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 utility model relates to the field of inductively coupled plasma mass spectrometer, especially to a kind of inductively coupled plasma mass spectrometry integrated multipole rod collision reaction cell. BACKGROUND

[0002] A typical structure of an inductively coupled plasma mass spectrometry (ICP-MS) system 200 is shown in Figure 1 Figure 1, and includes a plasma-based ion source; the ion source is used to generate a plasma to decompose molecules of a sample into atoms, and then ionize the atoms in preparation for elemental analysis. In a typical operation, a liquid sample is nebulized, i.e., converted into an aerosol (fine spray or mist), by a gas-driven (typically argon) nebulizer 201, and the coarse aerosol is removed within a nebulization chamber 202, and the remaining fine aerosol is directed into a plasma generated by a plasma source. The plasma source is often configured as a flow-through plasma torch tube 203 having two or more concentric tubes. Typically, a plasma-forming gas (argon) flows through the inner tube of the torch tube and is excited into a plasma by a suitably powered load coil 204, such as a radio frequency (RF). The aerosol flows through the coaxial center tube of the torch tube 203 and is emitted into the generated plasma, where exposure to the plasma decomposes the sample molecules into atoms, or alternatively, partially decomposes the sample molecules into molecular fragments and ionizes the atoms or molecular fragments; these analyte atoms or molecular fragments ionize to generate an ion beam. Since these ions are not generated in a vacuum region, the ion beam is gradually transitioned into a high vacuum region by a sampling cone 205 and skimmer cone 206. After the ion beam enters the high vacuum region, it is focused by an extraction lens 207 and enters an off-axis or deflection lens 208, Figure 1 Figure 1 is a schematic diagram of a square plate off-axis lens to explain the working principle of ICP-MS. After the ions pass through the off-axis or deflection lens 208, they are separated from photons and neutral species, and then enter a collision reaction cell 209, where interfering ions are eliminated by collision or reaction, and then focused by a collision reaction cell exit lens 210 and enter a secondary off-axis lens 211, which off-axes again to eliminate the influence of neutral species in the collision reaction cell on subsequent mass selection, thereby improving the signal-to-noise ratio. After passing through the secondary off-axis lens, the ion beam enters a mass analyzer 212; the mass analyzer generally adopts a quadrupole rod structure or other analyzers such as a sector magnetic field, a time-of-flight (TOF) analyzer, etc., and applies an alternating electric field or a combination of electric and magnetic fields to cause the ionized ions to be spectrally resolved according to their mass-to-charge ratio m / z, and then enable an ion detector 213 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] As the ion source of ICP-MS, the plasma cannot decompose all components in the sample into ions, and a part of undecomposed neutral substances will follow the ion beam to pass through the interface and be introduced into the subsequent collision reaction cell and quadrupole. Meanwhile, the high-temperature plasma will also produce strong photons. These neutral substances will pollute the subsequent ion mirror and collision reaction cell on the one hand, and will also produce new interfering ion when colliding with the collision reaction gas in the collision reaction cell on the other hand. The photons will also produce a lot of detection noise. Therefore, effective means are needed to separate the neutral substances and photons from the analyte ions before the ion beam enters the collision reaction cell.

[0004] In addition to the above off-axis mode, it is known that in the ICP-MS system, the neutral substances and photons are separated from the analyte ions by a 90-degree deflection between the ion source and the collision reaction cell. The advantage of 90-degree deflection is that a large number of neutral substances produced in the ion source are separated more thoroughly, so that the collision reaction cell remains clean for a longer period of time, reduces the performance degradation caused by contamination of the collision reaction cell, and reduces the cleaning frequency and maintenance cost. The working principle and ion flight trajectory of the existing 90-degree deflection system are shown in Figure 2 and Figure 3 .

