Integrated multi-pole collision reaction tank for inductively coupled plasma mass spectrometry

Abstract

An integrated multi-pole collision reaction cell for inductively coupled plasma mass spectrometry, the integrated collision reaction cell comprising two sets of ion guides, the first set to deflect ions 90 DEG and focus at an inlet of the collision reaction cell; the second group is a collision reaction multi-pole rod ion guider; and the two groups of ion guiders are arranged at an angle of 90 degrees and are separated by a round hole. Ions enter the group of ion guiders from an inlet lens at the front end of the first group of ion guiders, deflect by 90 degrees under the action of an electrostatic field of the group of ion guiders, are simultaneously focused to an inlet of the collision reaction tank, and are guided out from a small hole in the middle of an outlet lens after being collided or reacted. The outlet of the deflection lens and the inlet of the collision reaction tank are combined, and the ion beam is directly focused to the inlet of the collision reaction tank after deflection, so that the ion flight distance can be shortened, the space charge effect can be reduced, and the automatic tuning process can be simplified.

Description

Technical Field

[0001] The invention relates to the field of inductively coupled plasma mass spectrometers, and in particular to an integrated multipole collision reaction cell for inductively coupled plasma mass spectrometry analysis. Background Art

[0002] The typical structure of the inductively coupled plasma mass spectrometry (ICP-MS) system 200 is as follows: Figure 1 As shown, a plasma-based ion source is included; the ion source is used to generate plasma to break the molecules of the sample into atoms and then ionize the atoms to prepare for elemental analysis. In typical operation, the liquid sample is atomized, that is, converted into an aerosol (fine spray or mist) by a gas-driven (usually argon) nebulizer 201, and the coarse aerosol is removed in the atomization chamber 202, and the remaining fine aerosol is guided into the plasma generated by the plasma source. The plasma source is often configured as a flow-through plasma torch 203 with two or more concentric tubes. Typically, the plasma-forming gas (argon) flows through the inner tube of the torch and is excited into a plasma by a suitable energy source, such as radio frequency (RF), powering the load coil 204. The aerosol flows through the coaxial central tube of the torch 203 and is emitted into the plasma generated, and exposure to the plasma will break the sample molecules into atoms, or alternatively partially break the sample molecules into molecular fragments and ionize the atoms or molecular fragments; these analyte atoms or molecular fragments are ionized to generate an ion beam. Since these ions are not generated in the vacuum region, they gradually transition to the high vacuum region through the sampling cone 205 and the skimmer cone 206. After entering the high vacuum region, the ion beam is focused by the extraction lens 207 and then enters the off-axis or deflection lens 208. Figure 1 The schematic diagram uses the square plate off-axis lens as an example to explain the working principle of ICP-MS. After the ions pass through the off-axis or deflection lens 208, they are separated from the photons and neutral substances, and then enter the collision reaction pool 209. After the interference ions are eliminated by collision or reaction, they are focused by the collision reaction pool exit lens 210 and enter the secondary off-axis lens 211. The off-axis again can eliminate the influence of the neutral substances in the collision reaction pool on the subsequent mass screening, and improve the signal-to-noise ratio. The ion beam after the secondary off-axis enters the mass analyzer 212; the mass analyzer generally adopts a quadrupole structure or other such as a sector magnetic field, a time-of-flight (TOF) analyzer, etc., and applies an alternating electric field, or a combination of an electric field and a magnetic field, so that the ionized ions are spectrally decomposed according to their mass-to-charge ratio m / z, and then the ion detector 213 is able to count each type of ion of a given m / z ratio reaching the ion detector from the mass analyzer, and the intensity of each peak indicates the concentration (or abundance) of the corresponding element of the sample.

[0003] The plasma used as the ion source of ICP-MS cannot decompose all the components in the sample into ions. Some undecomposed neutral substances will be introduced into the subsequent collision reaction cell and quadrupole through the interface along with the ion beam. At the same time, the high-temperature plasma will also produce strong photons. These neutral substances will contaminate the subsequent ion mirror and collision reaction cell on the one hand, and will also produce new interfering ions when colliding with the collision reaction gas in the collision reaction cell on the other hand. Photons will also produce a lot of detection noise. Therefore, effective means are needed to separate neutral substances and photons from analyte ions before the ion beam enters the collision reaction cell.

