CN116403884A - Time-of-flight mass spectrometer and ion trapping release device and control method thereof - Google Patents
Time-of-flight mass spectrometer and ion trapping release device and control method thereof Download PDFInfo
- Publication number
- CN116403884A CN116403884A CN202111615193.8A CN202111615193A CN116403884A CN 116403884 A CN116403884 A CN 116403884A CN 202111615193 A CN202111615193 A CN 202111615193A CN 116403884 A CN116403884 A CN 116403884A
- Authority
- CN
- China
- Prior art keywords
- pole piece
- electrode pole
- ion
- penetrating
- time
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims description 26
- 150000002500 ions Chemical class 0.000 claims abstract description 182
- 230000000149 penetrating effect Effects 0.000 claims abstract description 91
- 230000005405 multipole Effects 0.000 claims abstract description 39
- 238000000605 extraction Methods 0.000 claims abstract description 38
- 230000005684 electric field Effects 0.000 claims abstract description 28
- 238000005040 ion trap Methods 0.000 claims description 20
- 238000001816 cooling Methods 0.000 claims description 7
- 230000005540 biological transmission Effects 0.000 description 9
- 238000010586 diagram Methods 0.000 description 6
- 230000035945 sensitivity Effects 0.000 description 6
- 238000004885 tandem mass spectrometry Methods 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 230000009471 action Effects 0.000 description 4
- 230000001133 acceleration Effects 0.000 description 3
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 3
- 238000010884 ion-beam technique Methods 0.000 description 3
- 230000000737 periodic effect Effects 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- 238000001269 time-of-flight mass spectrometry Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- -1 ion ions Chemical class 0.000 description 1
- 230000037427 ion transport Effects 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000000452 restraining effect Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000001196 time-of-flight mass spectrum Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 230000032258 transport Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J49/00—Particle spectrometers or separator tubes
- H01J49/26—Mass spectrometers or separator tubes
- H01J49/34—Dynamic spectrometers
- H01J49/40—Time-of-flight spectrometers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J49/00—Particle spectrometers or separator tubes
- H01J49/0027—Methods for using particle spectrometers
- H01J49/0031—Step by step routines describing the use of the apparatus
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J49/00—Particle spectrometers or separator tubes
- H01J49/02—Details
- H01J49/06—Electron- or ion-optical arrangements
- H01J49/062—Ion guides
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/10—Nuclear fusion reactors
Landscapes
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Electron Tubes For Measurement (AREA)
- Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
Abstract
The ion trapping and releasing device comprises a multipole rod, a penetrating electrode pole piece and an extraction electrode pole piece, wherein the penetrating electrode pole piece is arranged on the multipole rod in a penetrating way, and the extraction electrode pole piece is arranged at the tail end of the multipole rod; the axial electric field generated by the multipole rod accelerates ions to pass through the penetrating electrode pole piece, and when the relative voltage between the penetrating electrode pole piece and the leading-out electrode pole piece is not increased, the ions passing through the penetrating electrode pole piece are cooled, collided and focused between the penetrating electrode pole piece and the leading-out electrode pole piece, so that the trapping of the ions is realized. When the relative voltage between the penetrating electrode pole piece and the extracting electrode pole piece is increased, the ion packets between the penetrating electrode pole piece and the extracting electrode pole piece are released through the extracting electrode pole piece in a pulse mode. The continuous ion flow is enabled to be a relatively continuous pulse ion packet flow through the trapping and releasing of ions, so that the utilization rate of ions is improved through a simple structure, and the application range is wide.
Description
Technical Field
The application relates to the technical field of ion transmission, in particular to a time-of-flight mass spectrometer, an ion trapping and releasing device and a control method thereof.
Background
The time-of-flight mass spectrum (TOF) has the advantages of high resolution, wide mass range, single full spectrum scanning and the like, can be coupled with various ion sources, and is also widely applied to tandem mass spectrometry. Sensitivity is an important performance parameter of a time-of-flight mass spectrometer, and the method for improving the utilization rate of ions is an important method for improving the sensitivity of the time-of-flight mass spectrometer.
The traditional method for improving the ion utilization rate is to add a radio frequency ion trap mass analyzer, trap and release the ions, but the method is limited by space charge effect, the space structure of the instrument, complicated radio frequency electric field control and the like, so that the application of the method is limited.
