Multipole rod ion transport device and method

Abstract

The application provides a multi-pole rod ion transmission device and method, which comprises a fixing frame and a power supply; further comprises: a first bearing fixed on the fixing frame and having a plurality of grooves for fixing pole rods; a second bearing fixed on the fixing frame and having a plurality of grooves for fixing pole rods; a plurality of conductive wires with rigidity and flexibility respectively penetrating the grooves on the first bearing and the second bearing, so that the plurality of conductive wires between the grooves on the first bearing and the grooves on the second bearing enclose an ion channel; the output of the power supply is connected to the conductive wires; and a tensioning unit is used for tensioning the conductive wires so that the conductive wires are in a straight line. The application has the advantages of easy processing and simple installation.

Description

TECHNICAL FIELD

[0001] The present application relates to mass spectrometry, in particular to a multipole ion transmission device and method. BACKGROUND

[0002] In mass spectrometers, multipole rods are often used as ion transmission devices and are widely used in vacuum interfaces, ion traps, collision cells and other occasions. Ion transmission devices are indispensable for mass spectrometry, and their performance has a great impact on the sensitivity, mass range, scanning speed and other parameters of mass spectrometry.

[0003] In existing multipole ion transmission schemes, the following problems exist:

[0004] 1. Compared with a quadrupole rod, the central electric field flat area of a multipole rod is larger under the same r0, which means that the multipole rod can receive ions from a larger range, and at the same time, within the central electric field, the ions have lower space charge effects due to their more dispersion. Therefore, compared with a quadrupole rod, a multipole rod has better ion receiving and transmission capabilities, but this also means that the multipole rod cannot focus ions into a small point, causing ion loss when entering the next optical device. In view of this, the designer must make a trade-off between transmission performance and focusing performance.

[0005] 2. The more the number of poles of a multipole rod, the stronger the above-mentioned ion receiving and transmission capabilities. At the same time, with the increase in the number of poles, the ratio of the rod diameter to the inscribed circle radius will be smaller. A multipole rod with a too thin rod diameter will result in poor rod rigidity, and its positioning and installation will become difficult. The conventional installation and positioning method cannot guarantee the installation accuracy.

[0006] The conventional quadrupole rod or sextupole rod structure is often implemented by a structure with holes punched on the back of the rod body to fix the electrode rod, but such a form is limited to quadrupole or sextupole structures. For structures with 8 poles or more, due to the too thin size of the rod body, such a fixing form cannot be used.

[0007] In order to realize an octupole structure, Agilent uses a clamping type metal bracket to fix the poles in its collision cell. The diameter of the pole is about 1.2 mm, the diameter of the inscribed circle is about 4 mm, and the length is about 100 mm. The electrode shape accuracy is guaranteed by the pole itself, and the positioning accuracy between electrodes is guaranteed by the metal bracket. This structure is easy to realize only in the case of 8 poles. When the number of poles is further increased (such as 10 poles, 12 poles), the rod will lose rigidity due to its too thin diameter, resulting in difficulty in maintaining accuracy.

[0008] In order to solve the above problems in the prior art, the AB SCIEX Djet (12-pole rod) technology provides a relatively feasible solution, which constructs an electrode surface gradually shrinking to the center of the circle by the intersection of two sets of inclined surfaces, has a larger electrode surface and an inscribed circle radius at the inlet end, and has a smaller electrode surface and an inscribed circle radius at the outlet end, thereby forming a gradually shrinking 12-pole field, receiving more ions at the inlet section and better converging the ions at the outlet section to pass through the small hole between the two-stage vacuum more efficiently. The inlet end inscribed circle is about 8 mm, the electrode surface width is about 1.6 mm, the outlet end inscribed circle diameter is about 2 mm, and the electrode surface width is about 0.4 mm.

[0009] Although the method of AB SCIEX Djet solves the above contradictions and to some extent solves the problem of installation and positioning, it also brings some problems:

[0010] 1. The opposite area between the poles is large, resulting in a high overall capacitance, and a large power loss when RF is applied;

[0011] 2. With the increase of the number of poles, the equivalent potential field change of the multipole field will become more and more unobvious, and the diameter of the rod will tend to be a thin wire, and the rod will be easily bent due to being too thin, and processing and installation will become difficult, which is not conducive to most technologies. SUMMARY

[0012] In order to solve the above problems in the prior art, the AB SCIEX Djet (12-pole rod) technology provides a relatively feasible solution, which constructs an electrode surface gradually shrinking to the center of the circle by the intersection of two sets of inclined surfaces, has a larger electrode surface and an inscribed circle radius at the inlet end, and has a smaller electrode surface and an inscribed circle radius at the outlet end, thereby forming a gradually shrinking 12-pole field, receiving more ions at the inlet section and better converging the ions at the outlet section to pass through the small hole between the two-stage vacuum more efficiently. The inlet end inscribed circle is about 8 mm, the electrode surface width is about 1.6 mm, the outlet end inscribed circle diameter is about 2 mm, and the electrode surface width is about 0.4 mm.