[0004] In addition to the above-mentioned off-axis method, it is known that in the ICP-MS system, neutral substances and photons are separated from analyte ions by a 90-degree deflection between the ion source and the collision reaction cell. The advantage of the 90-degree deflection is that the large amount of neutral substances generated in the ion source are separated more thoroughly, so that the collision reaction cell can be kept clean for a longer period of time, reducing the performance degradation caused by the contamination of the collision reaction cell, while reducing the cleaning frequency and maintenance costs. The working principle of the existing 90-degree deflection system and the ion flight trajectory are as follows. Figure 2 and Figure 3 shown.

[0005] Figure 2 The 90-degree deflection lens shown in the figure uses a single round rod for deflection. Figure 3 The diagram shows a deflection method using a quadrupole. The ion beam generated by the ion source gradually transitions to the high vacuum region through sampling cones 301, 401 and interceptor cones 302, 402. After the ion beam enters the high vacuum region, it is focused for the first time by extraction lenses 303, 403; after passing through the focus, the ions gradually diverge, and then the deflection focusing lens group 304, 404 and 305, 405 focus the ions to the position of the center of a single round rod 306 or a quadrupole 406 deflection lens. After passing through the focus, the ions diverge again, and then another group of symmetrical deflection exit focusing lens groups 304, 404 and 305, 405 refocus the ions, and cooperate with the collision reaction cell entrance focusing lenses 307, 407 to focus the ions to the small holes 308, 408 in the middle of the collision reaction cell entrance lenses, and after passing through the collision reaction cells 309, 409, they leave from the collision reaction cell exit lenses 310, 410. The ions undergo three focusing steps before entering the collision reaction cell.

[0006] The above method can eliminate the influence of neutral substances and photons generated by the ion source. The 90-degree deflection method of the quadrupole can also perform preliminary screening of the ions to be tested; however, multiple sets of focusing lenses are required to focus the ion beam before and after the deflection lens, and a focusing lens is also required before the entrance of the collision reaction cell to focus the ions into the small hole at the entrance of the collision reaction cell. Compared with the off-axis method mentioned above, the above method has an additional focusing process. Therefore, in the above 90-degree deflection method, the flight distance of the ions will be longer than that of the off-axis method. Under the influence of the space charge effect, the loss of light-mass ions will increase, thereby reducing the sensitivity of light-mass elements. In addition, since the ions need to be focused repeatedly, the number of ion lenses is large, which will have mutual influence during tuning, increasing the difficulty of automatic tuning and making the automatic tuning process longer.

[0007] The interaction between ions is based on the principle of like repels like. Since the plasma mass spectrometer has a high negative voltage (about -150 volts) on the extraction lens, it is impossible for negative ions or electrons to enter the high vacuum region. A large number of positive ions repel each other during flight. According to Coulomb's law, the interaction force between two ions in a vacuum is as follows:

[0008]

[0009] Among them, q1 and q2 are the charges carried by the two ions, k is the ratio constant, and r is the distance between the ions.

[0010] The spatial charge effect in ion flight is very complex, and we must consider both the interaction perpendicular to the ion flight direction and the interaction in the same direction as the ion flight direction. Since the ion beam generated by ICP-MS is usually continuous, for the sake of simplicity, it can be assumed that there are other ions in front and behind a certain ion, so that their forces cancel each other out; however, the interaction perpendicular to the ion flight direction will cause the ions to begin to diverge while flying, resulting in the inability of ions in the edge area to continue to focus and fly in the established direction; the consequence is the loss of ions. Generally speaking, ions with large mass numbers will push ions with small mass numbers to the edge of the ion beam and gradually away from the center of the ion beam; some ions will not be focused by subsequent ion lenses, resulting in ion loss. Usually this part of the loss will increase with the increase in the total number of ions in the ion beam and the increase in flight distance.

