A segmented quadrupole system incorporating phase control and applications thereof

Abstract

This invention discloses a segmented quadrupole system incorporating phase control, comprising a segmented quadrupole structure, a direct digital synthesizer, a first phase shifting device, a second phase shifting device, a first radio frequency high voltage output device, and a second radio frequency high voltage output device. Compared to traditional quadrupole systems that increase radio frequency high voltage and frequency, this invention achieves high resolution while reducing electrical noise and power loss in the radio frequency system and improving power supply control accuracy, as it eliminates the need to increase high voltage and frequency. This results in higher instrument reliability while maintaining high resolution. By dividing the long quadrupole into multiple short segments—at least one first quadrupole and at least one second quadrupole—the manufacturing precision requirements for single-segment quadrupole electrodes are effectively reduced, simplifying the manufacturing process, improving overall mechanical stability, and minimizing the impact of thermal deformation and mechanical vibration on mass spectrometer performance.

Description

Technical Field

[0001] This invention relates to the field of mass spectrometry analysis technology, and in particular to a segmented quadrupole system incorporating phase control and its applications. Background Technology

[0002] A mass spectrometer is an analytical instrument widely used in chemical analysis, biological analysis, environmental monitoring, and other fields to determine the molecular mass and composition of compounds. A quadrupole mass spectrometer (QMS) is a type of mass spectrometer that uses four electrodes to generate an alternating electric field to perform mass analysis of ions.

[0003] A quadrupole mass spectrometer consists of four precisely parallel rods carrying a direct current (DC) voltage and a superimposed radio frequency (RF) voltage. Opposite pairs of electrodes are at the same potential, while the potentials of the two pairs of electrodes are opposite. When a group of ions with different mass-to-charge ratios enters the electric field composed of DC and RF along the parallel rod axis, only ions meeting specific conditions can oscillate stably through the quadrupole. In recent years, the resolution and sensitivity of mass spectrometers have been continuously improved to meet the needs of complex sample analysis and detection. Traditional quadrupole mass spectrometers have adopted various methods to improve resolution, including increasing the quadrupole length, increasing the RF voltage and frequency, and employing multi-stage quadrupole systems. However, while these methods achieve high resolution, they also bring a series of problems, such as increased manufacturing difficulty and increased system complexity.

[0004] Existing quadrupole mass spectrometers used to improve resolution include long quadrupole mass spectrometers, quadrupole mass spectrometers with increased radio frequency voltage and frequency, and multi-stage quadrupole systems. Long quadrupole mass spectrometers improve resolution by increasing the length of the quadrupole, thereby increasing the number of ion oscillations in the electric field. This method requires extremely high manufacturing precision and mechanical stability and is susceptible to thermal deformation and mechanical vibration. Quadrupole mass spectrometers with increased radio frequency voltage and frequency improve resolution by increasing the ion oscillation amplitude in the quadrupole, but this places higher demands on the power supply and control system, and is prone to electrical noise and power loss problems. Multi-stage quadrupole systems use multiple quadrupoles connected in series or parallel to provide higher resolution and two-dimensional information, but this system is complex, costly, and requires more complex data processing and analysis methods. Therefore, a new improvement scheme is urgently needed to overcome these problems. Summary of the Invention

[0005] To overcome the problems existing in related technologies, the purpose of this invention is to provide a segmented quadrupole system combined with phase control and its application.

[0006] In a first aspect, this application provides a segmented quadrupole system combined with phase control, including a segmented quadrupole structure, a direct digital synthesizer, a first phase shifting device, a second phase shifting device, a first radio frequency high voltage output device, and a second radio frequency high voltage output device.

[0007] The segmented quadrupole structure includes at least one first quadrupole and at least one second quadrupole corresponding to the first quadrupole, with the first quadrupole and the second quadrupole being alternately arranged in the ion path;

[0008] The direct digital synthesizer is connected to the circuits of the first phase shifting device and the second phase shifting device respectively. The direct digital synthesizer is used to generate radio frequency signals and send them to the first phase shifting device and the second phase shifting device.

