LC-MS Analysis of Peptides
LTQ-FTICR allows analysis with ultra-high resolution and sensitivity coupled with sub ppm mass accuracy. This hybrid instrument consists of a linear ion trap (LTQ) capable of very fast and sensitive peptide sequencing combined with an ion cyclotron resonance trap (ICR). In the ICR trap ions circulate in a 7 Tesla magnetic field and their image current is detected and converted to a mass spectrum by Fourier transformation (FT-ICR). While this high resolution and high mass accuracy spectrum is acquired, the LTQ part of the mass spectrometer simultaneously isolates, fragments and obtains MS/MS spectra on peptide ions.