[0011] Usually, before the instrument formally analyzes the sample, the ion focusing system will be optimized, that is, tuned. Its function is to optimize the ion pass rate of the instrument in each mass range by adjusting the voltage of a series of ion mirrors, that is, the sensitivity is optimized. Since the matrix of actual samples varies greatly, tuning is generally performed using pure standard solutions. Compared with actual samples, the matrix is ​​very simple, but due to the complexity of the matrix of actual samples, the total number of various ions in the ion beam is far greater than that of pure standard solutions, which inevitably causes ion loss in sample testing. The shortest possible ion flight distance and optimized ion focusing are effective means to reduce this effect. Summary of the invention

[0012] The purpose of the present invention is to solve the problems existing in the prior art, and to propose an integrated multipole collision reaction cell for inductively coupled plasma mass spectrometry. The integrated collision reaction cell comprises two groups of ion guides, the first group is a multipole structure, using multiple poles arranged in parallel, which are used to deflect ions by 90° and focus on the entrance of the collision reaction cell; the second group is a collision reaction multipole ion guide, each guide electrode adopts a parallel or rotating structure, and the field diameter at the entrance end can be greater than or less than the field diameter at the exit end; the two groups of ion guides are arranged at 90 degrees to each other and separated by a circular hole. There is an entrance lens of the ion beam at the front end of the first group of ion guides, which adopts a relatively large aperture; there is an exit lens at the tail end of the second group of multipole structure ion guides. Ions enter the group of ion guides from the entrance lens at the front end of the first group of ion guides, and are deflected by 90° under the action of the electrostatic field of the group of ion guides, and are focused on the second group of ion guides, that is, the entrance of the collision reaction cell. After collision or reaction, the ions are extracted from the small hole in the middle of the exit lens.

[0013] The present invention provides an integrated multipole collision reaction cell for inductively coupled plasma mass spectrometry (ICP-MS), comprising a deflection multipole ion guide and a multipole collision reaction cell, wherein:

[0014] The deflection ion guide comprises a deflection entrance lens; the deflection entrance lens is located at the front end of the vertical position outside the deflection ion guide;

[0015] The deflection ion guide comprises N elongated deflection ion guide electrodes, wherein N is 1, 2, 3, or 4; the deflection ion guide electrodes are arranged at a certain radial distance orthogonal to the vertical axis of the deflection ion guide;

[0016] The multi-pole collision reaction cell comprises a collision reaction cell entrance lens, a collision reaction cell body, and a collision reaction cell exit lens; the collision reaction cell entrance lens is located at the side end of the vertical position outside the deflection ion guide and is distributed at 90 degrees with the deflection lens entrance lens;

[0017] Ions enter the deflection ion guide from the deflection entrance lens at the front end of the deflection ion guide, are deflected 90° under the action of the electrostatic field of the deflection ion guide, and are focused onto the collision reaction cell entrance lens of the multi-pole collision reaction cell.

[0018] Further, the center portion of the deflection entrance lens and the center portion of the deflection entrance lens both correspond to the center position of the deflection ion guide.

[0019] Furthermore, when two or more deflection ion guide electrodes are provided, the deflection ion guide electrodes are parallel to each other.

[0020] Furthermore, the deflection ion guide electrode is a round rod, a semi-round rod, a 1 / 4 round rod, a flat rod, a concave rod, a hyperbolic rod or a trapezoidal rod.

[0021] Furthermore, the deflected ion guide electrode is fixed by a fixing device, and the fixing device includes an upper fixing plate and a lower fixing plate; two ends of the deflected ion guide electrode are respectively fixed on the upper fixing plate and the lower fixing plate.

[0022] Furthermore, the deflected ion guide comprises a fixed bracket, and the deflected entrance lens and the collision reaction cell entrance lens are both fixed on the fixed bracket.

[0023] Furthermore, a plurality of collision reaction multipole ion guide electrodes are arranged in the multipole collision reaction cell; the collision reaction multipole ion guide electrodes are configured to generate an RF confinement field that effectively confines ions in a radial direction orthogonal to the longitudinal axis of the collision reaction cell body.

[0024] Furthermore, the deflection entrance lens, the collision reaction cell entrance lens, and / or the collision reaction cell exit lens are connected to a direct current voltage.

[0025] Furthermore, the DC voltage is respectively combined with RF+ and RF- through two resistors and then connected to two groups of mutually spaced collision reaction multipole ion guide electrodes.

[0026] Furthermore, a DC voltage is connected to the deflection ion guide electrode; when the number of the deflection ion guide electrodes is 2, 3 or 4, two DC voltages are respectively connected to electrodes spaced apart from each other.