[0005] Figure 2 The 90-degree deflection lens shown is a deflection mode using a single circular rod, Figure 3 The deflection mode using a quadrupole rod is shown. The ion beam generated by the ion source gradually transitions to the high-vacuum region through the sampling cone 301, 401 and the intercepting cone 302, 402. After entering the high-vacuum region, the ion beam is focused by the extraction lens 303, 403 for the first time; the ions gradually diverge after the focal point, and then the deflection focusing lens group 304, 404 and 305, 405 focuses the ions to the center of the single circular rod 306 or the quadrupole rod 406 deflection lens. The ions diverge again after passing through the focal point, and then another set of symmetrical deflection outlet focusing lens group 304, 404 and 305, 405 focuses the ions again, and cooperates with the collision reaction cell inlet focusing lens 307, 407 to focus the ions to the small hole 308, 408 in the middle of the collision reaction cell inlet lens. After passing through the collision reaction cell 309, 409, the ions exit from the collision reaction cell outlet lens 310, 410. The ions pass through three focusing processes before entering the collision reaction cell.

[0006] The above mode can eliminate the influence of neutral substances and photons generated by the ion source, and the quadrupole 90-degree deflection mode can also preliminarily screen the ions to be detected; however, a plurality of focusing lenses are needed before and after the deflection lens to focus the ion beam, and a focusing lens is also needed before the collision reaction cell to focus the ions into the small hole of the collision reaction cell entrance. Compared with the foregoing off-axis mode, the above mode has an additional focusing process, so that in the foregoing 90-degree deflection mode, the flight distance of the ions is longer than that in the off-axis mode, and under the influence of the space charge effect, the loss of light mass ions increases, 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, and mutual influence occurs during tuning, thereby increasing the difficulty of automatic tuning and prolonging the automatic tuning process.

[0007] The interaction between ions is the principle of repulsion between the same kind. Since the plasma mass spectrometer has a high negative voltage (about -150 volts) on the extraction lens, negative ions or electrons cannot enter the high vacuum region, and 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] where q1 and q2 are the charges carried by the two ions, k is a proportionality constant, and r is the distance between the ions.

[0010] The space charge effect in ion flight is very complex, and both the interaction perpendicular to the ion flight direction and the interaction consistent with the ion flight direction need to be considered. Since the ion beam generated by ICP-MS is usually continuous, for the sake of simplicity, it can be assumed that a certain ion is affected by other ions before and after it, so that the forces of action cancel each other out; however, the interaction perpendicular to the ion flight direction will cause the ions to start to diverge while flying, thereby causing the ions in the edge area to be unable to continue to be focused and flown in the established direction; the result is the loss of ions. Generally, 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; part of the ions will not be focused by the subsequent ion lenses, thereby causing the loss of ions. Generally, this part of the loss will increase with the increase in the total number of ions in the ion beam and the increase in the flight distance.

[0011] The ion focusing system is usually optimized, i.e. tuned, before the instrument is formally analyzing a sample, which is to adjust the voltage of a series of ion mirrors so that the instrument is optimized in the ion passing rate of each mass section, i.e. the sensitivity is optimized. Since the matrix of the actual sample is different, the general tuning is usually performed by using pure standard solution. The matrix is very simple compared with the actual sample, but the total number of various ions in the ion beam is much more than that of the pure standard solution due to the complex matrix of the actual sample, which inevitably causes the ion loss in the sample test, and the shortest ion flight distance and the optimized ion focusing are effective means to reduce this effect. Practical new type content

[0012] The utility model discloses a kind of integrated multipole rod collision reaction cell of inductively coupled plasma mass spectrometry, which comprises two groups of ion guides, the first group is multipole rod structure, and a plurality of poles are arranged in parallel, which is used to deflect 90 ° and focus in the collision reaction cell entrance;The second group is collision reaction multipole rod ion guide, each guide electrode adopts parallel or rotary structure, and the field diameter of the entrance end can be greater than or less than the field diameter of the exit end;Two groups of ion guides are arranged at 90 degrees to each other, and separated by a round hole. There is an ion beam entrance lens in front of the first group of ion guides, which has a relatively large aperture;There is an exit lens at the tail end of the second group of multipole rod structure ion guides. Ions enter the first group of ion guides from the entrance lens in front of the first group of ion guides, and are deflected by 90 ° under the action of the electrostatic field of the first group of ion guides, and focused into the entrance of the second group of ion guides, i.e. the collision reaction cell. After collision or reaction, the ions are guided out from the small hole in the middle of the exit lens.

