector 27 through the particle outlet, thereby realizing the detection of charged particles.

[0094] In practice, the mass spectrometry teaching instrument can also select a detection mode and adjust the frequency of the radio frequency voltage of the ring electrode 23 so that the charged particles reach the boundary of the stable region and are ejected in sequence. The ejected charged particles pass through the particle outlet on the cap electrode and are then detected by the charge detector 27.

[0095] More preferably, the charged particle outlets on the charge detector 27 and the second cover electrode 25 are located on the same axis; this can further reduce losses caused by collisions between particles and container pipes.

[0096] More preferably, a detector copper cover 26 is provided between the charge detector 27 and the second cover electrode 25 to electromagnetically shield the charge detector 27 and reduce electromagnetic interference from ion traps and the like.

[0097] Specifically, in order to better illustrate this utility model, in conjunction with Figure 5 Further explanation:

[0098] D1 is the z-axis viewing direction; D2 is the sample injection direction; D3 is the laser incident direction; D4 is the y-axis viewing direction; charged particles enter through D2 and move within the ring electrode; the laser enters through D3, and the scattered light generated by the laser irradiation of the charged particles is recognized and captured by the display in the D1 direction.

[0099] Specifically, the mass spectrometry teaching instrument is also equipped with a data acquisition card 18, which is fixed on the side of the base 0 away from the vacuum chamber 5, to realize the opening and closing of the micro solenoid valve 10, the voltage input of high voltage amplification, the acquisition of data from the charge detector 27, the acquisition of data from the vacuum gauge 12, and the internal timing control in the instrument's frequency sweep mode.

[0100] Specifically, the mass spectrometry teaching instrument is also equipped with a high-voltage amplifier 28, which is fixed to the base 0 by a high-voltage amplifier fixing piece 29 between the vacuum chamber 5 and the data acquisition card 18. It is responsible for receiving the voltage adjustment signal of the ring electrode 23 output by the data acquisition card 18 and amplifying the signal voltage to radio frequency high voltage.

[0101] Preferably, the data acquisition card 18 is equipped with a separate trapping mode control circuit and a frequency sweep mode control circuit. The trapping mode control circuit is used for trapping mode control, and the frequency sweep mode control circuit is used for frequency sweep control in detection mode. The adjustable frequency accuracy in trapping mode can be 0.01Hz; the adjustable frequency accuracy in frequency sweep mode can be 0.1Hz.

[0102] It should be noted that the trapping mode control circuit and the sweep frequency mode control circuit can be implemented using existing technology components. For example, taking the trapping mode circuit as an example, a commercially available DC-DC switching power supply module, an AD8421 instrumentation amplifier, an AD9833 high-speed DDS signal source, and an STM32 microcontroller can be integrated and programmed to achieve the following functions:

[0103] Based on the DDS circuit, through programming, the circuit can automatically output waveforms of a specified form;

[0104] Based on a given precision, the frequency modification variable is sent in real time, and the frequency of the output voltage waveform is also adjusted in real time through programming.

[0105] Specifically, the mass spectrometry teaching instrument is also equipped with a 24V DC power supply 1 to power the data acquisition card 18, high voltage amplifier 28, etc.

[0106] Specifically, the mass spectrometry teaching instrument operates in the confinement mode as follows:

[0107] Step 1: Turn on the vacuum system and wait for the vacuum chamber 5 to drop to the working pressure;

[0108] Step 2: Connect the external circuit of the confinement mode and set the corresponding voltage parameters; compared with the conventional mass spectrometer, the voltage is halved. The miniaturized mass spectrometer has a compact structure, and the components are more likely to affect each other. Excessive voltage here will interfere with the operation of the display.

[0109] Step 3: Using an ionization source, the sample particles deposited on the glass slide are injected through a micro solenoid valve 10 and ionized to obtain charged particles;

[0110] Step 4: The charged particles enter the ion trap through the inlet on the ring electrode 23 and are trapped within it. The ion trap, formed by a high-frequency electric field, binds the charged particles to the central region of the electrode. The ring electrode 23 also plays a role, along with the two grounded cap electrodes.