[0027] Compared with the prior art, the integrated multipole collision reaction cell for inductively coupled plasma mass spectrometry provided by the present invention combines a quadrupole ion deflection lens and a multipole collision reaction cell into one, the outlet of the deflection lens and the inlet of the collision reaction cell are merged, and the ion beam is directly focused to the inlet of the collision reaction cell after deflection, which has the following advantages:

[0028] 1. Shorten the ion flight distance, reduce the space charge effect, and achieve high-efficiency deflection of all ions from low mass to high mass;

[0029] 2. Completely separate the analyte ions from the neutral substances and photons generated by the ion source, keep the collision reaction cell clean, and reduce the number of maintenance times;

[0030] 3. Pre-screen the ions to allow the ions to be tested and similar ions to enter the collision reaction cell to improve the efficiency of the collision reaction;

[0031] 4. Reduce the number of ion lenses and simplify the automatic tuning process. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the structure of an inductively coupled plasma mass spectrometer (ICP-MS) system in the prior art.

[0033] Figure 2 It is a schematic diagram of a 90-degree deflection lens structure and a flight trajectory using a single round rod in the prior art; wherein, Figure 2 (a) is a schematic diagram of a 90-degree deflection lens structure using a single round rod; Figure 2 (b) is a schematic diagram of ion flight trajectory;

[0034] Figure 3 It is a schematic diagram of a 90-degree deflection lens structure and a flight trajectory using a quadrupole in the prior art; wherein, Figure 3 (a) is a schematic diagram of the 90-degree deflection lens structure using a quadrupole; Figure 3 (b) is a schematic diagram of ion flight trajectory;

[0035] Figure 4 Schematic diagram of an integrated collision reaction cell for inductively coupled plasma mass spectrometry (ICP-MS) of the present invention;

[0036] Figure 5 is a schematic diagram of the circuit connection of the rod electrode of the present invention; wherein, Figure 5 (a) is the case where N=4; Figure 5 (b) is the case where N=3; Figure 5 (c) and 5(d) are for the case where N = 2; Figure 5 (e) is the case where N=1;

[0037] Figure 6 is a schematic diagram of the working principle of the integrated collision reaction cell provided by the present invention; wherein, Figure 6 (a) is a schematic diagram of the structure of a 90-degree deflection lens using a multi-stage rod; Figure 6 (b) is a schematic diagram of ion flight trajectory;

[0038] Figure 7 It is a schematic diagram of simulated equipotential lines and ion beam flight trajectories of an integrated collision reaction cell in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0040] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "orthogonal", "opposite", "one end", "the other end", etc. used in the present invention to indicate the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0041] The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] The present invention provides an integrated multipole collision reaction cell for inductively coupled plasma mass spectrometry (ICP-MS), such as Figure 4 As shown, the deflection multipole ion guide 100 and the multipole collision reaction cell 110 are included, wherein the outlet of the deflection multipole ion guide 100 is merged with the inlet of the multipole collision reaction cell 110 .

[0043] The deflection ion guide 100 includes N elongated deflection ion guide electrodes 101, wherein N is 1, 2, 3, or 4. The deflection ion guide electrodes 101 are arranged at a certain radial distance orthogonal to the vertical axis of the deflection ion guide 100. When two or more deflection ion guide electrodes 101 are provided, the deflection ion guide electrodes 101 are parallel to each other.

[0044] like Figure 4An embodiment of the present invention is shown, and when N=4, the deflection ion guide electrodes 101 are evenly distributed on a circle with the same distance from the central axis of the deflection ion guide 100 and are parallel to each other. Figure 4 When N is 1, the deflection ion guide electrode 101 is specifically the deflection ion guide electrode 1011; when N is 2, the deflection ion guide electrode 101 is specifically the deflection ion guide electrodes 1011, 1012 or the deflection ion guide electrodes 1011, 1013; when N is 3, the deflection ion guide electrode 101 is specifically the deflection ion guide electrodes 1011, 1012, and 1013.

[0045] The deflection ion guide electrode 101 can be a round rod, a semi-circular rod, a 1 / 4 round rod, a flat rod, a concave rod, a hyperbolic rod, a trapezoidal rod or other shapes. Figure 4 An embodiment of the present invention is shown, wherein the deflection ion guide electrode 101 is a 1 / 4 circular rod.

