Abstract: A method of pulsing gas in a quadrupole ion trap to reduce excess internal energy of ions formed externally to the trap at high-vacuum conditions by laser desoprtion is disclosed. With pulsed gas introduction, pressures greater than those under which traps are normally operated can be achieved over a few milliseconds. Under these elevated pressure transients, the process of translational cooling is accelerated and ions undergo thermalized collisions before dissociation occurs. Minimization of uncontrolled fragmentation (thermalization) and enhanced sensitivity are observed at pressures exceeding a threshold of about 1 mTorr.

Abstract: The compensation potentials on the compensation electrodes of an ICR measuring cell are sequentially adjusted so that an ICR measurement with the longest possible usable image current transient is produced. Then, subsequent ICR measurements are made using the ICR cell with the optimally adjusted compensation potentials. Depending on the kind of ion mixture involved, measurements with image current transients from 10 to more than 20 seconds long can be performed, from which mass spectra with a maximum mass resolution without peak coalescence can be obtained.

Abstract: A multipole ion guide comprises rods disposed about an axis, each of the rods having a first end and a second end remote from the first end. Each of the rods is disposed at a respective greater distance from the axis at the first end than at the second end. The multipole ion guide comprises means for applying a radio frequency (RF) voltage between adjacent pairs of rods, wherein the RF voltage creates a multipole field in a region between the rods; and means for applying a direct current (DC) voltage drop along a length of each of the rods. A mass spectroscopy system is also disclosed.

Abstract: If a scanning rate of a mass scanning is set to be high, the amount of change in an applied voltage between a time of an incidence of a certain ion into a quadrupole mass filter and a time of an emission of the ion therefrom increases. This leads to a change in the condition of a passage of ions, causing the amount of ions to decrease and thereby deteriorating detection sensitivity. In order to avoid this problem, according to the present invention, the values of direct current voltage U and an amplitude V of radio-frequency voltage, both voltages being applied to rod electrodes during a mass scanning, are respectively determined so that a voltage ratio U/V of the voltage U to the amplitude V becomes smaller as the scanning rate becomes higher.

Abstract: A technique is disclosed for conducting collision induced dissociation (CID) in a quadrupole ion trap (QIT) having higher order field components. In order to compensate for the shift in the frequency of motion with amplitude of the excited ions arising from the influence of higher-order field components, the amplitude of the RF voltages applied to the QIT is monotonically varied during the excitation period to prolong the condition of resonance, resulting in higher average kinetic energies of the excited ions. Thus, higher fragmentation efficiencies may be obtained, or a targeted level of fragmentation may be achieved in less time relative to conventional CID.

Abstract: While applying a square wave voltage to the ion electrode (21) so that ions already captured in the ion trap (20) do not disperse, the timing of irradiating a laser light for ion generation is controlled in such a manner that ions reach the ion inlet (25) at a predetermined timing of a cycle of the voltage. In the case of a positive ion (cation) for example, the timing of laser light irradiation is adjusted in such a manner that the target ions reach the ion inlet (25) in the low level period of a cycle of the square wave voltage. By injecting ions in addition to the ions already captured in the ion trap (20) in this manner, the amount of ions can be increased, and by performing a mass separation and detection after that, the signal intensity in one mass analysis can be increased. Accordingly, by decreasing the number of repetitions of the mass analysis for summing up mass profiles, the measuring time can be shortened.

Abstract: A two-dimensional substantially quadrupole field is provided. The field comprises a quadrupole harmonic of amplitude A2 and an octopole harmonic of amplitude A4, wherein A4 is greater than 0.01% of A2, A4 is less than 5% of A2, and, for any other higher order harmonic with amplitude An present in the field, n being any integer greater than 2 except 4, A4 is greater than ten times An.

Abstract: In a three-dimensional Paul RF ion trap the ring electrode and end cap electrodes are formed from pairs of pole rods. This multipole rod system is then operated as a linear ion trap with a constant field distribution along the multipole rod system. While the system is operating as a linear ion trap, analyte ions are introduced and stored within the linear ion trap. After the ions have been stored, a single-phase RF voltage is supplied to all rods of a middle segment thus forming a three-dimensional ion trap, thereby collecting the ions in a spherical cloud within this middle segment. The collected analyte ions can then be reacted in the three-dimensional ion trap and the product ions resulting from the reactions can be ejected for mass analysis.

