Abstract: A mass spectrometer (MS) that is adapted to allow rapid gas-phase hydrogen/deuterium exchange (HDX) labeling of ions in one or more traveling wave ion guides (TWIGs) with or without ion mobility separation. The addition of isotopic labeling by gas-phase HDX offers a sensitive alternative dimension for conformational detection, which enables high resolution detection of gaseous conformations based on shape and surface reactivity. Gas-phase, isotopic HDX labeling or “curtain” labeling, can be performed by infusing a reactive, isotopic labeling gas, e.g., ND3, into one or more of the traveling-ion wave guides (TWIG) in the MS. Analyte ions retained in the potential wells of a traveling wave generated by one or more of the TWIGs can be isotopic labeled at adjustable gas pressures. Labeling times can also be controlled by adjusting the speed of the traveling wave and can be performed within milliseconds of ionizations, probing protein conformations present in solution.

Abstract: A mass spectrometer (MS) that is adapted to allow rapid gas-phase hydrogen/deuterium exchange (HDX) labeling of ions in one or more traveling wave ion guides (TWIGs) with or without ion mobility separation. The addition of isotopic labeling by gas-phase HDX offers a sensitive alternative dimension for conformational detection, which enables high resolution detection of gaseous conformations based on shape and surface reactivity. Gas-phase, isotopic HDX labeling or “curtain” labeling, can be performed by infusing a reactive, isotopic labeling gas, e.g., ND3, into one or more of the traveling-ion wave guides (TWIG) in the MS. Analyte ions retained in the potential wells of a traveling wave generated by one or more of the TWIGs can be isotopic labeled at adjustable gas pressures. Labeling times can also be controlled by adjusting the speed of the traveling wave and can be performed within milliseconds of ionizations, probing protein conformations present in solution.

Abstract: An ion detector (27) for use in a time-of-flight mass spectrometer (1) is disclosed. The ion detector (27), which has an extended dynamic range, comprises at least one microchannel plate electron multiplier (42, 32) together with first and second collection electrodes (36, 38; 39). The second collection electrode (36, 38) is arranged such that in receives more electrons per ion entering the ion detector (27) than the first collection electrode (39). In one embodiment the collection electrodes (36, 38; 39) are formed in an array consisting of a larger plate-like collection electrode (36, 38) and a smaller plate-like collection electrode (39). In an alternative embodiment a second microchannel plate electron multiplier is arranged between the first collection electrode (46) and the second collection electrode (47).

Abstract: An electrospray and/or atmospheric pressure ionization mass spectrometer includes an evacuated chamber, a sampling region within which is maintained a pressure greater than in the evacuation chamber, a sampling orifice that communicates between the sampling region and the evacuation chamber, and a mass analyzer that receives charged particles along a first axis through the sampling orifice from the sampling region into the evacuated chamber. A plurality of charged-particle jet generators, each having an associated jet axis, are adapted to be alternatively, selectively aligned such that a respective jet axis intersects with the first axis associated with the mass analyzer. This alignment is performed through the use of a hollow member which functions to guide charged particles through the sampling orifice to the evacuated chamber and, subsequently, to the mass analyzer.

Abstract: An ion detector (27) for use in a time-of-flight mass spectrometer (1) is disclosed. The ion detector (27), which has an extended dynamic range, comprises collection electrodes (36, 38; 39) of different surface areas. In one embodiment the collection electrodes (36, 38; 39) are formed in an array consisting of a larger plate-like collection electrode (36, 38) and a smaller plate-like collection electrode (39). Microchannel multiplier plates (31, 32) may be arranged in front of the collection electrodes (36, 38; 39). In an alternative embodiment the collection electrodes consist of a grid (42) or, more preferably, a wire electrode (50) disposed in front of a plate-like electrode (43).

Abstract: A mass spectrometer is provided having a plurality of analyzers and including at least one magnetic sector analyzer and, typically, an orthogonal-acceleration time-of-flight mass analyzer. Bypass means are provided so that by switching of the direction of the ion beam, the magnetic sector analyzer may be bypassed and the time-of-flight analyzer used either to analyse the beam of ions from the source or daughter ions produced by fragmentation of that beam.

