Double-path traveling wave ion migration tube device for ion mobility spectrometry instrument

Abstract

The invention 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. The main component is a printed circuit board, and the principle is that an electric field for pushing ions to move is formed by using electrodes drawn on the assembled circuit board after a traveling wave signal is accessed, and the ions are separated according to the collision sectional area of the ions and the difference of the charge quantity carried by the ions. Compared with the traditional design, the traveling wave ion migration tube disclosed by the invention 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 an electric field. Therefore, the power supply is more flexible, and the performance requirement of an external power supply is lower.

Description

Technical Field

[0001] The 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 wide application. Its main structure includes vacuum system, ion source, ion transmission device, ion migration tube and signal detection system. It is widely used in many fields such as environment, food, medical treatment, medicine, life science, etc. Traditional mass spectrometry relies on the different mass-to-charge ratios between different types of ions after the sample is ionized to distinguish various samples. It has the advantages of high throughput, high sensitivity and high accuracy. With the deepening of research, especially the progress of life sciences, more and more isomer molecules are discovered, and the unique role of isomer molecules in life activities is increasingly valued. However, due to the characteristics of isomer molecules, they often have the same molecular weight and charge, which makes it difficult to distinguish them by mass spectrometry alone. The ion mobility spectrometry technology can solve this problem. Ion mobility spectrometry is a technology that uses a specific electric field and airflow to distinguish ions by different ion charge numbers and volumes. It has formed a good complementary characteristic with mass spectrometry technology in the separation of substances such as isomers.

[0003] Traveling wave ion mobility spectrometry is a type of mobility spectrometry technology that relies on applying periodic traveling waves to stacked electrodes to form a constantly changing electric field to promote ion separation. The periodic changing electrical signal applied by the power supply to the electrodes can make the ions gradually separated in the migration tube according to the difference in collision cross-sectional area as they continue to move forward, and within a certain range, the longer the distance of the migration tube, the better the separation effect, that is, the higher the resolution. However, due to various factors, such as the limitation of physical space, it is almost impossible to extend the migration tube indefinitely. Then how to achieve the best possible separation effect and higher resolution within a limited distance is one of the core issues facing ion mobility spectrometry. But at the same time, improving the resolution within a limited distance requires more complex electric field changes, such as allowing ions to travel back and forth in the migration tube to achieve an equivalent separation distance increase to improve the resolution. However, this demand undoubtedly raises the requirements for various performance indicators of the power supply. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to disclose a dual-path traveling wave ion transfer tube device for an ion mobility spectrometer. The device has two sets of traveling wave electrode arrays, which can be connected to two different traveling wave power supplies to input different electrical signals at the same time, and can achieve more rapid and complex electric field changes without improving the power supply performance, thereby achieving better ion separation effect.

[0005] The invention provides a dual-path traveling wave ion migration tube device for an ion migration spectrometer, which comprises 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, and circuit interfaces are arranged 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 arranged to form a rectangular channel; wherein: two parallel traveling wave electrode arrays are arranged on the working surfaces to form an electric field after power is turned on, 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 mutually independent electrodes, the electrodes of each traveling wave electrode group are numbered from front to back according to serial numbers, the same traveling wave electrode group has no circuit connection with each other, and the electrodes with the same numbers in different traveling wave electrode groups are connected in series in sequence; when working, the two traveling wave electrode arrays alternately change their working, so as to realize more complex and rapid electric field changes without improving the 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 the ion exit, and are used to apply 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, 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, when working, 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 capacity 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 source can apply electrical signals to 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 mutually independent electrodes, and there are more than one traveling wave electrode group.

[0012] In the present invention, circuit connection lines are arranged 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, and each circuit connection port is used to connect different power supplies to apply different traveling wave signals.

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

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

[0015] Compared with the prior art, the present invention has the following beneficial effects: A traditional single-channel traveling wave migration tube requires a power supply with extremely high chopping and conversion capabilities when converting a traveling wave electrical signal into a reverse direction electrical signal. At the same time, repeated high-speed conversions have higher requirements on the filtering, output, and rectification stability of the power supply. The dual-channel traveling wave ion migration tube of the present invention can achieve the above-mentioned changes by utilizing the cooperative and independent switching of the dual power supplies without the need for a higher-performance power supply. It has lower power supply requirements and can more easily realize complex electric field changes through combination, thereby achieving better ion separation capabilities and improving the resolution of the migration tube per unit length.

[0016] Compared with the traditional ion transfer tube design, the device of the present invention requires fewer components and can realize the function by assembling only four circuit boards. At the same time, the dual-channel traveling wave array can realize more complex and efficient electric field transformation by inputting two sets of different traveling wave electrical signals. It also has multiple functions such as ion transmission and ion separation, low installation cost, low difficulty in use, and low subsequent maintenance and replacement costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is an appearance diagram of a single-chip circuit board according to an embodiment of the present invention.

[0018] Figure 2 This is an assembly diagram of a migration tube according to an embodiment of the present invention.

