Bruker Daltonik Gmbh

Shimadzu Research Laboratory (europe) Limited

Evgenij Nikolaev

Jochen Franzen

Li Ding

Oliver Räther

Gökhan Baykut

Carsten Stoermer

Alan Joseph Smith

Ivan Boldin

In a mass spectrometer that uses a space-restricted magnetic field, such as an ion cyclotron resonance mass spectrometer, ions with a wide mass range generated in an ion supply located outside the magnetic field are transported in the direction of the magnetic field lines to an ion storage device located inside the magnetic field without losing ions by guiding the ions through the region in which the magnetic field strength increases with a special ion guide. This ion guide consists of an arrangement of coaxial ring diaphragms which are alternately supplied with the phases of an RF voltage. In an alternative embodiment, the ion guide uses two wires wound in a double helix where each wire is supplied with one phase of a two-phase RF voltage.

Introduction of ions into a magnetic field

Devices and methods for the acquisition of mass spectra with very high mass resolution in ion cyclotron resonance mass spectrometers include cylindrical ICR measuring cells with special electrode geometries to generate harmonic trapping potentials for orbiting ions. The sheath of the cylindrical cell is divided by longitudinal gaps into a multitude of sheath electrodes, which either have to carry layers with resistance profiles able to generate parabolic voltage profiles along the sheath electrodes, or which form sheath electrodes of varying width by parabolic gaps. Orbiting ions of a given mass m/z oscillate harmonically in an axial direction with the same frequency, independent of the radius of their orbit and their oscillation amplitude. Ideally, the cylinders are closed by endcaps with rotationally hyperbolic form, divided into partial electrodes. The ions are excited by dipolar excitation fields. The orbiting ion clouds are kept together for much longer periods than was possible hitherto.

Ion cyclotron resonance measuring cells with harmonic trapping potential

An ion cell having an axis includes a sheath of individual electrodes that extends along the axis and defines an internal volume. Adjacent individual electrodes are electrically insulated from each other. The individual electrodes each receive a DC potential and RF voltage. At least some of the individual electrodes have a width that varies in the axial direction such that an electrical effect on an axis potential varies along the axis of the ion cell.

Ion manipulation cell with tailored potential profiles

Charged spray droplets are guided in a pseudopotential distribution generated by audio frequency voltages at electrodes of a guiding device, focusing the spray droplets toward the axis. An axial electric field profile and an axial flow profile of a drying gas in the guiding device allow the drift of different-sized droplets to be controlled in the longitudinal direction of the guiding device, so that the droplets are roughly equal in size when they leave the guiding device and finally dry up shortly after leaving. As a result, the ions are formed in a relatively small spatial region. Electrostatic potentials guide the analyte ions from this small spatial region to the entrance aperture of the inlet capillary; during this process, very light ions, especially protons and water-proton complexes, can be filtered out by a mobility filter.

Guiding charged droplets and ions in an electrospray ion source

The invention relates to measuring devices of an electrostatic Fourier transform mass spectrometer and measurement methods for the acquisition of mass spectra with high mass resolution. The measuring device includes electrostatic measuring cells according to the Kingdon principle, in which ions can, when appropriate voltages are applied, orbit on circular trajectories around the cylinder axis between two concentric cylindrical surfaces, which are composed of specially shaped sheath electrodes, insulated from each other by parabolic gaps, and can harmonically oscillate in the axial direction, independently of their orbiting motion. In the longitudinal direction, the two cylindrical surfaces of the measuring cell are divided by the parabolic separating gaps into different types of double-angled and tetragonal sheath electrode segments. Appropriate voltages at the sheath electrode segments generate a potential distribution between the two concentric cylindrical surfaces which forms a parabolic potential well in the axial direction for orbiting ions. The ion clouds oscillating harmonically in the axial direction in this potential well induce image currents in suitable electrodes, from which the oscillation frequencies can be determined by Fourier analyses.

