title: An external matrix-assisted laser desorption ionization source for flexible FT-ICR Mass spectrometry imaging with internal calibration on adjacent samples.
abstract: We describe the construction and application of a new MALDI source for FT-ICR mass spectrometry imaging. The source includes a translational X-Y positioning stage with a 10×10 cm range of motion for analysis of large sample areas, a quadrupole for mass selection, and an external octopole ion trap with electrodes for the application of an axial potential gradient for controlled ion ejection. An off-line LC MALDI MS/MS run demonstrates the utility of the new source for data- and position-dependent experiments. A FT-ICR MS imaging experiment of a coronal rat brain section yields ∼200 unique peaks from m/z 400-1100 with corresponding mass-selected images. Mass spectra from every pixel are internally calibrated with respect to polymer calibrants collected from an adjacent slide.
authors.affiliation: FOM Institute for Atomic and Molecular Physics, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Donald F
authors.initials: DF
authors.lastname: Smith
authors.forename: Konstantin
authors.initials: K
authors.lastname: Aizikov
authors.forename: Marc C
authors.initials: MC
authors.lastname: Duursma
authors.forename: Frans
authors.initials: F
authors.lastname: Giskes
authors.forename: Dirk-Jan
authors.initials: DJ
authors.lastname: Spaanderman
authors.forename: Liam A
authors.initials: LA
authors.lastname: McDonnell
authors.forename: Peter B
authors.initials: PB
authors.lastname: O'Connor
authors.forename: Ron M A
authors.initials: RM
authors.lastname: Heeren
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis; D001923:Brain Chemistry; D002138:Calibration; D005583:Fourier Analysis; D006651:Histocytochemistry; D008055:Lipids / Q000032:analysis; D057054:Molecular Imaging / Q000379:methods*; D051381:Rats; D012697:Serine Endopeptidases / Q000032:analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D001426:Bacterial Proteins; D008055:Lipids; D012697:Serine Endopeptidases; C032923:microbial serine proteinases