Patent classifications
H01J49/406
PRINTED CIRCUIT ION MIRROR WITH COMPENSATION
Improved ion mirrors (10) are proposed for multi-reflecting TOF MS and electrostatic traps at various analyzer topologies. Ion mirrors (10) are constructed of printed circuit boards (11) with improved precision and flatness. To compensate for the remaining geometrical imperfections of mirror electrodes there are proposed electrode sets (17) and field structures in the ion retarding region for electronically adjusting of the ion packets time fronts, for improving the ion injection into the analyzer and for reversing the ion motion in the drift direction.
ION INJECTION INTO MULTI-PASS MASS SPECTROMETERS
An improved multi-pass time-of-flight or electrostatic trap mass spectrometer (70) with an orthogonal accelerator, applicable to mirror based multi-reflecting (MR) or multi-turn (MT) analyzers. The orthogonal accelerator (64) is tilted and after first ion reflection or turn the ion packets are back deflected with a compensated deflector (40) by the same angle to compensate for the time-front steering and for the chromatic angular spreads. The focal distance of deflector (40) is control by Matsuda plates or other means for producing quadrupolar field in the deflector. Interference with the detector rim is improved with dual deflector (68). The proposed improvements allow substantial extension of flight path and number of ion turns or reflections. The problems of analyzer angular misalignments by tilting of ion mirror (71) is compensated by electrical adjustments of ion beam (63) energy and deflection angles in deflectors (40) and (68).
MULTI-PASS MASS SPECTROMETER
Improved multi-pass time-of-flight mass spectrometers MPTOF, either multi-reflecting (MR) or multi-turn (MT) TOF are proposed with elongated pulsed converterseither orthogonal accelerator or radially ejecting ion trap. The converter (35) is displaced from the MPTOF s-surface of isochronous ion motion in the orthogonal Y-direction. Long ion packets (38) are pulsed deflected in the transverse Y-direction and brought onto said isochronous trajectory s-surface, this way bypassing said converter. Ion packets are isochronously focused in the drift Z-direction within or immediately after the accelerator, either by isochronous trans-axial lens/wedge (68) or Fresnel lens. The accelerator is improved by the ion beam confinement within an RF quadrupolar field or within spatially alternated DC quadrupolar field. The accelerator improves the duty cycle and/or space charge capacity of MPTOF by an order of magnitude.
ELECTROSTATIC LINEAR ION TRAP DESIGN FOR CHARGE DETECTION MASS SPECTROMETRY
An electrostatic linear ion trap has first and second axially aligned ion minors separated by a charge detection cylinder axially aligned with each ion minor. Electric fields are selectively established within the first and second ion minors in a manner which causes an ion in the trap to oscillate back and forth through the charge detection cylinder between the first and second ion minors with a duty cycle, corresponding to a ratio of time spent by the ion passing through the charge detection cylinder and total time spent traversing a combination of the first and second ion mirrors and the charge detection cylinder during one complete oscillation cycle, of approximately 50%.
MASS SPECTROMETER AND METHOD FOR TIME-OF-FLIGHT MASS SPECTROMETRY
A mass spectrometer comprising: a pulsed ion source for generating pulses of ions having a range of masses; a time-of-flight mass analyzer for receiving and mass analyzing the pulses of ions from the ion source; and an energy controlling electrode assembly located between the pulsed ion source and the time-of-flight mass analyzer configured to receive the pulses of ions from the pulsed ion source and apply a time-dependent potential to the ions thereby to control the energy of the ions depending on their m/z before they reach the time-of-flight mass analyzer. Mass dependent differences in average energy of ions can be reduced for injection into a time-of-flight mass analyzer, which can improve ion transmission and/or instrument resolving power.
GC-TOF MS with improved detection limit
For improving sensitivity, dynamic range, and specificity of GC-MS analysis there are disclosed embodiments of novel apparatuses based on improved characteristics of semi-open source with electron impact ionization, providing much higher brightness compared to known open EI sources. In an implementation, the source becomes compatible with multi-reflecting TOF analyzers for higher resolution analysis for improving detection limit. With improved schemes of spatial and temporal refocusing there are proposed various tandem TOF-TOF spectrometers with PSD, CID, and SID fragmentation and using either singly reflecting TOF or MR-TOF analyzers.
PROCESSING ION PEAK AREAS IN MASS SPECTROMETRY
A method of analysing a signal generated by a mass analyser comprises receiving a signal generated by the mass analyser, determining the area of a first ion peak of one or more ion peaks in the signal, and estimating the number of ions that contributed to the first ion peak. The number of ions that contributed to the first ion peak is estimated by determining a correction to be applied to the area of the first ion peak from a correction function, and applying the correction to the area of the first ion peak. The correction function describes a relationship between average single ion area and ion mass, mass-to-charge ratio and/or charge for the mass analyser.
Right angle time-of-flight detector with an extended life time
There is proposed a right angle time-of-flight detector comprising a conductive converter for emitting and accelerating secondary electrons, a magnetic field formed by at least one magnet for deflecting the secondary electrons at a right angle and a sealed photo-multiplier. The detector is expected to provide an extended resource and dynamic range and may be fit into tight assemblies, such as MR-TOF MS.
Electrostatic trap
An electrostatic trap such as an orbitrap is disclosed, with an electrode structure. An electrostatic trapping field of the form U(r, , z) is generated to trap ions within the trap so that they undergo isochronous oscillations. The trapping field U(r, , z) is the result of a perturbation W to an ideal field U(r, , z) which, for example, is hyperlogarithmic in the case of an orbitrap. The perturbation W may be introduced in various ways, such as by distorting the geometry of the trap so that it no longer follows an equipotential of the ideal field U(r, , z), or by adding a distortion field (either electric or magnetic). The magnitude of the perturbation is such that at least some of the trapped ions have an absolute phase spread of more than zero but less than 2 radians over an ion detection period T.sub.m.
Multi-reflecting mass spectrometer with high throughput
An ion guide includes electrodes and an RF generator. The electrodes extend in a Z-axis that is straight or curved with a radius that is larger than a distance between the electrodes. The electrodes are made of carbon filled ceramic resistors, silicon carbide, or boron carbide to form bulk resistance with specific resistance between 1 and 1000 Ohm*cm. Conductive Z-edges are disposed on each electrode. An insulating coating is disposed on one side of each electrode and oriented away from an inner region of the ion guide surrounded by said electrodes. At least one conductive track per electrode is attached on a top side of the insulating coating. The conductive track is connected to one conductive electrode edge. The RF generator has at least two sets of secondary coils with DC supplies connected to central taps of the sets of secondary coils to provide at least four distinct signals.