Imaging mass spectrometry with SIMS

Malmberg, P.,Nygren, H. (2008) Methods for the analysis of the composition of bone tissue, with a focus on imaging mass spectrometry (TOF-SIMS). Proteomics, 8, 3755-3762. 

Figure 13.7. The image of a fingerprint taken from a glass sheet surface (10,000 x 10,000 j,m). (Reprinted from Szynkowska, M. I. et al., 2007. Preliminary Studies Using Scanning Mass Spectrometry (TOF-SIMS) in the Visualisation and Analysis of Fingerprints, Imaging Sci. J., 55 180-187. With permission from Maney Publishing.) (See color insert.)...

The development of surface analytical techniques such as LA-ICP-MS, GDMS and SIMS focuses on improvements to sensitivity and detection limits in order to obtain precise and accurate analytical data. With respect to surface analytical investigations, an improvement of spatial and depth resolution is required, e.g., by the establishment of a near field effect or the apphcation of fs lasers in LA-ICP-MS. There is a need for the improvement of analytical techniques in the (j,m and nm range, in depth profiling analysis and especially in imaging mass spectrometry techniques to perform surface analyses faster and provide more accurate data on different materials to produce quantitative 3D elemental, isotopic and molecular distribution patterns of increased areas of interest with high spatial and depth resolution over an acceptable analysis time. 

ToF-secondary ion mass spectrometry (ToF-SIMS) is a versatile surface analytical technique that provides detailed information about molecular composition and imaging of surface monolayers with high sensitivity and resolution. In a typical SIMS sample, surfaces are exposed to a beam of energetic primary ions or atoms (5—25 keV), which results in the emission of secondary ions including quasimolecular ions, atoms, and molecules (Benninghoven, 1994). The secondary ions formed as a result of this... 

An AFM probe equipped with a thermal probe heats up sample resulting topographical imaging and thermal analysis of specific areas of the sample surface, sudden change in deflection of the heated cantilever indicates a thermeil transition Hme-of-flight secondary ion mass spectrometry (ToF-SIMS) Mass spectrometry of sample surface maps spatial compositional information the distribution of compounds within 1-2 nm depth... 

Mass spectrometry imaging with time-of-flight secondary ion mass spectrometry (ToF-SIMS) has revealed the spatial distribution of chemicals on a surface (1). When applied to biological samples, this method offers spatial information on biologically relevant small molecules (<1,000 Da). Indeed, ToF-SIMS imaging has been shown to be a powerful analytical tool for mapping the distribution of lipids on a cell membrane at the single-cell... 

Solid samples can be analyzed by mass spectrometry with techniques providing ionization by desorption (13) such as MALDI (matrix assisted laser desorption ionization) (14) and S-SIMS (static-secondary ion mass spectrometry) (15). Ions are produced by energy deposition on the sample surface. The analysis can be performed at the bead level. Most of all, chemical images can be produced to localize specific compounds on the studied surfaces. 

Passarelli, M.K. and Winograd, N. (2011) Lipid imaging with time-of-flight secondary ion mass spectrometry (ToF-SIMS). Biochim. Biophys. Acta 1811, 976-990. 

This method has to be compared with the other preexisting mass spectrometric imaging methods. Time-of-flight-secondary ion mass spectrometry (TOF-SIMS) imaging has already existed for more than 40 years," and recent improvements in polyatomic ion... 

Nevertheless, the introduction of time-of-flight (ToF) analysers for SIMS analyses at the beginning of the 1980s, as well as the recent development of liquid ion sources delivering cluster projectiles now permit the analysis of organic materials with high sensitivity and selectivity. