Abstract: An electrode member (11, 12) having two electrode plain plate portions (21) and one circular portion (20) is created from a single metal plate, where the two electrode plain plate portions (21) belong to every other virtual rod electrode around the ion optical axis and face across the ion optical axis, and the circular portion (20) electrically connects these two electrode plain plate portions (21). A predetermined number of resin electric holders (13) each holding the electrode member (11, 12) are stacked in the ion optical axis direction, with every other electric member rotated by 90° around the ion optical axis, to form a virtual quadrupole rod type ion guide. Since this configuration reduces the number of components more than ever before and saves a cable for connecting electrode plain plate portions (21, 25) to which the same voltage should be applied, it is possible to reduce the cost and facilitate assembly and regulation in manufacturing and use.

Abstract: The exemplary embodiments provide a method, system, and device for identifying chemical species in a sample. According to one embodiment, the method, system, and device may include introducing a sample gas into a differential ion mobility device, ionizing at least a portion of the sample gas to generate at least one ion species, filtering the at least one ion species between a pair of filter electrodes, generating a detection signal in response to the at least one ion species depositing a charge on a collector electrode, and detecting a spectral peak associated with the at least one ion species.

Abstract: The direct current bias voltage to be applied to the pre-filter provided in the previous stage of the quadrupole mass filter for selecting an ion according to the mass-to-charge ratio is changed in accordance with the mass-to-charge ratio of the target ion to be allowed to pass through, in order that the time period required for an ion to pass through the pre-filter is uniformed regardless of the mass-to-charge ratio, and simultaneously the phase of the oscillation of ions at the entrance of the quadrupole mass filter is also uniformed. In the range where the mass-to-charge ratio is larger than some degree, the ion's oscillation itself is small, and in addition, the ion's passage efficiency deteriorates rather than enhances, due to the potential barrier created by the voltage difference from the direct current bias voltage applied to the quadrupole mass filter.

Abstract: A chip-scale ion-trap mass spectrometer driven by a monolithic photodiode array and a method of fabricating the same. A high-voltage photovoltaic source is located in proximity to the ion-trap mass spectrometer structure. The high-voltage photovoltaic source includes monolithically fabricated and serially connected photodiodes. An external light source illuminates the photodiodes to generate a high voltage across the photodiode array. An RF voltage modulation is attained by modulating the light source at a desired RF frequency. The high-voltage photodiode array may be monolithically fabricated in association with the ion-trap mass spectrometer. The photodiode array requires a small area compared to the ion-trap mass spectrometer size as the spectrometer typically possess a very small capacitance and a low power consumption.

Abstract: The apparatus introduces a second adjustable resonant point in a QMS at a frequency that is close to a multiple of the fundamental frequency by adjusting driving point impedance characteristics of the QMS. The apparatus measures the first and second resonant point of the QMS to account for changes in the operational characteristics of the QMS.

Abstract: A dual ion trap mass analyzer includes adjacently positioned first and second two-dimensional ion traps respectively maintained at relatively high and low pressures. Functions favoring high pressure (cooling and fragmentation) may be performed in the first trap, and functions favoring low pressure (isolation and analytical scanning) may be performed in the second trap. Ions may be transferred between the first and second trap through a plate lens having a small aperture that presents a pumping restriction and allows different pressures to be maintained in the two traps. The differential-pressure environment of the dual ion trap mass analyzer facilitates the use of high-resolution analytical scan modes without sacrificing ion capture and fragmentation efficiencies.

Abstract: An electrostatic trap such as an orbitrap is disclosed, with an electrode structure. An electrostatic trapping field of the form U?(r, ?, z) is generated to trap ions within the trap so that they undergo isochronous oscillations. The trapping field U?(r, ?, z) is the result of a perturbation W to an ideal field U(r, ?, z) which, for example, is hyperlogarithmic in the case of an orbitrap. The perturbation W may be introduced in various ways, such as by distorting the geometry of the trap so that it no longer follows an equipotential of the ideal field U(r, ?, z), or by adding a distortion field (either electric or magnetic). The magnitude of the perturbation is such that at least some of the trapped ions have an absolute phase spread of more than zero but less than 2 ? radians over an ion detection period Tm.