Disclosure of Invention
In view of the above, it is desirable to provide a time-of-flight mass spectrometer with a wide range of applications, and an ion trapping release device and control method therefor.
The ion trapping and releasing device of the time-of-flight mass spectrometer comprises a multipole rod, a penetrating electrode pole piece and an extraction electrode pole piece, wherein the penetrating electrode pole piece is arranged on the multipole rod in a penetrating way, and the extraction electrode pole piece is arranged at the tail end of the multipole rod; the axial electric field generated by the multipole rod accelerates ions to pass through the penetrating electrode pole piece, when the relative voltage between the penetrating electrode pole piece and the extracting electrode pole piece is not increased, the ions passing through the penetrating electrode pole piece are cooled, collided and focused between the penetrating electrode pole piece and the extracting electrode pole piece, and when the relative voltage between the penetrating electrode pole piece and the extracting electrode pole piece is increased, ion packets between the penetrating electrode pole piece and the extracting electrode pole piece are released through the extracting electrode pole piece in a pulse mode.
In one of the embodiments, the multipole is a segmented multipole, or the multipole is a straight rod with a resistance.
In one embodiment, the multipole is a hyperbolic or cylindrical multipole.
In one embodiment, the multipole rod is a quadrupole rod, the opposite rods of the quadrupole rod are correspondingly connected, and a pair of radio-frequency voltages with equal amplitude and 180-degree phase difference are respectively applied to the two groups of mutually parallel rods; and two ends of the four rods of the quadrupole rod are respectively applied with different direct current voltages.
In one embodiment, the penetrating electrode sheet is penetrating and disposed at a position of the multipole near the end.
In one embodiment, the penetrating electrode plate is a circular plate with a central hole of a round hole or a grid mesh; the leading-out electrode pole piece is a round pole piece with a round hole as a center hole.
In one embodiment, the through electrode pole piece and the extraction electrode pole piece apply pulse voltages with the same frequency and different amplitudes and phases respectively, or one of the through electrode pole piece and the extraction electrode pole piece applies direct current voltage.
The ion trapping release control method of the time-of-flight mass spectrometer is realized based on the ion trapping release device, and comprises the following steps:
maintaining the relative voltage between the penetrating electrode pole piece and the extracting electrode pole piece, so that an axial electric field generated by a multipole rod accelerates ions passing through the penetrating electrode pole piece, and cooling, collision and focusing are performed between the penetrating electrode pole piece and the extracting electrode pole piece;
and increasing the relative voltage between the penetrating electrode pole piece and the extraction electrode pole piece, so that ion packets between the penetrating electrode pole piece and the extraction electrode pole piece are released through the extraction electrode pole piece in a pulse mode.
A time-of-flight mass spectrometer comprises an ion guide device, a time-of-flight mass analyzer and the ion trapping and releasing device.
In one embodiment, the ion guide comprises an electrostatic lens.
According to the flight time mass spectrometer, the ion trapping release device and the control method thereof, the multipole rod generates the axial electric field to enable ions to accelerate to pass through the penetrating electrode pole piece, and when the relative voltage between the penetrating electrode pole piece and the extraction electrode pole piece is not increased, the ions passing through the penetrating electrode pole piece are cooled, collided and focused between the penetrating electrode pole piece and the extraction electrode pole piece, so that the trapping of the ions is realized. When the relative voltage between the penetrating electrode pole piece and the extracting electrode pole piece is increased, the ion packets trapped between the penetrating electrode pole piece and the extracting electrode pole piece are released through the extracting electrode pole piece in a pulse mode. Through the trapping-releasing of ions, the continuous ion flow is changed into a relatively continuous pulse ion packet flow, the duty ratio of the flight time mass spectrometer is improved, the utilization rate of ions is improved by a simple structure, and the application range is wide.
Drawings
FIG. 1 is a schematic diagram of an ion trapping release device of a time-of-flight mass spectrometer according to one embodiment;
FIG. 2 is a schematic diagram of a structure of a penetrating electrode sheet according to an embodiment;
FIG. 3 is a schematic view of another embodiment of a penetrating electrode sheet;
FIG. 4 is a schematic diagram of an ion trapping release device for Q-TOF according to one embodiment;
FIG. 5 is a schematic diagram of a quadrupole radiofrequency voltage application mode in an embodiment;
FIG. 6 is a schematic diagram of Q2 DC voltage application in one embodiment;
FIG. 7 is a schematic diagram of voltage application across electrode pads and out electrode pads in an embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.
