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Imaging with biomolecular ions generated by massive cluster impact in a time‐of‐flight secondary ion microscope
Author(s) -
Zhang Jitao,
Franzreb Klaus,
Williams Peter
Publication year - 2014
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.7006
Subject(s) - chemistry , mass spectrometry , ion , maldi imaging , mass spectrometry imaging , biomolecule , microscope , mass spectrum , analytical chemistry (journal) , secondary ion mass spectrometry , resolution (logic) , reflectron , ion source , ionization , time of flight mass spectrometry , chromatography , optics , matrix assisted laser desorption/ionization , desorption , physics , biochemistry , organic chemistry , adsorption , artificial intelligence , computer science
RATIONALE Imaging mass spectrometry can allow the correlation of molecular identification and spatial organization in biological samples. A useful technique would rapidly generate, from untreated samples, images of lipids, peptides and small proteins with intracellular spatial resolution. We describe the use of massive, highly charged glycerol cluster impact to produce images using ionized, intact biomolecules, with few‐micrometer lateral resolution and few‐minute acquisition times. METHODS An electrospray primary ion source generating massive clusters of electrolyte‐doped glycerol was coupled with a microscope‐imaging time‐of‐flight secondary ion mass spectrometer. A continuous stream of primary cluster ions ejected secondary ions from the sample surface. The secondary ion stream was pulsed in the secondary column and either time‐of‐flight mass spectra or mass‐selected ion images were projected onto a position‐sensitive ion detector. The image acquisition times were a few minutes. RESULTS Ionized intact molecules of some common lipids, peptides and small proteins have been detected. A lateral image resolution of ~3 µm has been measured for a bradykinin ion image. CONCLUSIONS Massive cluster impact (MCI) combined with microscope‐mode ion imaging allows rapid imaging using ionized intact biomolecules, with a lateral resolution acceptable for applications with biological samples. Copyright © 2014 John Wiley & Sons, Ltd.