[0019] The reference numerals are: 1-power interface, 2-gate electrode, 3-dual-channel traveling wave array, 4-single traveling wave electrode, 5-traveling wave electrode group, 6-card hole, 7-card tooth, 8-fixing through hole. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. Example

[0021] like Figure 1-Figure 2 As shown, the present invention provides a traveling wave ion transfer tube device for an ion mobility spectrometer, the main component of which is a printed circuit board. The principle is to use the electrodes drawn on the assembled circuit board to form an electric field to push the ions to move after the traveling wave signal is connected, and the ions are separated according to the collision cross-sectional area of ​​the ions and the difference in the amount of charge carried. It includes an ion transfer tube composed of four printed circuit boards in a group, a mechanical interlocking structure for interlocking and fixing, and matching additional reinforcement fixing parts; the ion transfer tube is provided with an electrode assembly for applying voltage to form an electric field, and a power supply interface 1 for electrical connection between different circuit boards and between the circuit board and the power supply.

[0022] Taking the positive ion mode as an example, when working, the ionized sample is injected into the starting position of one end of the migration tube in batches in a constant pulse manner after preliminary treatment. Under the traction of the electric field of the migration tube, the ions move from one end of the migration tube to the other end to complete the ion separation and are gradually transmitted out of the migration tube and delivered to the subsequent instrument. When a batch of ions completely flies out of the migration tube, the voltage on the gate electrode 2 is reduced so that the next batch of ions can be pulsed into the migration tube. From the injection of a batch of ions into the migration tube to their complete flight out of the migration tube is a complete working cycle. Thus, the mobility separation function of the ions is realized.

[0023] Specifically, power interfaces 1 are provided at both ends of the long sides for connecting to an external power source and circuit connections between printed circuit boards. The circuits and electrode components that make up the migration tube are manufactured using printed circuit board technology. Each set of migration tubes requires a total of four printed circuit boards to be spliced ​​together.

[0024] Each printed circuit board is divided into two sides: one side is the working side, which uses the exposed pad to make and form electrodes. The electrodes are rectangular and are arranged on the circuit board in sequence at equal intervals. One side is the buried wire side, and the electrodes are connected internally by wiring. The electrodes on the exposed electrode surface are connected in series from any end to form a traveling wave electrode group 5. The electrodes in each traveling wave electrode group 5 are numbered 1 to 8 respectively. The electrodes in each group are independent of each other and are not connected. The electrodes with the same number in different groups are connected in series through the wiring surface to form a circuit. The circuit formed by the series connection of the electrodes with the same number needs to apply a traveling wave external power supply signal, that is, each migration tube needs 16 (two-way) traveling wave power supply input signals. There are 16 circuit connection lines on the card heads at the front and rear ends of a single circuit board, each circuit connection line corresponds to a column of series electrodes on the circuit board, and each circuit connection line is used to connect different power interfaces 1 to apply different traveling wave signals. In a specific embodiment, the power interface 1 on each circuit board can be connected in series with wires one by one, that is, the same power supply can be used to apply electrical signals to the same column of electrodes on four circuit boards. The two-channel models are provided by different signal sources, applying traveling wave signals with 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 a greater degree of separation.

[0025] Each printed circuit board is rectangular in shape, and has a card hole 6 and a card tooth 7 on the two long sides as a mechanical interlocking structure for mutual locking and fixing. When assembling, you only need to confirm the working surface and wiring surface of one circuit board, align the card tooth 7 with the card slot 6 of another circuit board, press and clamp it, and the four circuit boards can be installed in the same way. If the migration tube needs additional fixation, it can be additionally reinforced after the migration tube is assembled by passing screws through the fixing holes 8 of multiple circuit boards and tightening them with nuts. Avoid loose connections or falling apart due to vibration, external force extrusion and distortion, and other unexpected factors during use.

[0026] 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 system. First, four printed circuit boards are connected to the teeth of another circuit board 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 has a plurality of traveling wave electrode groups 5 composed of a single traveling wave electrode 4, and two front and rear gate electrodes 2. After the circuit boards are spliced, 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.

[0027] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

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; wherein: the working surface is arranged with two parallel traveling wave electrode arrays, which are used to form an electric field after power is turned on, each traveling wave electrode array is composed of a number of traveling wave electrode groups, each traveling wave electrode group is composed of a number of 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 mode to achieve more complex and rapid electric field changes without improving the power supply performance.

2. The dual-path traveling wave ion migration tube device for an ion migration spectrometer according to claim 1, characterized in that: Gate electrode arrays are drawn at both ends of a single printed circuit board, which are respectively at the ion entrance and ion exit, and are used to apply DC voltages of different magnitudes to control the on-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: When working, 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 capacity 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 source can apply electrical signals to 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 arranged 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, and each circuit connection port is used to connect different power supplies to apply different traveling wave signals.

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 provided with a mechanical structure that interlocks with other circuit boards for mutually fixed mounting.

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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