A dual-path traveling wave ion mobility tube device for an ion mobility spectrometer instrument

Abstract

The present application belongs to the technical field of mass spectrum and ion mobility spectrum analysis, and particularly relates to a double-path traveling wave ion mobility tube device for an ion mobility spectrometer; main components of the device are printed circuit boards, and the principle is to form an electric field for pushing ions to move by using electrodes drawn on the assembled circuit board after inputting a traveling wave signal, and to separate ions according to different collision cross sections and different amounts of carried charges. Compared with a traditional design, the traveling wave ion mobility tube of the present application adopts a double-path traveling wave array design, and two groups of traveling wave electric signals can be simultaneously input into a single group of channels to adjust the electric field, so that the device is more flexible and has lower requirements on the performance of an external power supply.

Description

Technical Field

[0001] The present invention relates to the technical field of mass spectrometry and ion mobility spectrometry, in particular to a dual-path traveling wave ion mobility tube device for an ion mobility spectrometer. Background Art

[0002] Ion mobility spectrometry is an advanced, high-end analytical instrument with high sensitivity, strong specificity, and widespread application. Its main components include a vacuum system, ion source, ion transport device, ion transfer tube, and signal detection system. It is widely used in a variety of fields, including environmental, food, medical, pharmaceutical, and life sciences. Traditional mass spectrometry relies on the differences in mass-to-charge ratios between different ions after ionization to distinguish between samples. It offers advantages such as high throughput, high sensitivity, and high accuracy. With the advancement of research, especially in life sciences, an increasing number of molecular isomers have been discovered, and their unique roles in biological processes are gaining increasing attention. However, due to the characteristics of molecular isomers, they often have similar molecular weights and charges, making them difficult to distinguish using mass spectrometry alone. Ion mobility spectrometry can address this problem. Ion mobility spectrometry uses a specific electric field and airflow to distinguish ions based on their charge and size. It complements mass spectrometry in separating substances such as isomers.

[0003] Traveling-wave ion mobility spectrometry (TWS) relies on applying a periodically varying traveling wave across a stack of electrodes to create a continuously changing electric field that drives ion separation. This periodic electric signal, applied by a power supply to the electrodes, causes ions to gradually separate based on differences in collision cross-section as they travel through the migration tube. Within a certain range, the longer the migration tube, the better the separation, and thus the higher the resolution. However, due to various factors, such as physical space limitations, extending the migration tube indefinitely is virtually impossible. Therefore, achieving the best possible separation and higher resolution within a limited distance remains a core challenge for ion mobility spectrometry. Improving resolution within this limited distance requires more complex electric field manipulation, such as forcing the ions to travel back and forth within the migration tube to achieve an equivalent increase in separation distance and resolution. This requirement undoubtedly raises the performance requirements for the power supply. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, the present invention discloses a dual-path traveling-wave ion transfer tube device for ion mobility spectrometry. This device features two sets of traveling-wave electrode arrays, capable of simultaneously connecting to two different traveling-wave power supplies to input different electrical signals. This allows for more rapid and complex electric field changes without compromising power supply performance, resulting in improved ion separation.

[0005] The present invention provides a dual-path traveling-wave ion migration tube device for an ion mobility spectrometer, comprising four printed circuit boards, one side of which is a working surface, and the other side is a wiring surface for internal wiring to connect different metal electrodes. Circuit interfaces are provided at the front and rear ends of the printed circuit boards for connecting an external power supply and for mutual electrical connection between the circuit boards. The working surfaces of the four printed circuit boards are inwardly directed to form a rectangular channel. The working surfaces are provided with two parallel traveling-wave electrode arrays for forming an electric field after power is applied. Each traveling-wave electrode array is composed of a plurality of traveling-wave electrode groups, each traveling-wave electrode group is composed of a plurality of independent electrodes, and the electrodes of each traveling-wave electrode group are numbered from front to back according to a serial number. There is no circuit connection between electrodes in the same traveling-wave electrode group, and electrodes with the same number in different traveling-wave electrode groups are sequentially connected in series. During operation, the two traveling-wave electrode arrays alternately switch working modes to achieve more complex and rapid electric field changes without improving power supply performance.