[0009] The first phase shifting device is connected to the first quadrupole via a first RF high-voltage output device. The first phase shifting device is used to shift the phase of the RF signal to obtain a first shifted RF signal. The first RF high-voltage output device outputs RF high voltage to the first quadrupole based on the first shifted RF signal. The second phase shifting device is connected to the second quadrupole circuit via a second RF high-voltage output device. The second phase shifting device is used to shift the phase of the RF signal to obtain a second shifted RF signal. The second RF high-voltage output device outputs RF high voltage to the second quadrupole based on the second shifted RF signal.

[0010] In one embodiment, the phase difference between the first offset radio frequency signal and the second offset radio frequency signal is 45-135 degrees.

[0011] In one embodiment, the phase difference between the first offset radio frequency signal and the second offset radio frequency signal is 90 degrees.

[0012] In one embodiment, the first radio frequency high voltage output device includes a first VGA amplitude modulation circuit for adjusting the strength of a first offset radio frequency signal, and the second radio frequency high voltage output device includes a second VGA amplitude modulation circuit for adjusting the strength of a second offset radio frequency signal.

[0013] In one embodiment, the first radio frequency high voltage output device further includes a first inverting amplifier circuit and a first inverting amplifier circuit. The first inverting amplifier circuit outputs radio frequency high voltage to one set of electrodes in the first quadrupole according to the first offset radio frequency signal with altered intensity. The first inverting amplifier circuit outputs radio frequency high voltage to another set of electrodes in the first quadrupole according to the first offset radio frequency signal with altered intensity. The second radio frequency high voltage output further includes a second inverting amplifier circuit and a second inverting amplifier circuit. The second inverting amplifier circuit outputs radio frequency high voltage to one set of electrodes in the second quadrupole according to the second offset radio frequency signal with altered intensity. The second inverting amplifier circuit outputs radio frequency high voltage to another set of electrodes in the second quadrupole according to the second offset radio frequency signal with altered intensity.

[0014] In one embodiment, the phase difference of the radio frequency high voltage between the two sets of electrodes in the first quadrupole is 180 degrees, and the phase difference of the radio frequency high voltage between the two sets of electrodes in the second quadrupole is 180 degrees.

[0015] In one embodiment, the first quadrupole consists of four parallel metal cylinders or hyperboloids; the second quadrupole consists of four parallel metal cylinders or hyperboloids.

[0016] In one embodiment, an ion focusing and collimation device is provided between the first quadrupole and the second quadrupole, which are alternately arranged on the ion path.

[0017] In one embodiment, the radio frequency signal generated by the direct digital synthesizer is a sine wave.

[0018] Secondly, this application also provides an application of the above-mentioned segmented quadrupole system combined with phase control in a mass spectrometer.

[0019] The present invention has the following advantages and beneficial effects:

[0020] The segmented quadrupole structure includes a first quadrupole and a second quadrupole. The first and second quadrupoles are alternately positioned along the ion path, i.e., a cyclical arrangement of first quadrupole, second quadrupole, first quadrupole, second quadrupole. A first phase shifter and a second phase shifter are incorporated to shift the phase of the radio frequency (RF) signal. Then, RF high voltage output devices are used to output RF high voltage to the first and second quadrupoles respectively, creating a phase difference between the RF voltages on the first and second quadrupoles. This causes the ions to exhibit different oscillation behaviors in the first and second quadrupoles. Due to the phase difference in the RF voltages between the first and second quadrupoles, when a non-candidate ion, after a small displacement within the first quadrupole, enters the second quadrupole, its initial phase transitions to a phase space with a certain angle to the initial phase, thus affecting its oscillation behavior. An additional driving force with a phase difference of a certain angle from the first quadrupole amplifies the mass filtration effect, causing the ion oscillation in the second quadrupole to become unstable. This process is then repeated from the second quadrupole to the first quadrupole, eventually resulting in rapid oscillation out of the quadrupole system, thus improving mass selectivity. Compared to the traditional approach of increasing RF high voltage and frequency in quadrupole systems, this method eliminates the need for increased voltage and frequency, achieving high resolution while reducing electrical noise and power loss in the RF system and improving power control accuracy. This results in higher instrument reliability while maintaining high resolution. Furthermore, dividing the long quadrupole into multiple short segments—at least one first quadrupole and at least one second quadrupole—effectively reduces the precision requirements for manufacturing single-segment quadrupole electrodes, simplifies the manufacturing process, improves overall mechanical stability, and reduces the impact of thermal deformation and mechanical vibration on mass spectrometer performance.

