Methods and systems for fourier transform mass spectrometry

Abstract

In various aspects, the methods and systems disclosed herein are capable of operating a Fourier transform mass spectrometer (FTMS) quadrupole mass analyzer in two modes of operation: transmission mode and trapped mode. In trapped mode, ions are first trapped and cooled within the FTMS mass analyzer, then subjected to an excitation pulse and ejected from the FTMS mass analyzer for detection. However, in transmission mode, the FTMS mass analyzer can provide faster analysis because the excitation pulse is applied to ions of a beam of ions that are continuously transmitted through the FTMS mass analyzer.

Description

[0001] Related Applications

[0002] This application claims priority to U.S. Provisional Application No. 62 / 928,052, filed October 30, 2019, entitled “Methods and Systems of FourierTransform Mass Spectrometry,” which is incorporated herein by reference in its entirety. Technical Field

[0003] This teaching generally relates to mass spectrometry, and more specifically, to methods and systems that combine Fourier transform mass analyzers, which can be used with a variety of different mass spectrometers. Background Technology

[0004] Mass spectrometry (MS) is an analytical technique used to determine the elemental composition of a substance being tested, with both quantitative and qualitative applications. For example, MS can be used to identify unknown compounds, determine the isotopic composition of elements in a molecule, determine the structure of a specific compound by observing fragments of that compound, and quantify the amount of a specific compound in a sample.

[0005] The Fourier transform is a mathematical algorithm used to transform a time-domain signal to the frequency domain and vice versa. In known Fourier transform mass spectrometry (FTMS) techniques, ions are excited and their oscillations are measured in the time domain. The measured time-domain oscillations of the ions are then transformed to the frequency domain using the Fourier transform. Since the oscillation frequency of an ion is inversely proportional to its mass-to-charge ratio (m / z), the frequencies found from the Fourier transform are converted into m / z values, thus generating a mass spectrum.

[0006] Although FTMS can sometimes provide better resolution and mass accuracy than other types of mass spectrometry, there is still a need for improved FTMS systems and methods that offer improved resolution, sensitivity, and / or speed. Summary of the Invention

[0007] Improved methods and systems for performing FTMS are disclosed according to various aspects of this teaching. While known FTMS techniques generally require relatively long steps for ion capture and cooling before ion excitation, various embodiments of the methods and systems disclosed herein are capable of operating the FTMS analyzer in two modes of operation: transport mode and capture mode. In transport mode, for example, the FTMS mass analyzer according to various aspects of this teaching can provide faster analysis compared to capture mode because an excitation pulse is applied to ions in an ion beam that is continuously transported through the FTMS mass analyzer. However, in cases where the mass spectrum calculated from the time-varying signal generated in transport mode provides insufficient intensity and / or resolution, for example, the FTMS mass analyzer can instead be triggered to operate in capture mode, wherein ions from the ion beam are first captured and cooled within the FTMS mass analyzer and then subjected to an excitation pulse, and the excited ions are ejected from the FTMS mass analyzer for detection.

[0008] According to various aspects of this teaching, improved FTMS-based methods and systems are disclosed that can provide improved resolution, sensitivity, and / or speed, depending on the operating mode of, for example, the FTMS mass analyzer being operated. In some aspects, a method for performing mass spectrometry analysis is provided, comprising triggering a quadrupole assembly to operate in one of a transport mode and a capture mode, and transporting multiple ions into the quadrupole assembly. In various aspects, the quadrupole assembly includes a quadrupole group and multiple auxiliary electrodes, the quadrupole group including an input end for receiving ions, the output end for exiting the quadrupole group, wherein an exit lens is deployed adjacent to the output end of the quadrupole group. When in transport mode and during ion transport to the quadrupole assembly, ions are transported through the quadrupole assembly without being trapped therein by applying at least one radio frequency (RF) voltage to each pole of the quadrupole group, thereby generating a field for radially confining the ions (DC pole offset and / or DC resolution voltage may be additionally applied to the poles of the quadrupole group in transport mode), and a voltage pulse is applied across the quadrupole assembly to excite at least a portion of the ions transported through the quadrupoles to radially oscillate at their long-term frequency, wherein the edge field near the output end converts the radial oscillation of at least a portion of the excited ions into axial oscillation as the excited ions leave the quadrupole group. On the other hand, when in trapping mode, ions transported to the quadrupole assembly are trapped therein by i) applying at least one DC voltage and at least one RF voltage to each quadrupole of the quadrupole group, ii) applying one or more DC voltages to a plurality of auxiliary electrodes, and iii) applying a DC voltage and an RF voltage to the exit lens. For example, after ions are trapped within a quadrupole assembly and cooled, a voltage pulse is applied across the quadrupole assembly to excite radial oscillations of at least a portion of the ions trapped within the quadrupole assembly at their long-term frequency. The excited ions are then axially ejected from the quadrupole assembly. In either emission or trapping mode, the method may further include detecting at least a portion of the excited ions exiting the quadrupole assembly to generate a time-varying signal. In some aspects, the analytical spectrum of the ions exiting the quadrupole assembly can be obtained from the time-varying signal. For example, the analytical spectrum can be obtained by performing a Fourier transform on the time-varying signal to generate a frequency domain signal. In various aspects, the analytical spectrum can provide information about the ion beam composition, including the intensity of the ion beam and at least one of the intensities of one or more ions having a specific m / z.

[0009] The quadrupole assembly can be triggered (e.g., manually or automatically, such as under the control of a controller) to operate in either a transport mode or a capture mode for various reasons, including, by way of non-limiting examples, by user selection, based on prior or empirical knowledge of a particular instrument, experiment, and / or sample, and / or based on data obtained from previous analyses. For example, the quadrupole assembly can switch from transport mode to capture mode based on the results of a previous analysis. In some aspects, the quadrupole assembly can switch from transport mode to capture mode if the intensity of at least one ion with one or more specific m / z values ​​in the analytical spectrum is below a threshold. Additionally or alternatively, the quadrupole assembly can switch from transport mode to capture mode to increase the resolution of the analytical spectrum. For example, the quadrupole assembly can switch from transport mode to capture mode if the FWHM of at least one ion with one or more specific m / z values ​​in the analytical spectrum is above a threshold.

[0010] The quadrupole assembly can have various configurations. In some aspects, for example, the quadrupole group may include a first pair of rods and a second pair of rods extending along a central longitudinal axis from the input to the output, wherein the rods of the quadrupole group are spaced apart from the central longitudinal axis such that each pair of rods is deployed on opposite sides of the central longitudinal axis, and a plurality of auxiliary electrodes may include pairs of auxiliary electrodes extending along the central longitudinal axis on opposite sides of the central longitudinal axis, each auxiliary electrode positioned between a single rod in the first pair of rods and a single rod in the second pair of rods. In some related aspects, a voltage pulse may be applied to one of the first pair and the second pair of rods of the quadrupole group. In some aspects, the voltage pulse may alternatively be applied to the auxiliary electrodes. In various aspects, the auxiliary electrode pairs may be linear accelerator (LINAC) electrodes. Additionally or alternatively, the plurality of electrodes may also include a ring electrode surrounding the quadrupole group and deployed between the input and the auxiliary electrode pairs.

[0011] For example, the amplitude and duration of the voltage pulse applied during transmission or capture modes can be selected based on the specific application. For instance, the duration of the voltage pulse can range from approximately 10 nanoseconds (ns) to approximately 1 millisecond, for example, from approximately 1 microsecond to approximately 100 microseconds, or from approximately 5 microseconds to approximately 50 microseconds, or from approximately 10 microseconds to approximately 30 microseconds. Additionally, the voltage pulse can have an amplitude, for example, in the range of approximately 10 volts to approximately 100 volts. For example, the amplitude of the voltage pulse can range from approximately 20 volts to 30 volts. In some embodiments, the voltage pulse is applied as a dipole voltage, i.e., by applying a positive voltage to one pole and a negative voltage to another pole (typically, diagonally opposite poles). In other embodiments, the voltage pulse can be applied to a single pole. In various aspects, the voltage pulse applied during transmission and capture modes can vary in amplitude and / or duration.

[0012] In some aspects, the method may further include applying pressure and gas flow within the quadrupole assembly to cool the trapped ions when in capture mode. In some aspects, the method may further include adjusting one or more of the DC voltage applied to the auxiliary electrode and the DC voltage of the exit lens.

[0013] In some aspects, the method may also include applying a resolving DC voltage to the quadrupole assembly when in transport mode, so as to selectively transport a portion of ions in a selected m / z range through the quadrupoles.

[0014] According to various aspects of this teaching, a mass spectrometer system is provided, comprising an ion source for generating a plurality of ions and a quadrupole assembly including a quadrupole group and a plurality of auxiliary electrodes, the quadrupole group including an input for receiving ions and an output for ions exiting the quadrupole group therethrough. An exit lens is deployed adjacent to the output of the quadrupole group. In various aspects, the system may further include one or more power supplies coupled to the quadrupole assembly and a detector for detecting at least a portion of the ions exiting the quadrupole group to generate a time-varying signal. A controller operatively coupled to various components of the system may also be provided, the controller being configured to trigger the quadrupole assembly to operate in one of a transport mode and a capture mode. In transmission mode, the controller can be configured to: control one or more power sources to apply at least one radio frequency (RF) voltage to each pole of the quadrupole assembly, thereby generating a radially confining field for transmitting ions through the quadrupole assembly without trapping ions therein; and control one or more power sources to apply voltage pulses across the quadrupole assembly, thereby exciting radial oscillations of at least a portion of the ions transmitted through the quadrupole at their long-term frequency, wherein an edge field near the output end converts the radial oscillations of at least a portion of the excited ions into axial oscillations as the excited ions leave the quadrupole assembly. In transmission mode, the controller can be configured to: control one or more power sources to i) apply at least one direct current (DC) voltage and at least one RF voltage to each quadrupole of the quadrupole assembly, ii) apply one or more DC voltages to a plurality of auxiliary electrodes, and iii) apply DC voltage and RF voltage to an exit lens to trap ions within the quadrupole assembly; control one or more power sources to apply voltage pulses across the quadrupole assembly to excite radial oscillations of at least a portion of the ions trapped within the quadrupole assembly at their long-term frequency; and control one or more power sources to axially eject the excited ions from the quadrupole assembly. The controller can also be configured to generate an analytical spectrum of ions leaving the quadrupole group based on a time-varying signal in either a transmission or capture mode. For example, the controller can be configured to perform a Fourier transform of the time-varying signal to generate a frequency domain signal containing information about ions excited by voltage pulses in either the transmission or capture mode.