[0006] In the present invention, gate electrode arrays are drawn at both ends of a single printed circuit board, which are respectively at the ion entrance and ion exit, for applying DC voltages of different magnitudes to control the on-off of the entire ion transmission path and the front and rear ion paths.

[0007] In the present invention, the two parallel traveling wave electrode arrays on each printed circuit board are independent of each other and are used to apply traveling wave electrical signals respectively.

[0008] In the present invention, during operation, the amplitudes of the input dual-path traveling wave electrical signals are opposite, and are used to apply forces in different directions to the ionized sample to increase the separation capability of the migration tube.

[0009] In the present invention, the circuit interfaces on each circuit board are connected in series using wires in a one-to-one correspondence, so that the same power supply can apply electrical signals to the electrodes with the same number, that is, the same column, on the four circuit boards.

[0010] In the present invention, the printed circuit board is made of a hard circuit board, and electrodes are made on the circuit board by using bare copper, immersion gold or tin spraying technology.

[0011] In the present invention, each traveling wave electrode group is composed of 6-10 independent electrodes, and there are more than one traveling wave electrode group.

[0012] In the present invention, circuit connection lines are provided on the front and rear ends of each circuit board, each circuit connection line corresponds to a column of series electrodes on the circuit board, and each circuit connection port is used to connect a different power supply to apply a different traveling wave signal.

[0013] In the present invention, each printed circuit board is provided with a mechanical structure for interlocking with other printed circuit boards to fix them to each other.

[0014] In the present application, the interlocking mechanical structure adopts a clamping tooth and clamping groove structure.

[0015] Compared with the prior art, the present application has the following advantages:

[0016] The conventional single-path traveling wave ion migration tube needs a power supply with extremely high chopping and conversion capability when the traveling wave electrical signal needs to be converted into an electrical signal in the opposite direction. Meanwhile, the repeated high-speed conversion has higher requirements for the filter output rectification stability of the power supply. The double-path traveling wave ion migration tube of the present application can realize the above changes by using the cooperation of the independent on-off of the double-path power supply without the need for a power supply with higher performance. The power supply requirement is lower, and the complex electric field change is easier to achieve by combination, thereby realizing better ion separation capability and improving the resolution of the migration tube per unit length.

[0017] Compared with the conventional ion migration tube design, the device of the present application requires fewer components and only four circuit boards to assemble to realize the function. Meanwhile, the double-path traveling wave array can rely on the input of two different traveling wave electrical signals to realize more complex and efficient electric field conversion. The device has multiple functions such as ion transmission and ion separation, has low installation cost, low use difficulty, and low subsequent maintenance and replacement cost. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The single-chip circuit board appearance diagram of the embodiment of the present application.

[0019] Figure 2 The migration tube assembly diagram of the embodiment of the present application.

[0020] The reference numerals are as follows:

[0021] 1 - power supply interface, 2 - gate electrode, 3 - double-path traveling wave array, 4 - single traveling wave electrode, 5 - traveling wave electrode group, 6 - clamping groove, 7 - clamping tooth, 8 - fixing through hole. DETAILED DESCRIPTION

[0022] The present application will be further described below in combination with the drawings and embodiments. EMBODIMENT

[0023] As Figure 1-Figure 2As shown, the present invention provides a traveling-wave ion transfer tube device for ion mobility spectrometers. Its primary component is a printed circuit board. The device utilizes electrodes drawn on the assembled circuit board after receiving a traveling-wave signal to form an electric field that propels ions, separating ions based on their collision cross-sectional area and the amount of charge they carry. The device comprises an ion transfer tube composed of four printed circuit boards, a mechanical interlocking structure for interlocking and securing them, and additional supporting fixings. The ion transfer tube is equipped with an electrode assembly for applying voltage to form an electric field, and a power interface 1 for electrically connecting the different circuit boards and between the circuit boards and a power source.

