Simultaneous Isolation of Nonadjacent / Ions Using Mirror Switching in an Electrostatic Linear Ion Trap.

Simultaneous isolation of ions of disparate mass-to-charge (/) ratios is demonstrated via appropriately timed pulsing of entrance and exit ion mirrors in an electrostatic linear ion trap (ELIT) mass spectrometer. Manipulation of the voltages of the entrance and exit mirrors, referred to as "mirror switching", has been demonstrated as a method in which ions can be both captured and isolated. High resolution isolation (>35 000) was previously demonstrated by selective gating of trapping electrodes to avoid ion lapping while closely spaced ions could continue to separate [ Johnson et al.

Mirror Switching for High-Resolution Ion Isolation in an Electrostatic Linear Ion Trap.

Ion isolation was achieved via selective pulsing of the entrance and exit ion mirrors in an electrostatic linear ion trap mass spectrometer (ELIT). Mirror switching has been described previously as a method for capturing injected ions in ELIT devices. After ion trapping, mirror switching can be used as a method for ion isolation of successively narrower ranges of mass-to-charge (/) ratio.

A Miniaturized Fourier Transform Electrostatic Linear Ion Trap Mass Spectrometer: Mass Range and Resolution.

Mass resolution (M/ΔM) was increased by reducing the axial length of a Fourier transform electrostatic linear ion trap (FT-ELIT) mass spectrometer. The increase in mass resolution corresponds directly to increased axial ion frequencies in the FT-ELIT. Increased mass resolution was demonstrated for equivalent transient lengths in a 5.

Fourier-Transform MS and Closed-Path Multireflection Time-of-Flight MS Using an Electrostatic Linear Ion Trap.

An electrostatic linear ion trap (ELIT) has been configured to allow for the simultaneous acquisition of mass spectra via Fourier transform (FT) techniques (frequency measurement) and via time-of-flight (TOF; time measurement). In the former case, the time-domain image charge derived from a pick-up electrode in the field-free region of the ELIT is converted to frequency-domain data via Fourier transformation (i.e.

Determination of Collision Cross Sections Using a Fourier Transform Electrostatic Linear Ion Trap Mass Spectrometer.

Collision cross sections (CCSs) were determined from the frequency-domain linewidths in a Fourier transform electrostatic linear ion trap. With use of an ultrahigh-vacuum precision leak valve and nitrogen gas, transients were recorded as the background pressure in the mass analyzer chamber was varied between 4× 10 and 7 × 10 Torr. The energetic hard-sphere ion-neutral collision model, described by Xu and coworkers, was used to relate the recorded image charge to the CCS of the molecule.

Utility of Higher Harmonics in Electrospray Ionization Fourier Transform Electrostatic Linear Ion Trap Mass Spectrometry.

Mass resolution (M/ΔM fwhm) is observed to linearly increase with harmonic order in a Fourier transform electrostatic linear ion trap (ELIT) mass spectrometer. This behavior was predicted by Grosshans and Marshall for frequency-multiple detection in a Fourier transform ion cyclotron resonance mass spectrometer only for situations when the prominent mechanism for signal decay is ion ejection from the trap. As the analyzer pressure in our ELIT chamber is relatively high, such that collisional scattering and collision-induced dissociation are expected to underlie much of the ion loss, we sought to explore the relationship between harmonic order and mass resolution.