Tryptic peptides from a mixture of bovine ß crystallins were measured on the QTOF with a nanoflow electrospray ionisation source. Approximately 20 spectra were obtained on sub femtomole levels of peptides in 30 minutes. The MS/MS spectra show higher resolution and signal-to-noise ratios compared to those obtained on conventional MS/MS instruments. The presence of abundant C terminal sequence ions (yn ions) and the increased resolution enables the interpretation of the MS/MS spectra of ions with more than one charge state to be simplified.
MS/MS spectra of variety of different peptides and oligonucleotides obtained on the magnetic sector-TOF instrument will also be presented. This instrument allows precursor ions to be selected with high resolution and has the capability for accessing laboratory collision energies up to 400 eV (with electrospray ionisation). This is especially an advantage for higher mass precursor ions
(> 1500 Da) since the available energy for inducing fragmentation decreases with increasing precursor ion mass. Finally, the MS/MS spectra from the mag-TOF will be compared to those obtained on a triple quadrupole mass spectrometer.