[0021] Meanwhile, by dividing the long quadrupole into multiple short segments, different DC voltages can be applied to each segment of the electrode. By applying different DC voltages to each segment of the quadrupole, a potential well structure is formed, allowing ions to repeatedly filter mass in the quadrupole, thereby improving the selectivity and resolution of specific mass ions and enhancing the detection capability of the mass spectrometer. At the same resolution, the rod size can be reduced, making it suitable for use in compact and portable mass spectrometers.

[0022] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0024] Figure 1 This is a schematic diagram of the segmented quadrupole system with phase control in Embodiment 1 of the present invention.

[0025] Figure 2 This is a schematic diagram of the alternating arrangement of the first and second quadrupoles in a segmented quadrupole system with phase control in an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the structure of the first quadrupole, the second quadrupole, and the ion focusing and collimation device of the segmented quadrupole system with phase control in an embodiment of the present invention.

[0027] Figure 4 This is a phase space schematic diagram of a segmented quadrupole system with phase control in an embodiment of the present invention;

[0028] Figure 5 This is a resolution comparison diagram of the segmented quadrupole system with phase control in this embodiment of the invention and the traditional filter rod at m / z = 100.

[0029] Figure 6 This is a schematic diagram illustrating the formation of a potential well by applying different DC voltages to a segmented quadrupole system with phase control in an embodiment of the present invention.

[0030] Figure label:

[0031] 1. First quadrupole; 2. Second quadrupole; 3. Ion focusing and collimation device. Detailed Implementation

[0032] Option embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While optional embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be more thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “described,” and “the” as used in the invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0034] It should be understood that although the terms "first," "second," "third," etc., may be used in this invention to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another.

[0035] Unless otherwise specified, the methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[0036] To facilitate understanding of the embodiments of the present invention, the quadrupole mass spectrometer in related technologies will first be described. In the prior art, quadrupole mass spectrometers used to improve resolution include long quadrupole mass spectrometers, quadrupole mass spectrometers with increased radio frequency voltage and frequency, and multi-stage quadrupole systems. The prior art has the following problems in improving the resolution of quadrupole mass spectrometers: 1. Manufacturing difficulty and cost: Increasing the quadrupole length and increasing the radio frequency voltage and frequency place higher demands on manufacturing precision, mechanical stability, and power control, leading to a significant increase in manufacturing difficulty and cost; 2. System complexity and maintenance: Multi-stage quadrupole systems have complex structures, increasing system complexity and maintenance difficulty, while also placing higher demands on data processing and analysis; 3. Electrical noise and power loss: Increasing the radio frequency voltage and frequency easily causes electrical noise and power loss problems, affecting the performance and reliability of the mass spectrometer; 4. Mechanical stability and thermal deformation: Long quadrupoles are susceptible to thermal deformation and mechanical vibration, leading to electric field instability and affecting resolution and accuracy; Therefore, a new improvement scheme is urgently needed to overcome these problems. Based on this, this application provides a segmented quadrupole system incorporating phase control.

[0037] As attached Figure 1-3 As shown, Embodiment 1 of this application provides a segmented quadrupole system incorporating phase control.

[0038] It includes a segmented quadrupole structure, a direct digital synthesizer, a first phase shifting device, a second phase shifting device, a first radio frequency high voltage output device, and a second radio frequency high voltage output device;

[0039] The segmented quadrupole structure includes at least one first quadrupole 1 and at least one second quadrupole 2 corresponding to the first quadrupole 1, wherein the first quadrupole 1 and the second quadrupole 2 are alternately arranged in the ion path;

[0040] The direct digital synthesizer is connected to the circuits of the first phase shifting device and the second phase shifting device respectively. The direct digital synthesizer is used to generate radio frequency signals and send them to the first phase shifting device and the second phase shifting device.