[0015] In some aspects, the controller can be configured to switch the quadrupole assembly from transport mode to capture mode based on a previously analyzed spectrum. For example, the controller can be configured to switch the quadrupole assembly from transport mode to capture mode if the intensity of at least one ion with one or more specific m / z values ​​in the analyzed spectrum is below a threshold. Alternatively or additionally, the controller can be configured to switch the quadrupole assembly from transport mode to capture mode to increase the resolution of the analyzed spectrum. For example, the controller can be configured to switch the quadrupole assembly from transport mode to capture mode if the FWHM of at least one ion with one or more specific m / z values ​​in the analyzed spectrum is above a threshold.

[0016] In some aspects, the system may also include at least one gas inlet and at least one gas outlet, and the controller is further configured to control the gas inlet and gas outlet to adjust the pressure and airflow within the quadrupole assembly. For example, in capture mode, the controller may be configured to control the gas inlet and gas outlet to maintain the quadrupole assembly at approximately 0.5 × 10⁻⁶. -5 Up to approximately 5×10 -5 The pressure within the range is used to cool the ions inside the quadrupole assembly.

[0017] In some embodiments, a computer program product is disclosed, comprising a non-transitory and tangible computer-readable storage medium containing a program having instructions executable on a processor for performing a method of mass spectrometry. The method includes providing a system comprising one or more distinct software modules, wherein the distinct software modules include an operation mode selection module, a transport mode module, a capture mode module, and an analysis module. The method further includes using the operation mode selection module to select one of a transport mode and a capture mode to operate a quadrupole assembly and an associated exit lens, the quadrupole assembly including a quadrupole group and a plurality of auxiliary electrodes disposed between the rods of the quadrupole group, the quadrupole group including an input for receiving ions and an output for ions exiting the quadrupole group therethrough, wherein the exit lens is disposed adjacent to the output of the quadrupole group. In transport mode, the transport mode module is used to transport ions through the quadrupole assembly without trapping ions by applying at least one radio frequency (RF) voltage to each pole of the quadrupole assembly to generate a field for radial confinement of ions; and to apply a voltage pulse across the quadrupole assembly to excite radial oscillations at their long-term frequency of at least a portion of the ions transported through the quadrupoles, wherein an edge field near the output end converts the radial oscillations of at least a portion of the excited ions into axial oscillations as the excited ions leave the quadrupole assembly. In trapping mode, the trapping mode module is used to trap transported ions in the quadrupole assembly by i) applying at least one direct current (DC) voltage and at least one RF voltage to each quadrupole of the quadrupole assembly, ii) applying one or more DC voltages to a plurality of auxiliary electrodes, and iii) applying a DC voltage and an RF voltage to the exit lens while transporting ions into the quadrupole assembly; applying a voltage pulse across the quadrupole assembly to excite radial oscillations at their long-term frequency of at least a portion of the ions trapped within the quadrupole assembly; and axially ejecting the excited ions from the quadrupole assembly. The analysis module is used to generate the analytical spectrum of ions leaving the quadrupole assembly based on the time-varying signal provided by the detector in either transmission or capture mode.

[0018] A further understanding of the various aspects of this teaching can be obtained by referring to the following detailed description and the accompanying figures, which are briefly described below. Attached Figure Description

[0019] Figure 1 An example of a property spectrometer system based on various aspects of the applicant's teachings is schematically depicted.

[0020] Figure 2A It schematically depicts the suitability of various aspects based on the applicant's education for... Figure 1 An exemplary quadrupole component of the system. Figure 2B -D indicates that the quadrupole assembly is in Figure 2A A schematic cross-section at the identified location.

[0021] Figure 3 This is a series of exemplary timing diagrams depicting how the quadrupole components are controlled during transmission modes according to various embodiments.

[0022] Figure 4 This is a series of exemplary timing diagrams depicting how the quadrupole components are controlled during capture mode according to various embodiments.

[0023] Figure 5A An example of a time-varying signal obtained in transmission mode is shown. Figure 5B and 5C Corresponding to the frequency domain and the mass spectrum derived therefrom according to various embodiments. Figure 5D An example is shown of a mass spectrum generated from the same sample, but with the quadrupole assembly operating in capture mode.

[0024] Figure 6 An exemplary implementation of a controller suitable for use with a quadrupole assembly, based on various aspects of the applicant's teachings, is schematically depicted.

[0025] Figure 7 An exemplary method for operating a mass spectrometer system according to various aspects of the applicant's teachings is described.

[0026] Figure 8 Another exemplary method for operating a mass spectrometer system according to various aspects of the applicant's teachings is described. Detailed Implementation

[0027] It will be appreciated that, for clarity, the following discussion will explain various aspects of embodiments of the applicant's teachings, while certain specific details are omitted where convenient or appropriate. For example, the discussion of similar or analogous features in alternative embodiments may be simplified. Well-known ideas or concepts may also not be discussed in detail for the sake of brevity. Those skilled in the art will recognize that some embodiments of the applicant's teachings may not require certain details among those specifically described in each implementation, which are set forth herein merely to provide a thorough understanding of the embodiments. Similarly, it will be apparent that the described embodiments may be readily altered or varied based on well-known common sense without departing from the scope of this disclosure. The following detailed description of the embodiments should not be construed as limiting the scope of the applicant's teachings in any way. As used herein, the terms "about" and "substantially equal to" refer, for example, to numerical variations that may occur through real-world measurement or disposal processes; through negligence or errors in these processes; through differences in the manufacture, origin, or purity of the composition or reagent; and so on. Generally, as used herein, the terms "about" and "substantially" refer to values ​​or ranges greater than or less than 1 / 10 (e.g., ±10%) of the stated value. For example, a concentration value of approximately 30% or substantially equal to 30% can mean a concentration between 27% and 33%. These terms also refer to variations that are considered equivalent by those skilled in the art, provided that such variations do not cover values ​​known in prior art practice.

[0028] This paper illustrates FTMS-based methods and systems that can provide improved resolution, sensitivity, and / or speed for analyses, depending on, for example, the operating mode of the FTMS mass analyzer. While known FTMS-based techniques generally require trapping and cooling ions before causing coherent excitation, the methods and systems disclosed herein can operate quadrupoles not only in trap mode (where trapped ions are subjected to an excitation pulse) but also alternatively in a faster transport mode (where the ion beam continuously transported through the quadrupole is subjected to an excitation pulse). That is, the quadrupole according to this teaching can be triggered (e.g., manually or automatically, such as under the control of a controller) to operate in either transport or trap mode, depending on, for example, user preference, experience with a particular instrument, experiment, and / or sample, and / or based on data obtained from previous mass spectrometry analyses. For example, if experimental results from a quadrupole operating in transport mode indicate insufficient intensity and / or resolution, the quadrupole can be triggered to operate in trap mode, allowing a larger group of trapped ions to be subjected concurrently to a relatively longer transient electric field caused by the excitation pulse. In this way, the quadrupole can be configured to switch between an operating mode that provides very fast data acquisition (e.g., about 0.5-1 kHz) and an operating mode that provides increased sensitivity and / or spectral resolution but a relatively slow data acquisition rate (e.g., about 10 Hz).

[0029] Although the systems, apparatus, and methods described herein can be used in conjunction with many different mass spectrometry systems, the example mass spectrometry system 100 used according to this teaching is... Figure 1 The diagram is schematically illustrated. It should be understood that mass spectrometry system 100 represents only one possible configuration and other mass spectrometry systems modified according to this teaching can also be used. For example... Figure 1As schematically shown in the exemplary embodiments depicted herein, a mass spectrometry system 100 generally includes an ion source 102 for generating ions within a medium-pressure ionization chamber 110, a collision-focusing ion guide Q0 housed within a vacuum ion guiding chamber 112, a downstream vacuum chamber 114 containing one or more mass analyzers (one of which is a quadrupole assembly 120 according to this teaching), and a controller 109 for controlling the operation of various components of the system 100, as discussed further below. While the exemplary downstream vacuum chamber 114 is depicted as housing three quadrupoles (i.e., an elongated rod mass filter 115 (also referred to as Q1), a collision cell 116 (also referred to as Q2), and a quadrupole assembly 120), it will be appreciated that a system according to this teaching may include more or fewer mass analyzers or ion processing elements. Although the mass filter 115 and the collision cell 116 are generally referred to herein as quadrupoles (i.e., they have four rods), the elongated rod assemblies 115, 116 may be other suitable multi-pole configurations. For example, the collision cell 116 may include hexa-pole, octupole, etc. It will also be recognized that mass spectrometry systems may include any of the triple quadrupole, linear ion trap, quadrupole time-of-flight, orbital trap, or other Fourier transform mass spectrometry systems, all of which are non-limiting examples.

[0030] Reference Figure 1 Each of the various stages of the exemplary mass spectrometer system 100 is discussed in more detail. Initially, the ion source 102 is generally configured to generate ions from the sample to be analyzed and may include any known or later developed ion source modified in accordance with this teaching. Non-limiting examples of ion sources suitable for use in this teaching include atmospheric pressure chemical ionization (APCI) sources, electrospray ionization (ESI) sources, continuous ion sources, pulsed ion sources, inductively coupled plasma (ICP) ion sources, matrix-assisted laser desorption / ionization (MALDI) ion sources, glow discharge ion sources, electron collision ion sources, chemical ionization sources, or photoionization ion sources, etc.

