Ion trapping mass spectrometry method and apparatus therefor
AssigneeHitachi, Ltd.
InventorsTakashi Baba, Izumi Waki
Life of this patent
Estimating the term…
Abstract
An ion trapping mass spectrometer permitting highly sensitive mass spectrometry through in-situ observation. The mass spectrometer comprises ion trapping electrodes, a laser device for generating a cooling laser beam and a photo detector. The ion trapping electrodes generate a field in which to store sample ions and laser-cooled probe ions concurrently. The ions are cooled by laser as well as by the effect of sympathetic cooperative cooling, whereby intense resonance scattering light is acquired from the probe ions. An analyzing AC electric field is applied to the sample ions while the field is being scanned in frequency. Resulting changes in the resonance scattering light and spatial distribution of the probe ions are observed for mass spectrometry.
Claims24
An ion trapping mass spectrometry method for use with an electrode structure so as to generate an ion trapping field constituting an ion trapping region, said ion trapping region trapping sample ions which are analyzed through oscillation by resonance with a frequency of an analyzing AC electric field applied to said ion trapping field, said ion trapping mass spectrometry method comprising the steps of:
- (a) trapping probe ions and said sample ions inside said ion trapping region, the mass-to-charge ratio of said probe ion being known;
- (b) radiating a laser beam of a predetermined wavelength to said probe ions, thereby causing said probe ions to emit fluorescence through optical excitation;
- and
- (c) causing said analyzing AC electric field to act on said sample ions;
- wherein, when said sample ions oscillate depending on the mass-to-charge ratio thereof under the influence of said analyzing AC electric field, the oscillating sample ions interact with said probe ions in a Coulomb collision leading to kinetic changes of said probe ions inside said ion trapping region, said kinetic changes resulting in scattered fluorescence changes which are detected to verify the presence of said sample ions.
An ion trapping mass spectrometer comprising:
- (a) a plurality of ion trapping electrodes forming an ion trapping region in which to trap sample ions;
- (b) sample ion introducing means for introducing said sample ions into said ion trapping region;
- (c) probe ion introducing means for introducing into said ion trapping region probe ions of which the mass-to-charge ratio is known;
- (d) laser radiating means for radiating a laser beam having a predetermined wavelength to said probe ions;
- (e) AC voltage applying means for applying an AC voltage having a predetermined frequency to some of said ion trapping electrodes so as to cause an analyzing AC electric field to act on said sample ions;
- and
- (f) detecting means used when said sample ions oscillate depending on the mass-to-charge ratio thereof under the influence of said analyzing AC electric field, the oscillating sample ions interacting with said probe ions in a Coulomb collision leading to kinetic changes of said probe ions inside said ion trapping region, said detecting means detecting scattered fluorescence changes resulting from said kinetic changes of said probe ions.
An ion trapping mass spectrometer comprising:
- (a) a plurality of ion trapping electrodes forming an ion trapping region in which to trap sample ions, said ion trapping electrodes arranged in an axially linear manner including a mass spectrometry part and end electrodes placed at both ends of said mass spectrometry part, said mass spectrometry part comprising quadruple electrode portions constituting a linear ion trapping structure, said end electrodes being composed of one or more electrodes with a means to supply DC bias to said end electrodes to confine both the probe and sample ions within the trap axially;
- (b) sample ion introducing means for introducing said sample ions into said ion trapping region;
- (c) probe ion introducing means for introducing into said ion trapping region probe ions of which the mass-to-charge ratio is known;
- (d) laser radiating means for radiating a laser beam having a predetermined wavelength to said probe ions;
- (e) AC voltage applying means for applying an AC voltage having a predetermined frequency to some of said ion trapping electrodes so as to cause an analyzing AC electric field to act on said sample ions;
- and
- (f) detecting means used when said sample ions oscillate depending on the mass-to-charge ratio thereof under the influence of said analyzing AC electric field, the oscillating sample ions interacting with said probe ions in a Coulomb collision leading to kinetic changes of said probe ions inside said ion trapping region, said detecting means detecting scattered fluorescence changes resulting from said kinetic changes of said probe ions.
Dependencies are inferred from the claim text.