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 (3σ) 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. Keywords: ion mobility • time-of-flight mass spectrometry • matrix-assisted laser desorption/ionization • high repetition rate • two-dimensional separation • peptide mass mapping