Time-of-flight mass spectrometry can be coupled to a variety of ion sources, such as: EI. ESI, MLIDI, etc., are also widely used in tandem mass spectrometry such as: Q-TOF, etc. Sensitivity is an important performance parameter of a time-of-flight mass spectrometer and Duty Cycle (Duty Cycle) is an important factor affecting the sensitivity of a time-of-flight mass spectrometer. The continuous ion stream generated by the ion source enters the TOF acceleration region where most of the ions pass directly through the repulsion region and are not effectively repelled and accelerated. The formula of the repulsion duty cycle of the mass number ions in the acceleration region is as follows:
the duty cycle of ions of a particular mass-to-charge ratio depends on the pulse frequency f, the effective length of the repulsive zone aperture, l, and the kinetic energy of the ions, E k For a TOF analyzer with a fixed pulse frequency for structural determination, the main way to increase ion utilization is to convert a continuous ion beam generated by an ion source into a continuous pulsed ion packet. At present, for the mode of improving the utilization rate of ions, a radio frequency ion trap and a TOF (time of flight) are mainly used for connecting in series, for example, a linear ion trap is added in front of the TOF, and continuous ion flow entering an accelerating region of the TOF is converted into a pulse ion packet through trapping and axial resonance excitation of the ion beam by the ion trap, so that the utilization rate of ions is improved. However, due to space charge effects, a larger volume of storage space is required, which requires a larger volume of ion trap, often limited in practice.
The existing novel ion trap structure is characterized in that a radio frequency electric field (RF), an alternating current electric field (AC) and a direct current electric field (DC) are superposed on an ion trap, trapping of ions is realized through a pseudopotential well formed in the trap, AC voltage is reduced, ions with different mass-to-charge ratios are sequentially released from large to small, the ions with different mass-to-charge ratios synchronously reach the center of a TOF accelerating region, the TOF pulse frequency is adjusted, and when ion packets with different mass-to-charge ratios are focused at the center of the TOF repulsive region, pulses start (called Zeno pulses). This approach can bring the duty cycle of the TOF close to 100%. But also has the following drawbacks and disadvantages: (1) MS/MS dependent implementation; (2) The Zeno pulse is different from the pulse frequency in the normal mode, and when the conversion occurs, a certain time is needed to maintain the stability of the pulse amplitude; (3) High precision, complex radio frequency, pulsed power timing control also limits its practical application.
The main method for improving the utilization rate of TOF ions is to improve the duty ratio, which comprises the following steps: (1) The pulse frequency f is improved, but the development of a high-voltage high-frequency pulse power supply has certain complexity; (2) Increasing the effective length l of the TOF repulsive area opening is limited by the geometry of the detector, and the TOF repulsive area opening cannot be infinitely increased; (3) The kinetic energy Ek of the ions entering the TOF acceleration region is reduced and the ions must have a certain lateral kinetic energy to reach the detector. Therefore, improving ion utilization by converting a continuous ion stream generated by an ion source into a relatively continuous pulsed ion packet stream is an important method to improve the sensitivity of time-of-flight mass spectrometers. The most common method for improving the utilization rate of ions is to add a radio frequency ion trap mass analyzer, trap and release the ions, but the method is limited by space charge effect, the space structure of the instrument, complicated radio frequency electric field control and the like, so that the application of the method is limited.
The above prior art has the following disadvantages:
(1) Space charge effects require a larger volume ion trap and implementation relies on MS/MS (ion trap tandem TOF) to do so.
(2) The Zeno pulse is different from the pulse frequency in the normal mode, and requires a certain time to maintain the stability of the pulse amplitude when the transition occurs.
(3) High precision, complex radio frequency, pulsed power timing control also limits its practical application.
(4) The existing novel ion trap structure comprises 2 ion gates and an intermediate electrode, wherein the intermediate electrode is formed by four-pole rods or three-section four-pole rods, and the structure can realize high extraction rate of ions and improve the duty ratio of a time-of-flight mass spectrometer. This solution requires a tandem ion trap structure in the transport structure, increasing the complexity of the mass spectrometer in the structure and control system.
