Invited Paper TM+AS-MoM1
In Situ MS/MS Analysis on Biological Samples using Imaging Secondary Ion Mass Spectrometry (SIMS)

Monday, October 30, 2017, 8:20 am, Room 5 & 6

SIMS imaging allows characterization of biomaterials with high lateral resolution. The method has not, however, yet gained popularity within the biological community. One reason is the need for MS/MS analysis due to isobaric interferences associated with the complex composition of biomaterials. Although MS/MS has been routine in imaging mass spectrometry (IMS) with matrix assisted laser desorption ionization (MALDI), it is rarely incorporated with SIMS imaging. Until recently, only a few SIMS instruments had the capability of tandem or parallel MS/MS imaging, for example the J105 3D Chemical Imager, PHI nanoTOF II and IonToF Orbitrap Hybrid ^1-3. The identification of lipids and metabolites in various biosystems, such as Drosophila brain section⁴, Zebra Finch brain section, Zebrafish whole body section¹ and bacteria ², has been reported so far. The precise precursor selection, high lateral resolution and high energy collisional fragmentation are the must-have for the design of new instrumentation for MS/MS capability. Gas cluster ion source (GCIB) is also a necessity for generating sufficient precursor ions especially at extended mass range of SIMS spectra, allowing for a much greater variety of biomolecule studies. Here, we present a review of the current state of MS/MS in SIMS, and illustrate the power of this technique using a hybrid mass spectrometer that employs shaped field bunching for injection into the collision cell. The possibility to utilize laser-induced photo-fragmentation in this instrument is also discussed.

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3. Hybrid SIMS. https://www.iontof.com/hybrid-sims-ms-ms-organic-mass-spectrometry-surface-analysis.html (accessed April 28, 2017).

4. Phan, N. T. N.; Munem, M.; Ewing, A. G.; Fletcher, J. S., MS/MS analysis and imaging of lipids across Drosophila brain using secondary ion mass spectrometry. Analytical and Bioanalytical Chemistry 2017, 1-10.