Abstract: An ion detector system for a mass spectrometer is disclosed comprising an ion detector comprising an array of detector elements. The ion detector system is arranged to correct for tilt and non-linear aberrations in an isochronous plane of ions. The ion detector system generates separate first mass spectral data sets for each detector element and then applies a calibration coefficient to each of the first mass spectral data sets to produce a plurality of second calibrated mass spectral data sets. The plurality of second calibrated mass spectral data sets are then combined to form a composite mass spectral data set.

Abstract: A method and device for separating ions according to their ion mobility are disclosed. An ion guide is provided having a plurality of electrodes arranged to form an ion guiding path that extends in a closed loop. RF voltages are supplied to at least some of the electrodes in order to confine ions within said ion guiding path. A DC voltage gradient is maintained along at least a portion of a longitudinal axis of said ion guide, wherein the voltage gradient urges ions along the ion guide such that the ions separate according to their ion mobility as the ions pass along the ion guide. As time progresses the portion of the ion guide along which the DC voltage gradient is maintained is moved along the ion guide. An ion exit region is provided which moves around said ion guide such that ions exit said ion guide at different locations at different times.

Abstract: An ion trap is provided between a collision cell and a time-of-flight mass separator. During a time period in which precursor ions derived from the same compound are selected with a quadrupole mass filter, a collision energy is changed from one to another. Various product ions that are produced by dissociation respectively under collision energies of the plurality of stages and precursor ions that are not dissociated are temporarily trapped in the ion trap, and are ejected in a packet form in the state where these ions are mixed, and are introduced into the time-of-flight mass separator 6 to be subjected to a mass spectrometry. Thereby, in a data processing unit, one MS/MS spectrum in which product ions produced in various dissociation modes under various CID conditions appear is created.

Abstract: The invention relates to a method for identifying gases, which are ionized and the drift times of the positive and negative product ions through drift spaces are measured and the measured drift times are evaluated, wherein for measuring the drift times the product ions are accelerated to drift velocities by a resulting electrical field. It is provided that the positive and negative product ions move synchronously and in parallel in the same direction. The invention further relates to a device for identifying gases, which includes at least two drift tubes, wherein each of the drift tubes has at least one respective detector for detecting product ions. For this purpose, at least two drift tubes are arranged in parallel next to each other and are delimited, on one hand, by a common inlet system and, on the other hand, by at least one detector.

Abstract: An ion trap includes a containment region for containing ions, and a plurality of electrodes positioned on a regular polyhedral structure encompassing the containment region. An electrode is positioned on each vertex of the encompassing structure and at least one of the polygonal surfaces includes additional electrodes configured to form a plurality of quadrupoles on the surface. Alternating RF voltage is applied to the plurality of electrodes, so that directly neighboring electrodes are of equal amplitude and opposite polarity at any point in time. This configuration on the polyhedral structure forms a potential barrier for repelling the ions from each of the regular polygonal surfaces and containing them in the trap. Mass selective filters can be formed from the quadrupoles for parallel mass analysis in different m/z windows. Application of a small DC potential to a plate electrode outside the quadrupoles preferentially depletes single charged ions for enhanced signal-to-noise analysis.

Abstract: The invention relates to a method and a device for optimization of electric fields in measurement cells of Fourier transform ion cyclotron resonance mass spectrometers. The invention is based on the rationale that asymmetric electric fields with uniformly or non-uniformly perturbed field axes can appear in ion cyclotron resonance cells and therefore the axis of the magnetron orbit can become radially displaced. Shifted magnetron orbits negatively affect the cyclotron excitation, deteriorate the FT-ICR signal, increase the intensity of an even-numbered harmonics peak, lead to stronger side bands of the FT-ICR signal, and in extreme cases, cause loss of ions. The present invention helps in probing the shift of the magnetron motion, detecting parameters indicative of the offset of the electric field axis and/or correcting it by trimming it back to the geometric axis of the cell.

Abstract: A method for transmitting ions entrained in a flowing carrier gas into and through a gap defined by a pair of mutually facing curved electrodes comprises: inputting the ions and flowing gas into the gap through an ion inlet orifice of a first one of the pair of electrodes, the ion inlet orifice comprising an orifice wall, an orifice inlet end and an orifice outlet end, the orifice wall being smoothly convexly curved between the inlet end and the outlet end, wherein a width of the gap and a flow rate of the carrier gas through the ion inlet orifice and gap are such that the gas flow is laminar within the ion inlet orifice and gap.

