An instrument for analyzing ions may include an ion source to generate ions, at least one ion processing instrument to process the generated ions by one or both of filtering the ions according to a molecular characteristic and dissociating the ions, and an electrostatic linear ion trap (ELIT) to receive and trap ions exiting the at least one ion processing instrument. The ELIT has first and second ion mirrors separated by a charge detection cylinder, and is configured such that trapped ions oscillate back and forth through the charge detection cylinder between the first and second ion mirrors with a duty cycle, corresponding to a ratio of time spent by the trapped ions traversing the charge detection cylinder and total time spent by the trapped ions traversing a combination of the first and second ion mirrors and the charge detection cylinder during one complete oscillation cycle, of approximately 50%.

An instrument for analyzing ions may include an ion source to generate ions, at least one ion processing instrument to process the generated ions by one or both of filtering the ions according to a molecular characteristic and dissociating the ions, and an electrostatic linear ion trap (ELIT) to receive and trap ions exiting the at least one ion processing instrument. The ELIT has first and second ion mirrors separated by a charge detection cylinder, and is configured such that trapped ions oscillate back and forth through the charge detection cylinder between the first and second ion mirrors with a duty cycle, corresponding to a ratio of time spent by the trapped ions traversing the charge detection cylinder and total time spent by the trapped ions traversing a combination of the first and second ion mirrors and the charge detection cylinder during one complete oscillation cycle, of approximately 50%.

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.

An electrostatic linear ion trap has first and second axially aligned ion mirrors separated by a charge detection cylinder axially aligned with each ion mirror. Electric fields are selectively established within the first and second ion mirrors 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 mirrors 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%.

A low power mass spectrometer assembly includes at least an ionization component, an electrostatic analyzer, a lens assembly, a magnet assembly and at least one detector located in a same plane as the entrance to the magnet assembly for detecting the deflected sample ions and/or fragments of sample ions, including ions or ion fragments indicative of the Vitamin D metabolite within the sample.

Provided is a compact two-dimensional electron spectrometer that is capable of variably adjusting the deceleration ratio over a wide range, and performing simultaneous measurement of the two-dimensional emission angle distribution with a high energy resolution over a wide solid angle of acquisition. The two-dimensional electron spectrometer is configured from: a variable deceleration ratio spherical aberration correction electrostatic lens; a cylindrical mirror type energy analyzer or a wide angle energy analyzer; and a projection lens. The variable deceleration ratio spherical aberration correction electrostatic lens is configured from: an electrostatic lens that consists of an axially symmetric spherical mesh having a concave shape with respect to a point source, and one or a plurality of axially symmetrical electrodes, and that adjusts the spherical aberration of charged particles generated from the point source; and an axially symmetric deceleration field generating electrode that is placed coaxially with the electrostatic lens.

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.

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.

A low power mass spectrometer assembly includes at least an ionization component, an electrostatic analyzer, a lens assembly, a magnet assembly and at least one detector located in a same plane as the entrance to the magnet assembly for detecting the deflected sample ions and/or fragments of sample ions, including ions or ion fragments indicative of the Vitamin D metabolite within the sample.

Disclosed embodiments include a time-of-flight mass spectrometer with a straight ion optical axis comprising: an ion gate is electrically insolated electrode on which applied voltages to reject/pass ions through ion gate, entrance module and exit module set in focus/mirror modes, and create ion optical image on image plane located in field view aperture, electrostatic object lens, entrance module in focus mode and, transport electrostatic lens, exit module in focus mode and projection lens focused and map ions from image plane of field view aperture to image plane of ion detector, projection lens configured to form ion optical image of sample holder on image plane of ion detector and ion optical components with corrected geometrical, chromatic and timed aberrations configured to compensate time arriving disturbance in image plane of ion detector and improve mass and spatial resolution of image on image plane of ion detector.