Abstract: A mass spectrometer is provided that is configurable for operation in both a Kinetic Energy Discrimination (KED) mode and a dynamic reaction cell (DRC) mode. To operate in the KED mode, a collision cell can be filled with a quantity of the inert gas, and an energy barrier can be formed between the collision cell and a downstream mass analyzer. To operate instead in the mode, the collision cell can be filled with a quantity of gas that is reactive with the interferer ions.

Abstract: A novel system and methods for accelerating analytes including, without limitation, molecular ions, biomolecules, polymers, nano- and microparticles, is provided. The invention can be useful for increasing detection sensitivity in applications such as mass spectrometry, performing collision-induced dissociation molecular structure analysis, and probing surfaces and samples using accelerated analyte.

Abstract: A method for differential mobility separation of ions using digital-drive based high voltage fast switching electronics. The digital waveform delivered to the spectrometer is characterized by at least two substantially rectangular pulses of different amplitude and polarity. The control circuitry allows for waveform frequency, duty cycle and pulse amplitudes to be varied independently. Balanced as well as unbalanced asymmetric waveforms can be designed for optimum differential mobility separation of ions. The digital drive is designed for differential mobility spectrometers including parallel plate and segmented plate multipoles of planar symmetry, as well as multipoles of cylindrical symmetry, which may optionally be arranged in series. The use of the digital drive establishes alternating electric fields during which the displacement as a result of ion oscillation is determined by mobility coefficients.

Abstract: A mass spectrometer with an ionization chamber with a feed channel for a gas to be examined, including an electron source (d, n) for ionizing the gas to be examined, electrodes (c) for accelerating the ionizing electrons, electrodes (g, h, j, m) for the mass-dependent separation of the ions by acceleration/deceleration thereof, a detector (l) for the separated ions, a wiring with metallic conductors. The components are arranged on a plane nonconductive substrate (1), having an energy filter (k) for the ions, the energy filter being embodied as a 90° sector, is constructed in completely planar fashion. The ionization chamber (b), the electrodes (g, h, j, m) for accelerating the electrons and ions, the detector (l) for the ions and the energy filter (k) are produced by a single step of photolithography and etching of a doped semiconductor die (6) applied to the substrate (1) and the wiring (2) and the abovementioned parts are covered by a second flat nonconductive substrate (7).

Abstract: One virtual rod electrode is composed by a plurality of electrode plane plates arranged in the ion optical axis direction, and four virtual rod electrodes are arranged around the ion optical axis to form a virtual quadrupole rod type ion transport optical system (30). In one virtual rod electrode, the interval between the adjacent electrode plane plates is set to be large in the anterior area (30A) and small in the posterior area (30B). As the interval between electrodes becomes larger, high-order multipole field components increase and therefore the ion acceptance is increased, which enables an efficient acceptance of ions coming from the previous stage. On the other hand, if the interval between electrodes is small, the quadrupole field components relatively increase and the ion beam's convergence is improved. Therefore, ions can be effectively introduced into a quadrupole mass filter for example in the subsequent stage, which contributes to the enhancement of the mass analysis' sensitivity and accuracy.

Abstract: An ion cyclotron spectrometer may include a vacuum chamber that extends at least along a z-axis and means for producing a magnetic field within the vacuum chamber so that a magnetic field vector is generally parallel to the z-axis. The ion cyclotron spectrometer may also include means for producing a trapping electric field within the vacuum chamber. The trapping electric field may comprise a field potential that, when taken in cross-section along the z-axis, includes at least one section that is concave down and at least one section that is concave up so that ions traversing the field potential experience a net magnetron effect on a cyclotron frequency of the ions that is substantially equal to zero. Other apparatuses and a method for performing ion cyclotron spectrometry are also disclosed herein.

Abstract: An ion transport apparatus includes an ion entrance end, an ion exit end, and electrodes arranged along a longitudinal axis from the ion entrance end toward the ion exit end. The electrodes are configured for applying an RF electrical field that varies along the longitudinal axis such that at the ion entrance end, the RF electrical field comprises a major first multipole component of 2n1 poles where n1?3/2, and at the ion exit end the RF electrical field comprises predominantly a second multipole component of 2n2 poles where n2?3/2 and n2<n1.

Abstract: Methods for cooling ions retained in an ion trap are described. In various embodiments, a cooling gas is delivered into a linear ion trap causing a non-steady state pressure elevation in at least a portion of the trap above about 8×10?5 Torr for a duration less than the ion-retention time. In various embodiments, the duration of pressure elevation can be based upon a period of time required for an ion to lose a desired amount of its kinetic energy.