Abstract: The invention generally relates to systems and methods for mass spectrometry analysis of microorganisms in samples.

Abstract: An ion manipulation method and device is disclosed. The device includes a pair of substantially parallel surfaces. An array of inner electrodes is contained within, and extends substantially along the length of, each parallel surface. The device includes a first outer array of electrodes and a second outer array of electrodes. Each outer array of electrodes is positioned on either side of the inner electrodes, and is contained within and extends substantially along the length of each parallel surface. A DC voltage is applied to the first and second outer array of electrodes. A RF voltage, with a superimposed electric field, is applied to the inner electrodes by applying the DC voltages to each electrode. Ions either move between the parallel surfaces within an ion confinement area or along paths in the direction of the electric field, or can be trapped in the ion confinement area.

Abstract: The invention provides a method of producing a mass spectrum, comprising: obtaining a transient from the oscillation of ions in a mass analyser; Fourier transforming the transient to obtain a complex spectrum having a real component and an imaginary component; and calculating an enhanced spectrum which comprises a combination of (i) and (ii) wherein (i) comprises a Positive spectrum; and (ii) comprises an Absorption spectrum. Also provided are an apparatus for producing a mass spectrum suitable for carrying out the method as well as a method of determining a phase correction for a complex spectrum obtained by Fourier transformation from a detected transient obtained from a mass analyser.

Abstract: A method, apparatus and algorithms are disclosed for operating an open electrostatic trap (E-trap) or a multi-pass TOF mass spectrometer with an extended flight path. A string of start pulses with non equal time intervals is employed for triggering ion packet injection into the analyzer, a long spectrum is acquired to accept ions from the entire string and a true spectrum is reconstructed by eliminating or accounting overlapping signals at the data analysis stage while using logical analysis of peak groups. The method is particularly useful for tandem mass spectrometry wherein spectra are sparse. The method improves the duty cycle, the dynamic range and the space charge throughput of the analyzer and of the detector, so as the response time of the E-trap analyzer. It allows flight extension without degrading E-trap sensitivity.

Abstract: An apparatus and method for coupling RF and AC signals to provide power to a multipole in a mass spectrometer is provided. A first circuit comprises: an RF power source for providing difference mode power to the multipole via the RF signal; at least one inductor for forming at least one resonant LC circuit with the multipole for providing voltage gain for the RF signal; and a transformer, comprising a secondary tap, the transformer connected in parallel to the RF power source and further connected to the at least one inductor such that the signals injected into the secondary tap are communicated to the at least one resonant LC circuit.

Abstract: A RF only quadrupole rod set mass filter or mass analyser and a linear quadrupole ion trap with axial ejection are disclosed comprising a first pair of rod electrodes, a second pair of rod electrodes and an energy filter. The first pair of rod electrodes is longer than the second pair of rod electrodes. Ions having desired mass to charge ratios experience fringing fields at an exit region which results in the ions possessing sufficient axial kinetic energy to be transmitted by the energy filter. Other ions possess insufficient axial kinetic energy to be transmitted by the energy filter and are attenuated.

Abstract: A method for raising the resolving power, specificity, and peak capacity of conventional ion mobility spectrometry is disclosed. Ions are separated in a dynamic electric field comprising an oscillatory field wave and opposing static field, or at least two counter propagating waves with different parameters (amplitude, profile, frequency, or speed). As the functional dependencies of mean drift velocity on the ion mobility in a wave and static field or in unequal waves differ, only single species is equilibrated while others drift in either direction and are mobility-separated. An ion mobility spectrum over a limited range is then acquired by measuring ion drift times through a fixed distance inside the gas-filled enclosure. The resolving power in the vicinity of equilibrium mobility substantially exceeds that for known traveling-wave or drift-tube IMS separations, with spectra over wider ranges obtainable by stitching multiple segments.

Abstract: A mass analyzer comprises: an electrical field generator, providing a time-varying electric field for injection of ions to be analyzed, excitation of ions to be analyzed or both; first and second detection electrodes, each of which receives a respective voltage pickup due to the time-varying electric field and provides a respective detection signal based on a respective image current at the detection electrode; and a differential amplifier, providing an output based on the difference between the detection signal for the first detection electrode and the detection signal for the second detection electrode. It may also be provided that the electrical field generator comprises at least one field generating electrode without a spatially symmetrical counterpart and the capacitance between each field generating electrode and the first detection electrode is substantially the same as the capacitance between that field generating electrode and the second detection electrode.