Abstract: The invention typically provides a double focusing mass spectrometer comprising an ion source (55), an ion momentum analyzer (56), a multichannel detector (58) and a multielectrode electrostatic ion-energy analyzer (57), wherein the energy dispersing field is generated by arrays of electrodes disposed in groups above and below the ion beam. By appropriate selection of the potentials applied to the electrodes, the focusing properties of the analyzer can be changed, allowing different extents of the mass spectrum to be accurately focused on the face of the detector (58) as it is tilted by the actuator (61) at different angles to the ion beam (64) emerging from the analyzer (57). This enables the spectrometer to simultaneously record either a small part of a mass spectrum at high resolution or a larger part at a lower resolution. Alternative arrangements of the detector which allow a similar result to be obtained are also disclosed.

Abstract: An electrostatic analyzer (1) for dispersing a beam of charged particles (10) according to their energy comprises two groups (2, 3) of spaced-apart linear electrodes (4, 8, 9, 20) respectively disposed above and below the charged particle beam. The potentials of the electrodes (4, 8, 9, 20) in each group progressively increase from one to the next, thereby providing an electrostatic field in a central plane (7) between the groups which is capable of deflecting the charged particles along different curved trajectories (11, 12) according to their energies. Various mass spectrometers incorporating such an analyzer are also disclosed.

Abstract: The invention relates to a variable dispersion double-focusing mass spectrometer comprising at least a magnetic sector analyzer (4) preceding an electrostatic analyzer (6), which analyzers cooperate to form a direction and velocity focused image on a multichannel detector (34) locatable in a focal plane of the electrostatic analyzer (6). The geometrical parameters of the electrostatic analyzer are selected so that the magnification of the electrostatic analyzer is substantially zero, which makes it possible to use a variable radius electrostatic analyzer to vary the extent of the mass spectrum imaged on the detector (34) while still maintaining double focusing. A variable radius electrostatic analyzer suitable for use in the invention is also described.

Abstract: The invention provides a mass spectrometer capable of detecting both positive and negative ions. Positive ions emerging from the mass analyzer strike a conversion electrode to release secondary electrons which pass through an annular electrode to strike a phosphor, releasing photons. Negative ions strike the surface of the annular electrode to release secondary electrons which also strike the phosphor, releasing photons. The photons are detected with a conventional photomultiplier. The electrodes are biased and disposed so that both positive ions and negative ions may be detected without changing the potentials applied to them.

Abstract: The invention provides a mass spectrometer for the analysis of a sample dissolved in a fluid, and in particular a spectrometer for the analysis of high molecular weight compounds in the eluent of a liquid chromatograph. The fluid to be analyzed is at least partly vaporized and sprayed into the cathode dark space of a glow discharge. Ions characteristic of the sample are extracted from the discharge and subsequently mass analyzed. conveniently, spraying into the cathode dark space is achieved by making the cathode electrode of the discharge comprise the spraying means through which the fluid is sprayed. Little fragmentation of the high mass ions is caused by the process, and the invention extends the range of compounds which can be analyzed in comparison with similar prior art thermospray type mass spectrometers.

Abstract: The invention relates to a mass spectrometer having a magnetic sector analyzer in which the magnetic field is developed neither by a permanent magnet nor by an electromagnet having the conventional ferromagnetic core. In particular, the spectrometer has a magnetic sector analyzer through which ions of a mass-to-charge ratio selected by said analyzer may travel along a substantially circular trajectory disposed in a first plane, said analyzer comprising at least two electrical conductor portions of substantially circular arcuate form, respectively of greater and smaller radius than said circular trajectory and disposed on radially opposite sides of a curved plane which is aligned with said circular trajectory and perpendicular to said first plane, and wherein substantially all of the magnetic flux generated by the passage of electrical current through said conductor portions passes only through non-ferromagnetic materials.

Abstract: There is provided a mass spectrometer having at least three analyser sectors of the electrostatic or magnetic types, at least one sector being of the electrostatic type and at least one further sector being of the magnetic type. The spectrometer includes a focusing sector array having at least three analyzer sectors, the sectors of the array being dimensioned and positioned so as to cooperate to form a velocity- and direction- focused image. The sectors of the array are dimensioned and positioned as to form no velocity focused image within the array. One sector of said array is disposed adjacent to and between two sectors of the other type.