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Investigations into the interactions of a MALDI Matrix with organic thin films using C 60 + SIMS depth profiling
Author(s) -
Lerach Jordan O.,
Keskin Selda,
Winograd Nicholas
Publication year - 2014
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.5545
Subject(s) - chemistry , ionization , analytical chemistry (journal) , matrix assisted laser desorption/ionization , mass spectrometry , thin film , desorption , secondary ion mass spectrometry , matrix (chemical analysis) , ion , materials science , nanotechnology , chromatography , adsorption , organic chemistry
Molecular depth profiling of multilayer organic films is now an established protocol for cluster SIMS. This unique capability is exploited here to study the ionization mechanism associated with matrix‐enhanced SIMS and possibly matrix‐assisted laser desorption/ionization. Successful depth profiling experiments were performed on model bi‐layer systems using 2,5‐dihydroxybenzoic acid as the matrix with dipalmitoylphosphatidylcholine or phenylalanine. The interaction between the matrix and organic analyte is monitored at the interface of the films. Tri‐layer films with D 2 O as a thin film sandwiched between the matrix and organic layers are also investigated to determine what role, if any, water plays during ionization. The results show successful depth profiles when taken at 90 K. Mixing is observed at the interfaces of the films due to primary ion bombardment, but this mixing does not recreate the conditions necessary for ionization enhancement. Copyright © 2014 John Wiley & Sons, Ltd.