Abstract: A method and apparatus for multiplexing ions in an MSn mass spectrometer is provided. Ion are filtered to produce a group of ions of interest, the group of ions below a space charge limit of the MSn mass spectrometer. At least a portion of the group of ions are fragmented to form a fragmented group of ions. At least a portion of the fragmented group are stored such that a plurality of portions of the fragmented group can be sequentially selected for mass spectrometry analysis. Each of the plurality of portions of the fragmented group are sequentially selected and re-fragmented prior to mass spectrometry analysis. Each of the plurality of portions of the fragmented group are analyzed, via mass spectrometry, once each of the plurality of portions of the fragmented group has been fragmented.

Abstract: A method of determining the arrival time of one or more ions at an ion detector is disclosed. Ions arriving at the ion detector produce a signal and the time when a leading edge of the signal and when a trailing edge of the signal cross an intensity threshold are determined. The two times are then averaged to provide an ion arrival time.

Abstract: A mass analysis is initially performed while applying appropriate voltages to the electrodes so that ions injected through an entrance gate electrode (5) into a loop orbit (3) are guided through approximately one half of the loop orbit (3) and diverted at an exit gate electrode (6) toward an ion detector (7). Based on the intensities of the peaks appearing on a mass spectrum obtained by this mass analysis, one or more objective ions are selected and a time parameter is specified so that the voltage applied to the exit gate electrode (6) changes when none of the ions flying along the loop orbit (3) are passing through the exit gate electrode (6). As a result, the orbit of the objective ions will assuredly changed so that they will be directed toward the ion detector (7) after flying through the loop orbit (3) multiple times. Thus, the mass information of the objective ions can be assuredly obtained.

Abstract: An ion guide includes a plurality of curved electrodes and an ion deflecting device. The electrodes are arranged about and radially spaced from a central curved axis, and circumscribe a curved ion guide region from an ion entrance to an ion exit. The ion deflecting device may include a device for applying a DC electric field to one or more electrodes in a radial direction. The magnitude of the DC electric field, and thus the ion deflecting force, varies along the curved axis. The ion guide may for example operate as a collision cell or like instrument.

Abstract: An array-based ion storage system includes an ion generation section, and an ion storage section having a first end electrode coupled to the ion generation section and having multiple holes, a second end electrode having multiple holes, an intermediate electrode having multiple holes, a first insulator formed as a ring between the first end electrode and the intermediate electrode, and a second insulator formed as a ring between the intermediate electrode and the second end electrode. The ion storage section can be made thinner to facilitate consistency in ion extraction and reduce the spread of an ion mobility spectrum peak. The insulators have a big hole, and the ions cannot bump onto the insulation material during ion vibration or thermal movement in the storage space. Therefore, charge transfer and accumulation at the insulator and the subsequent discharge will not occur, suppressing instability of storage and loss of ions.

Abstract: In a linear ion trap ions of both positive and negative polarities are stored simultaneously for fragmentation reactions caused by electron transfer dissociation (ETD). The ion trap comprises a plurality of parallel pole rods or stacked rings and the ions are stored by applying two phases of a first RF voltage to the pole rods or stacked rings in alternation, thereby radially confining both positive and negative ions. A second, single-phase RF voltage is applied to all the pole rods or stacked rings in common and creates a pseudopotential barrier at the ends of the linear ion trap that acts axially on ions of both polarities in order to maintain the ions in the trap.

Abstract: A mass spectrometer is disclosed comprising a quadrupole rod set ion guide or mass filter device. Broadband frequency-signals (13, 14, 15) having a plurality of frequency notches (16a; 16b; 16c) are applied sequentially to the rods of the quadrupole rod set. The notched broadband frequency signals (16a, 16b, 16c) cause undesired ions to be resonantly or parametrically ejected from the ion guide. The resulting ion signals are deconvoluted to provide a mass spectrum.

Abstract: A system for guiding an ion beam along an axis (Z), comprises at least one section having upper flat plate strip electrodes (Iu, 2u, 3u, 4u and 5u) and lower flat plate strip electrodes (Id, 2d, 3d, 4d and 5d) for producing at least one electric field of substantially symmetric in a parallel direction and substantially antisymmetric in a perpendicular direction with respect to a plane including a beam axis and a fringe-field boundary that is located at the end of the at least one section.