Abstract: A mass analyser is provided comprising a plurality of electrodes having apertures through which ions are transmitted. A plurality of pseudo-potential corrugations are created along the axis of the mass analyser. The amplitude or depth of the pseudo-potential corrugations is inversely proportional to the mass to charge ratio of an ion. Transient DC voltages are applied to the electrodes in order to urge ions along the length of the mass analyser. 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 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.

Abstract: An ion manipulation method and device is disclosed. The device includes a pair of substantially parallel surfaces. An array of inner electrodes is contained within, and extends substantially along the length of, each parallel surface. The device includes a first outer array of electrodes and a second outer array of electrodes. Each outer array of electrodes is positioned on either side of the inner electrodes, and is contained within and extends substantially along the length of each parallel surface. A DC voltage is applied to the first and second outer array of electrodes. A RF voltage, with a superimposed electric field, is applied to the inner electrodes by applying the DC voltages to each electrode. Ions either move between the parallel surfaces within an ion confinement area or along paths in the direction of the electric field, or can be trapped in the ion confinement area.

Abstract: An object is to measure both cations and anions with high duty cycle. In a mass spectrometer comprising an ion source (1), an ion guide part (31), and an ion trap (32), while ions are being mass-selectively ejected from the ion trap, ions having a polarity reverse to that of the ions trapped in the ion trap are introduced into the ion guide part.

Abstract: A mass spectrometer for analyzing a sample utilizing an ion trap comprises an entrance end cap defining an entrance aperture configured to receive the sample entering the ion trap; a ring electrode defining a ring cavity configured to generate, based on a radio frequency (RF) voltage applied to the ring electrode, an electric field configured to trap the sample received through the entrance aperture; an exit end cap defining an exit aperture configured to receive sample ions exiting the ion trap; and an end cap controller configured to generate a bias control voltage for applying a DC bias potential to at least one of the entrance end or the exit end cap, wherein a value of the bias control voltage is based on an operational parameter of the mass spectrometer.

Abstract: An ion trap for a mass spectrometer is disclosed. The ion trap includes a ring electrode and first and second electrodes which are arranged on opposite sides of the ring electrode. The ring electrode and the first and second electrodes are configured to generate an electric field based on the received RF signal. The first electrode defines a first aperture and the second electrode defines a second aperture, the first aperture and the second aperture being asymmetric relative to each other and configured to generate a hexapole field.

Abstract: A mass spectrometer comprising a controller configured to generate an RF signal to be applied to an electrode during the mass scan, wherein the electrode generates, based on the RF signal, an electric field to be applied to sample ions during a mass scan; an ion detector configured to detect sample ions passing through the electric field and generate a corresponding ion detection signal; and a sampling circuit configured to sample the ion detection signal; wherein the controller is configured to adjust a phase of the at least one RF signal relative to a sample timing of the sampling circuit and average successive mass scans to cancel a portion of the RF signal present in the ion detection signal.

Abstract: The present invention generally relates to mass spectrometry and related techniques, and in some cases, to determining single species using mass spectrometry. In certain instances, polymers such as DNA or RNA can also be sequenced. Certain embodiments of the invention relate to passing a polymer, such as DNA, RNA, a protein, a polypeptide, a polysaccharide, etc., through a pore and cleaving the polymer in sequence. For instance, the polymer may be cleaved using a laser or an electric field. In some embodiments, a property of at least one subunit of a polymer is determined using mass spectrometry. In some embodiments, a single ion (which may be a subunit of a polymer, or an ion based on another species) can be isolated in a mass spectrometer and a signal generated from the single ion.

Abstract: A glass ceramic including an alkali metal earth oxide, e.g. SrO suitable for overmolding a RF component provides a good RF response and good mechanical robustness. Specifically, SrO reduces the flow temperature of the ceramic while maintaining the RF and mechanical performance. The resulting glass formulation contains 10-50 mol % SrO, 5-30 mol % Al2O3, and 20-60 mol % B2O3.

Abstract: An ion mobility separator or spectrometer is disclosed comprising an inner cylinder and an outer cylinder defining an annular volume through which ions are transmitted. Spiral electrodes a-f are arranged on a surface of the inner cylinder and/or on a surface of the outer cylinder. A first device is arranged and adapted to maintain a DC electric field or a pseudo-potential force which acts to urge ions from a first end of the ion mobility separator or spectrometer to a second end of the ion mobility separator or spectrometer. A second device is arranged and adapted to apply one or more transient DC voltages to the spiral electrodes in order to urge ions towards the first end of the ion mobility separator or spectrometer. The net effect is to extend the effective path length of the ion mobility separator.