[0046] The deflected ion guide electrode 101 is fixed by a fixing device. The fixing device includes an upper fixing plate 102 (not shown in the exploded view) and a lower fixing plate 103. The two ends of the deflected ion guide electrode 101 are respectively fixed on the upper fixing plate 102 and the lower fixing plate 103. The fixing device can be made of insulating material, or a metal plate material connected to other components through an insulating gasket.

[0047] The deflection ion guide 100 includes a deflection entrance lens 104. The deflection entrance lens 104 is located at the front end of the deflection ion guide 100 at a vertical position outside.

[0048] The deflection entrance lens 104 is directly connected to the lens fixing bracket 106 of the deflection ion guide 100 via an insulating gasket 105 , and the center of the deflection entrance lens 104 corresponds to the center of the deflection ion guide 100 .

[0049] Preferably, the opening of the deflection entrance lens 104 is designed to be relatively large, and may be conical or annular.

[0050] Preferably, the deflection entrance lens 104 is configured with a certain DC bias voltage.

[0051] The deflection ion guide 100 is also fixedly provided with a connection terminal 107 .

[0052] The multi-stage rod collision reaction cell 110 includes a collision reaction cell entrance lens 111 , a collision reaction cell body 112 , and a collision reaction cell exit lens 113 .

[0053] The collision reaction cell entrance lens 111 is directly connected to the outside of the deflection ion guide 100 at a vertical position through an insulating gasket 114 , and is distributed at 90 degrees to the deflection lens entrance lens 104 .

[0054] Preferably, the collision reaction cell entrance lens 111 is fixed to the lens fixing bracket 106 via an insulating gasket 114 , and the center of the collision reaction cell entrance lens 111 corresponds to the center position of the deflection ion guide 100 and is distributed at 90 degrees with the deflection lens entrance lens 104 .

[0055] The collision reaction pool entrance lens 111 is a sheet electrode with a small hole in the middle for ions to fly in; it can also be composed of multiple electrodes to form an Einzel lens group to enhance the focusing effect. The direction of the small hole is 90 degrees to the entrance direction of the deflection lens entrance lens 104. After passing through the deflection lens entrance lens 104, the ions are deflected 90 degrees under the action of the electric field and focused on the small hole in the center of the collision reaction pool entrance lens 111, and directly enter the multi-pole collision reaction pool 110.

[0056] Preferably, the collision reaction cell entrance lens 111 is configured with a certain DC bias voltage.

[0057] A plurality of collision reaction multipole ion guide electrodes 115 are disposed in the collision reaction cell body 112. The collision reaction multipole ion guide electrodes 115 are disposed inside the collision reaction cell body 112 along the longitudinal axis of the collision reaction cell body 112. The collision reaction multipole ion guide electrodes 115 are configured to generate an RF confinement field that effectively confines ions in a radial direction orthogonal to the longitudinal axis of the collision reaction cell body 112.

[0058] The collision reaction multipole ion guide electrode 115 is an elongated rod electrode, which can be a round rod, a square rod, a hyperbolic rod or a concave rod; the number of the collision reaction multipole ion guide electrodes 115 can be 2n, where n is greater than or equal to 2. The plurality of collision reaction multipole ion guide electrodes 115 are arranged in a parallel or rotating structure around the longitudinal axis of the collision reaction cell body 112 to generate a certain restraining force on the ions entering the multipole collision reaction cell 110 and make the ion beam oscillate forward.

[0059] The plurality of collision reaction multipole ion guide electrodes 115 are fixed in relative position by two collision reaction multipole ion guide fixing rings 116 made of PEEK or other insulating materials to keep them parallel and concentric; they are then fixed by fixing screws and then installed as a whole into the collision reaction cell body 112 .

[0060] Preferably, the plurality of collision reaction multipole ion guide electrodes 115 are divided into two separate groups. The connection terminals 117 of the two collision reaction multipole ion guides connect the two separate groups of collision reaction multipole ion guide electrodes 115 to provide corresponding radio frequency and direct current voltages.

[0061] The collision reaction cell outlet lens 118 is fixed to the rear of the collision reaction cell body 112 through an insulating gasket 114 .