[0013] The utility model provides a kind of integrated multipole rod collision reaction cell of inductively coupled plasma mass spectrometry (ICP-MS), it includes deflection multipole rod ion guide and multistage rod collision reaction cell, wherein the outlet of the deflection multipole rod ion guide is merged with the entrance of the multistage rod collision reaction cell.

[0014] Further, the deflection ion guide includes N elongated deflection ion guide electrodes, wherein N is 1, 2, 3, or 4; the deflection ion guide electrodes are disposed at a certain radial distance orthogonal to the vertical axis of the deflection ion guide;

[0015] When two or more deflection ion guide electrodes are provided, the deflection ion guide electrodes are parallel to each other.

[0016] Further, the deflection ion guide electrodes are round rods, half-round rods, 1 / 4 round rods, flat plate rods, concave rods, hyperboloid rods or trapezoidal rods.

[0017] Further, the deflection ion guide electrode is fixed by a fixing device, the fixing device comprising an upper end fixing disc and a lower end fixing disc; two ends of the deflection ion guide electrode are fixed on the upper end fixing disc and the lower end fixing disc respectively.

[0018] Further, the deflection ion guide comprises a deflection inlet lens; the deflection inlet lens is located at the front end of the vertical position outside the deflection ion guide, and the central part of the deflection inlet lens corresponds to the central position of the deflection ion guide.

[0019] Further, the multi-stage rod collision reaction cell comprises a collision reaction cell inlet lens, a collision reaction cell main body and a collision reaction cell outlet lens; the collision reaction cell inlet lens is located at the side end of the vertical position outside the deflection ion guide, and the central part of the deflection inlet lens corresponds to the central position of the deflection ion guide, and is distributed at 90 degrees with the deflection lens inlet lens.

[0020] Further, a plurality of collision reaction multipole rod ion guide electrodes are arranged in the multi-stage rod collision reaction cell; the collision reaction multipole rod ion guide electrodes are configured to generate an RF confinement field of ions effectively confined in a radial direction orthogonal to the longitudinal axis of the collision reaction cell main body.

[0021] Further, the deflection inlet lens, the collision reaction cell inlet lens and / or the collision reaction cell outlet lens are connected with a direct current voltage.

[0022] Further, the direct current voltage is combined with RF+ and RF- through two resistances respectively and then connected to two groups of the collision reaction multipole rod ion guide electrodes which are spaced apart from each other.

[0023] Further, the direct current voltage is connected to the deflection ion guide electrode; when the deflection ion guide electrode is arranged as 2, 3 or 4, two direct current voltages are connected to the electrodes which are spaced apart from each other respectively.

[0024] Compared with the prior art, the integrated multipole rod collision reaction cell of inductively coupled plasma mass spectrometry provided by the utility model combines the quadrupole ion deflection lens and the multipole rod collision reaction cell, combines the outlet of the deflection lens and the inlet of the collision reaction cell, and focuses the ion beam directly to the collision reaction cell inlet after deflection, and has the following advantages:

[0025] 1. Shorten the ion flight distance, reduce the space charge effect, and realize high efficiency deflection of all ions from low mass to high mass;

[0026] 2. The analyte ions are completely separated from the neutral substances and photons generated by the ion source, the collision reaction cell is kept clean, and the maintenance frequency is reduced;

[0027] 3. The ions are pre-selected, so that the to-be-tested ions and similar ions enter the collision reaction cell, and the collision reaction efficiency is improved;

[0028] 4. The number of ion lenses is reduced, and the automatic tuning process is simplified. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of an inductively coupled plasma mass spectrometer (ICP-MS) system in the prior art.