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: Ions supplied in the form of a pulse are introduced into an ion trap through an ion entering orifice while a rectangular voltage of a frequency higher than the frequency at which the best trap is accomplished is applied to a ring electrode from a trap voltage generating unit. With this, since a well of a pseudo ion potential is formed in a radial direction in the ion trap, the spread of ions of low m/z values introduced previously is suppressed. A part of ions is introduced into the ion trap, and thereafter the frequency of the rectangular voltage applied to the ring electrode is lowered stepwise to the frequency at which the best trap is accomplished. As a result, the ions of the low m/z values introduced previously can be efficiently trapped, and introduction of ions of high m/z values reaching the ion trap later is not hindered.

Abstract: An ion trap includes an electrode structure, including a first and a second opposed mirror electrodes and a central lens therebetween, that produces an electrostatic potential in which ions are confined to trajectories at natural oscillation frequencies, the confining potential being anharmonic. The ion trap also includes an AC excitation source having an excitation frequency f that excites confined ions at a frequency of about twice the natural oscillation frequency of the ions, the AC excitation frequency source preferably being connected to the central lens. In one embodiment, the ion trap includes a scan control that mass selectively reduces a frequency difference between the AC excitation frequency and about twice the natural oscillation frequency of the ions.

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 trace detection system includes at least two stages coupled to operate in series. An ion mobility spectrometer (IMS) stage has a sampling inlet to receive a sample to be analyzed. An ion source ionizes the sample. The IMS applies an electrical field to the ionized sample to move the ionized sample toward an IMS outlet. A differential mobility spectrometer (DMS) stage coupled in series with the IMS stage receives the ionized sample from the IMS stage. Preferably, the system includes a mass spectrometer (MS) stage coupled in series with the DMS stage to receive the ionized sample from the DMS stage via a vacuum interface. A roughing vacuum pump evacuates a first stage of the MS stage to a first pressure below atmospheric pressure. A high vacuum pump evacuates a second stage of the MS stage to a second pressure below the first pressure.

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: There has been a problem that both detection sensitivity and throughput cannot be improved simultaneously by a conventional MS/MS analysis method. A mass analyzer having an ion trap for ejecting ions in a specific mass range, a collisional dissociation part for causing ions ejected from the ion trap to be dissociated, a mass analyzing part for performing a mass analysis of ions ejected from the collisional dissociation part, and a control part including a list in which measurement conditions for each ion are stored selectively resonance-ejects ions introduced into and accumulated in the ion trap based on masses.

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 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: 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: A technique for performing precursor isolation with a desired mass-to-charge ratio (m/z) in a digital ion trap while maintaining the q value at a substantially constant value is provided. A data obtained by digitizing an FNF signal having a notch is stored beforehand in an FNF waveform memory 15. In the process of precursor isolation, a main voltage timing controller 7 and a main voltage generator 9 generate a rectangular-wave voltage based on a reference clock signal CK. An auxiliary signal generator 14 reads data from the FNF waveform memory 15 and generates an FNF signal by performing digital-to-analogue conversion of the data in accordance with a clock signal synchronized with the reference clock signal CK. Under the command of a controller 30, a reference clock generator 6 produces the reference clock signal CK having a frequency corresponding to the m/z value of a target ion.

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: A system and method for magnetically filtering an ion beam during an ion implantation into a workpiece is provided, wherein ions are emitted from an ion source and accelerated the ions away from the ion source to form an ion beam. The ion beam is mass analyzed by a mass analyzer, wherein ions are selected. The ion beam is then decelerated via a decelerator once the ion beam is mass-analyzed, and the ion beam is further magnetically filtered the ion beam downstream of the deceleration. The magnetic filtering is provided by a quadrapole magnetic energy filter, wherein a magnetic field is formed for intercepting the ions in the ion beam exiting the decelerator to selectively filter undesirable ions and fast neutrals.