[0031] Ions generated by ion source 102 are initially drawn in through orifices in sampling orifice plate 104. As shown, the ions pass through a medium-pressure ionization chamber 110 located between orifice plate 104 and skimmer 106 (e.g., evacuated to a pressure approximately in the range of about 1 Torr to about 4 Torr by a mechanical pump (not shown)) and are then transported through inlet orifice 112a into impact-focused ion director Q0, thereby generating a narrow and highly focused ion beam. In various embodiments, the ions may pass through one or more additional vacuum chambers and / or quadrupoles (e.g., Quadrupole or other RF ion directors utilize a combination of gas dynamics and radio frequency fields to enable efficient ion transport using a large-diameter sampling aperture. A collision-focused ion director Q0 generally includes a quadrupole assembly comprising four rods surrounding and parallel to the longitudinal axis along which it transports ions. As known in the art, applying various RF and / or DC potentials to components of the ion director Q0 causes collision cooling of the ions (e.g., combined with the pressure of the vacuum ion guiding chamber 112), and the ion beam is then transmitted through an exit aperture (e.g., an orifice plate) in IQ1 to a downstream mass analyzer for further processing. The vacuum ion guiding chamber 112, housed within the ion director Q0, can be associated with a pump (not shown, e.g., a turbomolecular pump) operable to evacuate the chamber to a pressure suitable for providing such collision cooling. For example, the vacuum ion guiding chamber 112 can be evacuated to a pressure approximately in the range of about 1 mTorr to about 30 mTorr, but other pressures can be used for this or other purposes. For example, in some aspects, the vacuum ion guiding chamber 112 can be maintained such that the pressure × quadrupole length is greater than 2.25 × 10⁻⁶. -2 The pressure is Torr-cm. A lens IQ1, deployed between the vacuum ion guiding chamber 112 and the downstream vacuum chamber 114 in Q0, isolates the two chambers and includes an aperture 112b through which the ion beam is transmitted from Q0 to the downstream vacuum chamber 114 for further processing.

[0032] Downstream vacuum chamber 114 can be evacuated to a pressure lower than that of vacuum ion guiding chamber 112, for example, from approximately 1 × 10⁻⁶. -6 Lift to approximately 1.5 × 10 -3 Within the range of Torr. For example, due to pumping provided by a turbomolecular pump and / or by controlling the gas inlet and outlet (not shown) through the use of an external gas supply, the downstream vacuum chamber 114 can be maintained at approximately 8 × 10⁻⁶. -5 To approximately 1×10 -4 To (e.g., 5 × 10) -5 To about 5×10 -4The pressure is within the range of (T)T, but other pressures can be used for this or other purposes. Ions enter the quadrupole mass filter 115 via the coarse rod ST1. As those skilled in the art will appreciate, the quadrupole mass filter 115 can operate as a conventional transmission RF / DC quadrupole mass filter, which can be operated to select ions of interest or a range of ions of interest. For example, the quadrupole mass filter 115 can be provided with an RF / DC voltage suitable for operation in mass-resolved mode. It should be appreciated that, taking into account the physical and electrical characteristics of the rods of the mass filter 115, the parameters for the applied RF and DC voltages can be selected such that the mass filter 115 establishes a transmission window with a selected m / z ratio, allowing these ions to pass through the mass filter 115 largely undisturbed. However, ions with m / z ratios falling outside the window cannot obtain a stable trajectory within the quadrupole and may be prevented from passing through the mass filter 115. It should be appreciated that this mode of operation is only one possible mode of operation for the mass filter 115. For example, in some aspects, the mass filter 115 can operate in RF-only transmission mode, where no resolving DC voltage is used, allowing substantially all ions of the ion beam to pass through the mass filter 115 largely undisturbed (e.g., ions stable at Mathieu parameter q = 0.908 and below). Alternatively, the lens IQ2 between the mass filter 115 and the collision cell 116 can be maintained at an offset potential much higher than that of the rod of the mass filter 115, allowing the quadrupole mass filter 115 to operate as an ion trap. Moreover, as is known in the art, the potential applied to the entering lens IQ2 can be selectively reduced (e.g., mass-selectively scanned), allowing ions trapped in the mass filter 115 to be accelerated into the collision cell 116, which can also, for example, operate as an ion trap.

[0033] Ions transported by mass filter 115 can pass through a post-filter coarse bar ST2 (e.g., an assembly of RF-only coarse bars that enhances the transport of ions leaving the quadrupole) and lens IQ2 into quadrupole 116, which, as shown, can be deployed in a pressurized chamber and can be configured to operate as a collision cell in a pressure range from approximately 1 mTorr to approximately 30 mTorr, but other pressures may be used for this or other purposes. A suitable collision gas (e.g., nitrogen, argon, helium, etc.) can be supplied through a gas inlet (not shown) to thermalize and / or break up ions in the ion beam. In some embodiments, applying a suitable RF / DC voltage to quadrupole 116 and inlet and outlet lenses IQ2 and IQ3 can provide optional mass filtration and / or trapping. Similarly, quadrupole 116 can also operate in an RF-only transport mode, allowing substantially all ions of the ion beam to pass through collision chamber 116 largely undisturbed.

[0034] Ions transported by collision cell 116 enter the adjacent quadrupole assembly 120, such as Figure 1As shown, its upstream is defined by IQ3 and the thick rod ST3, and its downstream is defined by the exit lens 117. The quadrupole assembly 120 can operate at a reduced operating pressure relative to the impact pool 116, for example, from approximately 1 × 10⁻⁶. -6 Lift to approximately 1.5 × 10 -3 To (for example, approximately 5 x 10) -5 (For example, pressure can be used for this or for other purposes).

[0035] For reference below Figures 2A-2D As discussed in detail, the quadrupole assembly 120 includes a quadrupole group and multiple auxiliary electrodes. Generally, the quadrupole assembly 120 is configured to operate in two modes by applying various electrical signals to its components. For example, applying an RF voltage (with or without a distinguishing DC voltage) to the quadrupoles can provide radial confinement when ions pass through the quadrupole group in transport mode (e.g., without trapping), while applying both RF and DC voltages to the individual components of the quadrupole assembly 120 can allow ions to be trapped and cooled therein (instead of being transported directly through it). Figure 1 As shown in the collision cell 116, the quadrupole assembly 120 may also be housed in a pressurized compartment having gas inlets and outlets (not shown) that allow for independent control of pressure and / or gas flow rate (e.g., relative to the downstream vacuum chamber 114) to enable cooling of ions trapped within the quadrupole assembly 120.

[0036] Furthermore, when in transport mode, and when the ion beam is received from the collision cell 116 and continuously transported through the quadrupole assembly 120 (e.g., without ion trapping), applying an excitation pulse across the quadrupole assembly 120 can excite at least a portion (and preferably all) of the radial oscillations of the ions, such that the edge field near the output of the quadrupole assembly 120 can convert the radial oscillations into axial oscillations for detection by the detector 118 as the excited ions exit the quadrupole assembly through the exit lens 117, thereby generating a time-varying ion signal. On the other hand, in trapping mode, after the ions transported to the quadrupole assembly 120 are trapped and cooled, applying an excitation pulse across the quadrupole assembly 120 can excite radial oscillations in the trapped ions, which are then axially ejected from the quadrupole assembly 120 through the exit lens 117. The detection of ions ejected from the quadrupole assembly 120 in trapping mode by the detector 118 can also generate a time-varying ion signal. As discussed in further detail below, the system controller 109, which communicates with detector 118, can operate (e.g., via one or more processors) on time-varying ion signals generated in transmission or capture modes to derive the mass spectrum of the detected ions. In some aspects, the controller can trigger quadrupole assembly 120 to operate in a different mode (e.g., under the control of system controller 109) after interrogating the ion beam to generate another analytical spectrum.

[0037] As shown in the figure Figure 1The example mass spectrometry system 100 also includes one or more power supplies 107, 108, which can be controlled by a controller 109 to apply potentials with RF and / or DC components to the quadrupole, lenses, and auxiliary electrodes to configure the elements of the mass spectrometry system 100 for various operating modes depending on the specific MS application. It will be appreciated that the controller 109 can also be linked to various elements to provide joint control over the executed time sequence. Thus, the controller 109 can be configured to provide control signals to one or more power supplies(s) supplied to the components in a coordinated manner to control the mass spectrometry system 100, as discussed elsewhere herein. For example, the controller 109 may include a processor for processing information, a data storage device for storing mass spectrometry data, and instructions to be executed, all of which are non-limiting examples. It will be appreciated that although the controller 109 is depicted as a single component, one or more controllers (whether local or remote) can be configured to operate the mass spectrometer system 100 according to any of the methods described herein. Furthermore, in some embodiments, controller 109 may be operatively associated with an output device (such as a display (e.g., a cathode ray tube (CRT) or liquid crystal display (LCD) for displaying information to a computer user) and / or an input device including alphanumeric keys and other keys and / or cursor control for transmitting information and command selections (e.g., selection of operating modes) to the processor. Consistent with certain embodiments of this teaching, controller 109 may, for example, execute one or more sequences of one or more instructions contained in a data storage device, or read into memory from another computer-readable medium such as a storage device (e.g., a disk). One or more controllers may take the form of hardware or software; for example, controller 109 may take the form of a suitably programmed computer containing a computer program that is executed to cause mass spectrometer system 100 to operate as otherwise described herein, but embodiments of this teaching are not limited to any particular combination of hardware circuitry and software. For example, various software modules associated with controller 109 may execute programmable instructions to perform the exemplary methods described herein, as referenced below. Figure 7 The subject of discussion.