[0030] Figure 2 It is a schematic diagram of the structure of a 90-degree deflection lens using a single round rod and a flight trajectory in the prior art; wherein, Figure 2 (a) is a schematic diagram of the structure of a 90-degree deflection lens using a single round rod; Figure 2 (b) is a schematic diagram of the ion flight trajectory;

[0031] Figure 3 It is a schematic diagram of the structure of a 90-degree deflection lens using a quadrupole rod and a flight trajectory in the prior art; wherein, Figure 3 (a) is a schematic diagram of the structure of a 90-degree deflection lens using a quadrupole rod; Figure 3 (b) is a schematic diagram of the ion flight trajectory;

[0032] Figure 4 It is a schematic diagram of an integrated collision reaction cell of an inductively coupled plasma mass spectrometer (ICP-MS) according to the present application;

[0033] Figure 5 It is a schematic diagram of the circuit connection of the rod electrode according to the present application; wherein, Figure 5 (a) is the case of N=4; Figure 5 (b) is the case of N=3; Figure 5 (c) and 5(d) are the case of N=2; Figure 5 (e) is the case of N=1;

[0034] Figure 6 It is a schematic diagram of the working principle of the integrated collision reaction cell according to the present application; 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 the ion flight trajectory;

[0035] Figure 7 It is a schematic diagram of the simulated equipotential line and ion beam flight trajectory of the integrated collision reaction cell in the embodiment of the present application. DETAILED DESCRIPTION

[0036] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present application, but not to limit the scope of the present application.

[0037] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "radial", "orthogonal", "opposite", "one end", "the other end" and the like in the present application are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0038] The terms "mounting", "connecting", "connection" should be broadly understood, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] The utility model provides a kind of integral type multipole rod collision reaction cell of inductively coupled plasma mass spectrometry (ICP-MS), as Figure 4 As shown, it includes deflection multipole rod ion guide 100 and multi-stage rod collision reaction cell 110, wherein the outlet of the deflection multipole rod ion guide 100 is merged with the inlet of the multi-stage rod collision reaction cell 110.

[0040] 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 disposed 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.

[0041] As Figure 4 An embodiment of the present application is shown, and when N=4, the deflection ion guide electrodes 101 are uniformly distributed on the same circle at the same distance from the central axis of the deflection ion guide 100, and are parallel to each other. In addition, referring to Figure 4When N is 1, the deflection ion guide electrode 101 is specifically deflection ion guide electrode 1011; when N is 2, the deflection ion guide electrode 101 is specifically deflection ion guide electrode 1011, 1012 or deflection ion guide electrode 1011, 1013; when N is 3, the deflection ion guide electrode 101 is specifically deflection ion guide electrode 1011, 1012 and 1013.

[0042] The deflection ion guide electrode 101 can be a circular rod, a semi-circular rod, a 1 / 4 circular rod, a flat plate rod, a concave rod, a hyperbolic rod, a trapezoidal rod and other shaped rod. As shown in the drawings, Figure 4 An embodiment of the utility model is shown, the deflection ion guide electrode 101 is 1 / 4 circular rod.

[0043] The deflection ion guide electrode 101 is fixed by a fixing device. The fixing device includes an upper end fixing disc 102 (not shown in the exploded view) and a lower end fixing disc 103. The two ends of the deflection ion guide electrode 101 are fixed on the upper end fixing disc 102 and the lower end fixing disc 103 respectively. The fixing device can be insulating material or metal plate material connected with other components through insulating gaskets.

[0044] The deflection ion guide 100 includes a deflection entrance lens 104. The deflection entrance lens 104 is located at the front end of the vertical position outside the deflection ion guide 100.

[0045] The deflection entrance lens 104 is directly connected on the lens fixing bracket 106 of the deflection ion guide 100 through an insulating gasket 105, and the central part of the deflection entrance lens 104 corresponds to the central position of the deflection ion guide 100.

[0046] Preferably, the opening of the deflection entrance lens 104 is designed to be relatively large, which can be conical or circular ring-shaped.

[0047] Preferably, the deflection entrance lens 104 is configured with a certain DC bias.

[0048] The deflection ion guide 100 is also fixedly provided with a wiring terminal 107.

