Ion mobility spectrometry device based on traveling wave technology

Abstract

The invention belongs to the technical field of mass spectrum and ion mobility spectrum analysis, and particularly relates to an ion mobility spectrum device based on a traveling wave technology. The traveling wave ion migration tube does not depend on direct current protection and comprises four printed circuit boards, and an electrode assembly drawn on the circuit boards is used for applying an axial traveling wave electric field changing periodically. Compared with the traditional nondestructive ion transport mobility spectrometry based on direct current and traveling wave, the traveling wave ion mobility tube device disclosed by the invention can complete the transport separation of ions without applying a direct current protection electric field. The device is simple in structural design, few in required components and wide in application range.

Description

Technical Field

[0001] The invention relates to the technical field of mass spectrometry and ion mobility spectrometry, and in particular to an ion mobility spectrometry device based on traveling wave technology. Background Art

[0002] Ion mobility spectrometry and mass spectrometry are both advanced high-end analytical instruments with high sensitivity, strong specificity and wide application. The main structures include 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 have been discovered, and the unique role of isomer molecules in life activities has become more and more important. 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 periodically changing traveling waves to stacked electrodes to form a constantly changing electric field to promote ion separation. In order to prevent disordered radial diffusion of ions and reduce ion loss during the separation process, the general solution is to arrange DC protection electrodes on both sides of the traveling wave electrode to form a pseudopotential field that blocks the radial diffusion of ions. This increases the demand for circuit input and the complexity of circuit layout. 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 an ion migration spectrometer based on traveling wave technology that can transmit and separate ions without the need for DC protection electrodes. It has the advantages of simple structure, low manufacturing cost, low assembly difficulty, easy disassembly and maintenance, and low space requirement. The present invention forms a rectangular channel by splicing four printed circuit boards in a group, and applies a specific voltage on it to cooperate with airflow control to finally achieve ion traction and separation. The technical solution of the present invention is specifically described as follows.

[0005] An ion mobility spectrometer based on traveling wave technology comprises four identical printed circuit boards, one side of the printed circuit boards is a working surface, on which a plurality of metal electrodes with fixed spacing are arranged for forming a pseudopotential field after being energized, and the other side is a wiring surface for internal wiring to connect different metal electrodes. The working surfaces of the four printed circuit boards are inwardly formed into a rectangular channel; 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, so as to control the gas flow rate in the channel and realize the function of an ion mobility tube.

[0006] In the present invention, there are several groups of metal electrodes, and n adjacent metal electrodes are counted from any end as a group. The metal electrodes in each group are numbered 1-n respectively. The electrodes in each group are independent of each other and not connected. Electrodes with the same number in different groups are connected in series through the wiring surface to form a circuit. Preferably, n is an integer between 6 and 10, and the number of electrode groups is more than 1. Generally, the longer the required transmission distance, the more electrode groups.

[0007] In the present invention, n circuit connection lines are arranged 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. Each circuit connection port is used to connect different power sources to apply different traveling wave signals.

[0008] In the present invention, the circuit interfaces of different circuit boards are connected in series using wires in a one-to-one correspondence, that is, the same power supply is used to apply electrical signals to the same column of electrodes on four circuit boards.

[0009] In the present invention, a hard printed circuit board is used for manufacturing, and the upper electrode is manufactured using an exposed pad, that is, any circuit board material and pad process that meet the above requirements can be used to manufacture the device.

[0010] In the present invention, each printed circuit board is provided with a mechanical structure interlocking with other circuit boards so as to be fixedly installed with each other.

[0011] In the present invention, two long sides of the printed circuit board are respectively provided with fixing buckles and fixing slots for mutual locking and fixing.

[0012] The present invention also includes fixing members for connecting and reinforcing two circuit boards.

[0013] In view of the problems that conventional traveling wave ion funnels require DC protection electrodes to apply DC voltage to constrain ions, many related accessories are required, and assembly and disassembly are troublesome, an ion migration tube that does not require DC protection electrodes is designed. Since the general traveling wave ion funnel based on printed circuit boards has only two pieces, i.e. a pair of electrodes facing each other to form an electric field, it is not possible to effectively constrain the radial diffusion of ions between the circuit boards. Therefore, additional DC electrodes are required on both sides to constrain the ions. In the present invention, a rectangular traveling wave electrode array composed of four circuit board groups is used to form a pseudopotential field that can effectively constrain ions and prevent radial diffusion. Therefore, no DC protection electrodes are required. This device integrates the functions of ion transmission, separation, and guidance. At the same time, only four identical circuit boards need to be fixed to each other to complete the assembly. After connecting an external power supply to apply a wave voltage, the interface realizes the function. Compared with the prior art, the beneficial effects of the present invention are: Compared with the traditional ion migration tube design, the device of the present invention has a greatly reduced number of components. Only four identical circuit boards are needed to realize the functions. The components can be completely replaced and reused with each other. It is simple to disassemble and assemble, convenient to maintain, and has low replacement cost. The space requirement is small, and different length dimensions can be changed according to actual needs on site, and it can be placed in a narrow space for work. At the same time, there is no need for additional DC protection electrodes and DC power supplies to form a pseudopotential field to constrain ions, which reduces the complexity of the design and the requirements for the type of external power supply. It realizes multiple functions such as ion transmission and ion separation, with low installation cost and low difficulty in use. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is an appearance diagram of a single-chip circuit board according to an embodiment of the present invention.

[0015] Figure 2 This is an appearance diagram of a single fixing member according to an embodiment of the present invention.