[0038] Now for reference Figure 2A -D, depicting a quadrupole assembly 220 comprising a quadrupole group 222 and multiple auxiliary electrodes (LINAC electrodes 230a, b and ring electrodes 230c) according to various aspects of this teaching. As shown, the quadrupole group 222 consists of four parallel rod electrodes 222a-d, which are arranged around and parallel to a central longitudinal axis (Z) extending from the input end (e.g., toward the ion source 102) to the output end (e.g., toward the detector 118). Figure 2BAs best shown in the cross-section of -D, the rods 222a-d have a cylindrical shape (i.e., a circular cross-section), with the innermost surface of each rod 222a-d equidistant from the central axis (Z), and each rod 222a-d being identical to one another in size and shape. The rods 222a-d are generally grouped into two pairs of rods (e.g., the first pair includes rods 222a and c deployed on the X-axis, and the second pair includes rods 222b and d deployed on the Y-axis), wherein the rods in each pair are deployed on opposite sides of the central axis (Z) and can be subjected to identical electrical signals. The minimum distance between each of the rods 222a-d and the central axis (Z) is defined by a distance r0, such that the minimum distance between the innermost surface of each of the rods 222a-d and the innermost surface of the other rod in its pair from the central longitudinal axis (Z) is 2r0. It will be appreciated that although rods 222a-d are depicted as cylindrical, the cross-sectional shape, dimensions, and / or relative spacing of rods 222a-d can vary as is known in the art. For example, in some aspects, rods 222a-d can be determined according to the equation It exhibits a radially inner hyperbolic surface, where r0 (field radius) is the radius of the inscribed circle between the electrodes in order to generate a quadrupole field.

[0039] The poles 222a-d are conductive (i.e., they can be made of any conductive material such as metal or alloy) and can be coupled to one or more power sources, such that one or more electrical signals can be applied individually or in combination to each pole 222a-d. As is known in the art, applying a radio frequency (RF) voltage to the poles 222a-d of the quadrupole assembly 222 can effectively generate a quadrupole field that radially confines ions as they pass through the quadrupole assembly 222, with or without a selectable amount of resolvable DC voltage applied concurrently to one or more of the quadrupoles 222a-d. Generally, as is known in the art, in order to generate a radially confined quadrupole field for at least a portion of the ions transported through the quadrupole assembly 222, the power system can apply a potential of rod offset voltage (RO) + [U – VcosΩt] to the first pair of rods 222a, c, where U is the magnitude of a resolved DC electrical signal provided by DC voltage source 208a, V is the zero-to-peak amplitude of an RF signal provided by RF voltage source 207a, Ω is the angular frequency of the RF signal, and t is time. The power system can also apply an electrical signal of RO - [U - VcosΩt] to the second pair of rods 222b, d, such that the polarities of the resolved DC signals of the electrical signals applied to the first pair of rods 222a, c and the second pair of rods 222b, d are different (i.e., the sign of U), while the RF portions of the electrical signals will be 180° out of phase with each other. Those skilled in the art will recognize that the quadrupole assembly 222 can therefore be configured as a quadrupole mass filter that selectively transports ions in a selected m / z range by a suitable selection of the DC / RF ratio. Alternatively, it will be recognized that the quadrupole assembly 222 can operate in an RF-only transport mode, wherein no DC resolution voltage (U) is applied, such that ions stable at the Mathieu parameter q = 0.908 or below entering the quadrupole assembly 222 will be transported through the quadrupole assembly 222 without impacting the rods 222a-d.

[0040] In addition to being electrically coupled to RF voltage source 207a and / or DC voltage source 208a to operate the quadrupoles in RF-only or filter-only modes as discussed above, one or more of the quadrupoles 222a-d of the quadrupole assembly 220 may be coupled to pulsating voltage source 208c for applying short excitation pulses across the quadrupole assembly 220 in either transmit or capture modes, as discussed separately herein. In various embodiments, the excitation pulse may include a very narrow dipole excitation pulse with a sharp leading edge. For example, pulsating voltage source 208c may apply a dipole voltage pulse to the X-bar (i.e., the first pair of bars 222a, c), but in other embodiments, a dipole pulsating voltage may instead be applied to the Y-bar (i.e., the second pair of bars 222b, d). In this case, the dipole pulse means that a positive voltage is applied to one bar in the bar pair (e.g., bar 222a), while a negative voltage of the same amplitude is applied to the other bar in the bar pair (e.g., bar 222c).

[0041] Generally, various pulse amplitudes and durations can be used. In many embodiments, the longer the pulse width, the smaller the pulse amplitude used to generate radial oscillations according to this teaching. In various embodiments, the amplitude of the applied voltage pulse can, for example, be in the range of about 5 volts to about 100 volts, or in the range of about 20 volts to about 30 volts, but other amplitudes may also be used. Additionally, the duration of the voltage pulse (pulse width) can, for example, be in the range of about 10 nanoseconds (ns) to about 1 millisecond, for example, in the range of about 1 microsecond to about 100 microseconds, or in the range of about 1 microsecond to about 5 microseconds, but other pulse durations may also be used.

[0042] The waveform associated with the voltage pulse can have a variety of different shapes, with the aim of providing a fast, broadband excitation signal in accordance with this teaching. For example, an exemplary voltage pulse may include a square time shape. In some embodiments, the rise time of the voltage pulse (i.e., the duration it takes for the voltage pulse to increase from zero voltage to reach its maximum value) may, for example, be in the range of about 1 to 100 nanoseconds. In other embodiments, the voltage pulse may have different time shapes.

[0043] For details, please refer to the following: Figure 2A The input lens IQ3 is shown positioned near the input of the quadrupole assembly 222 (for clarity). Figure 2A The middle part is omitted Figure 1The input lens IQ3 (ST3) and the exit lens 217 are positioned near the output of the quadrupole assembly 222. DC voltage sources 208b and c, operating under the control of controller 209, can apply DC voltages (e.g., attractive in the range of approximately 1 to 50 V relative to the DC offset applied to quadrupoles 222a-d) to the input lens IQ3 and the exit lens 217, respectively. In some embodiments, the DC voltage applied to the input lens IQ3 causes the generation of an electric field that promotes ion entry into the quadrupole assembly 222. Additionally, applying a DC voltage to the exit lens 217 can promote ion exit from the quadrupole assembly 222. Similarly, the input lens IQ3 and the exit lens 217 can be coupled to an RF power source, allowing RF signals to be applied to them. For example, as... Figure 2A As shown, the RF voltage source 207b, operating under the control of controller 209, can apply an RF signal to the exit lens 217. It will be appreciated that lenses 217 and 217 can be implemented in a variety of different ways. For example, in some embodiments, the lens can be in the form of a plate with an opening through which ions pass. In other embodiments, at least one (or two) lens can be implemented as a grid. As mentioned above, Brubaker lenses ST2 and ST3 (RF only) can also be present at the input and output terminals of the quadrupole assembly 222.

[0044] As described above, the quadrupole assembly according to various aspects of this teaching additionally includes multiple auxiliary electrodes, which may include a ring electrode 230c and multiple linear accelerator (LINAC) electrodes 230a, b, such as Figure 2A The exemplary quadrupole assembly 220 of -D is shown. Generally, the auxiliary electrodes are conductive (i.e., they can be made of any conductive material such as metal or alloy) and can be coupled to one or more power sources, allowing one or more electrical signals to be applied individually or in combination to each auxiliary electrode. While Figure 2A The quadrupole assembly 220 depicted in -D includes three auxiliary electrodes, but more or fewer auxiliary electrodes may be used in accordance with this teaching. For example, in various alternative embodiments, it is not necessary to provide a ring electrode and the multiple auxiliary electrodes may consist of only a pair of LINAC electrodes 230a, b. Alternatively, for example, in some embodiments, four LINAC electrodes may be provided, each inserted between the bars of the quadrupole assembly.

[0045] like Figure 2CAs shown in the cross-section, the ring electrode 230c surrounds the central portion of the quadrupole assembly 222 and can be coupled to a DC voltage source 208e operating under the control of a controller 109, which can apply a DC voltage to the ring electrode 230c to aid in ion trapping and / or ejection, as discussed separately herein. It will be appreciated that although the ring electrode 230c is depicted as a cylindrical tube, the cross-sectional shape, dimensions, and / or relative spacing of the ring electrode 230c can vary according to various aspects of this teaching.

[0046] Now for specific reference Figure 2A and Figure 2D In the cross-section, LINAC electrodes 230a and b extend along the longitudinal axis (Z) between the ring electrode 230c and the output terminal of the quadrupole assembly 222. For example... Figure 2D As best shown, LINAC electrodes 230a, b include a pair of T-shaped electrodes deployed on opposite sides of the longitudinal axis, such that each of LINAC electrodes 230a, b is inserted between a single rod of the first pair of rods 222a, c and a single rod of the second pair of rods 222b, d. Figure 2A As shown, the radial portions of the LINAC electrodes 230a and b gradually taper along the length of the quadrupole assembly 222. That is, the distance between the innermost surface of the LINAC electrode adjacent to the ring electrode 230c and the longitudinal axis is less than the distance between the innermost surface of the LINAC electrode adjacent to the output end of the quadrupole assembly 222. As discussed below, when a DC voltage is applied to the LINAC electrodes 230a and b (e.g., via a DC voltage source 208f), this taper establishes an electric field component along the axis (Z) that contributes to the axial ejection of radially oscillating ions while the quadrupole assembly operates in trap mode. It will be appreciated that although the LINAC electrodes 230a and b are depicted as having a T-shaped cross-section, the cross-sectional shape, size, and / or relative spacing of the LINAC electrodes 230a and b can be varied, as is known in the art. For example, in some aspects, LINAC electrodes 230a, b may include four rods having a circular cross-sectional area, which are tilted (e.g., not parallel to the central axis) such that the innermost surface of LINAC electrodes 230a, b is farther from the axis (Z) as they are closer to the output of quadrupole group 222.