[0013] The purpose of the present application is achieved by the following technical solutions:

[0014] The multipole rod ion transmission device comprises a fixing frame and a power supply; the multipole rod ion transmission device further comprises:

[0015] A first bearing member is fixed on the fixing frame and has a plurality of grooves for passing through the conductive wires;

[0016] A second bearing member is fixed on the fixing frame and has a plurality of grooves for passing through the conductive wires;

[0017] A plurality of conductive wires having rigidity and flexibility pass through the grooves on the first bearing member and the second bearing member respectively, so that the plurality of conductive wires between the grooves on the first bearing member and the second bearing member enclose an ion channel; the output of the power supply is connected to the conductive wires;

[0018] A tensioning unit is used to tension the conductive wires, so that the conductive wires are in a straight line.

[0019] The application also aims to provide an ion transmission method.

[0020] The ion transmission method based on the multi-pole rod ion transmission device of the application is characterized in that:

[0021] The power supply applies voltage to the plurality of conductive wires, the conductive wires between the grooves on the first carrier and the grooves on the second carrier are tensioned to be straight, the voltage directions of the conductive wires in the adjacent grooves on the first carrier and the second carrier are opposite, a multi-pole rod electric field is formed, and the plurality of conductive wires enclose an ion channel.

[0022] The ions enter the ion channel for transmission.

[0023] Compared with the prior art, the application has the beneficial effects that:

[0024] 1. Easy to process;

[0025] The conductive wires with rigidity and flexibility are fixed between the first carrier and the second carrier, specifically passing through the grooves and being tensioned, so that the straight conductive wires become pole rods and form a multi-pole rod electric field, and the conductive wires are easy to process.

[0026] The pole rods are easy and simple to form, and the multi-pole rod electric field is easy to realize.

[0027] 2. Simple structure;

[0028] The entire multi-pole rod is formed by only two conductive wires, each of which passes through the grooves on the carriers, so that the voltage polarities of the conductive wires in the adjacent grooves are opposite, and the power supply output only needs to be connected to the two conductive wires.

[0029] The first carrier and the second carrier each adopt an insulating member, or the first carrier (or the second carrier) is composed of two parts that are insulated from each other, and the two adjacent grooves of each part are the grooves of the other part, so that each part can adopt a conductor, and the power supply can be connected to the two parts and apply opposite voltages.

[0030] 3. Good reliability;

[0031] The use of nickel-titanium alloy as the conductive wire and / or the tensioning unit improves the reliability. BRIEF DESCRIPTION OF DRAWINGS

[0032] The disclosure of the application will become more apparent with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only used to illustrate the technical solutions of the application, and are not intended to limit the protection scope of the application. In the drawings:

[0033] Figure 1 is a flow chart of the ion transmission method according to an embodiment of the present application. DETAILED DESCRIPTION

[0034] Figure 1 The following description describes optional embodiments of the present application to teach those skilled in the art how to implement and reproduce the present application. Some conventional aspects have been simplified or omitted for the sake of teaching the present application. Those skilled in the art should understand that variations or substitutions from these embodiments will be within the scope of the present application. Those skilled in the art should understand that the following features can be combined in various ways to form multiple variations of the present application. Thus, the present application is not limited to the following optional embodiments, but is only limited by the claims and their equivalents.

[0035] Embodiment 1:

[0036] The multipole ion transmission device according to an embodiment of the present application comprises:

[0037] a fixed frame and a power supply;

[0038] a first carrier fixed on the fixed frame and having a plurality of grooves for the conductive wires to pass through;

[0039] a second carrier fixed on the fixed frame and having a plurality of grooves for the conductive wires to pass through;

[0040] a plurality of conductive wires, having rigid and flexible conductive wires respectively passing through the grooves on the first carrier and the second carrier, so that the plurality of conductive wires between the grooves on the first carrier and the second carrier enclose an ion channel; the output of the power supply is connected to the conductive wires;

[0041] a tensioning unit for tensioning the conductive wires so that the conductive wires are in a straight line, functioning as a pole.

[0042] In order to improve the ion transmission efficiency, further, the conductive wires and the central axis of the ion channel are coplanar, or the conductive wires are in a spiral shape and are non-coplanar with the central axis of the ion channel.

