Instrument with a combination of a linear ion trap and a mass spectrometer with a Fourier transformation (FT-MS). Instead of a ICR cell placed in a strong magnetic field of a super-conductive magnet as it has been used in the FT-MS system, trap equipped with a cell in the electrostatic field. At the 1 Hz scan frequency (1 scan per second) a trap giving resolutions up to 100 000 with a mass measurement accuracy better than 2 ppm (usually sub-ppm), which is oppositely to the hybrid TOF systems given in a wide dynamic range also for the ions in MS/MS and MSn spectra. The advantage against FT-ICR is also the absence of a magnet and thus, cheaper running and easy maintenance. The main reason for the use of a linear ion trap detector is its extremely high sensitivity and accuracy of measured molecular masses, and the possibility of application to gain information about both the structure of individual precursors of metabolic pathways and the target metabolites.
