66 results about "Quadrupole ion trap" patented technology

A three section linear or two-dimensional (2D) quadrupole ion trap as a high performance mass spectrometer is described. Mass analysis is performed by ejecting ions radically out a slot formed in one of the rods using the mass selective instability mode of operation. The slot geometry is optimized to yield high ejection efficiencies. Resolution can be controlled by using appropriate end section potentials to control the axial spread of the ion cloud. Multiple detectors can be used for enhancing sensitivity and for enabling enhanced ion analysis techniques in the ion trap.

The invention relates to a method and instrument for the fragmentation of large molecular analyte ions, preferably biopolymer ions, by reactions between multiply charged positive analyte ions and negative reactant ions in RF quadrupole ion traps. Some of these reactions involve electron transfer reactions with subsequent dissociation of the biopolymer analyte ions, and some involve the loss of a proton, leading to stable product ions. The invention can use any type of ion traps, particularly three-dimensional RF quadrupole ion traps, for the reactions between positive and negative ions. The fragmentation yield can be increased because ions that remain stable as radical cations after transfer of an electron are further fragmented by collisionally induced fragmentation, forming fragment ions that are typical of electron transfer, and not those typical of collisionally induced fragmentation. The invention preferentially introduces positive ions and negative ions into the ion trap sequentially through the same aperture.

A method of ejecting ions to be analyzed from a quadrupole ion trap in which a trapping field is created by one or more RF voltages applied to one or more electrodes of the trap, the method comprising the steps of cooling the ions to be analyzed within the quadrupole ion trap until the ions are thermalized, reducing the amplitude of one or more RF voltages applied to the quadrupole ion trap and applying the reduced amplitude RF voltages for one half cycle after the one or more RF voltages have reached a zero crossing point, turning off the RF voltages applied to the quadrupole ion trap, and ejecting the ions to be analyzed from the quadrupole ion trap.

An apparatus and method are disclosed for efficient detection of ions ejected from a quadrupolar ion trap, in which the ions are ejected as first and second groups of ions having different directions. The first and second groups of ions are received by a conversion dynode structure, which responsively emits secondary particles that are directed to a shared detector, such as an electron multiplier. The conversion dynode structure may be implemented as a common dynode or as two dynodes (or sets of dynodes), with each dynode positioned to receive one of the groups of ions.

The invention relates to methods and devices for the effective capturing of externally generated ions in an RF operated quadrupole ion trap. The invention involves applying a voltage consisting of positive and negative pulses, instead of a sinusoidal RF voltage, during the capturing process, with capturing intervals between each pulse in which the voltage is low.

The invention relates to a device and a method for producing, from any previously configured ion beams, precisely localized small packages of ions which all fly at the same velocity. The invention consists of damping the ions in a damping-gas filled series of apertured diaphragms (which are firstly subjected alternately to the two phases of an RF voltage and secondly to a multiphase low-frequency travelling field voltage) into the axis of the apertured diaphragm arrangement and packaging the ions in bundles which are propelled axially at the same velocity for ions of different specific masses. These ion packages, which are restricted both in an axial and a radial direction, can be used to advantage for injection into different types of mass spectrometer, both storage ion-trap mass spectrometers, such as cyclotron resonance mass spectrometers or quadrupole ion traps and, especially, for time-of-flight mass spectrometers with orthogonal injection. The arrangement of a damping-gas filled series of apertured diaphragms can also be used for ion fragmentation.