Patent classifications
H01J49/406
MASS SPECTROMETER HAVING HIGH SAMPLING DUTY CYCLE
A multi-reflecting time of flight mass spectrometer (8) comprising: a mass filter or mass separator (6); an ion accelerator (14) for pulsing packets of ions; ion mirrors (10) arranged to receive the ions from the ion accelerator (14) and reflect them in a first dimension (x-dimension) between the ion mirrors (10) as the ions travel in a second dimension (z-dimension); first (20) and second (22) ion reflectors arranged such that when they are both activated they reflect the ions back and forth in the second dimension; an ion detector (16) arranged to receive the ions, when a first of the ion reflectors (20,22) is deactivated; and control circuitry configured to: control the ion accelerator (14) to perform a first pulse sequence that pulses a first plurality of packets of ions into the ion mirrors (10); control the reflectors (20,22) such that ions in said plurality of packets are reflected back and forth in the second dimension by the reflectors (20,22) at the same time; and control the range of mass to charge ratios that is able to be transmitted by the mass filter or mass separator (6) to the ion accelerator (14), and the timings at which the first reflector (20) is activated and deactivated, such that substantially all of the ions from said plurality of packets of ions undergo the same number of reflections in the second dimension before being received at the detector (16).
SELF-CALIBRATION OF HIGH RESOLUTION MASS SPECTRUM
A method of self-calibrating a mass spectrometer or mass spectral data is disclosed. At least some first observed mass to charge ratios are matched with or against a comprehensive reference set of possible or predicted elemental compositions having known precise mass to charge ratios. One or more calibration parameters of a calibration routine are then adjusted so as to optimise the match between one or more of the first observed mass to charge ratios and the corresponding known precise mass to charge ratios of one or more possible or predicted elemental compositions contained within the reference set.
Ion trap mass spectrometer
An apparatus 41 and operation method are provided for an electrostatic trap mass spectrometer with measuring frequency of multiple isochronous ionic oscillations. For improving throughput and space charge capacity, the trap is substantially extended in one Z-direction forming a reproduced two-dimensional field. Multiple geometries are provided for trap Z-extension. The throughput of the analysis is improved by multiplexing electrostatic traps. The frequency analysis is accelerated by the shortening of ion packets and either by Wavelet-fit analysis of the image current signal or by using a time-of-flight detector for sampling a small portion of ions per oscillation. Multiple pulsed converters are suggested for optimal ion injection into electrostatic traps.
Blanking out of pulses in pulsed lasers for LDI mass spectrometers
The invention relates to optically pumped and pulsed solid-state lasers which are used in mass spectrometers in particular for ionization by matrix-assisted laser desorption (MALDI) and which operate at pulse frequencies of up to 10 kilohertz or even higher. The invention proposes that, instead of interrupting the clocked sequence of the laser operation, individual light pulses or groups of light pulses are blanked out so that subsequent light pulses do not have a higher energy density, in accordance with the requirements for LDI processes. Methods and devices for the blanking out of light pulses are provided which are, in particular, low cost and considerably less complex than other methods.
Ion mirror for multi-reflecting mass spectrometers
Improved ion mirrors 30 (FIG. 3) are proposed for multi-reflecting TOF MS and electrostatic traps. Minor and controlled variation by means of arranging a localized wedge field structure 35 at the ion retarding region was found to produce major tilt of ion packets time fronts 39. Combining wedge reflecting fields with compensated deflectors is proposed for electrically controlled compensation of local and global misalignments, for improved ion injection and for reversing ion motion in the drift direction. Fine ion optical properties of methods and embodiments are verified in ion optical simulations.
Time of flight mass analyser with spatial focussing
A Time of Flight mass analyser is disclosed comprising: at least one ion mirror 34 for reflecting ions; an ion detector 36 arranged for detecting the reflected ions; a first pulsed ion accelerator 30 for accelerating an ion packet in a first dimension (Y-dimension) towards the ion detector 36 so that the ion packet spatially converges in the first dimension as it travels to the detector 36; and a pulsed orthogonal accelerator 32 for orthogonally accelerating the ion packet in a second, orthogonal dimension (X-dimension) into one of said at least one ion mirrors 34.
Method of targeted mass spectrometric analysis
A method of targeted mass spectrometric analysis is provided for analyzing trace compounds at sub-ppb level compared to sample matrix. Sample is chromatographically separated at standard conditions to employ a map of target mass (M) versus retention time (RT). Small mass ions under M(RT) are rejected by RF field, and remaining ions are accumulated for pulsed injection into a multi-reflecting TOF MS, either directly from EI source, or from linear RF trap or via a heated RF only quadrupole with axial ion trapping. In combination with EI source the method provides sub femtogram sensitivity at matrices loads in microgram range.
Multi-Reflecting Mass Spectrometer with High Throughput
Method and embodiments are provided for tandem mass spectrometer designed for extremely large charge throughput up to 1E+10ion/sec. In one operation mode, the initial ion flow with wide m/z range is time separated in a trap array. The array ejects ions with a narrower momentarily m/z range. Ion flow is collected and confined in a wide bore ion channel at a limited time spread. The ion flow with narrow m/z range is then analyzed in a multi-reflecting TOF at frequent and time-encoded operation of the orthogonal accelerator, thus forming multiple non overlapping spectral segments. In another mode, time separated ions are subjected to fragmentation for comprehensive, all-mass MS-MS analysis. The momentarily ion flow at MR-TOF entrance is characterized by lower spectral population which allows efficient decoding of overlapping spectra. Those modes are combined with conventional spectrometer operation to improve the dynamic range. To provide practical solution, there are proposed multiple novel components comprising trap arrays, wide bore confining channels, resistive multipole, so as long life TOF detector.
Orthogonal acceleration coaxial cylinder mass analyser
A mass analyzer is disclosed comprising an annular ion guide comprising a first annular ion guide section and a second annular ion guide section, wherein the annular ion guide comprises: (i) an inner cylindrical electrode arrangement which is axially segmented and comprises a plurality of first electrodes and (ii) an outer cylindrical electrode arrangement which is axially segmented and comprises a plurality of second electrodes. Ions are introduced into the first annular ion guide section so that the ions form substantially stable circular orbits. Ions are orthogonally accelerated from the first annular ion guide section into the second annular ion guide section and one or more parabolic DC potentials are maintained along a portion of the second annular ion guide section so that ions undergo simple harmonic motion. An inductive ion detector is arranged and adapted to detect ions within the second annular ion guide section.
Mass analyser and method of mass analysis
An electrostatic ion trap for mass analysis includes a first array of electrodes and a second array of electrodes, spaced from the first array of electrode. The first and second arrays of electrodes may be planar arrays formed by parallel strip electrodes or by concentric, circular or part-circular electrically conductive rings. The electrodes of the arrays are supplied with substantially the same pattern of voltage whereby the distribution of electrical potential in the space between the arrays is such as to reflect ions isochronously in a flight direction causing them to undergo periodic, oscillatory motion in the space, focused substantially mid-way between the arrays. Amplifier circuitry is used to detect image current having frequency components related to the mass-to-charge ratio of ions undergoing the periodic, oscillatory motion.