[0047] Operation of the quadrupole component in transmission mode

[0048] As described above, the quadrupole component 220 can be triggered (e.g., manually or automatically, such as under the control of the controller 209) to operate in transfer mode. In some respects, one of the transfer and capture modes may represent the default operating mode and can be switched, for example, based on user selection, prior or empirical knowledge of a particular instrument, experiment, and / or sample, and / or based on data obtained from previous analyses.

[0049] In transport mode (e.g., when an ion beam is continuously transported into and through quadrupole assembly 220), applying one or more RF voltages to the individual bars 222a-d can result in the generation of a radially confined quadrupole field within quadrupole assembly 220. In addition to the RF signal applied to the quadrupole assembly 222, in various aspects, the quadrupoles 222a-d can be additionally coupled to a DC voltage source 208a for applying a bar offset (RO) voltage and / or a resolution DC voltage (e.g., ±U as discussed above) to operate the bar assembly 222 such that only ions with a selected m / z ratio can be continuously transported from the input to the output. In various aspects, the controller 209 can additionally cause voltage sources 208e, f to apply DC voltages to ring electrode 230c and / or LINAC electrodes 230a, b, respectively, which is equivalent to RO applied to the quadrupoles 222a-d during transport mode. While the electric field within the quadrupole assembly 220 is generally a radially confined quadrupole field, it is also characterized by edge fields near the input and output terminals of the quadrupole group 222. For example, a decrease in the quadrupole potential in the region near the output of the quadrupole group 222 can lead to the generation of an edge field, which can exhibit a component along the longitudinal direction of the quadrupole (along the z-direction). In some embodiments, the amplitude of this electric field can increase with increasing radial distance from the longitudinal axis (Z) of the quadrupole group 222. As discussed in more detail below, such edge fields can be used to couple the radial and axial motion of ions within the quadrupole assembly 220 in accordance with this teaching.

[0050] For illustrative purposes and not limited to any particular theory, applying one or more RF voltages to quadrupoles 222a-d can result in the generation of a two-dimensional quadrupole potential as defined by the following relationship:

[0051]

[0052] in Let x and y represent the potential measured relative to the ground, and let x and y represent the Cartesian coordinates of the plane defined perpendicular to the direction of ion propagation (i.e., perpendicular to the z-direction). The electromagnetic field generated by the above potential can be calculated by obtaining the spatial gradient of the potential.

[0053] Again, without being limited to any particular theory, for the first approximation, the potentials associated with the edge fields near the input and output terminals of the quadrupole group 222 can be characterized by a function f(z) through the two-dimensional quadrupole potentials near the input and output terminals, as follows:

[0054]

[0055] in Represents the potential associated with the edge field and This represents the two-dimensional quadrupole potential discussed above. Due to the decrease in the two-dimensional quadrupole field, the axial component of the edge electric field (E) z,quad It can be described as follows:

[0056]

[0057] As discussed in more detail below, such a marginal field allows the radial oscillation of ions excited by applying voltage pulses to one or more of the quadrupoles 222a-d to be converted into axial oscillations, so that the axially oscillating ions can be detected by detector 218.

[0058] Continue to refer to Figure 2A The quadrupole assembly 220 may be coupled to a pulsating voltage source 208c for applying voltage pulses to at least one of the quadrupoles 222a-d. For example, the pulsating voltage source 208c may apply dipole voltage pulses to the first pair of poles 222a,c, but in other embodiments, dipole pulse voltages may instead be applied to the second pair of poles 222b,d. While excitation pulses are generally described herein as being applied to one or more of the quadrupoles 222a-d, in some alternative embodiments according to various aspects of this teaching, the pulsating voltage source 208d may instead be coupled to one or more of the LINAC electrodes 230a,b, such that excitation pulses may be applied to the LINAC electrodes 230a,b (e.g., a positive voltage at LINAC electrode 230a and a negative voltage at LINAC electrode 230b). In any case, ions passing through the quadrupoles are typically exposed to only a single excitation pulse. Once a “clump” of excited ions has passed through the quadrupole assembly 222 as discussed below, additional excitation pulses may be triggered. This can happen every 1 to 2 ms, resulting in approximately 500 to 1000 data acquisition cycles per second.

[0059] Without being bound by any particular theory, a voltage pulse (e.g., across two opposing quadrupoles 222a, c) applied in a transmission mode generates a transient electric field within the quadrupole assembly 220. Ions within the quadrupole assembly 222 exposed to this transient electric field can radially excite at least some of these ions at their long-term frequencies. This excitation can encompass ions with different mass-to-charge (m / z) ratios. In other words, using an excitation voltage pulse with a short duration can provide broadband radial excitation of ions within the quadrupole assembly 222. When the radially excited ions reach the end of the quadrupole assembly 222 near the output, they will interact with the exit edge field, such that the radial oscillations of at least a portion of the excited ions can be converted into axial oscillations, again without being bound by any particular theory.

[0060] Axially oscillating ions can thus exit the quadrupole assembly 222 via exit lens 217 to reach detector 218, such that detector 218 generates a time-varying ion signal in response to the detection of axially oscillating ions. It will be appreciated that various detectors known in the art and modified according to this teaching can be employed. Some examples of suitable detectors include, but are not limited to, conventional electron multipliers, which can be switching electrodes or high-energy dinterpoles (HEDs), such as the Photonis Channeltron Model 4822C and the ETP electron multiplier Model AF610. The analysis of the time-varying signal generated by detector 218 in response to the detection of axially oscillating ions will be described in more detail below regarding the analysis module.

[0061] Figure 3 This is an exemplary series 300 of timing diagrams schematically depicting how a quadrupole assembly 220 is controlled in transmission mode according to various embodiments. Timing diagrams 310 and 330 show the control of a quadrupole assembly 220 during the application of five dipole excitation pulses from an upstream analyzer (e.g., ...). Figure 1 The collision cell 116 continuously receives ions. When ions are received within the quadrupole assembly 220, an RF voltage signal is applied to the quadrupole 222 to generate a radially confined quadrupole field, such that stable ions at Mathieu parameter q = 0.908 or less (i.e., when U = 0) will be transmitted through the quadrupole assembly 222 without impacting the bars 222a-d. In some additional aspects, it will be appreciated that, by appropriately selecting the ratio of the resolving DC voltage applied to the bar assembly 222 to the amplitude of the RF signal applied to the bar assembly 222, the quadrupole assembly 220 can be configured as a mass filter that selectively transmits ions in a selected m / z range, such that only a portion of the ions received at the input of the quadrupole assembly 220 will be transmitted without impacting the bars 222a-d. In various respects, the exit lens 217 can be maintained at a slightly attractive DC potential relative to the RO voltage applied to the bar assembly 222 via a voltage source 208c operating under the control of controller 209. As a non-limiting example, for positive ions transmitted via quadrupole assembly 220, where rod assembly 222 is maintained at a +20V DC offset, the DC potential of exit lens 217 may be less positive for the ions (e.g., more attractive, around +10V DC).

[0062] For example, without adjusting the exit lens voltage as in timing diagram 340, each excitation pulse in timing diagram 330 can provide broadband radial excitation of at least some of the ions transmitted through quadrupole assembly 220 at their long-term frequencies. As shown in timing diagram 370, the first “clump” of radially excited ions corresponding to the first excitation pulse interacts with the exit edge field, such that the radial oscillations of at least a portion of the excited ions are converted into axial oscillations, which are detected by detector 218 to generate the time-varying oscillation signal schematically depicted. Since a continuous ion beam is transmitted through quadrupole assembly 220 when operating in transmission mode, another excitation pulse can be triggered and another oscillation signal acquired once the first oscillation signal generated by the first excitation pulse disappears. For a signal lasting approximately 1 ms, approximately 1000 such tracks can be acquired, or more precisely, data can be acquired at an acquisition rate of 1 kHz.

[0063] Operation of the quadrupole component in capture mode

[0064] In contrast to the transport mode illustrated above, the controller according to various aspects of this teaching can alternatively trigger the quadrupole assembly to operate in a capture mode by applying various potentials with RF and / or DC components to the quadrupole, auxiliary electrode and / or associated lens, such that ions are first captured in the quadrupole assembly before being excited by a voltage pulse.

[0065] For example, refer to Figure 2A For example, by applying RF voltage and DC voltage to quadrupole 222a-d via voltage sources 207a and 208a respectively, the voltage can be obtained from the upstream analyzer (e.g., Figure 1 Ions received in the collision cell 116 can be trapped within the quadrupole assembly 220 to generate a radially confined quadrupole field. Those skilled in the art will recognize that, in some aspects, the offset (RO) DC voltage applied to the quadrupole assembly 222 is more attractive to ions transported to the quadrupole assembly 220 relative to the inlet lens 1Q3 and / or the outlet lens 217, in order to generate a potential well away from the end electrodes. Furthermore, in some aspects, one or more DC voltages can be applied to multiple auxiliary electrodes (e.g., by controlling voltage sources 208e, f). For example, controller 209 can cause voltage source 208e to apply a DC voltage to the ring electrode 230c and voltage source 208f to apply a DC voltage to multiple LINAC electrodes 230a, b. Moreover, in some aspects, at least one of the RF voltage and DC voltage can be applied to the outlet lens 217 (e.g., by controlling voltage sources 207b and 208c) to prevent ions from being transported downstream through the outlet lens 217.

[0066] As those skilled in the art will recognize from this teaching, voltage signals applied to various components for trapping ions within the quadrupole assembly 220 can be selected, for example, depending on the polarity of the ions of interest. For example, to trap positive ions in the quadrupole assembly 220 during filling and cooling, the controller 209 can: i) cause voltage source 208f to apply a first DC LINAC voltage to the LINAC electrodes 230a, b; ii) cause voltage source 208e to apply a first DC ring voltage, more negative than the first DC LINAC voltage, to the ring electrode 230c; and iii) cause voltage source 208c to apply a first DC exit lens voltage, more positive than the first DC LINAC voltage, to the exit lens 217. In such a case, positive ions entering the quadrupole assembly 220 can be axially repelled from the exit lens 217 of the quadrupole assembly 220 because the ring electrode 230c and the LINAC electrodes 230a, b generally provide a more attractive (negative) potential, while the RF signals applied to the quadrupole rods 222a-d provide radial confinement.

