Tool Talk Express with Dr. Gregory L. Fisher
Sponsored by Physical Electronics
Thursday, March 1, 2018
36-428, Haus Room (4th floor)
50 Vassar St.
Cambridge, MA
11am-1pm (lunch included)
Abstract
The fundamental limitation of rapid, high lateral resolution mass spectrometry (MS) imaging, e.g. TOF-SIMS, has been the capacity for unambiguous identification of molecular and surface chemistry. A unique TOF-TOF imaging mass spectrometer, introduced globally in November 2016, allows TOF-SIMS (MS1) analysis and tandem MS (MS2) analysis to be achieved simultaneously and in parallel as illustrated by the data shown in Figure 1. Secondary ions for MS1 and MS2 analysis are produced from the same area of the surface by a pulsed and digitally raster-scanned primary ion nanoprobe. Practical lateral resolution (Δl) in both MS1 and MS2 images is always < 1 mm and is often ≤ 100 nm. The sensitivity of the TOF-TOF imaging mass spectrometer is high such that precious and one-of-a-kind samples may be probed without erosion or degradation of the specimen; even sub-monolayer 2D films have been characterized. Monoisotopic (1 Da) precursor selection combined with keV collision-induced dissociation (CID) enables identification of molecular or surface-bound moieties. The Parallel Imaging MS/MS capability has been brought to bear for straightforward molecular identification as well as multifaceted studies involving surface modification, polymers, composites, catalysis, forensic / failure analysis, biology, and pharmaceuticals. Discussion of 2D and 3D imaging will begin with materials examples wherein the Parallel Imaging MS/MS characteristics are readily described and understood, and then examples of biosynthesis and sub-cellular structural elucidation will be presented for discussion.