Method and devices for performing top down analysis of an antibody are described which involve utilizing an ion source to generate a plurality of ions from a sample containing at least one intact antibody. Further, transmitting said plurality of ions through a quadrupole rod set while applying an RF signal thereto and in the absence of a resolving DC voltage so as to preferentially transmit precursor ions having an m/z value greater than a low mass cutoff of about 1500 m/z from the quadrupole rod set to an ECD cell. The method and device can also performing an ECD reaction in the ECD cell on said precursor ions and also detect reaction products from the ECD reaction.

An ion guide defining a guide axis receives ions. The ion guide applies a potential profile that includes a pseudopotential well to the ions using an ion control field. The ion control field includes a component for restraining movement of the ions normal to the guide axis and a component for controlling the movement of the ions parallel to the guide axis. The ion guide sequentially injects the ions with the same ion energy and in decreasing order of m/z value into an ELIT aligned along an ELIT axis to focus the ions irrespective of m/z value at the same location on the ELIT axis within the ELIT at the same time by varying a magnitude of the pseudopotential well. The ELIT can trap the focused ions using in-trap potential lift or mirror-switching ion capture.

Methods and apparatus are disclosed for reducing ion reflections between multipole segments in a mass spectrometer by matching the effective potential between the two segments. Mass spectrometers having at least two multipole segments separated from each other along a longitudinal axis of the mass spectrometer such that a boundary region exists through which ions are drawn from an upstream segment to a downstream segment, and wherein each multipole segment further includes a set of spaced-apart rod-shaped electrodes disposed around the longitudinal axis and having a field radius defined by an inscribed circle between the innermost portions of each electrode. Effective potential matching can be achieved by either supplying RF signals of different amplitudes to each segment and/or by modifying the field strength of the segments. In one embodiment, the multipole segments are configured such that the upstream multipole segment has a smaller field radius than the downstream segment.

A system for trapping ions for measurement thereof may include an electrostatic linear ion trap (ELIT), a source of ions to supply ions to the ELIT, a processor operatively coupled to ELIT, and a memory having instructions stored therein executable by the processor to produce at least one control signal to open the ELIT to allow ions supplied by the source of ions to enter the ELIT, determine an ion inlet frequency corresponding to a frequency of ions flowing from the source of ions into the open ELIT, generate or receive a target ion charge value, determine an optimum threshold value as a function of the target ion charge value and the determined ion inlet frequency, and produce at least one control signal to close the ELIT when a charge of an ion within the ELIT exceeds the optimum threshold value to thereby trap the ion in the ELIT.

An electrostatic linear ion trap (ELIT) array includes multiple elongated charge detection cylinders arranged end-to-end and each defining an axial passageway extending centrally therethrough, a plurality of ion mirror structures each defining a pair of axially aligned cavities and an axial passageway extending centrally therethrough, wherein a different ion mirror structure is disposed between opposing ends of each cylinder, and front and rear ion mirrors each defining at least one cavity and an axial passageway extending centrally therethrough, the front ion mirror positioned at one end of the arrangement of charge detection cylinders and the rear ion mirror positioned at an opposite end of the arrangement of charge detection cylinders, wherein the axial passageways of the charge detection cylinders, the ion mirror structures, the front ion mirror and the rear ion mirror are coaxial to define a longitudinal axis passing centrally through the ELIT array. In a second aspect, an ELIT array comprises a plurality of non-coaxial ELIT regions, wherein ions are selectively guided into each of the ELIT regions.

A charge detection mass spectrometer may include an ion source, an electrostatic linear ion trap (ELIT) including a charge detection cylinder disposed between a pair of coaxially aligned ion mirrors, means for selectively establishing electric fields within the ion mirrors configured to cause the trapped ions in the ELIT to oscillate back and forth between the ion mirrors each time passing through the charge detection cylinder, and means for controlling a trajectory of the beam of ions entering the ELIT to cause the subsequently trapped ions to oscillate with different planar ion oscillation trajectories angularly offset from one another about the longitudinal axis with each extending along and crossing the longitudinal axis in each of the ion mirrors or with different cylindrical ion oscillation trajectories radially offset from one another about the longitudinal axis to form nested cylindrical trajectories each extending along the longitudinal axis.

An optimization control system may receive mass spectra of ions emitted from an ionization emitter toward an inlet of a mass spectrometer and control, based on the mass spectra, an automated motion system to adjust a position of the emitter relative to the inlet.

In one aspect, a method of performing Fourier Transform (FT) mass spectrometry is disclosed, which comprises passing a plurality of ions through an FT mass analyzer comprising a plurality of rods arranged in a multipole configuration, where the plurality of rods include an input port for receiving ions and an output port through which ions can exit the mass analyzer. The method can further include applying at least one RF voltage to at least one of the rods so as to generate an RF field for radial confinement of the ions as they pass through the mass analyzer, and applying a resonant burst of an AC signal to at least one of said rods so as to remove ions having selected m/z ratios, e.g., m/z ratios within a desired range, from the ions introduced into the FT mass analyzer.

A space-time buffer includes a plurality of discrete trapping regions and a controller. The plurality of discrete trapping regions is configured to trap ions as individual trapping regions or as combinations of trapping regions. The controller is configured to combine at least a portion of the plurality of trapping regions into a larger trap region; fill the larger trap region with a plurality of ions; split the larger trap region into individual trapping regions each containing a portion of the plurality of ions; and eject ions from the trapping regions.

A charge detection mass spectrometer may include an ion source to generate ions, a mass spectrometer to separate the generated ions as a function of ion mass-to-charge ratio to produce beam of separated ions, an electrostatic linear ion trap (ELIT) including a charge detection cylinder disposed between a pair of coaxially aligned ion mirrors, and means for controlling a trajectory of the beam of separated ions entering the ELIT to cause the ions subsequently trapped in the ELIT to oscillate therein with different planar ion oscillation trajectories angularly offset from one another about the longitudinal axis with each extending along and crossing the longitudinal axis in each of the ion mirrors or with different cylindrical ion oscillation trajectories radially offset from one another about the longitudinal axis to form nested cylindrical trajectories each extending along the longitudinal axis.