[0016] Figure 3 This is an assembly diagram of a migration tube according to an embodiment of the present invention.

[0017] Figure 4 A diagram showing the installation of fixings on the migration tube according to an embodiment of the present invention.

[0018] The reference numerals are: 1-power interface, 2-electrode, 3-fixing buckle, 4-fixing slot, 5-electrode group, 6-fixing screw hole, 7-printed circuit board, 8-fixing part, 9-circuit board fixing slot, 10-fixing screw hole. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. Example

[0020] like Figure 1-Figure 3As shown, the present invention provides a traveling wave ion migration tube device that does not require a DC protection electrode, which includes an ion migration tube composed of four printed circuit boards 7 in a group, a mechanical interlocking structure for locking and fixing each other, and matching additional reinforcement fixing parts; the ion migration 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.

[0021] During operation, the ionized samples are pre-processed and then injected into the starting position at one end of the migration tube in batches in a constant pulse manner. 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 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.

[0022] Specifically, power interfaces 1 are provided at both ends of the long sides for connecting to an external power source and for electrical connection between printed circuit boards 7. The circuits and electrode components constituting the migration tube are manufactured by printed circuit board technology. Each group of migration tubes requires four printed circuit boards 7 to be spliced ​​together.

[0023] Each printed circuit board 7 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 arranged on the circuit board in sequence with equal spacing. One side is the buried wire side, and the electrodes are connected internally by wiring. The electrodes on the exposed electrode surface are counted from any end as n adjacent electrodes as an electrode group 5. The electrodes in each electrode group 5 are respectively numbered 1 to n, where n is generally 6 or 8. The electrodes in each group are independent and not connected to each other. The electrodes with the same number in different groups are connected in series through the wiring surface to form a circuit. Each circuit formed by the series connection of electrodes requires an external power supply signal to be applied, that is, each group of migration tubes requires n groups of power input. There are n circuit connection lines on the card heads at the front and back 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 port is used to connect different power supplies to apply different traveling wave signals. In a specific embodiment, the circuit interface 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.

[0024] Each printed circuit board 7 is rectangular in shape as a whole, and a male head-fixing buckle 3 and a female head-fixing slot 4 are respectively provided on the two long sides as a mechanical interlocking structure for mutual locking and fixing. When assembling, it is only necessary to confirm the working surface and wiring surface of one circuit board, align the fixing buckle 3 with the fixing slot 4 of another circuit board, press and clamp it, and the four circuit boards can be installed in the same way. The migration tube is equipped with an additional fixing part 8, which can be made of any material with qualified structural strength such as metal, organic polymer, etc., and is used to reinforce the connection after the migration tube is assembled. Avoid loose or falling apart connections caused by vibration, external force extrusion and distortion and other unexpected factors during use.

[0025] 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 previous system. First, four printed circuit boards 7 are connected to the fixed card slots 4 of another circuit board 6 through their respective fixing buckles 3. After the assembly is completed, the shape is as follows: Figure 3 As shown. It should be noted that the circuit board 6 is divided into two sides, the wiring surface and the working surface, and the working surface is provided with a plurality of electrode groups 5 consisting of electrodes 2. After the circuit boards are spliced, the circuit board fixing groove 9 of the fixing member 8 can be additionally aligned and clamped at the junction of the card slot and the card mouth of the circuit board, and the two fixing screw holes 6 and 8 are aligned and then the two are fixed with screws. 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 the gas to separate the ion components entering the migration tube and transmit them out of the migration tube from the other end.

[0026] 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. An ion mobility spectrometer based on traveling wave technology, characterized in that: It includes four identical printed circuit boards, one side of which is a working surface, on which a number of metal electrodes with fixed spacing are arranged to form a pseudopotential field after power is applied, and the other side is a wiring surface, which is used for internal wiring to connect different metal electrodes. The working surfaces of the four printed circuit boards are inwardly facing to form a rectangular channel. Circuit interfaces are provided at the front and rear ends of the printed circuit board for connecting an external power source and for making electrical connections between the circuit boards to control the gas flow rate in the channel to realize the function of the ion transfer tube.

2. The ion mobility spectrometer based on traveling wave technology according to claim 1, characterized in that: There are several groups of metal electrodes. Starting from any end, n adjacent metal electrodes form a group. The metal electrodes in each group are numbered 1-n respectively. The electrodes in each group are independent of each other and not connected. Electrodes with the same number in different groups are connected in series through the wiring surface to form a circuit.

3. The ion mobility spectrometer based on traveling wave technology according to claim 2, characterized in that: N circuit connection lines are arranged 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; each circuit connection line is used to connect different power sources to apply different traveling wave signals.

4. The ion mobility spectrometer based on traveling wave technology according to claim 2, characterized in that: The circuit interfaces of different circuit boards are connected in series using wires in a one-to-one correspondence, that is, the same power supply is used to apply electrical signals to the same column of electrodes on the four circuit boards.

5. The ion mobility spectrometer based on traveling wave technology according to claim 1, characterized in that: The metal electrode is made by using an exposed pad, and the metal electrode is rectangular.

6. The ion mobility spectrometer based on traveling wave technology 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.

7. The ion mobility spectrometer based on traveling wave technology according to claim 6, characterized in that: The two long sides of the printed circuit board are respectively provided with fixing buckles and fixing slots for mutual locking and fixing.

8. The ion mobility spectrometer based on traveling wave technology according to claim 1, characterized in that: It also includes fixing parts for connecting and reinforcing two circuit boards.

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