MS - Orbi Trap Mass spectrometer

The latest development in ion trap mass spectrometers is the Orbitrap. The ion trap contains a central, spindle-shaped electrode. The ions are shot radially into the Orbitrap with respect to this electrode and move on circular paths (orbits) around the central electrode due to electrostatic attraction. Since the ions are injected decentrally rather than in the center of the chamber, they oscillate simultaneously along the axis of the central electrode. The frequency of this oscillation generates signals in detector plates, which are converted to the corresponding m/q ratios by Fourier transformation. The principle is therefore similar to FT-ICR-MS (see above), but works with an electrostatic field instead of a magnetic field. Orbitraps therefore do not require the complex cooling with liquid helium. The mass resolution of Orbitraps is only slightly worse than that of an FT-ICR instrument with a 7 Tesla magnet.