[0111] Step 5: Turn on laser source 4, align the optical path, and adjust the focal length of monitor 11 until a clear particle movement trajectory appears. At this time, there should be a large number of particles moving inside the trap.

[0112] Step 6: Adjust the signal voltage frequency multiple times to reduce the number of charged particles trapped in the ion trap until only the trajectory of a single particle can be observed; by repeatedly decreasing and increasing the signal voltage frequency, the particles in the trap are made to leave the stable region and be ejected from the ion trap.

[0113] In addition, the sweep-mode mass spectrometry teaching instrument for detecting charged particles operates as follows:

[0114] Step 1: Turn on the vacuum system and wait for the vacuum chamber 5 to drop to the working pressure;

[0115] Step 2: Connect the peripheral circuit for the sweep frequency mode and set the corresponding voltage parameters; Set the corresponding voltage parameters; Compared to conventional mass spectrometry, the voltage is halved. The miniaturized mass spectrometer has a compact structure, and the components are more likely to interfere with each other. Excessive voltage here will interfere with the operation of the display.

[0116] Step 3: Using an ionization source, the sample particles deposited on the glass slide are injected through a micro solenoid valve 10 and ionized to obtain charged particles;

[0117] Step 4: The charged particles enter the ion trap through the inlet on the ring electrode 23 and are trapped in the ion trap;

[0118] Step 5: Turn on the charge detector 27 and then start the frequency sweep program to scan the frequency of the radio frequency voltage connected to the ring electrode 23 from high frequency to low frequency, so that the charged particle reaches the boundary of the stable region and is ejected. The ejected charged particle passes through the particle outlet on the second cover electrode 25 and is then detected by the charge detector 27. Finally, the mass of the particle to be tested is calculated.

[0119] Please supplement the following embodiments and comparative examples to better illustrate this utility model:

[0120] Example 1

[0121] This embodiment discloses a three-dimensional ion trap particle mass spectrometry teaching instrument, such as... Figures 1 to 4 As shown, the interior includes: a vacuum chamber 5, a three-dimensional ion trap, an optical detection device, and a laser source 4;

[0122] The three-dimensional ion trap is set inside the vacuum chamber 5, and the vacuum chamber 5 provides a vacuum environment for the three-dimensional ion trap;

[0123] The three-dimensional ion trap is provided with a first cover electrode 21, a ring electrode 23, and a second cover electrode 25 arranged in an insulated manner from top to bottom; the first cover electrode 21, the ring electrode 23, and the second cover electrode 25 surround each other to form an ion trap region;

[0124] The ring electrode 23 has a vertically arranged laser inlet and a sample inlet 14 on its side. The laser inlet is connected to the laser source 4 through an optical path, and the sample inlet 14 is connected to an external ion source.

[0125] The first cover electrode 21 is connected to the detection optical path of the optical detection device.

[0126] The vacuum chamber 5 is fixed to the base 0 by the ion trap fixture 20; the first cover electrode 21 is insulated from the ring electrode 23 by the first ceramic ring 22; the second cover electrode 25 is insulated from the ring electrode 23 by the second ceramic ring 24.

[0127] The first and second ceramic rings are insulating structures, and the height of the ceramic rings is 10mm.

[0128] The first cap electrode 21, the second cap electrode 25 and the ring electrode 23 are conductive structures; the first cap electrode 21 and the second cap electrode 25 have holes as particle outlets with a radius of 1-3 mm.

[0129] The first cover electrode 21 and the second cover electrode 25 are grounded, and the ring electrode 23 is connected to the output port of the high voltage amplifier 28 through a high voltage connector, on which a radio frequency high voltage is applied.

[0130] The ring electrode 23 has at least two and at most four openings on its side. Adjacent openings are perpendicular to each other, and the relative openings are centrally symmetrically distributed. A set of mutually perpendicular openings is selected as the sample inlet and the laser inlet.