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: Among various ions introduced into an ion trap 1, those ions which are within a predetermined mass range including the mass-to-charge ratio of an objective ion are selected. Then, the frequency of a capturing voltage is set so that the objective ion will be captured with a high q-value, and a CID gas is introduced into the ion trap 1. An excitation voltage corresponding to the mass-to-charge ratio of the objective ion is applied to end-cap electrodes 3 and 4 to cause an oscillation of the objective ion and help dissociation of the ion by CID. The high q-value leads to a high dissociation efficiency. The application of the excitation voltage is discontinued before the low-mass ions produced by CID totally dissipate. Simultaneously with this operation, or slightly delayed therefrom, the frequency of the capturing voltage is switched so that the q-value will be lowered.

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: 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: Ion mobilities are measured by entraining the ions in a gas and adiabatically expanding the ion-containing gas through a nozzle to form a gas jet. An electrical field barrier with variable height is located at the nozzle exit. The field barrier may be located adjacent to the nozzle exit or an ion guide may be located between the nozzle and the field barrier. If a continuous ion current is supplied, the height of the barrier is varied and the ion current of the ions passing over the barrier is measured, the ion current can be differentiated to generate a mobility spectrum. Alternatively, the ions can be temporarily stored in the ion guide so that measurement of the ion current of the ions passing over the barrier results in a direct measurement of the mobility spectrum.

Abstract: An electron capture dissociation device to implement a combination of electron capture dissociation and collision dissociation and a mass spectrometer with the use thereof are provided. This device includes a linear ion trap provided with linear multipole electrodes applied with a radio frequency electric field and wall electrodes that are arranged on both ends in the axis direction of the linear multipole electrodes, have holes on the central axis thereof, and generate a wall electric field by being applied with a direct-current voltage, a cylindrical magnetic field-generating unit that generates a magnetic field parallel to the central axis of the linear multipole electrodes and surrounds the linear ion trap, and an electron source arranged opposite to the linear multipole electrodes with sandwiching one of the wall electrodes. The electron generation site of the electron source is placed in the inside of the magnetic field generated by the magnetic field-generating unit.

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 high pressure collision cell for use in a mass spectrometer. The high pressure collision cell has a cell length L selected to be in a range such that upon application of voltages to a pair of opposed elongate electrically conducting electrodes there is produced an electric field of sufficient strength across the collision cell length L in to aid in directing ions entering the collision cell to along a transverse flow axis. The pressure in the collision cell is maintained in a range from about 50 mTorr to 1000 mTorr and wherein the collision cell length L and the pressure are selected such that a target thickness, defined as a product of the collision cell length L and the pressure, is maintained in a range from about 0.2 to about 2 mm-Torr.

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 mass spectrometer is disclosed comprising a first chamber (10) and a second chamber (5). The second chamber (5) is located downstream of the first chamber 10 and an inter-chamber aperture (12) is provided between the two chambers (5,10). An ion guide (13) is located in the first chamber (10) and an ion mobility spectrometer (6) is located in the second chamber (5). Helium gas is provided to the first chamber (10). As ions are accelerated towards the ion mobility spectrometer 6 from a relatively low pressure region they pass initially into the first chamber (10). The helium gas provided in the first chamber (10) minimises ion fragmentation and ion discrimination effects as ions are accelerated into a relatively high pressure region. The ions are then transmitted by the ion guide (13) and are subsequently transmitted to the ion mobility spectrometer (6) located in the second chamber (5).

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: 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: In an embodiment, a collision cell comprises rods each having a first end and a second end remote from the first end; an inductor connected between adjacent pairs of rods; and means for applying a radio frequency (RF) voltage between adjacent pairs of rods. 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.

