3993 results about "Mass analyzer" patented technology

A mass spectrometer is configured with individual multipole ion guides, configured in an assembly in alignment along a common centerline wherein at least a portion of at least one multipole ion guide mounted in the assembly resides in a vacuum region with higher background pressure, and the other portion resides in a vacuum region with lower background pressure. Said multipole ion guides are operated in mass to charge selection and ion fragmentation modes, in either a high or low pressure region, said region being selected according to the optimum pressure or pressure gradient for the function performed. The diameter, lengths and applied frequencies and phases on these contiguous ion guides may be the same or may differ. A variety of MS and MS / MSn analysis functions can be achieved using a series of contiguous multipole ion guides operating in either higher background vacuum pressures, or along pressure gradients in the region where the pressure drops from high to low pressure, or in low pressure regions. Individual sets of RF, + / −DC and resonant frequency waveform voltage supplies provide potentials to the rods of each multipole ion guide allowing the operation of ion transmission, ion trapping, mass to charge selection and ion fragmentation functions independently in each ion guide. The presence of background pressure maintained sufficiently high to cause ion to neutral gas collisions along a portion of each multiple ion guide linear assembly allows the conducting of Collisional Induced Dissociation (CID) fragmentation of ions by axially accelerating ions from one multipole ion guide into an adjacent ion guide. Alternatively ions can be fragmented in one or more multipole ion guides using resonant frequency excitation CID. A multiple multipole ion guide assembly can be configured as the primary mass analyzer in single or triple quadrupole mass analyzers with or without mass selective axial ejection. Alternatively, the multiple multipole ion guide linear assembly can be configured as part of a hybrid Time-Of-Flight, Magnetic Sector, Ion Trap or Fourier Transform mass analyzer.

A microfluidic device comprising an MS-analyte presentation unit for a EDI-MS apparatus, said unit comprising an essentially planar support plate which on one side has one, two or more ports (MS-ports) comprising an area (EDI area) for presenting the MS-analyte to a mass spectrometer. The EDI area comprises a layer I of conducting material. The characteristic feature of the device is that layer (I) has a conductive connection and / or that there is a calibrator area in the proximity of the MS-port.

A sample preparation method is disclosed for volatilization and mass spectrometric analysis of nonvolatile high molecular weight molecules. Photoabsorbing molecules having significant sublimation rates at room temperature under vacuum, and preferably containing hydroxy functionalities, are disclosed for use as matrices in matrix-assisted laser desorption / ionization mass spectrometry. The samples are typically cooled in the mass spectrometer to temperatures significantly below room temperature.

To provide comprehensive (i.e. rapid and sensitive) MS-MS analysis, the inventor employs a time-nested separation, using two time-of-flight (TOF) mass spectrometers. Parent ions are separated in a slow and long TOF1, operating at low ion energy (1 to 100 eV), and fragment ions are mass analyzed in a fast and short TOF2, operating at much higher keV energy. Low energy fragmentation cell between TOF1 and TOF2 is tailored to accelerate fragmentation and dampening steps, mostly by shortening the cell and employing higher gas pressure. Since separation in TOF1 takes milliseconds and mass analysis in TOF2—microseconds, the invention provides comprehensive MS-MS analysis of multiple precursor ions per single ion pulse. Slow separation in TOF1 becomes possible with an introduction of novel TOF1 analyzers. The TOF-TOF could be implemented using a static TOF1, here described on the examples of spiratron, planar and cylindrical multi-pass separators with griddles spatial focusing ion mirrors. Higher performance is expected with the use of novel hybrid TOF1 analyzers, combining radio frequency (RF) and quadratic DC fields. RF field retains low-energy ions within TOF1 analyzer, while quadratic DC field improves resolution by compensate for large relative energy spread.

A mass spectrometer is disclosed wherein ions having a particular desired charge state are selected by operating an ion mobility spectrometer in combination with a quadrupole mass filter. Precursor ions are fragmented or reacted to form product ions in a collision cell ion trap and sent back upstream to an upstream ion trap. The fragment or product ions are then passed through the ion mobility spectrometer wherein they become temporally separated according to their ion mobility. Fragment or product ions are then re-trapped in the collision cell ion trap before being released therefrom in packets. A pusher electrode of a time of flight mass analyzer is energized a predetermined period of time after a packet of ions is released from the collision cell ion trap. Accordingly, it is possible to select multiply charged precursor ions from a background of singly charged ions, fragment them, and mass analyze the fragment ions with a near 100% duty cycle across the whole mass range.