In view of this, how to provide a device that has a simple structure, does not need additional tandem ion trap structures, realizes ion trapping-releasing device, improves the duty cycle of time-of-flight mass spectrometer, has important meaning.
In one embodiment, as shown in fig. 1, there is provided an ion trapping and releasing device of a time-of-flight mass spectrometer, comprising a multipole rod 110, a through electrode plate 120 and an extraction electrode plate 130, wherein the through electrode plate 120 is arranged on the multipole rod 110 in a penetrating way, and the extraction electrode plate 130 is arranged on the tail end of the multipole rod 110; the axial electric field generated by the multipole rod 110 accelerates ions through the through electrode pole piece 120, when the relative voltage between the through electrode pole piece 120 and the extraction electrode pole piece 130 is not increased, the ions passing through the through electrode pole piece 120 are cooled, collided and focused between the through electrode pole piece 120 and the extraction electrode pole piece 130, and when the relative voltage between the through electrode pole piece 120 and the extraction electrode pole piece 130 is increased, ion packets between the through electrode pole piece 120 and the extraction electrode pole piece 130 are released through the extraction electrode pole piece 130 in a pulse form.
The multipole 110 may be a quadrupole, an octapole, or the like, and the multipole 110 may be a segmented multipole, or a straight rod with a resistance value. Wherein, can be through evenly plating conductive coating such as indium tin oxide coating on the straight-bar surface, realize that the resistance of straight-bar increases along with length is even, when the different direct current voltage is applied to pole both ends, can produce even axial electric field. The shape of the multipole 110 is also not exclusive and may be a quadrupole of the hyperbolic or cylindrical type. For ease of understanding, four-pole rods are used as examples for illustration.
Four rods of the quadrupole rods are arranged in parallel in a ring shape. The quadrupole is functionally divided into two parts (but the structure is still a complete transmission quadrupole), the former part being used for ion transmission and the latter part being used for trapping and extraction of ions, the two functional parts being separated by a through electrode plate 120. The voltage may be supplied to the quadrupole, the through electrode pad 120 and the lead electrode pad 130 by a power supply device, and the voltage difference between the through electrode pad 120 and the lead electrode pad 130 may be periodically changed. Specifically, the corresponding rods of the quadrupole rods are correspondingly connected, and a pair of radio-frequency voltages with equal amplitude and 180-degree phase difference are respectively applied to the two groups of rods which are parallel to each other; different direct current voltages are respectively applied to two ends of four rods of the quadrupole rod. Pulse voltages of the same frequency and different magnitudes and phases are applied through the electrode tab 120 and the extraction electrode tab 130, respectively, or a direct current voltage is applied through one of the electrode tab 120 and the extraction electrode tab 130.
The specific position of the penetration electrode sheet 120 is not limited, and may be a position near the end of the multipole 110. Specifically, in this embodiment, the penetrating electrode sheet 120 is located at the rear half of the quadrupole (e.g., 1/4) and penetrates the quadrupole. As shown in fig. 2 and 3, the through electrode pole piece 120 may be a circular pole piece with a circular hole or a grid, and further, the extraction electrode pole piece 130 may be a circular pole piece with a circular hole at the center, and is located at the end of the quadrupole.
Specifically, in the ion trapping stage, ions with different mass-to-charge ratios are accelerated to pass through the penetrating electrode pole piece 120 under the action of a weak axial electric field in the quadrupole rod, the relative voltages of the penetrating electrode pole piece 120 and the extracting electrode pole piece 130 are controlled (for example, the voltage of the extracting electrode pole piece 130 is equal to or slightly larger than the voltage of the penetrating electrode pole piece 120), the ions entering the penetrating electrode pole piece 120 are decelerated under the axial electric field, and meanwhile, radial constraint is formed under the radio frequency electric field of the quadrupole rod, so that the cooling collision focusing of the ions between the penetrating electrode pole piece 120 and the extracting electrode pole piece 130 is realized, and the trapping of the ions is realized; in the release phase, the relative voltage of the penetrating electrode pole piece 120 and the extracting electrode pole piece 130 is increased, so that the voltage of the penetrating electrode pole piece 120 is larger than that of the extracting electrode pole piece 130, the trapped ion packet is released in a pulse form, and the trapped ion packet enters the TOF accelerating region through an ion guiding device (such as an electrostatic lens). The periodic trapping-release changes the continuous ion flow into a relatively continuous pulsed ion packet flow, thereby increasing the duty cycle of the time-of-flight mass spectrometer.