[0049] The multi-stage rod collision reaction cell 110 includes a collision reaction cell entrance lens 111, a collision reaction cell main body 112 and a collision reaction cell exit lens 113.

[0050] The collision reaction cell entrance lens 111 is directly connected on the vertical position outside the deflection ion guide 100 through an insulating gasket 114, and is distributed at 90 degrees with the deflection lens entrance lens 104.

[0051] Preferably, the collision cell entrance lens 111 is fixed on the lens fixing support 106 by an insulating gasket 114, and the central part of the collision cell entrance lens 111 corresponds to the central position of the deflection ion guide 100 and is distributed at 90 degrees with the deflection lens entrance lens 104.

[0052] The collision cell entrance lens 111 is a sheet electrode with a small hole in the middle for ion flying 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 at 90 degrees with the entrance direction of the deflection lens entrance lens 104. After passing through the deflection lens entrance lens 104, the ions are deflected by 90 degrees under the action of the electric field and focused on the small hole in the center of the collision cell entrance lens 111, directly entering the multi-stage rod collision cell 110.

[0053] Preferably, the collision cell entrance lens 111 is configured with a certain DC bias.

[0054] A plurality of collision reaction multipole ion guide electrodes 115 are arranged in the collision cell body 112. The collision reaction multipole ion guide electrodes 115 are arranged inside the collision cell body 112 along the longitudinal axis of the collision cell body 112. The collision reaction multipole ion guide electrodes 115 are configured to generate an RF confinement field for ions effectively confined in a radial direction orthogonal to the longitudinal axis of the collision cell body 112.

[0055] The collision reaction multipole ion guide electrodes 115 are elongated rod electrodes, which can be round rods, square rods, hyperboloid rods or concave rods; the number of the collision reaction multipole ion guide electrodes 115 can be 2n, n being greater than or equal to 2. A plurality of the collision reaction multipole ion guide electrodes 115 are arranged in parallel or in a rotating structure around the longitudinal axis of the collision cell body 112 to generate a certain confinement force on the ions entering the multi-stage rod collision cell 110 and make the ion beam oscillate forward.

[0056] The plurality of collision reaction multipole ion guide electrodes 115 fix their relative positions by two collision reaction multipole ion guide fixing rings 116 made of PEEK or other insulating materials, so as to keep them parallel and concentric; then they are fixed by fixing screws and are integrally installed in the collision cell body 112.

[0057] Preferably, the plurality of collision reaction multipole ion guide electrodes 115 are divided into two groups separated by a certain distance. The two collision reaction multipole ion guide terminals 117 connect the two groups of collision reaction multipole ion guide electrodes 115 separated by a certain distance, so as to provide corresponding RF and DC voltages.

[0058] The collision reaction tank outlet lens 118 is fixed to the tail of the collision reaction tank body 112 by an insulating gasket 114.

[0059] Figure 5 This is a schematic diagram of the circuit connection in this embodiment. U1-U6 represent DC voltages; RF+ and RF- represent radio frequency signals with the same amplitude and frequency but a 180-degree phase difference. As shown, U1 is connected to the collision reaction cell inlet lens 104. U2 and U3 are connected to the deflecting ion guide electrode 101. U4 is connected to the collision reaction cell inlet lens 111. U5, after being combined with RF+ and RF- respectively through two resistors, is connected to two sets of spaced-apart collision reaction multipole ion guide electrodes 115. U6 is connected to the collision reaction cell outlet lens 118.

[0060] There are multiple ways to connect U2 and U3, the most common being that U2 and U3 are connected to two electrodes spaced apart from each other.

[0061] by Figure 5 Taking the case of N=4 shown in (a) as an example, U2 is connected to the first deflecting ion guide electrode 1011 and the third deflecting ion guide electrode 1013, and U3 is connected to the second deflecting ion guide electrode 1012 and the fourth deflecting ion guide electrode 1014; or U2 is connected to the first deflecting ion guide electrode 1011, and U3 is connected to the second deflecting ion guide electrode 1012, the third deflecting ion guide electrode 1013 and the fourth deflecting ion guide electrode 1014.