[0041] The first phase shifting device is connected to the first quadrupole 1 via the first RF high voltage output device. The first phase shifting device is used to shift the phase of the RF signal to obtain a first shifted RF signal. The first RF high voltage output device outputs RF high voltage to the first quadrupole 1 according to the first shifted RF signal. The second phase shifting device is connected to the second quadrupole 2 via the second RF high voltage output device. The second phase shifting device is used to shift the phase of the RF signal to obtain a second shifted RF signal. The second RF high voltage output device outputs RF high voltage to the second quadrupole 2 according to the second shifted RF signal.

[0042] The segmented quadrupole structure includes a first quadrupole 1 and a second quadrupole 2. The first quadrupole 1 and the second quadrupole 2 are alternately arranged in the ion path, i.e., the first quadrupole 1, the second quadrupole 2, the first quadrupole 1, and the second quadrupole 2 are cyclically arranged. A first phase shifting device and a second phase shifting device are included to shift the phase of the radio frequency (RF) signal. Then, the first and second RF high-voltage output devices output RF high voltages to the first quadrupole 1 and the second quadrupole 2 respectively, creating a phase difference between the RF voltages on the first quadrupole 1 and the second quadrupole 2. This causes the ions to exhibit different oscillation behaviors in the first and second quadrupole 1. It can be understood that the first and second RF high-voltage output devices are equivalent to amplifier circuits. Due to the phase difference in the RF voltages between the first quadrupole 1 and the second quadrupole 2, non-candidate ions undergo a small-range displacement within the first quadrupole 1 before entering the second quadrupole 2. When the initial phase shifts to a phase space of a certain angle, it will be subject to an additional driving force with a phase difference of a certain angle from the first quadrupole 1. This additional driving force amplifies the mass filtration effect, causing the oscillation of ions in the second quadrupole 2 to become unstable. Then, the above process is repeated from the second quadrupole 2 to the first quadrupole 1, and finally, the ions are quickly oscillated out of the quadrupole system, thereby improving mass selectivity. Compared with the traditional approach of increasing the radio frequency high voltage and frequency in quadrupole systems, since there is no need to increase the high voltage and frequency, the electrical noise and power loss of the radio frequency system are reduced and the power supply control accuracy is improved while achieving high resolution. This makes the instrument more reliable while obtaining high resolution. Since the long quadrupole is divided into multiple short segments, namely at least one first quadrupole 1 and at least one second quadrupole 2, the requirements for the manufacturing precision of the single quadrupole electrode are effectively reduced, the manufacturing process is simplified, the overall mechanical stability is improved, and the impact of thermal deformation and mechanical vibration on the mass spectrometer performance is reduced.

[0043] Multi-segment quadrupoles are actually easier to manufacture than straight quadrupoles. As the length of a long straight quadrupole increases, the parallelism accuracy gradually deteriorates, weakening the resolving power. At the same time, by dividing a long quadrupole into multiple short segments, different DC voltages can be applied to each segment electrode. By applying different DC voltages to each quadrupole segment, a potential well structure is formed, allowing ions to repeatedly filter mass within the quadrupole, improving the selectivity and resolution of specific mass ions and enhancing the detection capability of the mass spectrometer. Under the same resolution effect, the rod size can be reduced, making it suitable for compact and portable mass spectrometers.

[0044] In one optional embodiment of the present invention, the phase difference between the first offset radio frequency signal and the second offset radio frequency signal is 45-135 degrees;