[0131] The optical detection device is a monitor 11;

[0132] A z-axis window 2 is provided at the connection between the top of the vacuum chamber 5 and the optical detection device. The center of the first cover electrode 21 has a hole and is coaxially arranged with the z-axis window 2, so that the optical detection device can detect the internal particle movement through the z-axis window 2.

[0133] A laser incident window 3 and a y-axis window 19 are provided on the side of the vacuum chamber 5 corresponding to the side of the ring electrode 23; the sample inlet on the opposite side of the y-axis window 19 passes through the vacuum chamber 5 and is sealed to the sample inlet; the laser source 4 is aligned with the center of the ring electrode 23 from the side of the vacuum chamber 5; the monitor 11 is aligned with the center of the first cover electrode 21 from the vertical direction.

[0134] The monitor 11 can achieve continuous magnification from 1x to 1200x and has two functions: video recording mode and photo taking mode. It is fixed to the z-axis viewing window 2 above the vacuum chamber 5 by a monitor 11 clamp.

[0135] The monitor 11 is a CMOS sensor, and the external ion source can provide charged particles with a diameter of 100 micrometers.

[0136] The laser source 4 is a 532nm green dot laser generator, which is fixed to the laser incident window 3 on the left side of the vacuum cavity 5 by a laser universal bracket.

[0137] This invention employs an optimized laser source 4 and a laser incident path that is directly parallel to the particle's orbital plane via a y-axis window 19, enabling rapid calibration of the laser's optical path. Compared to existing technologies, this greatly simplifies operation and facilitates teaching.

[0138] The z-axis window 2, laser incident window 3, and y-axis window 19 are made of glass and are fixed to the vacuum chamber 5 by fasteners. While serving as the entrance and exit points for the optical path, they also ensure the sealing of the vacuum chamber 5. The glass y-axis window 19 of this invention allows for a direct view of the internal structure of the ion trap, facilitating intuitive teaching of mass spectrometry principles.

[0139] A miniature solenoid valve 10 is installed at the sample inlet, which not only isolates the miniature vacuum system from the outside atmosphere but also serves as an ionization source. When a suitable pulse voltage is applied to it, the miniature solenoid valve 10 will open for a certain period of time, bringing the external sample into the ion trap, thus achieving pulsed sample introduction. This invention, by using a miniature solenoid valve 10 to control the sample introduction, greatly simplifies the sample introduction path, reduces the number of components and sample loss, and is easier to miniaturize compared to conventional equipment.

[0140] The central injection tube of the injection port 14 is a stainless steel capillary tube. The stainless steel capillary tube and the injection port on the ring electrode 23 are located on the same axis, and the distance between them is 3 mm.

[0141] Vacuum chamber 5 is fixed to base 0. On one side of vacuum chamber 5 on base 0, diaphragm pump 17 and molecular pump 15 are connected in series. Diaphragm pump 17 is fixed to base 17 through diaphragm pump fixing part 16. The inlet of diaphragm pump 17 is connected to vacuum chamber 5 through connector 13, and the outlet of diaphragm pump 17 is connected to molecular pump 15, forming a series two-stage vacuum system.

[0142] Connector 13 is connected to vacuum gauge 12, which can monitor the vacuum level inside vacuum chamber 5.

[0143] The diaphragm pump 17, as a backing pump, first evacuates the system to a low vacuum state (generally the ultimate vacuum is 1-0.3 mbar), creating conditions for the start-up of the molecular pump 15. The molecular pump 15 further evacuates gas on the basis of low vacuum, and uses high-speed rotating blades to collide with gas molecules, transporting gas molecules from the low-pressure end to the high-pressure end, thereby achieving a working pressure value of less than 1 Pa in the vacuum chamber 5.

[0144] The radius of the holes on the first and second cover electrodes is 1 mm.

[0145] like Figure 5 As shown:

[0146] D1 is the z-axis viewing direction; D2 is the sample injection direction; D3 is the laser incident direction; D4 is the y-axis viewing direction; charged particles enter through D2 and move within the ring electrode; the laser enters through D3, and the scattered light generated by the laser irradiation of the charged particles is recognized and captured by the display in the D1 direction.