[0043] In order to reduce the structural complexity, further, the conductive wires are two mutually insulated conductive wires, one of which passes through a plurality of spaced grooves on the first carrier and the second carrier, and the other of which passes through the remaining plurality of spaced grooves on the first carrier and the second carrier; the power supply applies voltages of opposite polarities to the two conductive wires.

[0044] To reduce the structural complexity, further, the first carrier comprises a first part and a second part, the grooves on the first part and the grooves on the second part are sequentially and adjacently arranged;

[0045] The second carrier comprises a third part and a fourth part, the grooves on the third part and the grooves on the fourth part are sequentially and adjacently arranged; one conductive wire passes through all the grooves on the first part and the third part, and another conductive wire passes through all the grooves on the second part and the fourth part.

[0046] To reduce the difficulty of voltage application on the conductive wire, further, the first part and the second part are insulated, and the third part and the fourth part are insulated.

[0047] To adapt to the requirements of the pole, further, the radius of the plurality of conductive wires surrounding the ion channel between the first carrier and the second carrier is greater than the radius of other parts.

[0048] To tension the conductive wire and maintain stability, further, the tensioning unit comprises:

[0049] A rigid elastic member, one end of the elastic member is fixed on the first carrier, and the other end is suspended, and the suspended part of the elastic member is deformed under the pressure of the conductive wire.

[0050] To increase the width of the pole, further, a plurality of conductive wires pass through a groove on the first carrier and a corresponding groove on the second carrier in parallel, forming the ion channel.

[0051] The ion transmission method based on the multi-pole ion transmission device of the embodiment is as follows: Figure 1 As shown in the figure, the ion transmission method is as follows:

[0052] The power supply applies voltage to the plurality of conductive wires, the conductive wire between the groove on the first carrier and the groove on the second carrier is tensioned in a straight line, and the voltage direction of the conductive wire in the adjacent grooves on the first carrier and the second carrier is opposite, forming a multi-pole electric field, and the plurality of conductive wires surround the ion channel;

[0053] The ion enters the ion channel for transmission.

[0054] Embodiment 2:

[0055] Application example of the multi-pole ion transmission device and method according to the embodiment 1 of the application.

[0056] In the application example, the fixed frame is a cylindrical component, the first carrier and the second carrier are respectively fixed at two ends of the fixed frame, and both are insulating components with a central through hole, the inner wall (the outer edge of the through hole) has 12 evenly distributed grooves, and the rigid and flexible conductive wires are made of nickel-titanium alloy; the conductive wires pass through the grooves on the first carrier and the corresponding grooves on the second carrier, and are tensioned by the tensioning unit, so that the 12 conductive wires in the cylindrical component are in a straight line, play the role of the pole, and enclose the ion channel, and the central axis of the ion channel is coplanar with any conductive wire.

[0057] The tensioning unit has a rigid elastic member, one end of the elastic member is fixed on the first carrier, the other end is suspended, and the suspended part of the elastic member is pressed by the conductive wire and has deformation, thereby tensioning the conductive wire; the elastic member is made of nickel-titanium alloy;

[0058] The power supply applies voltages with opposite polarities to the conductive wires in the adjacent two grooves.

[0059] The ion transmission method based on the multi-pole ion transmission device of the embodiment is shown in Figure 1 The ion transmission method is as follows:

[0060] The power supply applies voltages to the 12 conductive wires, the conductive wires between the grooves on the first carrier and the grooves on the second carrier are tensioned to be in a straight line, and the voltage directions of the conductive wires in the adjacent grooves on the first carrier and the second carrier are opposite, forming a multi-pole electric field, and the multiple conductive wires enclose an ion channel;

[0061] The ions enter the ion channel for transmission.

[0062] Embodiment 3:

[0063] The application example of the multi-pole ion transmission device and method according to the embodiment 1 of the application is different from the embodiment 2 in that:

[0064] 1. The first carrier includes a first part and a second part made of conductors and insulated from each other, the grooves on the first part and the grooves on the second part are sequentially and adjacently arranged, that is, the grooves of the second part (the first part) are arranged between the adjacent grooves on the first part (the second part); the second carrier includes a third part and a fourth part made of conductors and insulated from each other, the grooves on the third part and the grooves on the fourth part are sequentially and adjacently arranged, that is, the grooves of the fourth part (the third part) are arranged between the adjacent grooves on the third part (the fourth part);

[0065] The power supply applies voltages with opposite polarities to the first part and the second part, that is, applies voltages with opposite polarities to the only two conductive wires;

[0066] 2. There are only two conductive wires insulated from each other, one of which passes through all the grooves on the first and third parts, and the other of which passes through all the grooves on the second and fourth parts.

