110 results about "Ion cyclotron resonance" patented technology

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.

An ion separation instrument includes an ion source coupled to at least a first ion mobility spectrometer having an ion outlet coupled to a mass spectrometer. Instrumentation is further included to provide for passage to the mass spectrometer only ions defining a preselected ion mobility range. In one embodiment, the ion mobility spectrometer is provided with electronically controllable inlet and outlet gates, wherein a control circuit is operable to control actuation of the inlet and outlet gates as a function of ion drift time to thereby allow passage therethrough only of ions defining a mobility within the preselected ion mobility range. In another embodiment, an ion trap is disposed between the ion mobility spectrometer and mass spectrometer and is controlled in such a manner so as to collect a plurality of ions defining a mobility within the preselected ion mobility range prior to injection of such ions into the mass spectrometer. In yet another embodiment, an ion inlet of the ion trap may be electronically controlled relative to operation of the ion mobility spectrometer as a function of ion drift time to thereby allow passage therein only of ions defining a mobility within the preselected ion mobility range. The mass spectrometer is preferably a Fourier Transform Ion Cyclotron Resonance mass spectrometer, and the resulting ion separation instrument may further include therein various combinations of ion fragmentation, ion mass filtering, ion trap, charge neutralization and / or mass reaction instrumentation.

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.

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.

An ion cyclotron resonance cell having a large ion trapping volume is described. The cell includes elongated spaced concentric electrodes having a common axis in which the trapping volume is the space between the electrodes. The cell may also include trapping electrodes disposed at the ends of the elongated concentric electrodes.

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.