[0147] The mass spectrometry teaching instrument is also equipped with a data acquisition card 18, which is fixed on the side of the base 0 away from the vacuum chamber 5, to realize the opening and closing of the micro solenoid valve 10, the voltage input of high voltage amplification, the acquisition of data from the charge detector 27, the acquisition of data from the vacuum gauge 12, and the internal timing control in the instrument's frequency sweep mode.

[0148] The mass spectrometry teaching instrument is also equipped with a high-voltage amplifier 28, which is fixed to the base 0 by a high-voltage amplifier fixing piece 29 between the vacuum chamber 5 and the data acquisition card 18. It is responsible for receiving the voltage adjustment signal of the ring electrode 23 output by the data acquisition card 18 and amplifying the signal voltage to radio frequency high voltage.

[0149] The data acquisition card 18 is equipped with a separate trap mode control circuit for trap mode control. The trap mode control circuit is constructed using existing technology components, and the adjustable frequency accuracy in trap mode is 0.01Hz.

[0150] Based on the DDS circuit, through programming, the circuit can automatically output waveforms of a specified form;

[0151] Based on a given precision, the frequency modification variable is sent in real time, and the frequency of the output voltage waveform is also adjusted in real time through programming.

[0152] The mass spectrometry teaching instrument is also equipped with a 24V DC power supply 1 to power the data acquisition card 18, high voltage amplifier 28, etc.

[0153] In confinement mode, the mass spectrometry teaching instrument operates as follows:

[0154] Step 1: Turn on the vacuum system and wait for the vacuum chamber 5 to drop to the working pressure;

[0155] Step 2: Connect the external circuit of the confinement mode and set the corresponding voltage parameters; compared with the conventional mass spectrometer, the voltage is halved. The miniaturized mass spectrometer has a compact structure, and the components are more likely to affect each other. Excessive voltage here will interfere with the operation of the display.

[0156] Step 3: Using an ionization source, the sample particles deposited on the glass slide are injected through a micro solenoid valve 10 and ionized to obtain charged particles;

[0157] Step 4: The charged particles enter the ion trap through the inlet on the ring electrode 23 and are trapped within it. The ion trap, formed by a high-frequency electric field, binds the charged particles to the central region of the electrode. The ring electrode 23 also plays a role, along with the two grounded cap electrodes.

[0158] Step 5: Turn on laser source 4, align the optical path, and adjust the focal length of monitor 11 until a clear particle movement trajectory appears. At this time, there should be a large number of particles moving inside the trap.

[0159] Step 6: Adjust the signal voltage frequency multiple times to reduce the number of charged particles trapped in the ion trap until only the trajectory of a single particle can be observed; by repeatedly decreasing and increasing the signal voltage frequency, the particles in the trap are made to leave the stable region and be ejected from the ion trap.

[0160] Example 2

[0161] This embodiment discloses a three-dimensional ion trap particle mass spectrometry teaching instrument, such as... Figures 1 to 4 As shown, the interior includes: a vacuum chamber 5, a three-dimensional ion trap, an optical detection device, and a laser source 4;

[0162] The three-dimensional ion trap is set inside the vacuum chamber 5, and the vacuum chamber 5 provides a vacuum environment for the three-dimensional ion trap;

[0163] The three-dimensional ion trap is provided with a first cover electrode 21, a ring electrode 23, and a second cover electrode 25 arranged in an insulated manner from top to bottom; the first cover electrode 21, the ring electrode 23, and the second cover electrode 25 surround each other to form an ion trap region;

[0164] The ring electrode 23 has a vertically arranged laser inlet and a sample inlet 14 on its side. The laser inlet is connected to the laser source 4 through an optical path, and the sample inlet 14 is connected to an external ion source.

[0165] The first cover electrode 21 is connected to the detection optical path of the optical detection device.

[0166] The vacuum chamber 5 is fixed to the base 0 by the ion trap fixture 20; the first cover electrode 21 is insulated from the ring electrode 23 by the first ceramic ring 22; the second cover electrode 25 is insulated from the ring electrode 23 by the second ceramic ring 24.

