How sensitive is AP/MALDI?
It has been reported in the peer-reviewed literature that attomole quantities of peptides can be routinely analyzed using AP/MALDI on an ion trap MS. The signal-to-noise and mass spectra obtained from AP/MALDI are similar to vacuum MALDI. AP/MALDI compensates for the loss of ions going from atmospheric pressure to vacuum, by generating much less fragment ions than compared to vacuum MALDI, typically consuming greater sample quantities, and applying a new pulsed dynamic focusing (PDF) technique (described below) which focuses ions into the vacuum of the mass analyzer. As a result, AP/MALDI sensitivity performance is often the same as those from vacuum MALDI.