[0062] Figure 5 (b) shows the case when N=3, where U2 is connected to the first deflecting ion guide electrode 1011 and U3 is connected to the second deflecting ion guide electrode 1012 and the third deflecting ion guide electrode 1013.

[0063] Figure 5 (c) and (d) show two cases where N=2, where U2 is connected to the first deflecting ion guide electrode 1011 and U3 is connected to the second deflecting ion guide electrode 1012; or U2 is connected to the first deflecting ion guide electrode 1011 and U3 is connected to the third deflecting ion guide electrode 1013.

[0064] Figure 5 (e) shows the case when N=1, in which only U2 is connected to the first deflection ion guide electrode 1011.

[0065] A negative DC potential barrier is generated by the entrance lens 104 of the deflection lens near the entrance of the deflection ion guide 100, so that the ions can smoothly enter the deflection ion guide 100 while being focused; and a negative DC potential barrier is generated by the exit lens 118 of the multi-stage rod collision reaction cell 110 near the exit of the multi-stage rod collision reaction cell 110, so that the ions can smoothly exit from the multi-stage rod collision reaction cell 110.

[0066] RF+ and RF- are radio frequency signals with the same frequency and amplitude and exactly opposite phase (180° difference), and the frequency is between 0-1000MHz, so as to generate an RF confinement field for the ions.

[0067] The RF+ potential superimposed on the DC bias potential (U) is applied to a group of the collision reaction multi-pole rod ion guide electrodes 115, and the RF- potential superimposed on the DC bias potential (U) is applied to another group of the collision reaction multi-pole rod ion guide electrodes 115 which are separated from the group.

[0068] The integrated collision reaction cell combines the outlet of the deflection lens and the inlet of the collision reaction cell, and only retains the single focusing lens of the deflection lens inlet, and the working principle and ion flight trajectory diagram are as shown in Figure 6 The ions generated from the ion source enter the high-vacuum area after the sampling cone 122 and the intercepting cone 123, and then are focused for the first time by the extraction lens one 124 and the extraction lens two 125; the ions start to diverge after passing through the focal point and are focused again by the deflection inlet lens 104. By adjusting the voltages of the deflection inlet lens 104, the deflection ion guide electrodes 101 and the collision reaction cell inlet lens 111, the ion beam is deflected by 90 degrees and focused into the small hole in the middle of the collision reaction cell inlet lens 111. The collision reaction multi-pole rod ion guide electrodes 115 (taking an octupole rod as an example) are arranged inside the collision reaction cell main body 112 along the longitudinal axis of the collision reaction cell main body 112; the collision reaction multi-pole rod ion guide electrodes 115 are configured to generate an RF confinement field for the ions effectively confined in the radial direction perpendicular to the longitudinal axis of the collision reaction cell main body 112; a plurality of the collision reaction multi-pole rod ion guide electrodes 115 are arranged in parallel or in a rotating structure around the longitudinal axis of the collision reaction cell main body 112, so as to generate a certain confinement force on the ions entering the collision reaction multi-pole rod ion guide electrodes 115 and make the ion beam oscillate forward.

[0069] From Figure 7The simulation ion flight trajectory and equipotential line can see that the integrated multipole rod collision reaction cell of the inductively coupled plasma mass spectrometry (ICP-MS) provided by the utility model can focus the ion beam to the inlet of the multipole rod collision reaction cell after 90-degree deflection, and the ion beam enters the collision reaction cell through the small hole in the middle of the collision reaction cell inlet lens, and the ion beam is further introduced out of the collision reaction cell from the small hole in the middle of the collision reaction cell outlet lens under the action of the radio frequency and direct current bias applied on the collision reaction multipole rod.

[0070] The integrated collision reaction cell provided by the utility model embodiment can achieve good technical effects. Figure 2 As shown in the single-rod deflection, the ion beam center flight path from the interception cone inlet to the collision reaction cell inlet of the embodiment provided by the utility model is reduced from 190.6 millimeters to 115.2 millimeters, and the flight distance is reduced by about 40%.