[0067] However, in order to capture negative ions during filling and cooling, the controller 209 may alternatively: i) apply a first DC LINAC voltage to the LINAC electrode 330 via voltage source 208f; ii) apply a first DC ring voltage, which is more positive than the first DC LINAC voltage, to the ring electrode 230c via voltage source 208e; and iii) apply a first DC outlet lens voltage, which is more negative than the first DC LINAC voltage, to the outlet lens 217 via voltage source 208c. Therefore, negative ions entering the quadrupole assembly 220 can be repelled from the downstream region of the quadrupole assembly 220 because the ring electrode 230c and / or the LINAC electrodes 230a, b generally exhibit a more attractive (positive) potential.

[0068] Figure 4This is an exemplary timing diagram series 400, schematically depicting how a quadrupole assembly 220, according to various exemplary embodiments of the present teachings, is controlled in a capture mode to capture, excite, and eject positive ions. Timing diagram 410 shows positive ions (e.g., product ions and residual selective precursor ions) being introduced into the quadrupole assembly 220 over a period of time, which may be, for example, on the order of approximately 10 ms. After the positive ions are introduced into the quadrupole assembly 220 or after the quadrupole assembly 220 is filled with ions, the positive ions may be cooled for a period of time, as indicated in timing diagram 420. By way of a non-limiting example, this period of time for ion cooling may be on the order of approximately 50 ms. As schematically shown in timing diagrams 440, 450, and 460, during the ion introduction and cooling periods, the ring electrode 203c is maintained at -800 V DC, while the LINAC electrodes 203a, b are maintained at -50 V DC, and the exit lens 217 is maintained at +50 V DC. Furthermore, in some aspects, an RF voltage can be applied to the exit lens 217 (and the entrance lens IQ3), causing positive ions to be alternately attracted to and repelled from the exit lens 217. Although not in Figure 4 As shown, but will also be appreciated, applying an RF voltage signal to quadrupole 222 during capture and cooling can provide a radially confined quadrupole field, causing ions to be driven toward the central axis (Z). In this way, positive ions entering quadrupole assembly 220 can be prevented from being ejected through exit lens 217. The cooling period can also slow down the ions as they oscillate radially across the Z-axis and axially along the Z-axis due to the alternating attraction / repulsion potentials of the RF signal applied to one or more end electrodes.

[0069] It will be appreciated that the conditions described above for trapping either positive or negative ions within the quadrupole assembly 220 are merely one example of possible control signals according to this teaching. As is known in the art, a potential well for ions can be generated within the quadrupole assembly 222 regardless of the ring electrode 230c and / or LINAC electrodes 230a, b, for example by providing axial confinement through appropriate DC and / or RF voltages on the end electrodes (e.g., inlet lens IQ3 and outlet lens 217), while radial confinement is provided by RF signals applied to the quadrupoles 222a-d. An offset (RO) DC voltage applied to the quadrupole assembly 222 can also be used to generate a potential well within the center of the quadrupole assembly (e.g., away from the end electrodes), depending on, for example, the DC potential maintained at the end electrodes.

[0070] In any case, ions prevented from leaving the downstream end through exit lens 217 can, in some respects, be subjected to a higher operating gas pressure relative to the gas pressure within quadrupole assembly 220 during transport mode, in order to help rapidly cool the ions through collisions with gas molecules. As a non-limiting example, the background pressure used for quadrupole assembly 220 when in trap mode can be reduced to a lower background pressure than when in transport mode, for example, at approximately 0.5 × 10⁻⁶. -5 and 5×10 -4 Within the range between the inlet and outlet. In these respects, controller 209 can control the pressure and / or gas flow rate provided by the gas inlet and outlet according to the operating mode. Once the ions are cooled, they are excited.

[0071] In capture mode, coherent excitation is used to excite the captured ions of the quadrupole assembly 220 and can be any short waveform excitation. In various embodiments, short waveform excitation produces a short waveform with a sharp leading edge, for example, rising within less than 10 μs. The short waveform excitation can be, for example, a very narrow dipole excitation pulse, in which a positive DC voltage is applied to one pole of the quadrupole assembly 222 while a negative DC voltage with the same amplitude is applied to the other pole of the quadrupole assembly 222. In various aspects, a function generator can be used to generate excitation pulses, such as square wave pulses exhibiting an amplitude of approximately 5 V and a width between 0.5 and 5 μs. For example, an amplifier can also be used to provide excitation pulses with amplitudes ranging from approximately 5 V DC to 100 V DC from a 5 V input in a bipolar manner using a toroidal transformer. For example, an amplifier can be used on the X pole of the quadrupole assembly 222 (i.e., such as...). Figure 2B A dipole excitation pulse is applied between the bars 222a and c shown. Alternatively, this can be achieved by applying a dipole excitation pulse to the Y-bar of the quadrupole group 222 (i.e., as shown). Figure 2B A dipole pulse is applied between the rods 222b and d shown, or even between the auxiliary LINAC electrodes 230a and b, to apply an excitation pulse across the quadrupole assembly.

[0072] In various embodiments, the coherently oscillating ions ejected axially toward detector 218 can be achieved by appropriately adjusting the voltages of the ring electrode 230c and LINAC electrodes 230a, b of quadrupole assembly 220, as well as the voltage applied to exit lens 217. Preferably, detector 218 is configured to detect the oscillations of ejected ions fast enough to prevent loss of coherence, but slow enough to provide the high resolution typical of Fourier transform mass spectrometry. In some aspects of this teaching, this desired detection rate can be achieved by axially ejecting coherently oscillating ions from quadrupole assembly 220 at a precise rate, for example by precisely timing the application of RF and / or DC potentials to various components of quadrupole assembly 220 and exit lens 217.

[0073] For example, the controller 209 can adjust the DC voltage of the ring electrode 230c by controlling the DC voltage source 208e, adjust the DC voltage of the LINAC electrodes 230a and b by controlling the DC voltage source 208f, and adjust the DC and RF voltages of the exit lens 217 by controlling the DC voltage source 208c and the RF voltage source 207b.

[0074] Refer again Figure 4 Timing diagram 430 depicts a narrow dipole DC voltage excitation pulse used to oscillate and trap exemplary positive ions in quadrupole assembly 220. Because time is inversely proportional to frequency, a narrower excitation pulse in the time domain produces a wider spectrum, meaning that ions over a wider m / z range can be excited by the same pulse. As described above, the exemplary narrow dipole DC voltage excitation pulse is applied between the X bars (i.e., bars 222a, c) of quadrupole assembly 222. For example, the dipole DC voltage excitation pulse of timing diagram 430 has an amplitude ranging from approximately 5V DC to 100V DC and a width between 1 and 5 μs.

[0075] Refer again Figure 4 After the ions captured in the quadrupole assembly 220 are excited by the excitation pulse in timing diagram 430, they are axially ejected by adjusting the voltage of the auxiliary electrodes (LINAC electrodes 230a, b and ring electrode 230c) of the quadrupole assembly 200 and the exit lens 217 to measure the ions of the LIT over a period of time. As mentioned above, ejecting all ions at once may not provide a signal of sufficient duration to provide a sufficiently high resolution.

[0076] For example, in order to spray Figure 4 In the illustrated positive ion configuration, controller 209 is configured to change the DC voltage of ring electrode 230c from a first DC ring voltage (e.g., -800V DC) to a second DC ring voltage (e.g., -200V DC) and the DC voltage of exit lens 217 from a first DC exit lens voltage (e.g., +50V DC) to a second exit lens voltage (e.g., -50V DC), which is less negative than the first DC ring voltage but still more negative than the first LINAC voltage (e.g., -50V DC). The second exit lens voltage is the same as the first LINAC voltage.

[0077] Timing diagram 440 illustrates the change in DC voltage of the exit lens immediately following the excitation pulse. For example, the change in DC voltage of exit lens 217 from +50V to -50V causes more positive ions to be attracted to exit lens 217. However, this voltage is still more positive than the second DC ring voltage of ring electrode 230c to prevent all ions from leaving quadrupole 220 immediately.

[0078] Timing diagram 450 illustrates the change in DC voltage of the ring electrode 230c immediately after the excitation pulse. For example, the change in DC voltage of the ring electrode 230c from -800V to -200V makes positive ions less attracted to the quadrupole assembly 220 and therefore more likely to be ejected. However, because -200V is more attractive to positive ions (negative) than -50V at the exit lens 217, a barrier is maintained to prevent positive ions from immediately leaving the quadrupole assembly 220.

[0079] Timing diagram 460 shows that the voltages of LINAC electrodes 230a and b remain unchanged in this exemplary embodiment, instead being maintained at -50V before and after the excitation pulse. Due to the gradual tapering of LINAC electrodes 230a and c, as... Figure 2A As shown, LINAC electrodes 230a and 230b generate an axial electric field component that accelerates positive ions axially toward exit lens 217. Because the DC voltage of LINAC electrodes 230a and 230b remains unchanged after the excitation pulse, ion acceleration occurs both before and after the excitation pulse. However, ions are not ejected from quadrupole assembly 220 before the excitation pulse because the voltage of exit lens 217 is much more positive (e.g., +50V DC) than the voltage of the LINAC electrodes (e.g., -50V DC). After the excitation pulse, adjusting the voltage of the exit lens to the same voltage as the LINAC electrodes 230a and 230b (e.g., adjusting to -50V DC) causes positive ions to be ejected because there is no longer any voltage barrier for ions accelerated by the axial electric field component generated by the LINAC electrodes.

[0080] Therefore, coherent oscillating ions are axially ejected from the quadrupole assembly through the exit lens 240 for detection by the detector 218 (e.g., destructive detection), and the time-varying oscillating signal is schematically depicted as shown in the timing diagram 470.