[0067] Embodiment 4:

[0068] The application example of the multipole rod ion transmission device and method according to Embodiment 1 of the present application is different from Embodiment 2 in that:

[0069] 1. The diameter of the inlet of the ion channel is larger than that of the outlet, so that the ions have a focusing function in transmission;

[0070] 2. The conductive wire that is tensioned is not coplanar with the central axis of the ion channel, and the conductive wire surrounding the ion channel is in a spiral shape;

[0071] The radius of the portion of the conductive wire between the two grooves (i.e., the portion that functions as a pole rod) corresponding in position on the first carrier and the second carrier is larger than the radius of other portions.

[0072] Embodiment 5:

[0073] The application example of the multipole rod ion transmission device and method according to Embodiment 1 of the present application is different from Embodiment 2 in that:

[0074] The plurality of conductive wires pass through one groove on the first carrier and one groove on the second carrier corresponding in position in parallel, that is, the conductive wire winds around the two grooves corresponding in position (on the first carrier and the second carrier) for multiple times, thereby increasing the width of the conductive wire between the two grooves corresponding in position (i.e., the portion that functions as a pole rod).

[0075] The above embodiments only exemplarily show that the fixing frame adopts a cylindrical member, and of course, other structures, such as a hollow support, can also be used as long as the first carrier and the second carrier can be fixed; in addition, the tensioning unit adopts a rigid elastic member with one end fixed and the other end suspended, and of course, other solutions, such as a spring that tensions the conductive wire and uses the elastic force generated by the deformation of the spring to tension the conductive wire, can also be used.

Claims

1. A multipole rod ion transport device comprising a holder and a power supply; characterized in that, The multipole ion transmission device further comprises: a first carrier fixed on the fixed frame and having a plurality of grooves for the conductive wires to pass through; a second carrier fixed on the fixed frame and having a plurality of grooves for the conductive wires to pass through; a plurality of conductive wires, the rigid and flexible conductive wires passing through the grooves on the first carrier and the second carrier respectively, so that the plurality of conductive wires between the grooves on the first carrier and the second carrier enclose an ion channel; the output of the power supply is connected to the conductive wires; a tensioning unit for tensioning the conductive wires so that the conductive wires are in a straight line; the first carrier comprises a first part and a second part made of conductors and insulated from each other, the grooves on the first part and the second part are arranged in sequence and adjacent to each other, and the grooves of the second part are arranged between the adjacent grooves on the first part; the second carrier comprises a third part and a fourth part made of conductors and insulated from each other, the grooves on the third part and the fourth part are arranged in sequence and adjacent to each other, and the grooves of the fourth part are arranged between the adjacent grooves on the third part; one conductive wire passes through all the grooves on the first part and the third part, and the other conductive wire passes through all the grooves on the second part and the fourth part; the power supply applies voltages of opposite polarities to the first part and the second part respectively.

2. The multipole rod ion transmission device of claim 1, wherein, The central axis of the conductive wires and the ion channel are coplanar, or the central axis of the conductive wires and the ion channel are not coplanar.

3. The multipole rod ion transmission device of claim 1, wherein, The conductive wires are insulated from each other, one of which passes through a plurality of spaced grooves on the first carrier and the second carrier, and the other of which passes through the remaining plurality of spaced grooves on the first carrier and the second carrier; the power supply applies voltages of opposite polarities to the two conductive wires.

4. The multipole rod ion transmission device of claim 1, wherein, The tensioning unit comprises: a flexible member having rigidity, one end of the flexible member being fixed on the first carrier and the other end being suspended, and the suspended part of the flexible member being deformed by being pressed by the conductive wires.

5. The multipole rod ion transmission device of claim 4, wherein, The conductive wires and / or the flexible member are made of nickel-titanium alloy.

6. The multipole rod ion transmission device of claim 1, wherein, A plurality of conductive wires pass through one groove on the first carrier and one corresponding groove on the second carrier in parallel to form the ion channel.

7. An ion transmission method based on the multipole ion transmission device according to any one of claims 1-6, the ion transmission method being: the power supply applies voltages to the plurality of conductive wires, the conductive wires between the grooves on the first carrier and the second carrier are tensioned in a straight line, and the voltage directions of the conductive wires in the adjacent grooves on the first carrier and the second carrier are opposite, forming a multipole electric field, and the plurality of conductive wires enclose an ion channel; ions enter the ion channel for transmission.

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