[0071] It should be noted that the experimental results show that when N=4, the technical scheme of the utility model can achieve the best technical effect. However, when N is 1, 2 or 3, the effect is also obviously improved compared with the prior art.

[0072] The above is only the preferred embodiment of the utility model, and it should be pointed out that for ordinary technical personnel in the technical field, without departing from the technical principle of the utility model, a number of improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection range of the utility model. The above shows and describes the basic principle, main features and advantages of the utility model, and for those skilled in the art, it is obvious that the utility model is not limited to the details of the above preferred embodiment, the embodiments should be regarded as exemplary and non-limiting, the scope of the utility model is defined by the appended claims rather than the above description, therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the utility model.

[0073] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical scheme, and the description manner of the specification is only for the sake of clarity, those skilled in the art should regard the specification as a whole, and the technical schemes in the embodiments can also be properly combined to form other embodiments that those skilled in the art can understand.

Claims

1. An integrated multi rod collision cell for inductively coupled plasma mass spectrometry (ICP-MS) comprising a deflection multi rod ion guide and a multi stage rod collision cell, wherein, The deflection multipole ion guide and the multi-stage multipole collision cell are arranged at 90 degrees to each other, and the outlet of the deflection multipole ion guide is combined with the inlet of the multi-stage multipole collision cell.

2. The collision cell of claim 1, wherein, The deflection multipole ion guide comprises N elongated deflection multipole ion guide electrodes, wherein N is 1, 2, 3, or 4; the deflection multipole ion guide electrodes are arranged at a certain radial distance from the vertical axis of the deflection multipole ion guide; When two or more deflection multipole ion guide electrodes are arranged, the deflection multipole ion guide electrodes are parallel to each other.

3. The collision cell of claim 1, wherein, The deflection multipole ion guide electrodes are circular rods, semi-circular rods, 1 / 4 circular rods, flat plate rods, concave rods, hyperbolic rods, or trapezoidal rods.

4. The collision cell of claim 2, wherein, The deflection multipole ion guide electrodes are fixed by a fixing device, which comprises an upper end fixing disc and a lower end fixing disc; the two ends of the deflection multipole ion guide electrodes are respectively fixed on the upper end fixing disc and the lower end fixing disc.

5. The collision cell of claim 1, wherein, The deflection multipole ion guide comprises a deflection inlet lens; the deflection inlet lens is located at the front end of the vertical position outside the deflection multipole ion guide, and the central part of the deflection inlet lens corresponds to the central position of the deflection multipole ion guide.

6. The collision cell of claim 5, wherein, The multi-stage multipole collision cell comprises a collision cell inlet lens, a collision cell main body, and a collision cell outlet lens; the collision cell inlet lens is located at the side end of the vertical position outside the deflection multipole ion guide, and the central part of the deflection inlet lens corresponds to the central position of the deflection multipole ion guide, and is distributed at 90 degrees to the deflection inlet lens of the deflection multipole ion guide.

7. The collision cell of claim 1, wherein, A plurality of collision reaction multipole ion guide electrodes are arranged in the multi-stage multipole collision cell; the collision reaction multipole ion guide electrodes are configured to generate an RF confinement field for ions effectively confined in the radial direction orthogonal to the longitudinal axis of the collision cell main body.

8. The collision cell of claim 6, wherein, The deflection inlet lens, the collision cell inlet lens, and / or the collision cell outlet lens are connected to a direct current voltage.

9. The collision cell of claim 7, wherein, The direct current voltage is combined with RF+ and RF- through two resistances respectively, and then connected to two groups of collision reaction multipole ion guide electrodes which are spaced apart from each other.

10. The collision cell of claim 2, wherein, A DC voltage is connected to the deflection multipole ion guide electrodes; when the deflection multipole ion guide electrodes are arranged as 2, 3 or 4, two DC voltages are connected to electrodes which are spaced from each other.

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