[0167] The first and second ceramic rings are insulated structures, and the height of the ceramic rings is 15mm.

[0168] The first cap electrode 21, the second cap electrode 25 and the ring electrode 23 are conductive structures; the first cap electrode 21 and the second cap electrode 25 have holes as particle outlets with a radius of 1-3 mm.

[0169] The first cover electrode 21 and the second cover electrode 25 are grounded, and the ring electrode 23 is connected to the output port of the high voltage amplifier 28 through a high voltage connector, on which a radio frequency high voltage is applied.

[0170] The ring electrode 23 has at least two and at most four openings on its side. Adjacent openings are perpendicular to each other, and the relative openings are centrally symmetrically distributed. A set of mutually perpendicular openings is selected as the sample inlet and the laser inlet.

[0171] The optical detection device is a monitor 11;

[0172] A z-axis window 2 is provided at the connection between the top of the vacuum chamber 5 and the optical detection device. The center of the first cover electrode 21 has a hole and is coaxially arranged with the z-axis window 2, so that the optical detection device can detect the internal particle movement through the z-axis window 2.

[0173] A laser incident window 3 and a y-axis window 19 are provided on the side of the vacuum chamber 5 corresponding to the side of the ring electrode 23; the sample inlet on the opposite side of the y-axis window 19 passes through the vacuum chamber 5 and is sealed to the vacuum chamber 5; the laser source 4 is aligned with the center of the ring electrode 23 from the side of the vacuum chamber 5; the monitor 11 is aligned with the center of the first cover electrode 21 from the vertical direction.

[0174] The monitor 11 can achieve continuous magnification from 1x to 1200x and has two functions: video recording mode and photo taking mode. It is fixed to the z-axis viewing window 2 above the vacuum chamber 5 by a monitor 11 clamp.

[0175] The monitor 11 is a CMOS sensor, and the external ion source can provide charged particles with a diameter of 200 micrometers.

[0176] The laser source 4 is a 532nm green dot laser generator, which is fixed to the laser incident window 3 on the left side of the vacuum cavity 5 by a laser universal bracket.

[0177] This invention employs an optimized laser source 4 and a laser incident path that is directly parallel to the particle's orbital plane via a y-axis window 19, enabling rapid calibration of the laser's optical path. Compared to existing technologies, this greatly simplifies operation and facilitates teaching.

[0178] The z-axis window 2, laser incident window 3, and y-axis window 19 are made of glass and are fixed to the vacuum chamber 5 by fasteners. While serving as the entrance and exit points for the optical path, they also ensure the sealing of the vacuum chamber 5. The glass y-axis window 19 of this invention allows for a direct view of the internal structure of the ion trap, facilitating intuitive teaching of mass spectrometry principles.

[0179] A miniature solenoid valve 10 is installed at the sample inlet, which not only isolates the miniature vacuum system from the outside atmosphere but also serves as an ionization source. When a suitable pulse voltage is applied to it, the miniature solenoid valve 10 will open for a certain period of time, bringing the external sample into the ion trap, thus achieving pulsed sample introduction. This invention, by using a miniature solenoid valve 10 to control the sample introduction, greatly simplifies the sample introduction path, reduces the number of components and sample loss, and is easier to miniaturize compared to conventional equipment.

[0180] The central injection tube of the injection port 14 is a stainless steel capillary tube. The stainless steel capillary tube and the injection port on the ring electrode 23 are located on the same axis, and the distance between them is 7 mm.

[0181] Vacuum chamber 5 is fixed to base 0. On one side of vacuum chamber 5 on base 0, diaphragm pump 17 and molecular pump 15 are connected in series. Diaphragm pump 17 is fixed to base 17 through diaphragm pump fixing part 16. The inlet of diaphragm pump 17 is connected to vacuum chamber 5 through connector 13, and the outlet of diaphragm pump 17 is connected to molecular pump 15, forming a series two-stage vacuum system.