In the ion trapping and releasing device of the time-of-flight mass spectrometer, the axial electric field generated by the multipole rod 110 accelerates ions to pass through the penetrating electrode pole piece 120, and when the relative voltage between the penetrating electrode pole piece 120 and the extracting electrode pole piece 130 is not increased, the ions passing through the penetrating electrode pole piece 120 are cooled, collided and focused between the penetrating electrode pole piece 120 and the extracting electrode pole piece 130, so that the trapping of the ions is realized. When the relative voltage between the penetrating electrode tab 120 and the extracting electrode tab 130 increases, the ion packets trapped between the penetrating electrode tab 120 and the extracting electrode tab 130 are released through the extracting electrode tab 130 in a pulse form. Through the trapping-releasing of ions, the continuous ion flow is changed into a relatively continuous pulse ion packet flow, the duty ratio of the flight time mass spectrometer is improved, the utilization rate of ions is improved by a simple structure, and the application range is wide.
In one embodiment, there is also provided a method for controlling ion trapping release of a time-of-flight mass spectrometer, based on the implementation of the ion trapping release device, the method comprising: maintaining the relative voltage between the penetrating electrode pole piece and the extracting electrode pole piece, so that ions passing through the penetrating electrode pole piece are accelerated by the multipolar pole, and cooling, collision and focusing are performed between the penetrating electrode pole piece and the extracting electrode pole piece; the relative voltage between the penetrating electrode pole piece and the extracting electrode pole piece is increased, so that the ion packets between the penetrating electrode pole piece and the extracting electrode pole piece are released through the extracting electrode pole piece in a pulse mode.
In the ion trapping stage, ions with different mass-to-charge ratios are accelerated to pass through the penetrating electrode pole piece under the action of a weak axial electric field in the quadrupole rod, the relative voltages of the penetrating electrode pole piece and the extracting electrode pole piece are controlled (for example, the voltage of the extracting electrode pole piece is equal to or slightly larger than that of the penetrating electrode pole piece), the ions entering the penetrating electrode pole piece are decelerated under the axial electric field, and meanwhile, radial constraint is formed under the radio frequency electric field of the quadrupole rod, so that the cooling collision focusing of the ions between the penetrating electrode pole piece and the extracting electrode pole piece is realized, and the trapping of the ions is realized; in the release stage, the relative voltage of the penetrating electrode pole piece and the extracting electrode pole piece is increased, so that the voltage of the penetrating electrode pole piece is larger than that of the extracting electrode pole piece, and the trapped ion packets are released in a pulse mode and enter the TOF accelerating region through an ion guiding device (such as an electrostatic lens). The periodic trapping-release changes the continuous ion flow into a relatively continuous pulsed ion packet flow, thereby increasing the duty cycle of the time-of-flight mass spectrometer.
According to the ion trapping and releasing control method of the time-of-flight mass spectrometer, continuous ions become relatively continuous pulse ion packet flows through trapping and releasing of ions, the duty ratio of the time-of-flight mass spectrometer is improved, the utilization rate of the ions is improved through a simple structure, and the application range is wide.
In one embodiment, there is also provided a time-of-flight mass spectrometer comprising an ion guide, a time-of-flight mass analyser and an ion trapping release device as described above. The ion guiding device is connected in series with the rear end of the ion trapping and releasing device, and the rear end of the ion guiding device is connected with the time-of-flight mass analyzer. The number of ion guides may be one or more, and the type of ion guide is not exclusive, and in this embodiment, the ion guide includes an electrostatic lens.
According to the time-of-flight mass spectrometer, continuous ion flow is changed into relatively continuous pulse ion packet flow through trapping and releasing of ions, the duty ratio of the time-of-flight mass spectrometer is improved, the utilization rate of ions is improved through a simple structure, and the application range is wide.
In order to better understand the time-of-flight mass spectrometer, the ion trapping release device and the control method thereof, the following detailed explanation is provided with reference to specific examples.
The device and the implementation method for realizing the high duty ratio of the time-of-flight mass spectrometer are simple, convenient and high in universality, and can convert continuous ion flow generated by an ion source into relatively continuous pulse ion packet flow through trapping and releasing of ions without a serial ion trap structure, so that the utilization rate of ions is improved.
