Internal Energy of Preformed and Peptide Ions Produced by Laser Desorption/Ionization from Laser-Induced Silicon Microcolumn Arrays

摘要

TIs on PFP-derivatized LISMA exhibit higher survival yields and lower internal energies, indicating that changes in surface polarity affect energy transfer to the desorbing ions. Both native and PFP-derivatized LISMA show no change in their internal energies over a wide fluence range, resulting in stable fragment ion yields on LISMA. This is in contrast to matrix assisted laser desorption/ionization and can be explained by the one-dimensional heterogeneous plume which causes slower expansion and increased plume densities. While the SYs for these preformed ions are stable, results on peptides indicate fluence dependent fragmentation. These results point to a different fragmentation mechanism for peptides. Studies are conducted to compare the competing fragmentation pathways and the SYs of peptides.