[0182] Connector 13 is connected to vacuum gauge 12, which can monitor the vacuum level inside vacuum chamber 5.

[0183] The diaphragm pump 17, as a backing pump, first evacuates the system to a low vacuum state (generally the ultimate vacuum is 1-0.3 mbar), creating conditions for the start-up of the molecular pump 15. The molecular pump 15 further evacuates gas on the basis of low vacuum, and uses high-speed rotating blades to collide with gas molecules, transporting gas molecules from the low-pressure end to the high-pressure end, thereby achieving a working pressure value of less than 1 Pa in the vacuum chamber 5.

[0184] The second cap electrode 25 has a hole in the center, which can serve as an outlet for charged particles;

[0185] The charge detector 27 is connected to the central region of the second cap electrode 25. By adjusting the electric field of the ion trap, some particles become unstable, detach from the ion trap, and enter the charge detector 27 through the charged particle outlet, thus achieving the detection of charged particles. The mass spectrometry teaching instrument selects the detection mode and adjusts the frequency of the radio frequency voltage of the ring electrode 23 so that the charged particles reach the boundary of the stable region and are thus ejected. The ejected charged particles pass through the particle outlet on the cap electrode and are then detected by the charge detector 27.

[0186] The radius of the holes on the first and second cover electrodes is 3 mm.

[0187] The charge detector 27 and the charged particle outlets on the second cover electrode 25 are located on the same axis; this can further reduce losses caused by particle collisions with the container piping.

[0188] A detector copper cover 26 is provided between the charge detector 27 and the second cover electrode 25 to electromagnetically shield the charge detector 27 and reduce electromagnetic interference from ion traps and other sources to the detector.

[0189] The mass spectrometry teaching instrument is also equipped with a data acquisition card 18, which is fixed on the side of the base 0 away from the vacuum chamber 5, to realize the opening and closing of the micro solenoid valve 10, the voltage input of high voltage amplification, the acquisition of data from the charge detector 27, the acquisition of data from the vacuum gauge 12, and the internal timing control in the instrument's frequency sweep mode.

[0190] The mass spectrometry teaching instrument is also equipped with a high-voltage amplifier 28, which is fixed to the base 0 by a high-voltage amplifier fixing piece 29 between the vacuum chamber 5 and the data acquisition card 18. It is responsible for receiving the voltage adjustment signal of the ring electrode 23 output by the data acquisition card 18 and amplifying the signal voltage to radio frequency high voltage.

[0191] The data acquisition card 18 is equipped with a frequency sweep mode control circuit, which is used for frequency sweep control in detection mode. The frequency sweep mode control circuit is constructed using existing technology components, and the adjustable frequency accuracy in frequency sweep mode is 0.1Hz.

[0192] Based on the DDS circuit, through programming, the circuit can automatically output waveforms of a specified form;

[0193] Based on a given precision, the frequency modification variable is sent in real time, and the frequency of the output voltage waveform is also adjusted in real time through programming.

[0194] The mass spectrometry teaching instrument is also equipped with a 24V DC power supply 1 to power the data acquisition card 18, high voltage amplifier 28, etc.

[0195] Based on the above settings, in addition to the optical detection mode, this embodiment can also perform a frequency sweep mode for detecting charged particles, operating as follows:

[0196] Step 1: Turn on the vacuum system and wait for the vacuum chamber 5 to drop to the working pressure;

[0197] Step 2: Connect the peripheral circuit for the sweep frequency mode and set the corresponding voltage parameters; Set the corresponding voltage parameters; Compared to conventional mass spectrometry, the voltage is halved. The miniaturized mass spectrometer has a compact structure, and the components are more likely to interfere with each other. Excessive voltage here will interfere with the operation of the display.