Specifically, the application provides an ion trapping-releasing device, which does not need an additional serial ion trap structure, can realize functions similar to an ion trap, and can realize efficient trapping and extraction of ions, thereby improving the duty ratio of a time-of-flight mass spectrometer. The device is shown in fig. 1, and functionally divides the transmission quadrupole into two parts (but the structure of the transmission quadrupole is still the complete transmission quadrupole), wherein the former part is used for ion transmission, and the latter part is used for trapping and extracting ions. The two functional parts are separated by a through electrode. The ion trapping release device consists of a penetrating electrode plate 120, an extraction electrode plate 130 and a transmission quadrupole rod between the penetrating electrode plate and the extraction electrode plate, wherein in fig. 1, the penetrating electrode plate 120 and the extraction electrode plate 130 are adopted. The transmission quadrupoles can be segmented quadrupoles or straight rods without Linac (linear accelerator) but with a certain resistance (achieved by conductive coating) and with the same electrode structure, and the quadrupoles are hyperbolic or cylindrical in shape. When the quadrupole rod is a straight rod, the quadrupole rod has a certain resistance (instead of the Linac, weak axial electric field force is generated), and the uniform increase of the resistance of the straight rod along with the length is realized by uniformly plating a conductive coating, such as an indium tin oxide coating, on the surface of the straight rod. The opposite rods of the quadrupole rods are correspondingly connected together, and a pair of radio-frequency voltages with equal amplitude and 180-degree phase difference are respectively applied to the two groups of rods which are parallel to each other; different direct current voltages are respectively applied to two ends of the four rods.
The penetrating electrode pole piece 120 is a pole piece with a certain thickness, wherein the central hole is a round hole or a grid, and the penetrating electrode pole piece 1 is provided with a pole 20 pieces positioned at the rear half part (such as 1/4 part) of the quadrupole rod and penetrates the quadrupole rod; the extraction electrode pole piece 130 is a pole piece with a round hole in the center and is positioned at the tail end of the quadrupole. Pulse voltages of the same frequency, different amplitudes and phases are applied through the electrode tab 120 and the extraction electrode tab 130, respectively. In addition, the ion trapping release device may be followed by a plurality of ion guides in series, such as: electrostatic lenses (endzel Lens), etc., the ion guide is followed by a vertical lead-in time-of-flight mass spectrometer (TOF).
The application also provides a method for improving the duty cycle of a time-of-flight mass spectrometer as follows. Ion trapping stage: ions with different mass to charge ratios are accelerated to pass through the penetrating electrode pole piece under the action of a weak axial electric field in the quadrupole rod, the relative voltages of the penetrating electrode pole piece and the extracting electrode pole piece are controlled (for example, the extracting electrode pole piece is equal to or slightly larger than the voltage of the penetrating electrode pole piece), the ions entering the penetrating electrode pole piece are decelerated under the axial electric field, and meanwhile, radial constraint is formed under the radio frequency electric field of the quadrupole rod, so that the cooling collision focusing of the ions between the penetrating electrode pole piece and the extracting electrode pole piece is realized, and the trapping of the ions is realized; and in the release stage, the relative voltage of the penetrating electrode pole piece and the extracting electrode pole piece is increased, so that the voltage of the penetrating electrode pole piece is larger than that of the extracting electrode pole piece, the trapped ion packet is released in a pulse form, and the trapped ion packet passes through an ion guiding device (such as an electrostatic lens) and enters a TOF accelerating region. The periodic trapping-release allows a continuous ion stream to become a relatively continuous pulsed ion packet stream, increasing the duty cycle of the time-of-flight mass spectrometer.
Specifically, in the Q-TOF mass spectrometer shown in fig. 4, Q0 is ion transport, Q1 is a mass analyzer, Q2 is a collision cell (the Q2 cavity may be filled with inert gas to generate in-source CID), Q2 is followed by an ion guide (e.g., electrostatic Lens) followed by vertical time of flight mass spectrometry (OrthoTOF).