During the structural analysis of a protein or peptide by tandem mass spectroscopy, a peptide ion derived from a protein that has already been measured and that is expressed in great quantities is avoided as a tandem mass spectroscopy target. A peptide derived from a minute amount of protein, which has heretofore been difficult to analyze, can be automatically determined as a tandem mass spectroscopy target within the real time of measurement. Data concerning a protein that has already been measured and a peptide derived from the protein is automatically stored in an internal database. The stored data is collated with measured data with high accuracy to determine an isotope peak. In this way, the process of selecting a peptide peak that has not been measured as the target for the next tandem analysis can be performed within the real time of measurement and a redundant measurement of peptides derived from the same protein can be avoided. The information contained in the MSn spectrum is effectively utilized in each step of the MSn involving a multi-stage dissociation and mass spectroscopy (MSn), so that the flows for the determination of the next analysis content and the selection of the parent ion for the MSn+1 analysis, for example, can be optimized within the real time of measurement and with high efficiency and accuracy. Thus, a target of concern to the user can be subjected to tandem mass spectroscopy without wasteful measurement.

A new geometry ion trap and its use as a mass spectrometer is described. The ion traps can be combined linearly and in parallel to form systems for mass storage, analysis, fragmentation, separation, etc. of ions. The ion trap has a simple rectilinear geometry with a high trapping capacity. It can be operated to provide mass analysis in the mass-selective instability mode as well as the mass-selective stability mode. Arrays of multiple ion traps allow combinations of multiple gas-phase processes to be applied to the trapped ions to achieve high sensitivity, high selectivity and / or higher throughput in the analysis of ions.

A new geometry ion trap and its use as a mass spectrometer is described. The ion traps can be combined linearly and in parallel to form systems for mass storage, analysis, fragmentation, separation, etc. of ions. The ion trap has a simple rectilinear geometry with a high trapping capacity. It can be operated to provide mass analysis in the mass-selective instability mode as well as the mass-selective stability mode. Arrays of multiple ion traps allow combinations of multiple gas-phase processes to be applied to the trapped ions to achieve high sensitivity, high selectivity and / or higher throughput in the analysis of ions.

Disclosed is an apparatus for performing mass spectrometry and a method of analyzing a sample through mass spectrometry. In particular, the disclosure relates to an apparatus capable of ambient mass spectrometry and mass spectral imaging and a method for the same. The apparatus couples laser ablation, flowing atmospheric-pressure afterglow ionization, and a mass spectrometer.

The present invention relates to an apparatus and method for focusing, separating, and detecting gas-phase ions using the principles of quadrupole fields, substantially at or near atmospheric pressure. Ions are entrained in a concentric flow of gas and travel through a high-transmission element into a RF / DC quadrupole, through a second high-transmission element, and then impact on an ion detector, such as a faraday plate; or through an aperture with subsequent identification by a mass spectrometer. Ions with stable trajectories pass through the RF / DC quadrupole while ions with unstable trajectories drift off-axis collide with the rods and are lost. Embodiments of this invention are devices and methods for focusing, separating and detecting gas-phase ions without the need for a vacuum chamber when coupled to atmospheric ionization sources.

To provide comprehensive MS—MS analysis, a time-nested separation is employed using two time-of-flight (TOF) mass spectrometers. Parent ions are separated in a slow and long TOF1, operating at low ion energy (1 to 100eV), and fragment ions are mass analyzed in a fast and short TOF2, operating at much higher keV energy. A low energy fragmentation cell between TOF1 and TOF2 is tailored to accelerate fragmentation and dampening steps, mostly by shortening the cell and employing higher gas pressure. Slow separation in TOF1 becomes possible with an introduction of novel TOF1 analyzers. Higher performance is expected with the use of novel hybrid TOF1 analyzers, combining radio frequency (RF) and quadratic DC fields. An RF field retains low-energy ions within a TOF1 analyzer, while a quadratic DC field improves resolution by compensating for a large relative energy spread.