Abstract: An ion trap includes a containment region for containing ions, and a plurality of electrodes positioned on a regular polyhedral structure encompassing the containment region. An electrode is positioned on each vertex of the encompassing structure and at least one of the polygonal surfaces includes additional electrodes configured to form a plurality of quadrupoles on the surface. Alternating RF voltage is applied to the plurality of electrodes, so that directly neighboring electrodes are of equal amplitude and opposite polarity at any point in time. This configuration on the polyhedral structure forms a potential barrier for repelling the ions from each of the regular polygonal surfaces and containing them in the trap. Mass selective filters can be formed from the quadrupoles for parallel mass analysis in different m/z windows. Application of a small DC potential to a plate electrode outside the quadrupoles preferentially depletes single charged ions for enhanced signal-to-noise analysis.

Abstract: Described herein are methods and systems related to the use of the pre-existing ion injection pathway of a mass spectrometer to perform beam-type collision-activated dissociation, as well as other dissociation methods. The methods can be practiced using a wide range of mass spectrometer configurations and allows MSn experiments to be performed on very basic mass spectrometers, even those without secondary mass analyzers and/or collision cells. Following injection and selection of a particular ion type or population, that population can be fragmented via beam-type collision-activated dissociation (CAD), as well as other dissociation methods, using the pre-existing ion injection pathway or inlet of a mass spectrometer. For CAD applications, this is achieved by transmitting the ions back along the ion injection pathway with a high degree of kinetic energy. As the ions pass into the higher pressure regions located in or near the atmospheric pressure inlet, the ions are fragmented and then trapped.

Abstract: In order to provide an analysis method that is capable of determining a glycan structure with high detection sensitivity, a method of the present invention includes the steps of: carrying out triple quadrupole mass spectrometry at various values of CID energy; creating an energy-resolved profile including yield curves representing relationships between (i) a value of the CID energy and (ii) measured amounts of specific types of product ions; preparing a reference profile, and identifying a glycan structure of a test material by comparing the energy-resolved profile with the reference profile.

Abstract: An electrode changeover switch which switches the connection state of electrodes is provided in the wiring path between eight electrodes through, arranged rotation-symmetrically about ion optical axis, and voltage generation switch which generates square wave high voltage ±V. When switch is switched as shown in the drawing, two circumferentially adjacent rod electrodes are connected to form one set, a square wave voltage of opposite phase is applied to circumferentially adjacent sets, and an effectively quadrupole electric field is formed. When switch is switched, a square wave voltage of opposite phase is applied to circumferentially adjacent rod electrodes and an octupole electric field is formed. In this way, by switching the switch according to the mass range, etc., it becomes possible to rapidly switch the number of poles of a multipole electric field and to suitably transport ions.

Abstract: The present disclosure provides a new tandem mass spectrometer and methods of using the same for analyzing charged particles. The differentially pumped dual linear quadrupole ion trap mass spectrometer of the present disclose includes a combination of two linear quadrupole (LQIT) mass spectrometers with differentially pumped vacuum chambers.

Abstract: A mass spectrometer is disclosed comprising a RF ion guide wherein in a mode of operation a continuous, quasi-continuous or pulsed beam of ions is orthogonally sampled from the ion guide and wherein the continuous, quasi-continuous or pulsed beam of ions is not axially trapped or otherwise axially confined within the RF ion guide. The ion guide is maintained, in use, at a pressure selected from the group consisting of: (i) 0.0001-0.001 mbar; (ii) 0.001-0.01 mbar; (iii) 0.01-0.1 mbar; (iv) 0.1-1 mbar; (v) 1-10 mbar; (vi) 10-100 mbar; and (vii) >100 mbar.

Abstract: An orbital ion trap for electrostatic field ion trapping which includes an electrode structure defining an internal volume of the trap with at least some of electrode surfaces shaped to substantially follow equipotential lines of an ideal quadro-logarithmic electric potential around a longitudinal axis z. The ideal electric potential has an inner potential canyon, an outer potential canyon, and a low potential passage therebetween. The trap includes a trapping voltage supply which provides trapping voltages on the electrodes to generate a trapping electrostatic potential within the internal volume of the trap. The trapping electrostatic potential closely approximates at least a part of the ideal electric potential in at least a part of the internal volume of the trap.