[0045] In practical applications, the phase difference between the first offset RF signal and the second offset RF signal causes a phase difference in the RF voltages output to the first quadrupole 1 and the second quadrupole 2, resulting in different oscillation behaviors of ions in the first quadrupole 1 and the second quadrupole 2. Since the phase difference between the RF voltages of the first quadrupole 1 and the second quadrupole 2 is 45-135 degrees, when non-candidate ions, after a small-scale displacement within the first quadrupole 1, enter the second quadrupole 2, they experience an additional driving force with a 45-135 degree phase difference from the first quadrupole 1 because their initial phase changes to a phase space with the initial phase. This additional driving force enhances the filtration efficiency. As a result, the oscillation of ions in the second quadrupole 2 becomes unstable, and then the above process is repeated from the second quadrupole 2 to the first quadrupole 1, and finally they are quickly oscillated out of the quadrupole system, thereby improving mass selectivity. It should be noted that the initial phase of the first quadrupole 1 can be a radio frequency voltage with no phase shift, or a radio frequency voltage with a phase of 30 degrees, 45 degrees, 90 degrees, etc., so the second quadrupole 2 can be a radio frequency voltage with a phase of 45 degrees, 90 degrees, 135 degrees, etc., that is, the specific radio frequency voltages of the first quadrupole 1 and the second quadrupole 2 are not specifically limited, only the phase difference between the radio frequency voltages of the first quadrupole 1 and the second quadrupole 2 is limited to 45-135 degrees.

[0046] This embodiment, by setting the phase difference between the first offset RF signal and the second offset RF signal, compared with the traditional quadrupole system's approach of increasing RF high voltage and frequency, achieves high resolution without increasing high voltage and frequency, while reducing electrical noise and power loss of the RF system and improving power control accuracy. This results in higher instrument performance while maintaining high resolution.

[0047] In one optional embodiment of the present invention, the phase difference between the first offset radio frequency signal and the second offset radio frequency signal is 90 degrees;

[0048] In practical applications, the phase difference between the first offset RF signal and the second offset RF signal causes a phase difference in the RF voltages output to the first quadrupole 1 and the second quadrupole 2, resulting in different oscillation behaviors of ions in the first quadrupole 1 and the second quadrupole 2. The RF voltage phase difference between the first quadrupole 1 and the second quadrupole 2 is 90 degrees. This means that when non-candidate ions enter the second quadrupole 2 after a small-range expansion displacement in the first quadrupole 1, the initial phase changes to form a phase space with a 90-degree phase difference with the initial phase. When the phase difference between the two poles is 90 degrees, their common area is the smallest, so the filtration capacity is the strongest. They will be subjected to an additional driving force perpendicular to the first quadrupole 1. This additional driving force amplifies the filtration effect, causing the oscillation of ions in the second quadrupole 2 to become unstable. Then, the above process is repeated from the second quadrupole 2 to the first quadrupole 1, and finally, they are quickly oscillated out of the quadrupole system, thereby improving mass selectivity.

[0049] It should be noted that the initial phase of the first quadrupole 1 can be a radio frequency voltage with no phase shift, or a radio frequency voltage with a phase of 30 degrees, 45 degrees, etc. Therefore, the second quadrupole 2 can be a radio frequency voltage with a phase of 90 degrees, 120 degrees, 135 degrees, etc. That is, the specific radio frequency voltages of the first quadrupole 1 and the second quadrupole 2 are not specifically limited, only that the phase difference between the radio frequency voltages of the first quadrupole 1 and the second quadrupole 2 is 90 degrees.

[0050] Optional, see attached document Figure 4 This makes the first offset RF signal a signal with no phase offset (i.e., 0 degrees phase in the horizontal direction), and the second offset RF signal a signal with a 90-degree phase offset; that is, the output to the first quadrupole 1 is a RF voltage with no phase offset, and the output to the second quadrupole 2 is a RF voltage with a 90-degree phase offset; see attached... Figure 5 The resolution of the segmented quadrupole system with phase control in this embodiment and a traditional mass filter bar were tested at m / z of 100. The resolution comparison chart is attached. Figure 5 As shown, the segmented quadrupole system in this embodiment has a higher resolution.

[0051] In one optional embodiment of the present invention, the first radio frequency high voltage output device includes a first VGA amplitude modulation circuit for adjusting the strength of the first offset radio frequency signal, and the second radio frequency high voltage output device includes a second VGA amplitude modulation circuit for adjusting the strength of the second offset radio frequency signal.