Kingdon mass spectrometer with cylindrical electrodes

Components of a mixture are separated by feeding charged molecules of the components into a end surface of a suitable medium, for example a gel. The molecules are drawn in a first direction through the medium by means of an DC electric field, while at the same time being subjected to an alternating voltage with a strongly asymmetric profile in a direction transverse to the first direction. The nonlinear behavior of the electrically-generated migration causes a large number of molecules to migrate transversely out of the medium while only a small number of molecules reach the opposite end surface of the medium. A superimposed DC voltage in the transverse direction selects which of the mixture components migrate all the way through the medium in the first direction. The separated components can be sampled from the opposite end surface and from points on the upper and lower medium surfaces.

Stationary separation system for mixture components

A method of introducing ions into an ion trap and an ion storage apparatus are described. Introduction means are used to introduce first ions into an ion trap through an entrance aperture to the ion trap. An operating condition of the introduction means is adjusted to cause second ions, of different polarity to the first ions to be introduced into the ion trap through the same entrance aperture.

Method for introducing ions into an ion trap and an ion storage apparatus

A mass spectrometric analysis of surface material is performed by vaporizing the surface material with pulses of laser light and then collecting the vaporized material by dissolving it in a liquid. The liquid with the dissolved material is then fed to an ionization process, preferably an electrospray ionization process. The resulting ions are then analyzed with a mass spectrometer. The method is particularly suited for use with imaging mass spectrometry.

Mass spectrometry with laser ablation

The invention relates to measuring methods and corresponding measuring cells for ion cyclotron resonance mass spectrometers (FTMS). The invention provides measuring methods with measuring cells, the ends of which each incorporate a large number of trapping electrodes, DC voltages of opposite polarities being applied across adjacent electrodes. For orbiting ions this builds up a repelling pseudopotential, which holds the ions in the measuring cell by reflection. This facilitates measurement of the image currents without the disturbing influence of RF voltages.

Measuring methods for ion cyclotron resonance mass spectrometers

The invention relates to a measuring cell for an ion cyclotron resonance mass spectrometer (FTMS). The invention provides a measuring cell which, on the one hand, consists of two ion-repelling RF grids at the front ends as trapping electrodes and thus produces a pure cyclotron motion of the ions without the usually co-existing magnetron motion and, on the other hand, measures a multiplied cyclotron frequency by means of a plurality of detection electrodes, whereby either a higher mass accuracy or a shorter measuring time can be achieved.

Measuring cell for ion cyclotron resonance mass spectrometer

The invention relates to an ion guide consisting of RF multipole segments to transfer ions from an ion source into a mass analyzer. The invention consists in having movable RF multipole segments in the ion guide which extend or electrically connect other RF multipole segments along the axis of the ion guide, in which spaces have arisen as a result of a change in configuration of the mass spectrometer, comprising ion source, ion guide and mass analyzer. The moved RF multipole segments bridge the spaces which have arisen between the components of the mass spectrometer and facilitate the transfer of the ions from the ion source to the mass analyzer.

Ion guides with movable RF multiple segments

The invention relates to a reaction cell for reactions between different types of ion species and a related mass spectrometer to analyze the ion products. The invention consists in an RF-operated straight ion guide with a side inlet, particularly suitable for reactions between positive and negative ion species, one ion species being fed in through the side inlet. Particularly favorable is an ion guide made up of a set of coaxial apertured diaphragms with a slight axial potential gradient. The reactions can be used for a fragmentation of multiply charged protein or peptide ions by electron transfer, or for the removal of excess charges of multiply charged biopolymer ions, for example.

Mass spectrometer and reaction cell for ion-ion reactions

The invention describes an ion cyclotron resonance (ICR) mass spectrometer with an ICR trap, the ICR trap having as trapping electrodes two ion reflecting electrode structures operated by RF voltages without any DC voltage. The usual apertured ion trapping electrodes are replaced by multitudes of structural elements, electrically conducting, and repeating spatially in one or two directions of a surface, neighboring structure elements being connected each to different phases of an RF voltage. In the simplest case a grid of parallel wires can be used. The surface of such structures reflects ions of both polarities, if the mass-to-charge ratio of the ions is higher than a threshold.

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Moscow, Russia

Evgenij Nikolaev