Abstract: The invention relates to a linear multipole ion storage device which is suitable for reactions between positive and negative ions, and for fragmentation reactions by electron transfer dissociation (ETD) in particular. The invention uses a linear RF ion trap with at least three pairs of rods with a new type of electronic power supply. The two phases of a first RF voltage are applied to the pole rods alternately around the circumference and confine positive as well as negative ions in the radial direction. A second RF voltage is either applied single-phase to some of the pole rods, but not to all of them, or two-phase to unequal numbers of pole rods so that the axis potential oscillates with the frequency of this second RF voltage and generates a pseudopotential barrier which acts axially on ions of both polarities at the ends of the ion storage device. In the interior, the second RF produces a complex superposition field resulting in an increased fragmentation yield for ETD.

Abstract: A charged particle reaction cell of the present invention has a serially-arranged plurality of ring electrodes, wherein a modulated radio frequency voltage obtained by modulating the amplitude of a radio frequency voltage is applied, whereby ions are captured at the bottom of the ups and downs of a formed pseudopotential and are transferred with the move of the pseudopotential. In the charged particle reaction cell, the time required for the charged particle reaction can be secured and also the problem of the decrease of the throughput or the mass resolution can be solved, and the speed of the structure analysis of a measurement sample can be accelerated.

Abstract: A new pulsed multiple reaction monitoring process and system are disclosed that uses a pulsed ion injection mode for use in conjunction with triple-quadrupole instruments. The pulsed injection mode approach reduces background ion noise at the detector, increases amplitude of the ion signal, and includes a unity duty cycle that provides a significant sensitivity increase for reliable quantitation of proteins/peptides present at attomole levels in highly complex biological mixtures.

Abstract: The present invention provides a radio frequency (RF) power supply in a mass spectrometer. The power supply provides an RF signal to electrodes of a storage device to create a trapping field. The RF field is usually collapsed prior to ion ejection. In an illustrative embodiment the RF power supply includes a RF signal supply; a coil arranged to receive the signal provided by the RF signal supply and to provide an output RF signal for supply to electrodes of an ion storage device; and a shunt including a switch operative to switch between a first open position and a second closed position in which the shunt shorts the coil output.

Abstract: Methods for improved separation of ions from an ion trap employing a combination of low pressure and low amplitude ion excitation, including methods for removing, from an ion trap ion population, ions having a m/z value neighboring that of an ion of interest, mass spectrometry methods providing improved resolution of ion detection, and programmable apparatus programmed with instructions therefor.

Abstract: A mass analyser 2 is provided comprising a plurality of electrodes having apertures through which ions are transmitted in use. A plurality of pseudo-potential corrugations are created along the axis of the mass analyser 2. The amplitude or depth of the pseudo-potential corrugations is inversely proportional to the mass to charge ratio of an ion. One or more transient DC voltages are applied to the electrodes of the mass analyser 2 in order to urge ions along the length of the mass analyser 2. The amplitude of the transient DC voltages applied to the electrodes is increased with time and ions are caused to be emitted from the mass analyser 2 in reverse order of their mass to charge ratio. Two AC or RF voltages are applied to the electrodes. The first AC or RF voltage is arranged to provide optimal pseudo-potential corrugations whilst the second AC or RF voltage is arranged to provide optimal radial confinement of ions within the mass analyser 2.

Abstract: An Electrospray ionization ion source is disclosed comprising a capillary tube surrounded by a gas nebulizer tube. One or more wires are provided within the capillary tube. An analyte solution is supplied to the capillary tube and a nebulizing gas is supplied to the gas nebuliser tube.

Abstract: A particle trap and an associated method of trapping particles are provided. The particle trap includes a body formed of a high temperature superconductor (HTS). The body defines a cavity therethrough. The particle trap also includes first and second HTS end plates or first and second electrodes positioned at opposite ends of the cavity. At least one of the end plates or at least one of the electrodes defines at least one opening into the cavity to permit charged particles to enter and exit the cavity.

Abstract: While applying a square wave voltage to the ion electrode (21) so that ions already captured in the ion trap (20) do not disperse, the frequency of the square wave voltage is temporarily increased at the timing when the ions generated in response to the short time irradiation of a laser light reach the ion inlet (25). This decreases the Mathieu parameter qz, and the potential well becomes shallow, which makes it easy for ions to enter the ion trap (20). Although the ions that have been already captured become more likely to disperse, the frequency of the square wave voltage is decreased before they deviate from the stable orbit. Thus, the dispersion of the ions can also be avoided. Accordingly, while the number of captured ions is not decreased, new ions are further added, and thereby the amount of ions can be increased. By performing a mass separation and detection after that, the signal intensity in one mass analysis can be increased.