[0052] To ensure the stability of radio frequency (RF) signals, the amplitude in the RF system needs to be corrected. This correction comes from the system's feedback circuit. The VGA amplitude modulation circuit dynamically adjusts the signal gain based on the input signal strength and system requirements. This allows the system to adapt to input signals of varying amplitudes, automatically adjusting the gain to amplify weak signals while preventing overload of strong signals, thus ensuring signal quality and stability and keeping the output signal within a suitable range.

[0053] In one optional embodiment of the present invention, the first radio frequency high voltage output device further includes a first inverting amplifier circuit and a first inverting amplifier circuit. The first inverting amplifier circuit outputs radio frequency high voltage to one set of electrodes in the first quadrupole 1 according to the first offset radio frequency signal with altered intensity. The first inverting amplifier circuit outputs radio frequency high voltage to another set of electrodes in the first quadrupole 1 according to the first offset radio frequency signal with altered intensity. The second radio frequency high voltage output further includes a second inverting amplifier circuit and a second inverting amplifier circuit. The second inverting amplifier circuit outputs radio frequency high voltage to one set of electrodes in the second quadrupole 2 according to the second offset radio frequency signal with altered intensity. The second inverting amplifier circuit outputs radio frequency high voltage to another set of electrodes in the second quadrupole 2 according to the second offset radio frequency signal with altered intensity.

[0054] It is understandable that, based on the characteristics of the input phase of the non-inverting amplifier circuit being the same and the signal of the inverting amplifier circuit being out of phase, the phase difference of the radio frequency high voltage between the two sets of electrodes in the first quadrupole 1 is adjusted by setting the first non-inverting amplifier circuit and the first inverting amplifier circuit, and the phase difference of the radio frequency high voltage between the two sets of electrodes in the second quadrupole 2 is adjusted by setting the second non-inverting amplifier circuit and the second inverting amplifier circuit.

[0055] In one optional embodiment of the present invention, the phase difference of the radio frequency high voltage between the two sets of electrodes in the first quadrupole 1 is 180 degrees, and the phase difference of the radio frequency high voltage between the two sets of electrodes in the second quadrupole 2 is 180 degrees.

[0056] It should be noted that for a set of quadrupoles, whether it is the first or the second quadrupole, whether it belongs to an odd-numbered segment or an even-numbered segment, in order to perform the function of quadrupole filtration, it must have an arrangement of 0°, 180°, 0°, 180°. For example, if the four poles are arranged in a circle according to the numbers 1, 2, 3, 4, then the voltage between poles 1 and 3 is 100V, and the voltage between poles 2 and 4 is -100V.

[0057] In practical applications, the quadrupoles alternate between odd and even segments. The even segments can have a phase difference of 90° compared to the odd segments, but the internal independent quadrupole system is still arranged according to the voltage polarity mentioned above, and the two do not affect each other. Optionally, the first quadrupole is arranged in the above 0, 180°, 0, 180° arrangement, and the second quadrupole is arranged in 90°, 270°, 90°, 270°.

[0058] In one optional embodiment of the present invention, the first quadrupole 1 is composed of four metal cylinders or hyperboloids placed side by side; the second quadrupole 2 is composed of four metal cylinders or hyperboloids placed side by side.

[0059] A quadrupole typically consists of four strictly parallel electrodes spaced equidistant from the central axis, forming two sets of positive and negative electrodes. DC and RF voltages are applied to these electrodes to generate a dynamic electric field, known as a quadrupole field. In practical applications, two opposite electrodes are connected together to form a pair of X electrodes and a pair of Y electrodes. Using hyperboloid cylinders can generate an ideal quadrupole field, further improving instrument performance and resolution. Using metal cylinders may be easier and more stable during assembly, reducing assembly difficulty and complexity, and is also easier and cheaper to manufacture.

[0060] In one optional embodiment of the present invention, an ion focusing and collimating device 3 is further provided between the first quadrupole 1 and the second quadrupole 2, which are alternately arranged on the ion path. It should be noted that the ion focusing and collimating device 3 can be a single lens or a single electrode, which forms an axial voltage gradient with the DC voltage in the quadrupole, thus having the function of ion focusing. In practical applications, the ion focusing and collimating device 3 can be a single electrode, specifically a ring electrode with upper and lower halves separated. The difference in voltage between the upper and lower halves can adjust the vertical position of the focal point in the axial direction.