[0081] Analysis Module

[0082] like Figure 2A The exemplary analysis module 209a depicted can be associated with controller 209 to receive a detected time-varying signal from detector 218 and manipulate that signal to generate a mass spectrum associated with the detected ion. More specifically, as Figure 5A As shown in -D, the analysis module 209a can receive time-varying signals (such as...). Figure 5A (Example signal) and obtain its Fourier transform to generate a frequency domain signal (such as Figure 5B (in Chinese). Then, the analyzer can use the relationship between Mathieu parameters a and q and the m / z of the ion to convert the frequency domain signal (in Chinese). Figure 5B ) converted to mass spectrometry ( Figure 5C ).

[0083]

[0084]

[0085] Where z is the charge on the ion, U is the resolved DC voltage on the rod, V is the RF voltage amplitude, Ω is the RF angular frequency, and r0 is the characteristic dimension of the quadrupole. The radial coordinate r is given by the following formula:

[0086] r 2 =x 2 +y 2 Equation (6)

[0087] Furthermore, when parameter q < ~0.4, the parameter is given by the following formula:

[0088]

[0089] And the basic long-term frequency is determined as follows:

[0090]

[0091] Under the conditions that parameter a = 0 and parameter q < ~0.4, the long-term frequency is related to the m / z of a specific ion, and the approximate relationship is as follows:

[0092]

[0093] The exact value of β is based on a continuous fractional expression for the Mathieu parameters a and q. This continuous fractional expression can be found in J. Mass Spectro, Vol. 32, pp. 351-369 (1997), which is incorporated herein by reference in its entirety.

[0094] The relationship between m / z and long-term frequencies can be alternatively determined by fitting the set of frequencies to an equation:

[0095]

[0096] A and B are constants to be determined.

[0097] As the time-varying signal generated by detector 218 is transformed, the resulting frequency-domain signal thus contains information about the m / z distribution of ions within the ion beam, which are excited at their long-term frequencies by the application of voltage pulses in transport or capture modes, as discussed above. This information can be used in... Figure 5C The plot shown, for example, is called a "mass spectrometer," which depicts the signal intensity at each m / z (indicating the number of ions at that particular m / z that are sufficient to be excited to enable detection).

[0098] exist Figure 5A In an exemplary embodiment of -D, Figure 5A -C illustrates the result of applying an excitation pulse when operating in the transmission modes discussed above. See [link / reference] for details. Figure 5C In mass spectrometry, it will be recognized that peaks representing higher m / z ions exhibit reduced resolution (e.g., broader peak shapes) compared to peaks representing lower m / z ions. According to various aspects of this teaching, analyzer 209a can calculate the resolution of one or more of these peaks, for example, using the following formula:

[0099]

[0100] As is known in the art, Δ(m / z) can represent the peak width at a specified percentage of the peak height. For example, Δ(m / z) for a particular m / z is typically determined at 50% of the peak height (i.e., full width at half maximum (FWHM)), but any other known technique for determining resolution can be used. In various aspects, the calculated resolution of one or more peaks of a mass spectrum generated in one operating mode can be used to determine whether the quadrupole assembly can switch to another mode of operation in transport or capture modes, for example, by comparing the calculated resolution with a threshold (e.g., a default threshold, a threshold selected by the user). In some embodiments, a quadrupole assembly according to the present teachings can be used to generate mass spectra with resolutions in the range of approximately 100 to approximately 1000, and, for example, if the determined resolution is below a threshold (e.g., below 100, below 500), then it can be triggered to operate.

[0101] The examples provided are intended to further illustrate various aspects of this teaching and are not intended to provide the optimal way to practice this teaching or the best possible results. References Figure 5C Example property spectrum (which can be derived from...) Figure 5A (Similar time-varying signal derivation), using an improved 4000 A mass spectrometer is obtained, in which the opposing quadrupole of Q3 is coupled to a pulsed voltage source configured to provide it with a dipole excitation signal. Ions are generated from a sample containing a 0.17 pmol / μL reserpine solution via a nebulizer-assisted electrospray ionization source (not shown). Reserpine ions (m / z 609) are selected in Q1, fragmented in collision cell q2, and subjected to a dipole voltage pulse (1 V DC, 0.5 μs) so that product ions from q2 and unfragmented precursor ions are transported via the modified Q3. Figure 5CAs shown, the peak width increases with increasing m / z: 195+ has an FWHM of 0.90 amu, 397+ is measured at 2.7 amu, and 609+ is 5.9 amu. According to various aspects of this teaching, the analysis module 209a can determine that the resolution of one or more peaks representing ions with higher m / z is insufficient, allowing the controller to switch the quadrupole assembly to operate in capture mode instead. Figure 5D This indicates that after switching to capture mode, from and Figure 5C Mass spectra obtained from the same sample. (Compared to...) Figure 5C Similarly, reserpine ions (m / z 609) were selected in Q1 and fragmented in collision cell q2, but were trapped in Q3 (and cooled for 50 ms) before the application of a dipole voltage pulse (3V DC, 1.0 μs). It will be recognized that... Figure 5D Sharper peaks in the mass spectrum indicate relative to Figure 5C Increased resolution, especially for ions with higher m / z. For example... Figure 5D As shown, the product ion at m / z 195+ has an FWHM of 0.11 amu, 397+ is measured at 0.25 amu, and 609+ is at 0.44 amu, each at [missing value]. Figure 5C The faster acquisition of the corresponding ion results in a substantial improvement in resolution.

[0102] Controller (e.g., Figure 1 The controller 109 can be implemented in hardware and / or software in various different ways. For example, Figure 6 An embodiment of controller 609 is schematically depicted, which includes a processor 610 for controlling the operation of its various modules for performing analysis according to this teaching. As shown, controller 609 includes random access memory (RAM) 620 and permanent memory 630 for storing instructions and data. Communication module 640 allows controller 609 to communicate with detectors (e.g., Figure 1 The controller 609 communicates with the detector 118, for example, to receive detected ion signals, and with various electrodes, lenses, and / or power supplies as otherwise described herein. The communication bus 650 allows various components of the controller 609 to communicate with each other.

[0103] The controller 609 also includes an analysis module 660 for converting the time-varying ion signal received from the detector (e.g., via Fourier transform) into a frequency domain signal, and for calculating the mass spectrum of the detected ion based on the frequency domain signal as discussed elsewhere herein. An operation mode selection module 670 is used to select the operation mode of the quadrupole assembly, e.g., whether the quadrupole assembly operates in a transport mode or a capture mode. Depending on the operation mode (e.g., determined by the operation mode selection module 670), the quadrupole assembly according to this teaching can operate in one of a transport mode or a capture mode, with a corresponding transport mode module 680 or capture mode module 690 operating the quadrupole assembly and / or the exit lens, e.g., by controlling the application of RF and / or DC potentials to the various components according to appropriate timing as discussed elsewhere herein.

[0104] Figure 7 The text describes the operation of a mass spectrometer system according to various aspects of this teaching (e.g., via...). Figure 6 An exemplary method 700 of the controller 609. In step 701, ions are transferred to a quadrupole assembly. Depending on the operating mode, ions are either continuously transferred through the quadrupole assembly while an excitation pulse is applied (transfer mode), or trapped within the quadrupole assembly before an excitation pulse is applied to them (trapping mode). As described above, the controller can be based on user selection, prior or empirical knowledge of a particular instrument, experiment, and / or sample, and / or data obtained from previous analyses (e.g., by...). Figure 6 The analysis module 660 provides data to trigger the quadrupole assembly to operate in an operating mode. First, referring to the transport mode, in step 702, by applying at least one radio frequency (RF) voltage to each pole of the quadrupole assembly to generate a radially confining field for ions, ions can be transported through the quadrupole assembly without ion trapping, and voltage pulses can be applied across the quadrupole assembly to excite at least a portion of the ions to radial oscillations at their long-term frequency. In transport mode, the excited ions interact with the edge field near the output of the quadrupole assembly and convert the radial oscillations into axial oscillations as the excited ions leave the quadrupole assembly. In step 703, the detector detects axially oscillating ions to generate a time-varying signal. The spectrum is determined based on the time-varying signal (step 704), from which the mass spectrum can be calculated (step 705).

[0105] However, in the trapping mode, the quadrupole assembly is first filled with ions in step 706, for example, by applying DC and RF pulses to the various parts of the quadrupole assembly, such that ions transported into the trap cannot leave through the output, as discussed elsewhere herein. In step 707, the trapped ions may optionally be cooled for a period of time, and optionally, an airflow is provided to impingementally cool the ions within the quadrupole assembly. Subsequently, in step 708, voltage pulses may be applied across the quadrupole assembly to excite radial oscillations of the trapped ions. In step 703, the ions excited in the trapping mode are axially ejected, for example, by applying a coordinated sequence of DC and RF voltage signals to the various parts of the quadrupole assembly and its associated exit lens, as discussed elsewhere herein. At step 704, a detector detects the axially ejected ions and determines the spectrum based on the time-varying signal (step 705). The mass spectrum can then be calculated from this (step 706).

[0106] Figure 8 The text describes the operation of various aspects according to this teaching (e.g., via...). Figure 6 Another exemplary method 800 for a mass spectrometer system (controller 609) involves initiating the quadrupole assembly to operate in transport mode in step 801 (e.g., by default, depending on user selection). In step 802, ions are transported into the quadrupole assembly. Operating in transport mode, a voltage pulse is applied to the transported ions, and the detection of the excitation can be used to generate a mass spectrum, as discussed further herein (step 803). Then, in step 804, the resulting mass spectrum can be analyzed (e.g., by an analysis module) or presented to the user to confirm that the mass spectrum generated in transport mode has sufficient intensity and / or resolution. If so, one or more additional “clumps” of the continuous ion beam can be analyzed. However, if the intensity and / or resolution of the mass spectrum in transport mode is insufficient, the quadrupole assembly can be switched to capture mode, such that additional ions are transported into the quadrupole (step 805), where they are captured, cooled, excited, and ejected from the central axis to generate a mass spectrum in capture mode (step 806), as discussed further herein. Figure 8 As suggested in the document, for example, after acquiring data in capture mode, the quadrupole component can revert to the faster data acquisition associated with the transfer mode.