Abstract: An ion trap comprises substantially elongate electrodes 10, 20 some of which are curved along their axis of elongation and which define a trapping volume between them. The sectional area of this trapping volume towards the extremities of the trap in the direction of elongation is different to the sectional area away from its extremities (eg towards the middle of the trap). In a preferred embodiment, the trap has a plurality of elongate electrodes, wherein opposed electrodes have different radii of curvature so that the trap splays towards its extremities. Thereby, a wider mass range of ions can be trapped and ejected, a higher space charge capacity (for a given trap length) is provided, and sharper ion beam focussing on ejection is possible.

Abstract: A novel method and mass spectrometer apparatus is introduced to spatially and temporally resolve images of one or more ion exit patterns of a multipole instrument. In particular, the methods and structures of the present invention measures the ion current as a function of time and spatial displacement in the beam cross-section of a quadrupole mass filter via an arrayed detector. The linearity of the detected quadrupole ion current in combination with it reproducible spatial-temporal structure enables the deconvolution of the contributions of signals from individual ion species in complex mixtures where both sensitivity and mass resolving power are essential.

Abstract: Disclosed is an ion gate for a dual IMS and method. The ion gate includes an ion source, a first gate electrode placed on one side of the ion source, a second gate electrode placed on the other side of the ion source, a third gate electrode placed on the side of the first gate electrode away from the ion source, a fourth gate electrode placed on the side of the second gate electrode away from the ion source, wherein during the ion storage, the potential at the position on the tube axis of the ion gate corresponding to the first gate electrode is different from the potentials at the positions on the tube axis corresponding to the ion source and the third gate electrode, and the potential at the position on the tube axis corresponding to the second gate electrode is different from the potentials at the positions on the tube axis corresponding to the ion source and the fourth gate electrode.

Abstract: This invention relates to a method of operating a charged particle trap in which ions undergo multiple reflections back and forth and/or follow a closed orbit around, usually, a set of electrodes. The invention allows high-performance isolation of multiple ion species for subsequent detection or fragmentation by deflecting ions out of the ion trap according to a timing scheme calculated with reference to the ions' periods of oscillation within the ion trap.

Abstract: An ion mobility spectrometer has a reaction region separated from a drift region by an electrostatic gate. A doping circuit supplies a dopant to the reaction region but the drift region is undoped. Two high field ion modifiers are located one after the other in the drift region. One ion modifier can be turned on to remove dopant adducts from the admitted ions, or both ion modifiers can be turned on so that the ions are also fragmented. In this way, several different responses can be produced to provide additional information about the nature of the analyte substance and distinguish it from interferents.

Abstract: In a mass spectrometer with an electrostatic ion trap, the electrostatic ion trap has an outer electrode with an ion-repelling electric potential applied to it and a plurality of inner electrodes with ion-attracting potentials applied to each inner electrode. The outer electrode and the inner electrodes are shaped and arranged in such a way that a harmonic electric potential is formed in one spatial direction and, perpendicular to this spatial direction, an electric potential is formed in which ions move in stable, radial trajectories.

Abstract: An ion mobility spectrometer has two drift chambers and a common, doped reaction region. Each drift chamber includes an ion modifier, such as one that fragments the doped ions by a high electrical field. One of the drift chambers is doped and the other is undoped. In this way, the dopant adducts are removed by the modification process but then recombine with dopant only in the doped chamber so that different outputs are produced by the two drift chambers.

Abstract: A novel method and mass spectrometer apparatus is introduced to enable the simultaneous isolation of cations and anions (i.e., precursor and reagent ions) in a linear multipole ion trap via the application of an additional axial DC gradient in combination with coupled RF potential(s). Thus, the combination of the RF and DC voltages in such an arrangement forms a pseudopotential designed to provide for minima for the trapped positively and negatively charged particles that result in the overlap of the ion clouds so as to provide for beneficial ion/ion reactions.

Abstract: An ion trap comprising elongate rods, electrodes, a first circuit, and a second circuit. The rods are for defining the radial extent of a trapping volume. The first circuit is connected to the rods for applying thereto a first RF signal that generates adjacent the trapping volume a radial RF containment field that radially contains ions of different polarities within the trapping volume. The electrodes define the axial extent of the trapping volume. The second circuit is connected to the electrodes for applying thereto a second RF signal that generates adjacent the trapping volume an axial RF containment field that axially contains the ions of different polarities within the trapping volume. The axial RF containment field is independent of the radial RF containment field.