[0062] Figure 5 : is a schematic diagram of the circuit connection of this embodiment. Among them, U1-U6 are DC voltages; RF+ and RF- are radio frequency signals with the same amplitude and frequency but a phase difference of 180 degrees. As shown in the figure, U1 is connected to the collision reaction cell entrance lens 104. U2 and U3 are connected to the deflection ion guide electrode 101. U4 is connected to the collision reaction cell entrance lens 111. U5 is respectively connected to two groups of mutually spaced collision reaction multipole ion guide electrodes 115 after being combined with RF+ and RF- through two resistors. U6 is connected to the collision reaction cell exit lens 118.

[0063] There are many ways to connect U2 and U3, and the most common method is to connect U2 and U3 to two electrodes spaced apart from each other.

[0064] by Figure 5 Taking the case of N=4 shown in (a) as an example, U2 is connected to the first deflection ion guide electrode 1011 and the third deflection ion guide electrode 1013, and U3 is connected to the second deflection ion guide electrode 1012 and the fourth deflection ion guide electrode 1014; or U2 is connected to the first deflection ion guide electrode 1011, and U3 is connected to the second deflection ion guide electrode 1012, the third deflection ion guide electrode 1013 and the fourth deflection ion guide electrode 1014.

[0065] Figure 5 (b) shows the situation when N=3, U2 is connected to the first deflection ion guide electrode 1011, and U3 is connected to the second deflection ion guide electrode 1012 and the third deflection ion guide electrode 1013.

[0066] Figure 5 (c) and (d) respectively show two cases where N=2, wherein U2 is connected to the first deflection ion guide electrode 1011 and U3 is connected to the second deflection ion guide electrode 1012; or U2 is connected to the first deflection ion guide electrode 1011 and U3 is connected to the third deflection ion guide electrode 1013.

[0067] Figure 5(e) shows the situation when N=1, at this time, only U2 is connected to the first deflection ion guide electrode 1011.

[0068] A negative DC potential barrier is generated by the deflection lens entrance lens 104 near the entrance of the deflection ion guide 100, so that ions can smoothly enter the deflection ion guide 100 and the entering ions can be focused at the same time; a negative DC potential barrier is generated by the collision reaction cell exit lens 118 near the exit of the multi-pole collision reaction cell 110, so that ions can smoothly be exported from the multi-pole collision reaction cell 110.

[0069] RF+ and RF- are radio frequency signals with the same frequency and amplitude and opposite phases (180° difference), and their frequencies are between 0-1000MHz, thereby generating an RF confinement field for ions. The amplitudes of RF+ and RF- can be optimized according to the mass number of the measured ions.

[0070] An RF+ potential superimposed on a DC bias potential (U) is applied to one set of the collision reaction multipole ion guide electrodes 115, while an RF- potential superimposed on a DC bias potential (U) is applied to another set of the collision reaction multipole ion guide electrodes 115 separated therefrom.

[0071] The integrated collision reaction cell provided by the present invention combines the outlet of the deflection lens and the inlet of the collision reaction cell into one, and only retains a single focusing lens at the inlet of the deflection lens. Its working principle and schematic diagram of ion flight trajectory are shown in FIG. Figure 6 As shown. Ions generated from the ion source enter the high vacuum region after passing through the sampling cone 122 and the intercepting cone 123, and then are focused for the first time by the extraction lens 124 and the extraction lens 2 125; the ions begin to diverge after passing through the focus, and are focused again by the deflection entrance lens 104. By adjusting the voltage of the deflection entrance lens 104, the deflection ion guide electrode 101, and the collision reaction cell entrance lens 111, the ion beam is deflected 90 degrees and focused to the small hole in the middle of the collision reaction cell entrance lens 111. The collision reaction cell is equipped with a collision reaction multipole ion guide electrode 115 (taking an octopole as an example), which is arranged inside the collision reaction cell body 112 along the longitudinal axis of the collision reaction cell body 112; the collision reaction multipole ion guide electrode 115 is configured to generate an RF confinement field that effectively confines ions in a radial direction orthogonal to the longitudinal axis of the collision reaction cell body 112; a plurality of the collision reaction multipole ion guide electrodes 115 are arranged in a parallel or rotating structure around the longitudinal axis of the collision reaction cell body 112 to generate a certain confinement force on the ions entering the collision reaction multipole ion guide electrode 115 and make the ion beam oscillate forward.

