An ion guide or mass analyser is disclosed comprising a plurality of electrodes having apertures through which ions are transmitted in use. A pseudo-potential barrier is created at the exit of the ion guide or mass analyser. The amplitude or depth of the pseudo-potential barrier is inversely proportional to the mass to charge ratio of an ion. One or more transient DC voltages are applied to the electrodes of the ion guide or mass analyser in order to urge ions along the length of the ion guides or mass analyser. The amplitude of the transient DC voltage applied to the electrode may be increased with time so that ions are caused to be emitted from the ion guide or mass analyser in reverse order of their mass to charge ratio.

An ion transfer system includes an ion source coupled to an ion inlet; an ion transfer tube assembly including a concentric ion transfer tube with a porous material that is permeable to a gas, the concentric ion transfer tube coupled to the ion inlet and the ion source, where a first gas that includes an ion stream flows through the concentric ion transfer tube; and a concentric gas tube, the concentric ion transfer tube disposed within the concentric gas tube, where a second gas flows between the concentric ion transfer tube and the concentric gas tube; an ion detection device coupled to a capillary tube that is coupled to the concentric ion transfer tube, where the capillary tube transports the ion stream to the ion detection device; and a pump coupled to at least one of the concentric ion transfer tube or the concentric gas tube.

The present application is directed to a process for calibrating a detection apparatus, especially an ion mobility spectrometer, using isoflurane (CAS Reg. No. 26675-46-7) as a chemical standard whereby calibrating the detection apparatus for a known target chemical is based on an evaluation of the experimental data collected for the negative isoflurane monomer ion against the experimental data collected for the negative isoflurane dimer ion.

An ion transport optical system is disposed between a collision cell and an orthogonal acceleration unit. When releasing ions that are held in the collision cell, an accelerating electric field in which a large potential difference exists is created between an exit-side end of an ion guide and a first stage of the ion transport optical system, and a decelerating electric field in which a relatively small potential difference exists is created between a final stage of the ion transport optical system and an entrance end of the orthogonal acceleration unit. In the accelerating electric field, the velocity of ions is increased overall by imparting a large amount of energy to the ions, and spreading of ions in the ion travel direction that is caused by differences between the mass-to-charge ratios of the ions is reduced.

An ion optical apparatus and a mass spectrometer are provided. The ion optical apparatus includes at least one planar insulating substrate which is covered with metal patterns to form an electrode array including a plurality of cell electrodes, wherein each of the cell electrodes is arrayed according to a first direction to form a geometric pattern distribution of the electrode array, wherein cell electrodes are applied with radio frequency (RF) voltages having different phases to confine ions, a direct current (DC) voltage gradient is applied along at least part of the cell electrodes in the electrode array to drive ions to move in the first direction along the electrode array, and a corresponding electric field distribution is formed by the geometric pattern distribution to drive ions to move in a second direction substantially orthogonal to the first direction, thereby realizing ion deflection, focusing or defocusing.

Ions provided from an ion source are separated ions into a plurality of different ion groups according to at least one ion property. At least some of the different ion groups are stored in an ion storage array, which comprises a plurality of independently operable storage cells, each storage cell being arranged to receive and store a different ion group. A controller is programmed to cause selective switching of each of the storage cells between an ion receiving mode and an ion storage mode, and between the ion storage mode and an ion release mode. In particular, the switching of each storage cell is controllable independently of the switching of any of the other storage cells. Upon release from a respective storage cell of the array, ions are provided to one or more mass analyzers for subsequent analysis.

A linear ion trap includes at least two discrete trapping regions for processing ions, a RF electrical potential generator, a multi-output DC electrical potential generator, and a control unit. The RF electrical potential generator produces two RF waveforms each applied to a pair of pole electrodes of the linear ion trap forming a RF trapping field component to trap ions radially. The multi-output DC electrical potential generator produces multiple DC field components superimposed to the RF field component and distributed across the length of the linear ion trap to control ions axially. The control unit switches the DC electrical potentials and corresponding DC field components collectively forming a first trapping region populated with ions to alter ion potential energy from a first level to a second level, and enables a first ion processing step in at least one of the first and second levels.

A miniature electrode apparatus is disclosed for trapping charged particles, the apparatus including, along a longitudinal direction: a first end cap electrode; a central electrode having an aperture; and a second end cap electrode. The aperture is elongated in the lateral plane and extends through the central electrode along the longitudinal direction and the central electrode surrounds the aperture in a lateral plane perpendicular to the longitudinal direction to define a transverse cavity for trapping charged particles.

A mass spectrometer is disclosed wherein highly charged fragment ions resulting from Electron Transfer Dissociation fragmentation of parent ions are reduced in charge state within a Proton Transfer Reaction cell by reacting the fragment ions with a neutral superbase reagent gas such as Octahydropyrimidolazepine.

A focusing ion guiding apparatus includes at least one ion guiding inlet and ion guiding outlet connected to each other via a transport axial line; at least one group of focusing electrode structures comprising at least one smooth and non-concave focusing electrode or focusing electrode array to which a focusing voltage is applied, the focusing electrode structure causing the ions transported in the apparatus to be radially focused for many times under the action of a focusing electric field formed by the focusing electrode structure; and a neutral gas flow transported in the axial direction, a diffusion path of the gas flow in an at least partially radial direction relative to the axial direction being blocked by the focusing electrode or its bearing substrate to increase a transport velocity of the gas flow in the axial direction and reduce retention or turbulence of the transported ions.