[0024] Taking positive ion mode as an example, during operation, the ionized sample, after preliminary processing, is injected in batches into a starting position at one end of the migration tube in a constant pulse manner. Pulled by the electric field of the migration tube, the ions move from one end to the other, completing ion separation and being gradually transferred out of the migration tube and delivered to subsequent instruments. When a batch of ions has completely escaped the migration tube, the voltage on gate electrode 2 is reduced, allowing the next batch of ions to be pulsed into the migration tube. The cycle from the injection of a batch of ions into the migration tube to their complete exit from the migration tube constitutes a complete working cycle, thereby achieving ion mobility separation.

[0025] Specifically, power ports 1 are located at both ends of the long sides for connecting to an external power source and interconnecting the printed circuit boards. The circuitry and electrode components that comprise the migration tube are manufactured using printed circuit board technology. Each migration tube requires four printed circuit boards.

[0026] Each printed circuit board (PCB) has two sides: one is the working surface, where electrodes are fabricated and formed using exposed pads. The electrodes are rectangular and arranged in sequence with equal spacing on the PCB. The other is the embedded wiring surface, where the electrodes are connected internally by wiring. Eight adjacent electrodes on the exposed electrode surface, starting from either end, form a traveling wave electrode group 5. The electrodes within each traveling wave electrode group 5 are numbered 1 to 8. The electrodes within each group are independent and disconnected. Electrodes with the same number in different groups are connected in series via the wiring surface to form a circuit. This circuit formed by the same numbered electrodes requires the application of a traveling wave external power supply signal, meaning each migration tube requires 16 (two-way) traveling wave power supply input signals. Sixteen circuit connection wires are provided on the front and back headers of a single PCB. Each circuit connection wire corresponds to a column of series-connected electrodes on the PCB and is used to connect to different power supply interfaces 1 to apply different traveling wave signals. In a specific embodiment, the power supply interfaces 1 on each PCB can be connected in series using wires, allowing the same power supply to apply electrical signals to the same column of electrodes on four PCBs. The two-channel model is provided by different signal sources, applying traveling wave signals of opposite amplitudes, so that the ions in the migration tube can be continuously pulled back and forth by the forward and reverse electric field forces, achieving greater separation.

[0027] Each printed circuit board is rectangular in shape, with slots 6 and teeth 7 on its two long sides as mechanical interlocking structures for mutual locking and fixing. During assembly, simply align the teeth 7 of one circuit board with the slots 6 of another circuit board, confirm the working surface and wiring surface, and press down to tighten. The four circuit boards can be installed in the same way. If the migration tube needs additional fixation, screws can be passed through the fixing holes 8 of multiple circuit boards and tightened with nuts to complete the additional reinforcement after the migration tube is assembled. This prevents the connection from loosening or falling apart due to vibration, external force, squeezing, twisting, and other unexpected factors during use.

[0028] In a specific embodiment, when a traveling wave ion transfer tube device is used, it is loaded into the core cavity of the mobility instrument to receive the ions to be separated transmitted by the front-stage system. First, four printed circuit boards are connected to the other circuit board teeth through their respective slots 6. After the assembly is completed, the shape is as follows: Figure 2 As shown. It should be noted that the circuit board is divided into two sides, the wiring side and the working side. The working side is provided with a plurality of traveling wave electrode groups 5 consisting of a single traveling wave electrode 4, and two front and rear gate electrodes 2. After the circuit boards are assembled, additional screws can be used to pass through and penetrate the fixing through holes 8 of the two parallel circuit boards and tighten them with nuts. After the assembly is completed, the power interface 1 is used to connect to the power supply on the instrument or other given power supplies and is also used to connect to the corresponding power supplies on other circuit boards. The voltage given by the external power supply forms a traveling wave electric field, and the electric field cooperates with the flow of gas to separate the ion components entering the migration tube and transmit them out of the migration tube from the other end.