Abstract: A mass spectrometer is disclosed comprising a quadrupole rod set ion trap wherein a potential field is created at the exit of the ion trap which decreases with increasing radius in one radial direction. Ions within the ion trap are mass selectively excited in a radial direction. Ions which have been excited in the radial direction experience a potential field which no longer confines the ions axially within the ion trap but which instead acts to extract the ions and hence causes the ions to be ejected axially from the ion trap.

Abstract: An ion mobility spectrometer has an inlet for an analyte substance opening into an ionization region that produces ions of the substance. Parallel grid electrodes extend laterally across the ion flow path and apply an electric field to the ions that is switchable between a relatively low magnitude alternating field that varies in magnitude over multiple periods and an asymmetric alternating field of sufficiently high magnitude to cause differential mobility effects. A collector collects the passed ions, and an indication of the nature of the analyte substance is produced from the collected ions passed during both the low and high field intervals. Also disclosed is the application of a substantially alternating field between the electrodes, which field varies between a low value and a higher value over a time exceeding that of the alternating period.

Abstract: An ion guide that transports ions from an ion source at generally a high-pressure level to a mass analyzer at generally a low-pressure level has a plurality of identical electrodes fabricated with protruding elements that forming an ion tunnel or an ion funnel, when the electrodes are assembled around a common longitudinal axis. The protruding elements allow the generation of the radio frequency field necessary to radially confine ions. Each electrode may be machined from a solid block of conductive material, such as metal. The disclosed arrangement greatly simplifies the manufacturing process, reducing cost, and improving robustness and reliability of the ion guide itself.

Abstract: A system and method for mass spectrometry including a curtain gas chamber defined by a curtain plate having an aperture for receiving ions from an ion source and an orifice plate having an inlet into a mass spectrometer. At least one barrier separates the curtain chamber into a first curtain gas chamber region and a second curtain gas chamber region. At least one gas source provides a gas inflow into the second curtain gas chamber region and a gas outflow into the first curtain gas chamber region, a portion of the gas outflow directed out of the aperture. A heating element heats the gas inflow, a portion of the heated gas inflow directed into the inlet of the mass spectrometer wherein the portion of the heated gas inflow can be at a substantially higher temperature than the portion of the gas outflow.

Abstract: A mass analyser comprises: an electrical field generator, providing a time-varying electric field for injection of ions to be analysed, excitation of ions to be analysed or both; first and second detection electrodes, each of which receives a respective voltage pickup due to the time-varying electric field and provides a respective detection signal based on a respective image current at the detection electrode; and a differential amplifier, providing an output based on the difference between the detection signal for the first detection electrode and the detection signal for the second detection electrode. It may also be provided that the electrical field generator comprises at least one field generating electrode without a spatially symmetrical counterpart and the capacitance between each field generating electrode and the first detection electrode is substantially the same as the capacitance between that field generating electrode and the second detection electrode.

Abstract: Mass spectrometers and methods for measuring information about samples using mass spectrometry are disclosed.

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: Disclosed herein is an electrospray ionization source that provides improved temperature control compared to prior sources. A combination of a continuous flow sample design and the use of a long heat shield combine to improve thermal control and reduce memory effects observed with prior designs. The temperature-controlled source is particularly useful for the study of biomolecules, particularly the study of protein aggregation.

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: The present invention relates generally to the field of ion storage and analysis, in particular to a linear ion trap mass analyzer comprised by multiple columnar electrodes. High frequency voltages are applied on at least one of the columnar electrodes to form ion confining space, which mainly consists of two-dimensional quadrupole electric radial trapping field, and there is at least one through slot for ion ejection in at least one direction perpendicular to the axis of the ion trap, wherein an AC electric field superposition is applied to invoke dipole excitation. Opposite to the through slot, there is an elongated electrode for field adjusting between two columnar electrodes or inside the slit of one of the columnar electrodes mentioned above. The potential on the elongated electrode for field adjusting is set as the sum of a portion of the high frequency voltage which applied on one adjacent columnar electrode and a DC offset, which can be adjusted freely.