[0107] Those skilled in the art will recognize that various changes can be made to the above embodiments without departing from the scope of the invention. Furthermore, those skilled in the art will understand that features of one embodiment can be combined with features of another embodiment.

Claims

1. A method for performing mass spectrometry analysis, comprising: Multiple ions are transported to a quadrupole assembly including a quadrupole group and multiple auxiliary electrodes. The quadrupole group includes an input end and an output end. The input end is used to receive ions, and the ions exit the quadrupole group through the output end. An exit lens is deployed adjacent to the output end of the quadrupole group. The quadrupole component is triggered to operate in one of the transmission and capture modes; Mass spectra of at least a portion of the plurality of ions are generated, wherein a voltage pulse is applied to the at least a portion of the plurality of ions in a triggered mode to induce radial oscillations of the at least a portion of the plurality of ions; as well as Based on the Fourier analysis of the generated mass spectrum, a subsequent operating mode is determined, the subsequent operating mode being selected from the transport mode and the capture mode, the Fourier analysis including determining the resolution of one or more peaks of the generated mass spectrum of at least a portion of the radial oscillations in the plurality of ions; In the transport mode and during the step of transporting ions into the quadrupole assembly, the method includes: By applying at least one radio frequency (RF) voltage to each pole of the quadrupole assembly to generate a radially confining field for ions, ions are transported through the quadrupole assembly without being trapped within it. A voltage pulse is applied across the quadrupole assembly to excite radial oscillations at a long-term frequency in at least a portion of the ions transmitted through the quadrupoles, wherein the edge field near the output end converts the radial oscillations of at least a portion of the excited ions into axial oscillations as the excited ions leave the quadrupole assembly. In the capture mode, the method also includes: During the step of transferring ions into the quadrupole assembly, ions transferred into the quadrupole assembly are captured by i) applying at least one DC voltage and at least one RF voltage to each quadrupole of the quadrupole group, ii) applying one or more DC voltages to the plurality of auxiliary electrodes, and iii) applying DC voltage and RF voltage to the exit lens. A voltage pulse is applied across the quadrupole assembly to excite radial oscillations at the long-term frequency of at least a portion of the ions trapped within the quadrupole assembly. The excited ions are axially ejected from the quadrupole assembly; and At least a portion of the excited ions leaving the quadrupole assembly operating in one of the transport and capture modes are detected to generate a time-varying signal.

2. The method of claim 1, further comprising obtaining the analytical spectrum of ions leaving the quadrupole assembly from the time-varying signal.

3. The method of claim 2, wherein obtaining the analytical spectrum comprises performing a Fourier transform on the time-varying signal to generate a frequency domain signal containing information about ions excited by the voltage pulse.

4. The method of claim 1, wherein determining the subsequent operating mode further comprises switching the quadrupole component from a transmission mode to a capture mode.

5. The method of claim 4, wherein the quadrupole assembly is switched from transport mode to capture mode when the intensity of at least one ion having one or more specific m / z values ​​in the analyzed spectrum is below a threshold.

6. The method of claim 4, wherein the quadrupole assembly is switched from transmission mode to capture mode to increase the resolution of the analyzed spectrum; or If the FWHM of at least one ion with one or more specific m / z values ​​in the analysis spectrum is higher than a threshold, the quadrupole assembly is switched from transport mode to capture mode.

7. The method of claim 1, wherein the quadrupole assembly comprises a first pair of poles and a second pair of poles extending along a central longitudinal axis from the input end to the output end, wherein the poles of the quadrupole assembly are spaced apart from the central longitudinal axis such that each pair of poles is deployed on opposite sides of the central longitudinal axis, and The plurality of auxiliary electrodes includes pairs of auxiliary electrodes extending along the central longitudinal axis on opposite sides of the central longitudinal axis, wherein each of the auxiliary electrodes is inserted between a single rod in the first pair of rods and a single rod in the second pair of rods.

8. The method of claim 7, wherein applying a voltage pulse across the quadrupole assembly comprises applying a voltage pulse across one of the first pair of poles and the second pair of poles of the quadrupole assembly; or Applying a voltage pulse across the quadrupole assembly includes applying a voltage pulse across the auxiliary electrode.

9. The method of claim 7, wherein the auxiliary electrode pair comprises a linear accelerator LINAC electrode.

10. The method of claim 7, wherein the plurality of auxiliary electrodes further comprises a ring electrode surrounding the quadrupole assembly and disposed between the input terminal and the auxiliary electrode pair.

11. The method of claim 1, wherein, in the capture mode, the method further applies pressure and airflow within the quadrupole assembly to cool the ions captured in the quadrupole assembly.

12. A mass spectrometer system, comprising: An ion source, said ion source being used to generate multiple ions; The quadrupole assembly includes a quadrupole group and multiple auxiliary electrodes. The quadrupole group includes an input terminal and an output terminal. The input terminal is used to receive ions, and the ions leave the quadrupole group through the output terminal. An exit lens, wherein the exit lens is configured to be adjacent to the output end of the quadrupole assembly; One or more power sources, said one or more power sources being coupled to the quadrupole assembly; A detector for detecting at least a portion of the plurality of ions exiting the quadrupole assembly to generate a time-varying signal; as well as The controller is configured to: The quadrupole component is triggered to operate in one of the transmission and capture modes; Mass spectra of at least a portion of the plurality of ions are generated, wherein a voltage pulse is applied to the at least a portion of the plurality of ions in the triggered mode to generate radial oscillations of the at least a portion of the plurality of ions; as well as Based on the Fourier analysis of the generated mass spectrum, a subsequent operating mode is determined, the subsequent operating mode being selected from the transport mode and the capture mode, the Fourier analysis including determining the resolution of one or more peaks of the generated mass spectrum of at least a portion of the radial oscillations in the plurality of ions; In transmission mode, the controller is further configured as follows: The one or more power supplies are controlled to apply at least one radio frequency (RF) voltage to each pole of the quadrupole assembly to generate a field for radial confinement of ions. To allow ion transport through the quadrupole assembly without trapping ions within the quadrupole assembly; as well as The one or more power supplies are controlled to apply voltage pulses across the quadrupole assembly to excite at least a portion of the ions being transmitted through the quadrupoles to radially oscillate at their long-term frequency, wherein the edge field near the output end converts the radial oscillation of at least a portion of the excited ions into axial oscillation as the excited ions leave the quadrupole assembly. In capture mode, the controller is further configured as follows: The one or more power supplies are controlled to i) apply at least one DC voltage and at least one RF voltage to each quadrupole of the quadrupole assembly, ii) apply one or more DC voltages to the plurality of auxiliary electrodes, and iii) apply DC voltage and RF voltage to the exit lens in order to trap ions within the quadrupole assembly; Control the one or more power supplies to apply voltage pulses across the quadrupole assembly to excite radial oscillations at their long-term frequency of at least a portion of the ions trapped within the quadrupole assembly; Control the one or more power sources to axially eject the excited ions from the quadrupole assembly; as well as In either transmission or capture mode, the analytical spectrum of ions leaving the quadrupole group is generated from the time-varying signal.

13. The system of claim 12, wherein the controller is configured to perform a Fourier transform of the time-varying signal to generate a frequency domain signal containing information about ions excited by voltage pulses in either a transmission mode or a capture mode.

14. The system of claim 12, wherein the controller is configured to switch the quadrupole component from a transmission mode to a capture mode based on the analyzed spectrum.

15. The system of claim 14, wherein the controller is configured to switch the quadrupole assembly from a transport mode to a capture mode when the intensity of at least one ion having one or more specific m / z values ​​in the analysis spectrum is below a threshold.

16. The system of claim 14, wherein the controller is configured to switch the quadrupole component from a transmission mode to a capture mode to increase the resolution of the analyzed spectrum; or The controller is configured to switch the quadrupole assembly from transport mode to capture mode if the FWHM of at least one ion with one or more specific m / z values ​​in the analysis spectrum is above a threshold.

17. The system of claim 12, wherein the quadrupole assembly includes a first pair of poles and a second pair of poles extending along a central longitudinal axis from the input to the output, wherein the poles of the quadrupole assembly are spaced apart from the central longitudinal axis such that each pair of poles is deployed on opposite sides of the central longitudinal axis, and The plurality of auxiliary electrodes includes pairs of auxiliary electrodes extending along the central longitudinal axis on opposite sides of the central longitudinal axis, wherein each of the auxiliary electrodes is inserted between a single rod in the first pair of rods and a single rod in the second pair of rods.

18. The system of claim 17, wherein, In transmission mode or capture mode, the controller is configured to control the one or more power supplies to apply voltage pulses across one of the first and second pairs of the quadrupole groups; or In either transmission or capture mode, the controller is configured to control the one or more power supplies to apply voltage pulses across the auxiliary electrodes.

19. The system of claim 17, wherein the auxiliary electrode pair comprises a linear accelerator LINAC electrode; or The plurality of auxiliary electrodes also includes a ring electrode surrounding the quadrupole assembly and positioned between the input terminal and the auxiliary electrode pair.

20. The system of claim 13, further comprising at least one gas inlet and at least one gas outlet, the controller further configured to control the gas inlet and gas outlet to adjust the pressure and airflow within the quadrupole assembly.

21. The system of claim 20, wherein the controller is configured to, while in capture mode, control the gas inlet and gas outlet to maintain the quadrupole assembly at approximately 0.5 × 10⁻⁶. -5 Lift to approximately 5×10 -4 The pressure within the range is used to cool the ions in the quadrupole assembly.

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