Atmospheric pressure, intermediate pressure and vacuum laser desorption ionization methods and ion sources are configured to increase ionization efficiency and the efficiency of transmitting ions to a mass to charge analyzer or ion mobility analyzer. An electric field is applied in the region of a sample target to accumulate ions generated from a local ion source on a solid or liquid phase sample prior to applying a laser desorption pulse. The electric field is changed just prior to or during the desorption laser pulse to promote the desorption of charged species and improve the ionization efficiency of desorbed sample species. After a delay, the electric field may be further changed to optimize focusing and transmission of ions into a mass spectrometer or ion mobility analyzer. Charged species may also be added to the region of the laser desorbed sample plume to promote ion-molecule reactions between the added ions and desorbed neutral sample species, increasing desorbed sample ionization efficiency and / or creating desired product ion species. The cycling of electric field changes is repeated in a timed sequence with one or more desorption laser pulse occurring per electric field change cycle. Embodiments of the invention comprise atmospheric pressure, intermediate pressure and vacuum pressure laser desorption ionization source methods and devices for increasing the analytical flexibility and improving the sensitivity of mass spectrometric analysis.

An improved ion source and portable analyzer for collecting and focusing dispersed gas-phase ions from a reagent source at atmospheric or intermediate pressure, having a remote source of reagent ions generated by direct or alternating currents, separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and / or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques or probes containing samples are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources.

A quadrupole ion trap mass analyzer in which the trapping volume is defined by spaced linear rods in which linear elements located between the spaced linear rods produce image currents produced by motion of ions in the trapping volume.

A multipole ion guide capable of incorporating a plurality of ion sources (i.e., MALDI, ESI, EI / CI, etc.) to provide and analyze ions in a mass analyzer (i.e., ICR, TOF, quadrupole, etc.) has been designed. Such multipole ion guides comprise an array of pairs of parallel conducting rods (i.e., 3 pair, 4 pair, 5 pair, etc.), each pair being equally spaced from one another, with the array being bound on its top and bottom as well as its ends by DC electrodes. The ion guide then utilizes RF / DC potentials to accept ions from any of a multitude of ion sources to facilitate their transmission through differentially pumped regions to a high pressure mass analysis region.

An improved ion source for collecting and focusing dispersed gas-phase ions from a reagent source at atmospheric or intermediate pressure, having a remote source of reagent ions separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and / or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources.

The present invention is an improved apparatus and method for mass spectrometry using a dual ion trapping system. In a preferred embodiment of the present invention, three "linear" multipoles are combined to create a dual linear ion trap system for trapping, analyzing, fragmenting and transmitting parent and fragment ions to a mass analyzer-preferably a TOF mass analyzer. The dual ion trap according to the present invention includes two linear ion traps, one positioned before an analytic quadrupole and one after the analytic multipole. Both linear ion traps are multipoles composed of any desired number of rods-i.e. the traps are quadrupoles, pentapoles, hexapoles, octapoles, etc. Such arrangement enables one to maintain a high "duty cycle" while avoiding "memory effects" and also reduces the power consumed in operating the analyzing quadrupole.

An improved lens for collecting and focusing dispersed charged particles or ions having a stratified array of elements at atmospheric or near-atmospheric pressure, each element having successively smaller apertures forming a tapered terminus, wherein the electrostatic DC potentials are applied to each element necessary for focusing ions through the stratified array for introducing charged particles and ions into the vacuum system of a mass spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when coupled to both high and low electrostatic field atmospheric pressure ionization sources.

A mass spectrometer comprising an ion mobility separator for separating ions according to their ion mobility is disclosed. The ion mobility separator comprises a plurality of electrodes and one or more transient DC voltages or one or more transient DC voltage waveforms are progressively applied to the electrodes so that ions having a certain ion mobility are separated from other ions having different ion mobilities.

It is arranged so that ions can be analyzed accurately and with high sensitivity. A first electrode 11 is provided on the outer periphery of a dielectric cylindrical body 13 and a second electrode 12 is placed inside the cylindrical body 13 leaving a clearance between itself and the inner surface of the cylindrical body 13. When an AC high voltage is impressed across the first electrode 11 and second electrode 12, a barrier discharge occurs within the cylindrical body 13. When a distal end portion 12a of the second electrode 12 projects outwardly from the distal end of the cylindrical body 13, a thermal equilibrium plasma P having a low electron temperature is generated outwardly of the distal end of the cylindrical body 13 without a plasma jet ascribable to the barrier discharge emerging outwardly from the distal end of the cylindrical body 13. By exposing a sample S to the thermal equilibrium plasma P, particles (atoms, molecules) desorbed from the sample S undergo soft ionization without being decomposed or polymerized. The ions generated are introduced to a mass analyzer 50.