Abstract: An ion guide array is disclosed comprising a first ion guide section (1) and a second ion guide section (2) and optionally further ion guide sections. Each ion guide section (1, 2) may comprise a plurality of electrodes having an aperture through which ions are transmitted in use. A transfer section is arranged at the exit of the first ion guide section (1) and ions are transmitted radially from the first ion guide section (1) into the second ion guide section (2). The electrodes (1b, 2b) in the transfer section may have a radial aperture enabling ions to be transmitted radially from the first ion guide section (1) to the second ion guide section (2).

Abstract: A mass spectrometer includes a linear multipole electrode, an auxiliary electrode that applies a DC potential on the center axis of the linear multipole electrode, and a DC power supply that supplies a DC power to the auxiliary electrode. The DC potential slope formed on the center axis of the multipole electrode is changed according to the measuring condition. The ejection time of ions can be adjusted optimally by adjusting the potential slope so as to satisfy the measuring condition. If the ejection time of ions is shortened, confusion of different ion information items that might otherwise occur on a spectrum can be avoided. If the ejection time of ions is lengthened, detection limit exceeding can be avoided and ions can be measured efficiently, thereby highly efficient ion measurements are always assured.

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: 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: 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: In various aspects, the present teachings provide systems and methods for reducing chemical noise in a mass spectrometry instrument that use a neutral chemical reagent and one or more mass filters to reduce interfering chemical background ion signals that are generated by ionization sources of mass spectrometers. In various embodiments, the neutral chemical reagent belongs to the class of organic chemical species containing a disulfide functionality.

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: 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: 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: In a mass spectrometer a target volume is filled with ions of different mass but substantially the same energy from a distant storage device by forming a plurality of spatially-limited ion swarms consisting of ions having the same mass. The ion swarms are ordered either by a mass-sequential extraction from the storage device or by rearranging the order of flight as the ions are in flight, so that swarms of different mass ions simultaneously enter the target volume despite having different flight velocities. A mass-sequential extraction in the order of decreasing mass can be achieved in one embodiment by decreasing a pseudopotential barrier at the storage device which causes the heavy ions to emerge first. In another embodiment, the ions can be rearranged in flight by applying a bunching potential. A second reverse bunching potential then restores the energy of the ions to their original values.

Abstract: Ions carried in a flowing gas stream are transferred to another gas stream of different composition or purity through an ion selective aperture communicating between the gas streams. The ion selective aperture is formed of a central layer which has an electrically conductive layer on each of its surfaces. One or more open channels extend through the central layer and surface layers allowing physical movement of ions therethrough under the urging and influence of an electric field created by imposing a voltage differential between the conductive surface layers of the ion selective aperture. The gas flow rates of the different gas streams may be independently varied to allow adjustment of ion concentration and flow rate to meet the needs of the ion destination. This device can control sample ion introduction into gas-phase ion detectors, such as ion mobility analyzers, differential mobility analyzers, mass spectrometers, and combinations thereof.

Abstract: A mass spectrometer having an elongated rod set, the rod set having a first end, a second end, a plurality of rods and a central longitudinal axis is described as is a method operating same.

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: 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: A chemical sample gas tube that is capable of being rapidly heated and cooled allows rapid purging of condensed chemical vapor from its inside surface. The tube may include a thin foil with an electrically conducting surface, a rigidly separated pair of clamps to shape the thin foil into a cylinder shape, and a temperature-controlled source of electricity that can flow sequentially through the clamps and thin foil for heating. The temperature of the cylindrical thin foil may be increased at a rate of at least 25 degrees Celsius per second, and may be cooled at a rate of at least 10 degrees Celsius per second. A temperature control sequence may be provided that includes at least one temperature that performs at least one of: condensing the chemical vapor, transmitting the chemical vapor, desorbing the condensed chemical vapor, and decomposing the condensed chemical vapor.