[0061] In one optional embodiment of the present invention, the radio frequency signal generated by the direct digital synthesizer is a sine wave. Both sine waves and square waves can be transmitted by loading information onto them through modulation techniques (such as amplitude modulation, frequency modulation, and phase modulation).

[0062] In one optional embodiment of the present invention, the direct digital synthesizer generates an adjustable radio frequency signal of 1-5MHz. In practical applications, a quadrupole mass filter with a frequency greater than 5MHz requires an excessively high radio frequency voltage, which is generally impossible to achieve with conventional mass spectrometers.

[0063] In one optional embodiment of the present invention, the segmented quadrupole system of this embodiment can form a potential well by applying different DC voltages; see attached figure. Figure 6Since the quadrupole is segmented, different DC voltages can be applied to each segment of the electrode (first quadrupole 1, second quadrupole 2). By applying different DC voltages to each segment of the quadrupole, a potential well structure is formed, allowing ions to repeatedly filter mass in the quadrupole, thereby improving the selectivity and resolution of specific mass ions. Under the same resolution effect, the size of the quadrupole is reduced, which can be used in compact mass spectrometers and portable mass spectrometers.

[0064] Optionally, different DC voltages are applied to the first quadrupole 1 and the second quadrupole 2. At the same time, the aforementioned phase difference radio frequency voltage is applied to both the first quadrupole 1 and the second quadrupole 2 according to the first offset radio frequency signal and the second offset radio frequency signal with a phase difference. Optionally, the phase difference between the first offset radio frequency signal and the second offset radio frequency signal is 45-135 degrees, or optionally, the phase difference between the first offset radio frequency signal and the second offset radio frequency signal is 90 degrees.

[0065] Optionally, different DC voltages are applied to the first quadrupole 1 and the second quadrupole 2. At the same time, during the mass filtration process, the second quadrupole 2 is controlled to radio frequency (RF) only mode to ensure the stability of the trajectory of specific ions. That is, only the first quadrupole 1 or the second quadrupole 2 is selected to apply the RF voltage with mass filtration function, while the other set does not have the mass filtration function and is only set to RF-only operation to be used as a transmission rod to realize multiple gradual oscillations to complete the mass filtration operation.

[0066] This application provides a second embodiment of the application of any of the segmented quadrupole systems combined with phase control in a mass spectrometer, as described in the first embodiment.

[0067] When a segmented quadrupole system with phase control is applied to a mass spectrometer, due to the radio frequency voltage phase difference between the first quadrupole 1 and the second quadrupole 2, non-candidate ions, after a small-scale expansion of displacement within the first quadrupole 1, enter the second quadrupole 2. Because the initial phase changes to form a phase space with a certain angle from the initial phase, they are subjected to an additional driving force with a phase difference of a certain angle from the first quadrupole 1. This additional driving force amplifies the mass filtration effect, causing the ion oscillation in the second quadrupole 2 to become unstable. This process is then repeated from the second quadrupole 2 back to the first quadrupole 1, ultimately resulting in rapid oscillation. The quadrupole system improves mass selectivity. Compared to the traditional approach of increasing RF voltage and frequency in quadrupole systems, this embodiment of the mass spectrometer achieves high resolution while reducing electrical noise and power loss in the RF system and improving power control accuracy, as no additional voltage and frequency are required. This allows the mass spectrometer to simultaneously obtain high resolution and high stability. Furthermore, by dividing the long quadrupole into multiple short segments, the manufacturing precision requirements for each quadrupole electrode segment are effectively reduced, simplifying the manufacturing process, improving overall mechanical stability, and reducing the impact of thermal deformation and mechanical vibration on the mass spectrometer performance.