The four poles in the collision cell are respectively applied with radio frequency voltage and direct current voltage, the radio frequency voltage is applied as shown in figure 5, a pair of radio frequency voltages V with the same amplitude and frequency and 180 DEG phase difference are respectively applied on the two pairs of poles RF . Wherein 1, 2 each represent one of the two pairs of bars. Radial restraining force generated by applying radio frequency voltage to the quadrupole rods; in addition, the same direct current voltage U1 is applied to one end of the four poles DC The same direct current voltage U2 is applied to the other ends of the four poles DC To generate an axial electric field force. The quadrupole DC voltage application is shown in FIG. 5.
The application of the Q2 dc voltage is shown in fig. 6, and the surface of the quadrupole rod is coated with a uniform conductive layer such as indium tin oxide. The conductive layer can enable the quadrupole rod to have a certain resistance value, and the resistance value is linearly increased along with the increase of the rod length, so that the quadrupole rod is equivalent to the series connection of the segmented quadrupole rods with the same resistance value, as indicated in a broken line frame of the figure. Different direct current voltages are respectively applied to the two ends of the rod to generate axial electric field force, and the method can replace the conventional Linac (axial electric field force is generated through the Linac) in the straight rod, so that the structure is simpler.
The continuous ion flow generated by the ion source is transmitted by Q0, the mass of Q1 is filtered, the target parent ion is screened out, and the target parent ion beam is in Q2, and is subjected to cooling collision focusing through a radial radio frequency field, an axial direct current field and added inert gas, so as to generate target child ions. Ion trapping-releasing device is formed by the ion ions at the quadrupole rod part penetrating through the electrode pole piece, the extraction electrode pole piece and between the electrode pole piece and the extraction electrode pole piece. The manner of applying the voltage across the electrode pad and the lead-out electrode pad is shown in fig. 7. In the ion trapping stage, the voltage amplitude applied by the penetrating electrode pole piece is slightly lower than that of the leading electrode pole piece, ions are trapped between the penetrating electrode pole piece and the leading electrode pole piece under the axial force formed by the relative pressure difference of 2 electrode pole pieces and the radial constraint of a quadrupole radio frequency field, and then the trapped ions are continuously increased, so that the next stage, namely the release stage, is entered. The voltage of the penetrating electrode pole piece is regulated to be larger than that of the extracting electrode pole piece, the trapped ions are released in the form of ion packets under the action of a larger electric field force, enter a TOF accelerating area after passing through an ion guiding device, and the trapping-releasing period of the ions is carried out, so that the continuous ion flow generated by an ion source is converted into the relatively continuous ion packets, and the duty ratio of the flight time mass spectrometer is improved.
Terms appearing in the present application are explained as follows: q: quadrupole, quadrupoles; LIT: linear Ion Trap; TOF: time-Of-Flight, time-Of-Flight analyzer; RF: radio Frequency; DC: direct Current, direct Current; AC: alternating Current, alternating current; MS/MS: tandem mass spectrometry; Q-TOF: quadrupole time-of-flight mass spectrometer.
According to the ion trapping-releasing device and the method for improving the duty ratio of the time-of-flight mass spectrometer, an additional serial ion trap structure is not needed, continuous ions entering a TOF accelerating region are changed into a relatively continuous ion packet flow, and the duty ratio of the time-of-flight mass spectrometer is improved; the sensitivity and the dynamic range of the time-of-flight mass spectrometer are improved; the ion trap is not required to be connected in series, the space charge effect is avoided, the structure is simple, and the implementation is easy.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples merely represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the invention. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.
Claims (10)
1. The ion trapping and releasing device of the time-of-flight mass spectrometer is characterized by comprising a multipole rod, a penetrating electrode pole piece and an extraction electrode pole piece, wherein the penetrating electrode pole piece is arranged on the multipole rod in a penetrating way, and the extraction electrode pole piece is arranged at the tail end of the multipole rod; the axial electric field generated by the multipole rod accelerates ions to pass through the penetrating electrode pole piece, when the relative voltage between the penetrating electrode pole piece and the extracting electrode pole piece is not increased, the ions passing through the penetrating electrode pole piece are cooled, collided and focused between the penetrating electrode pole piece and the extracting electrode pole piece, and when the relative voltage between the penetrating electrode pole piece and the extracting electrode pole piece is increased, ion packets between the penetrating electrode pole piece and the extracting electrode pole piece are released through the extracting electrode pole piece in a pulse mode.