Abstract: Fragment ion spectra are acquired in Kingdon ion traps that have a potential well for harmonic oscillations of the ions in the longitudinal direction and in which the ions can oscillate radially in a plane between two or more inner electrodes. Metastable ions, preferably produced by laser desorption, are introduced into the Kingdon ion trap close to the minimum of the longitudinal potential well and stored there locally for a predetermined time period. Excess internal energy in the metastable ions causes most of the ions to decompose ergodically to fragment ions. Then the fragment ions and any remaining analyte ions are excited to execute harmonic oscillations in the longitudinal potential well. The harmonic oscillations are measured as image currents, from which a high-resolution mass spectrum of the fragment ions can be calculated.

Abstract: According to an aspect of the present invention, there are provided an ion trap mass spectrometry method and an ion trap mass spectrometry device using a mass spectrometer, the mass spectrometer including: an ion source part for ionizing a sample; an ion trap part for trapping ions generated in the ion source; a main high frequency power source for applying a main high frequency voltage to the ion trap part, and an auxiliary high frequency power source for applying an auxiliary high frequency voltage thereto; and a detector for detecting the ions ejected from the ion trap. The ion trap mass spectrometry method and the ion trap mass spectrometry device includes the steps of: accumulating desired ions into the ion trap part by ejecting undesired ions while accumulating ions into the ion trap part; and ejecting undesired ions that remain in the ion trap part and leaving the desired ions in the ion trap part are repeated alternately.

Abstract: A system and method of mass spectrometry is provided. Ions from an ion source are stored in a first ion storage device and in a second ion storage device. Ions are ejected from the first ion storage device to a first mass analysis device during a first ejection time period, for analysis during a first analysis time period. Ions are ejected from the second ion storage device to a second mass analysis device during a second ejection time period. The ion storage devices are connected in series such that an ion transport aperture of the first ion storage device is in communication with an ion transport aperture of the second ion storage device. The first analysis time period and the second ejection time period at least partly overlap.

Abstract: The present invention relates to an ion trap with a large trap capacity. A mass spectrometer comprises a first linear ion trap that performs mass selective ejection, and a second linear ion trap that accumulates and then mass selectively ejects ions ejected from the first linear ion trap. Directions of resonant excitation of ions of the first linear ion trap and of the second linear ion trap are orthogonal. Compared to conventional art, sensitivity is significantly improved.

Abstract: A radio frequency (RF) drive system and method for driving the ion trap or mass filter of a mass spectrometer has a programmable RF frequency source coupled to a RF gain stage. The RF gain stage is transformer coupled to a tank circuit formed with the ion trap or mass filter. The power of the RF gain stage driving the ion trap or mass filter is measured using a sensing circuit and a power circuit. A feedback value is generated by the power circuit that is used to adjust the RF frequency source. The frequency of the RF frequency source is adjusted until the power of the RF gain stage is at a minimum level. The frequency value setting the minimum power is used to operate the RF drive system at the resonance frequency of the tank circuit formed with the transformer secondary inductance and the ion trap or mass filter capacitance.

Abstract: The present invention relates generally to mass spectrometry and the analysis of chemical samples, and more particularly to ion guides for use therein. The invention described herein comprises an improved method and apparatus for transporting ions from a first pressure region in a mass spectrometer to a second pressure region therein. More specifically, the present invention provides a segmented ion funnel for more efficient use in mass spectrometry (particularly with ionization sources) to transport ions from the first pressure region to the second pressure region.

Abstract: An interface for use in a mass spectrometer is disclosed. The interface comprises a first ion funnel comprising a first inlet and a first outlet, and a first axis between the first inlet and the first outlet. The interface further comprises a second ion funnel in tandem with the first ion funnel, the second ion funnel comprising a second inlet and a second outlet, and a second axis between the second inlet and the second outlet. The first axis and the second axis are offset relative to one another. A mass spectrometer comprising the interface and a method are disclosed.

Abstract: The invention relates to the evaluation of mass spectra from mass spectrometers in which ions are excited to mass-specific oscillating or orbiting motions, and the ion motion is recorded as a time signal. The invention provides methods to detect parameter drift that occurs during the recording of a time signal in such a “frequency mass spectrometer” by analyzing the instantaneous frequency or the phase spectrum of a frequency component, and provides a method to correct for influence of the frequency drift on the mass spectrum correspondingly. In one embodiment a Fourier transformation converts a measured time signal into a frequency spectrum and examines the phase spectrum of a frequency component to establish whether this phase spectrum deviates from the phase spectrum of a harmonic time signal. The phase spectrum of a harmonic time signal is either linear or constant.