Sub-femtomole peptide detection in ion mobility-time-of-flight mass spectrometry measurements.

Sensitivity and detection limit enhancements are obtained for peptides by performing high repetition rate (150 Hz) matrix-assisted laser desorption/ionization (MALDI) coupled with ion mobility-time-of-flight mass spectrometry. Absolute limits of detection (3sigma) for model peptides are on the order of 0.1 fmol of peptide deposited and represent a factor of 40-60 improvement over data obtained using typical low repetition (20 Hz) MALDI. This increase in sensitivity is demonstrated for two-dimensional MALDI-IM-TOFMS peptide mass mapping of bovine hemoglobin.