2. The ion trapping release device of a time-of-flight mass spectrometer of claim 1, wherein the multipole is a segmented multipole or the multipole is a straight rod with a resistance.
3. The ion trapping release device of a time-of-flight mass spectrometer of claim 1, wherein the multipole is a hyperbolic or cylindrical multipole.
4. The ion trapping release device of a time-of-flight mass spectrometer of claim 1, wherein the multipole rods are quadrupole rods, and the rods of the quadrupole rods are correspondingly connected, and a pair of radio-frequency voltages with equal amplitude and 180 degrees phase difference are respectively applied to two groups of parallel rods; and two ends of the four rods of the quadrupole rod are respectively applied with different direct current voltages.
5. The ion trapping release device of a time-of-flight mass spectrometer of claim 1, wherein the through electrode pole piece is disposed through the multipole near the end.
6. The ion trapping and releasing device of a time-of-flight mass spectrometer of claim 1, wherein the through electrode plate is a circular plate with a circular hole or a grid; the leading-out electrode pole piece is a round pole piece with a round hole as a center hole.
7. The ion trap release device of a time-of-flight mass spectrometer of claim 1, wherein the through electrode plate and the extraction electrode plate apply pulse voltages of the same frequency and different magnitudes and phases, respectively, or wherein one of the through electrode plate and the extraction electrode plate applies a dc voltage.
8. A method for controlling ion trapping release in a time-of-flight mass spectrometer, the method comprising:
maintaining the relative voltage between the penetrating electrode pole piece and the extracting electrode pole piece, so that an axial electric field generated by a multipole rod accelerates ions passing through the penetrating electrode pole piece, and cooling, collision and focusing are performed between the penetrating electrode pole piece and the extracting electrode pole piece;
and increasing the relative voltage between the penetrating electrode pole piece and the extraction electrode pole piece, so that ion packets between the penetrating electrode pole piece and the extraction electrode pole piece are released through the extraction electrode pole piece in a pulse mode.
9. A time-of-flight mass spectrometer comprising an ion guide, a time-of-flight mass analyser and an ion trapping release device according to any one of claims 1 to 7.
10. The time-of-flight mass spectrometer of claim 9, in which the ion guide comprises an electrostatic lens.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111615193.8A CN116403884A (en) | 2021-12-27 | 2021-12-27 | Time-of-flight mass spectrometer and ion trapping release device and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111615193.8A CN116403884A (en) | 2021-12-27 | 2021-12-27 | Time-of-flight mass spectrometer and ion trapping release device and control method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116403884A true CN116403884A (en) | 2023-07-07 |
Family
ID=87006235
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111615193.8A Pending CN116403884A (en) | 2021-12-27 | 2021-12-27 | Time-of-flight mass spectrometer and ion trapping release device and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116403884A (en) |
-
2021
- 2021-12-27 CN CN202111615193.8A patent/CN116403884A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0904145B1 (en) | Ion transfer from multipole ion guides into multipole ion guides and ion traps | |
| US6797950B2 (en) | Two-dimensional quadrupole ion trap operated as a mass spectrometer | |
| EP2506288B1 (en) | Mass spectrometer | |
| US6762404B2 (en) | Mass spectrometer | |
| US9123517B2 (en) | Ion guide with different order multipolar field order distributions across like segments | |
| US9029764B2 (en) | Mass spectrometric ion storage device for different mass ranges | |
| CA2574349A1 (en) | Mass spectrometer | |
| GB2405526A (en) | Electron-ion fragmentation reactions in multipolar radiofrequency fields | |
| GB2484136A (en) | Increasing throughput in a mass spectrometry system | |
| Okumura et al. | A simple multi-turn time of flight mass spectrometer ‘MULTUM II’ | |
| CN216871894U (en) | Time-of-flight mass spectrometer and ion trapping and releasing device thereof | |
| CN116403884A (en) | Time-of-flight mass spectrometer and ion trapping release device and control method thereof | |
| CA2391148C (en) | Mass spectrometer | |
| US9536723B1 (en) | Thin field terminator for linear quadrupole ion guides, and related systems and methods | |
| Berkout et al. | Improving the quality of the ion beam exiting a quadrupole ion guide | |
| Iwamoto et al. | Development of an ion trap/multi-turn time-of-flight mass spectrometer with potential-lift | |
| Yavor | Time-of-Flight Mass Analyzers |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |