title: Internal energy deposition and ion fragmentation in atmospheric-pressure mid-infrared laser ablation electrospray ionization.
abstract: Mid-infrared laser ablation of water-rich targets at the maximum of the 2.94 μm absorption band is a two-step process initiated by phase explosion followed by recoil pressure induced material ejection. Particulates and/or droplets ejected by this high temperature high pressure process can be ionized for mass spectrometry by charged droplets from an electrospray. In order to gauge the internal energy introduced in this laser ablation electrospray ionization (LAESI®) process, we apply the survival yield method and compare the results with electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI). The results indicate that LAESI yields ions with internal energies indistinguishable from those produced by ESI. This finding is consistent with the recoil pressure induced ejection of low micrometre droplets that does not significantly change the internal energy of solute molecules.
authors.affiliation: Department of Chemistry, The George Washington University, Washington, DC 20052, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Nemes
authors.forename: Hehua
authors.initials: H
authors.lastname: Huang
authors.forename: Akos
authors.initials: A
authors.lastname: Vertes
mesh_terms: D007259:Infrared Rays; D007477:Ions / Q000737:chemistry; D007834:Lasers; D011312:Pressure; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013696:Temperature; D014805:Vitamin B 12 / Q000737:chemistry
chemical_list: D007477:Ions; D014805:Vitamin B 12