Abstract: A mass spectrometer is disclosed wherein an ion signal is split into a first and second signal. The first and second signals are multiplied by different gains and are digitised. Arrival time and intensity pairs are calculated for both digitised signals and the resulting time and intensity pairs are combined to form a high dynamic range spectrum. The spectrum is then combined with other corresponding spectra to form a summed spectrum.

Abstract: In one embodiment, a mass spectrometer includes an RF drive circuit for generating RF signals, a quadrupole mass filter, and a fixed connection assembly for delivering RF signals from the RF drive circuit to the quadrupole mass filter, the fixed connection assembly representing the entire delivery path of RF signals from the RF drive circuit to the quadrupole mass filter. By avoiding flexible components such as a freestanding wires or flexible circuit boards, the need for retuning when parts are removed or disturbed for testing or servicing is reduced, and a modular instrument in which components and connections are standardized and therefore interchangeable is realized.

Abstract: A novel scanning method of a mass spectrometer apparatus is introduced so as to relate by simple time shifts, rather than time dilations, the component signal (“peak”) from each ion even to an arbitrary reference signal produced by a desired homogeneous population of ions. Such a method and system, as introduced herein, is enabled in a novel fashion by scanning exponentially the RF and DC voltages on a quadrupole mass filter versus time while maintaining the RF and DC in constant proportion to each other. In such a novel mode of operation, ion intensity as a function of time is the convolution of a fixed peak shape response with the underlying (unknown) distribution of discrete mass-to-charge ratios (mass spectrum). As a result, the mass distribution can be reconstructed by deconvolution, producing a mass spectrum with enhanced sensitivity and mass resolving power.

Abstract: A mass analyzer is provided comprising a plurality of electrodes having apertures through which ions are transmitted. A plurality of pseudo-potential corrugations are created along the axis of the mass analyzer. The amplitude or depth of the pseudo-potential corrugations is inversely proportional to the mass to charge ratio of an ion. Transient DC voltages are applied to the electrodes in order to urge ions along the length of the mass analyzer. 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 analyzer 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 while the second AC or RF voltage is arranged to provide optimal radial confinement of ions within the mass analyzer.

Abstract: Described herein are methods and systems related to the use of the pre-existing ion injection pathway of a mass spectrometer to perform beam-type collision-activated dissociation, as well as other dissociation methods. Following injection and selection of a particular ion type or population, that population can be fragmented using the pre-existing ion injection pathway or inlet of a mass spectrometer. This is achieved by transmitting the ions back along the ion injection pathway. As the ions pass into the higher pressure regions located in or near the atmospheric pressure inlet, the ions are fragmented and then trapped. Following fragmentation and trapping, the ions can either be re-injected into the primary ion selection device or sent on to a secondary mass analyzer.

Abstract: A cross-flow ion mobility spectrometer consists of two parallel plates defining a volume between them. Analyte ions flow along an axis from an entrance end to an exit end through the volume. An RF confining field tends to guide ions along the axis. An analytical gas flow is established orthogonal to the axis. A DC electrostatic analytical field is oriented in opposition to the analytical gas flow such that the “drag force” on ions of the selected mobility due to the analytical gas flow is balanced by the force on the ions due to the electrostatic analytical field. The selected ions are thereby able to follow a stable path to the exit end of the cross-flow mobility analyzer. However, the force on ions of other than the selected mobility is unbalanced and these ions are deflected and lost.

Abstract: A quadrupole mass spectrometer alternates between increasing mass and decreasing mass scans for the purpose of decreasing inter-scan delays. By alternating increasing and decreasing mass scans, the next scan starts where the last scan ended reducing the settling time required. Backsteps may be eliminated by scanning the RF and DC non-linearly.

Abstract: An ion guide or mass analyser is disclosed comprising a plurality of electrodes having apertures through which ions are transmitted in use. A pseudo-potential barrier is created at the exit of the ion guide or mass analyser. The amplitude or depth of the pseudo-potential barrier 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 ion guide or mass analyser in order to urge ions along the length of the ion guides or mass analyser. The amplitude of the transient DC voltage applied to the electrode may be increased with time so that ions are caused to be emitted from the ion guide or mass analyser in reverse order of their mass to charge ratio.

Abstract: A mass spectrometer is disclosed comprising a first storage ion trap arranged upstream of a high performance analytical ion trap. According to an embodiment ions are simultaneously scanned from both the first and second ion trap. At any instant in time the quantity of charge present within the second ion trap is limited or restricted so that the second ion trap does not suffer from space charge saturation effects and hence the performance of the second ion trap is not degraded.