[0029] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and that those skilled in the art may make various changes or modifications within the scope of the claims, without affecting the essence of the present invention. Unless there is a conflict, the embodiments of this application and the features in the embodiments may be combined with each other in any manner.

Claims

1. A dual-path traveling wave ion transfer tube device for an ion mobility spectrometer, characterized in that: It includes four printed circuits, one side of the printed circuit board is the working surface, and the other side is the wiring surface, which is used for internal wiring to connect different metal electrodes. Circuit interfaces are set at the front and back ends of the printed circuit board, which are used to connect the external power supply and make electrical connections between the circuit boards; the working surfaces of the four printed circuit boards are inwardly formed into a rectangular channel; among them: two parallel traveling wave electrode arrays are arranged on the working surface to form an electric field after power is turned on, and each traveling wave electrode array is composed of several traveling wave electrode groups, and each traveling wave electrode group is composed of several independent electrodes. The electrodes of each traveling wave electrode group are numbered from front to back according to the serial number. There is no circuit connection between the same traveling wave electrode group, and the electrodes with the same number in different traveling wave electrode groups are connected in series in sequence; when working, the two traveling wave electrode arrays alternately change their working conditions to achieve more complex and rapid electric field changes without improving the power supply performance.

2. The dual-path traveling wave ion transfer tube device for an ion mobility spectrometer according to claim 1, characterized in that: Gate electrode arrays are drawn at both ends of a single printed circuit board, which are the ion entrance and ion exit respectively, and are used to apply DC voltages of different sizes to control the on and off of the entire ion transmission path and the front and rear ion paths.

3. The dual-path traveling wave ion transfer tube device for an ion mobility spectrometer according to claim 1, characterized in that: The two parallel traveling wave electrode arrays on each printed circuit board are independent of each other and are used to apply traveling wave electrical signals respectively.

4. The dual-path traveling wave ion transfer tube device for an ion mobility spectrometer according to claim 3, characterized in that: During operation, the amplitudes of the input dual-path traveling wave electrical signals are opposite, which are used to apply forces in different directions to the ionized sample to increase the separation capability of the migration tube.

5. The dual-path traveling wave ion transfer tube device for an ion mobility spectrometer according to claim 1, characterized in that: The circuit interfaces on each circuit board are connected in series using wires in a one-to-one correspondence, so that the same power supply can apply electrical signals to the electrodes with the same number, that is, the same column, on the four circuit boards.

6. The dual-path traveling wave ion transfer tube device for an ion mobility spectrometer according to claim 1, characterized in that: The printed circuit board is made of hard circuit board, and the electrodes are made of bare copper, immersion gold or tin spraying process.

7. The dual-path traveling wave ion transfer tube device for an ion mobility spectrometer according to claim 1, characterized in that: Each traveling wave electrode group is composed of 6-10 independent electrodes, and there are more than one traveling wave electrode group.

8. The dual-path traveling wave ion transfer tube device for an ion mobility spectrometer according to claim 1, characterized in that: Circuit connection lines are provided on the card heads at the front and rear ends of each circuit board. Each circuit connection line corresponds to a column of series electrodes on the circuit board. Each circuit connection port is used to connect a different power supply to apply a different traveling wave signal.

9. The dual-path traveling wave ion transfer tube device for an ion mobility spectrometer according to claim 1, characterized in that: Each printed circuit board is equipped with a mechanical structure that interlocks with other circuit boards to ensure mutual fixation.

10. The dual-path traveling wave ion transfer tube device for an ion mobility spectrometer according to claim 9, characterized in that: The interlocking mechanical structure adopts a tooth and slot structure.

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