A system and method for analyzing and imaging a sample containing molecules of interest combines modified MALDI mass spectrometer and SNOM devices and techniques, and includes: (A) an atmospheric-pressure or near-atmospheric-pressure ionization region; (B) a sample holder for holding the sample; (C) a laser for illuminating said sample; (D) a mass spectrometer having at least one evacuated vacuum chamber; (E) an atmospheric pressure interface connecting said ionization region and said mass spectrometer; (F) a scanning near-field optical microscopy instrument comprising a near-field probe for scanning the sample; a vacuum capillary nozzle for sucking in particles which are desorbed by said laser, the nozzle being connected to an inlet orifice of said atmospheric pressure interface; a scanner platform connected to the sample holder, the platform being movable to a distance within a near-field distance of the probe; and a controller for maintaining distance information about a current distance between said probe and said sample; (G) a recording device for recording topography and mass spectrum measurements made during scanning of the sample with the near-field probe; (H) a plotting device for plotting said topography and mass spectrum measurements as separate x-y mappings; and (I) an imaging device for providing images of the x-y mappings.

The present invention relates generally to a multi-reflecting time-of-flight mass spectrometer (MR TOF MS). To improve mass resolving power of a planar MR TOF MS, a spatially isochronous and curved interface may be used for ion transfer in and out of the MR TOF analyzer. One embodiment comprises a planar grid-free MR TOF MS with periodic lenses in the field-free space, a linear ion trap for converting ion flow into pulses and a C-shaped isochronous interface made of electrostatic sectors. The interface allows transferring ions around the edges and fringing fields of the ion mirrors without introducing significant time spread. The interface may also provide energy filtering of ion packets. The non-correlated turn-around time of ion trap converter may be reduced by using a delayed ion extraction from the ion trap and excessive ion energy is filtered in the curved interface.

An improved ion source for collecting and focusing dispersed gas-phase ions from a reagent source at sub-atmospheric or intermediate pressure, having a remote source of reagent ions separated from a low-field sample ionization region by a barrier, comprised of alternating laminates of metal and insulator, populated with a plurality of openings, wherein DC potentials are applied to each metal laminate necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and / or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to sub-atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermal-pneumatic ionization sources.

An atmospheric pressure ion source, e.g. for a mass spectrometer, that produces ions by atmospheric pressure photoionization (APPI). It includes a vaporizer, a photon source for photoionizing vapor molecules upon exit from the vaporizer, a passageway for transporting ions to, for example, a mass spectrometer system, and a means for directing the ions into the passageway. The center axis of the vaporizer and the center axis of the passageway form an angle that may be about 90 degrees. Included in the invention is a method for creating ions by atmospheric pressure photoionization along an axis and directing them into a passageway oriented at an angle to that axis.

An improved ion source and means for collecting and focusing dispersed gas-phase ions from a remote reagent chemical ionization source (R2CIS) at atmospheric or intermediate pressure is described. The R2CIS is under electronic control and can produce positive, negative, or positive and negative reagent ions simultaneously. This remote source of reagent ions is separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the R2CIS into the low-field sample ionization region where the reagent ions react with neutral and / or ionic sample forming sample ionic species. The resulting sample ionic species are then introduced into a mass spectrometer, ion mobility spectrometer or other sensor capable of detecting the sample ions. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources; and improving the sensitivity of chemical detectors or probes.

The present invention discloses methods for deconvolving and converting 1D mass spectra to 2D mass spectrum in order to obtain migration time centers and total intensities of the neutral mass envelopes of 2D spectra. The present invention also discloses devices that include a preparation / separation unit coupled to a mass spectrometer unit, and a computer unit capable of deconvolving mass spectra and calculating neutral mass envelopes.

Apparatus and methods are provided that enable the interaction of low-energy electrons and positrons with sample ions to facilitate electron capture dissociation (ECD) and positron capture dissociation (PCD), respectively, within multipole ion guide structures. It has recently been discovered that fragmentation of protonated ions of many biomolecules via ECD often proceeds along fragmentation pathways not accessed by other dissociation methods, leading to molecular structure information not otherwise easily obtainable. However, such analyses have been limited to expensive Fourier transform ion cyclotron resonance (FTICR) mass spectrometers; the implementation of ECD within commonly-used multipole ion guide structures is problematic due to the disturbing effects of RF fields within such devices. The apparatus and methods described herein successfully overcome such difficulties, and allow ECD (and PCD) to be performed within multipole ion guides, either alone, or in combination with conventional ion fragmentation methods. Therefore, improved analytical performance and functionality of mass spectrometers that utilize multipole ion guides are provided.