[0072] from Figure 7 It can be seen from the simulated ion flight trajectory and equipotential lines that, using the integrated multipole collision reaction cell of the inductively coupled plasma mass spectrometry (ICP-MS) provided by the present invention, the ion beam is perfectly focused at the entrance of the multipole collision reaction cell after being deflected by 90 degrees, and enters the collision reaction cell through the small hole in the middle of the collision reaction cell entrance lens. Under the action of the radio frequency and direct current bias applied to the collision reaction multipole, the ion beam is further drawn out of the collision reaction cell from the small hole in the middle of the collision reaction cell exit lens.

[0073] The integrated collision reaction cell provided by the embodiment of the present invention can achieve good technical effects. Figure 2 Taking the single-rod deflection as an example, the central flight path of the ion beam from the skimmer cone entrance to the collision reaction cell entrance provided by the embodiment of the present invention is reduced from 190.6 mm to 115.2 mm, reducing the flight distance by about 40%.

[0074] It should be noted that the experimental results show that when N=4, the technical solution of the present invention can achieve the best technical effect. However, when N is 1, 2 or 3, the effect is also significantly improved compared with the prior art.

[0075] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be regarded as the protection scope of the present invention. The basic principles, main features and advantages of the present invention are shown and described above. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above preferred embodiments. The embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention.

[0076] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An integrated multipole collision reaction cell for inductively coupled plasma mass spectrometry (ICP-MS), comprising a deflection multipole ion guide and a multipole collision reaction cell, wherein: The deflection ion guide comprises a deflection entrance lens; the deflection entrance lens is located at the front end of the vertical position outside the deflection ion guide; The deflection ion guide comprises N elongated deflection ion guide electrodes, wherein N is 1, 2, 3, or 4; the deflection ion guide electrodes are arranged at a certain radial distance orthogonal to the vertical axis of the deflection ion guide; The multi-pole collision reaction cell comprises a collision reaction cell entrance lens, a collision reaction cell body, and a collision reaction cell exit lens; the collision reaction cell entrance lens is located at the side end of the vertical position outside the deflection ion guide and is distributed at 90 degrees with the deflection lens entrance lens; Ions enter the deflection ion guide from the deflection entrance lens at the front end of the deflection ion guide, are deflected 90° under the action of the electrostatic field of the deflection ion guide, and are focused onto the collision reaction cell entrance lens of the multi-pole collision reaction cell.

2. The collision reaction cell according to claim 1, characterized in that: The center of the deflection entrance lens and the center of the collision reaction cell entrance lens both correspond to the center position of the deflection ion guide.

3. The collision reaction cell according to claim 1, characterized in that: When two or more deflection ion guide electrodes are provided, the deflection ion guide electrodes are parallel to each other.

4. The collision reaction cell according to claim 1, characterized in that: The deflection ion guide electrode is a round rod, a semi-round rod, a 1 / 4 round rod, a flat rod, a concave rod, a hyperbolic rod or a trapezoidal rod.

5. The collision reaction cell according to claim 1, characterized in that: The deflected ion guide electrode is fixed by a fixing device, which includes an upper fixing plate and a lower fixing plate; the two ends of the deflected ion guide electrode are respectively fixed on the upper fixing plate and the lower fixing plate.

6. The collision reaction cell according to claim 1, characterized in that: The deflection ion guide comprises a fixed bracket, and the deflection entrance lens and the collision reaction cell entrance lens are both fixed on the fixed bracket.

7. The collision reaction cell according to claim 1, characterized in that: A plurality of collision reaction multipole ion guide electrodes are arranged in the multipole collision reaction cell; the collision reaction multipole ion guide electrodes are configured to generate an RF confinement field that effectively confines ions in a radial direction orthogonal to the longitudinal axis of the collision reaction cell body.

8. The collision reaction cell according to claim 7, characterized in that: The deflection entrance lens, the collision reaction cell entrance lens, and / or the collision reaction cell exit lens are connected to a direct current voltage.

9. The collision reaction cell according to claim 8, characterized in that: The DC voltage is respectively combined with RF+ and RF- through two resistors and then connected to two groups of collision reaction multipole ion guide electrodes spaced apart from each other.

10. The collision reaction cell according to claim 1, characterized in that: A direct current voltage is connected to the deflection ion guide electrodes; when the number of the deflection ion guide electrodes is 2, 3 or 4, two direct current voltages are respectively connected to electrodes spaced apart from each other.

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