[0068] The long quadrupole is divided into multiple short segments, and different DC voltages can be applied to each segment. By applying different DC voltages to each quadrupole segment, a potential well structure is formed, allowing ions to repeatedly filter mass within the quadrupole, improving the selectivity and resolution of specific mass ions and enhancing the detection capability of the mass spectrometer. At the same resolution, the rod size is reduced, making it suitable for compact and portable mass spectrometers. This makes the mass spectrometer of this embodiment significantly advantageous and promising for use in multiple application fields (such as chemical analysis, biological analysis, environmental monitoring, and drug development).

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A segmented quadrupole system incorporating phase control, characterized in that, It includes a segmented quadrupole structure, a direct digital synthesizer, a first phase shifting device, a second phase shifting device, a first radio frequency high voltage output device, and a second radio frequency high voltage output device; The segmented quadrupole structure includes multiple first quadrupoles and multiple second quadrupoles corresponding to the first quadrupoles, with the first quadrupoles and the second quadrupoles alternately arranged in the ion path; The direct digital synthesizer is connected to the circuits of the first phase shifting device and the second phase shifting device respectively. The direct digital synthesizer is used to generate radio frequency signals and send them to the first phase shifting device and the second phase shifting device. The first phase shifting device is connected to the first quadrupole through the first radio frequency high voltage output device. The first phase shifting device is used to shift the phase of the radio frequency signal to obtain the first shifted radio frequency signal. The first radio frequency high voltage output device outputs radio frequency high voltage to the first quadrupole according to the first shifted radio frequency signal. The second phase shifting device is connected to the second quadrupole circuit through the second radio frequency high voltage output device. The second phase shifting device is used to shift the phase of the radio frequency signal to obtain the second shifted radio frequency signal. The second radio frequency high voltage output device outputs radio frequency high voltage to the second quadrupole according to the second shifted radio frequency signal. The phase difference between the first offset radio frequency signal and the second offset radio frequency signal is 45-135 degrees.

2. The segmented quadrupole system with phase control according to claim 1, characterized in that: The phase difference between the first offset radio frequency signal and the second offset radio frequency signal is 90 degrees.

3. The segmented quadrupole system with phase control according to claim 1, characterized in that: The first radio frequency high voltage output device includes a first VGA amplitude modulation circuit for adjusting the strength of the first offset radio frequency signal, and the second radio frequency high voltage output device includes a second VGA amplitude modulation circuit for adjusting the strength of the second offset radio frequency signal.

4. The segmented quadrupole system with phase control according to claim 3, characterized in that: The first radio frequency high voltage output device further includes a first inverting amplifier circuit and a first inverting amplifier circuit. The first inverting amplifier circuit outputs radio frequency high voltage to one set of electrodes in the first quadrupole according to the first offset radio frequency signal with changed intensity. The first inverting amplifier circuit outputs radio frequency high voltage to another set of electrodes in the first quadrupole according to the first offset radio frequency signal with changed intensity. The second radio frequency high voltage output device further includes a second inverting amplifier circuit and a second inverting amplifier circuit. The second inverting amplifier circuit outputs radio frequency high voltage to one set of electrodes in the second quadrupole according to the second offset radio frequency signal with changed intensity. The second inverting amplifier circuit outputs radio frequency high voltage to another set of electrodes in the second quadrupole according to the second offset radio frequency signal with changed intensity.

5. The segmented quadrupole system with phase control according to claim 4, characterized in that: The phase difference of the radio frequency high voltage between the two sets of electrodes in the first quadrupole is 180 degrees, and the phase difference of the radio frequency high voltage between the two sets of electrodes in the second quadrupole is also 180 degrees.

6. The segmented quadrupole system with phase control according to claim 1, characterized in that: The first quadrupole consists of four parallel metal cylinders or hyperboloids; the second quadrupole consists of four parallel metal cylinders or hyperboloids.

7. The segmented quadrupole system with phase control according to claim 1, characterized in that: An ion focusing and collimation device is also provided between the first quadrupole and the second quadrupole, which are alternately arranged on the ion path.

8. The segmented quadrupole system with phase control according to claim 1, characterized in that: The radio frequency signal generated by the direct digital synthesizer is a sine wave.

9. The application of the segmented quadrupole system with phase control as described in any one of claims 1-8 in a mass spectrometer.

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