[0198] Step 3: Using an ionization source, the sample particles deposited on the glass slide are injected through a micro solenoid valve 10 and ionized to obtain charged particles;

[0199] Step 4: The charged particles enter the ion trap through the inlet on the ring electrode 23 and are trapped in the ion trap;

[0200] Step 5: Turn on the charge detector 27 and then start the frequency sweep program to scan the frequency of the radio frequency voltage connected to the ring electrode 23 from high frequency to low frequency, so that the charged particle reaches the boundary of the stable region and is ejected. The ejected charged particle passes through the particle outlet on the second cover electrode 25 and is then detected by the charge detector 27. Finally, the mass of the particle to be tested is calculated.

[0201] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A three-dimensional ion trap particle mass spectrometry teaching instrument, characterized in that, include: Vacuum cavity, three-dimensional ion trap, optical detection device, laser source The three-dimensional ion trap is disposed inside a vacuum chamber, which provides a vacuum environment for the three-dimensional ion trap. The three-dimensional ion trap is provided with a first cover electrode, a ring electrode, and a second cover electrode arranged in an insulated manner from top to bottom; the first cover electrode, the ring electrode, and the second cover electrode surround each other to form an ion trap region; The ring electrode has a vertically arranged laser inlet and a sample inlet on its side. The laser inlet is connected to the laser source through an optical path, and the sample inlet is connected to an external ion source. The first cover electrode is connected to the detection optical path of the optical detection device.

2. The three-dimensional ion trap particle mass spectrometry teaching instrument according to claim 1, characterized in that, The vacuum chamber is fixed to the base by screws; The first cover electrode is insulated from the ring electrode by a first ceramic ring; the second cover electrode is insulated from the ring electrode by a second ceramic ring.

3. The three-dimensional ion trap particle mass spectrometry teaching instrument according to claim 2, characterized in that, The first cap electrode, the second cap electrode, and the ring electrode are conductive structures; the first cap electrode and the second cap electrode have holes as particle outlets; the ring electrode is connected to a radio frequency high voltage.

4. The three-dimensional ion trap particle mass spectrometry teaching instrument according to claim 3, characterized in that, The ring electrode has 2-4 openings on its side. Adjacent openings are perpendicular to each other, and the relative openings are centrally symmetrically distributed. A set of mutually perpendicular openings is selected as the sample inlet and the laser inlet.

5. The three-dimensional ion trap particle mass spectrometry teaching instrument according to claim 4, characterized in that, The top of the vacuum cavity is provided with a z-axis window at the connection between it and the optical detection device. The hole at the center of the first cover electrode is coaxially arranged with the z-axis window, so that the optical detection device can detect the movement of internal particles through the z-axis window. A laser incident window and a y-axis window are provided on the side of the vacuum chamber and at the corresponding positions on the side of the ring electrode.

6. The three-dimensional ion trap particle mass spectrometry teaching instrument according to claim 5, characterized in that, The optical detection device is a monitor, which is a CMOS sensor and has shooting and video recording functions; An external ion source provides charged particles with a particle size in the micrometer range.

7. The three-dimensional ion trap particle mass spectrometry teaching instrument according to claim 6, characterized in that, The laser source is a 532nm green dot laser generator.

8. The three-dimensional ion trap particle mass spectrometry teaching instrument according to claim 7, characterized in that, A miniature electromagnetic valve is installed at the sample inlet of the vacuum chamber.

9. The three-dimensional ion trap particle mass spectrometry teaching instrument according to claim 8, characterized in that, A diaphragm pump and a molecular pump connected in series are provided on one side of the vacuum chamber; The diaphragm pump is fixed to the base by a diaphragm pump fixing component; the inlet of the diaphragm pump is connected to the vacuum chamber through a connector, and the outlet of the diaphragm pump is connected to the molecular pump, forming a series two-stage vacuum system.

10. The three-dimensional ion trap particle mass spectrometry teaching instrument according to any one of claims 1-9, characterized in that, The mass spectrometry teaching instrument also includes a charge detector; The charge detector is connected to the central region of the second cap electrode. By reducing the frequency of the radio frequency voltage on the ring electrode, the electric field inside the ion trap is adjusted, causing the particles to lose stability in order of their mass-to-charge ratio, detach from the ion trap, and enter the charge detector through the charged particle outlet, thus realizing the detection of charged particles.

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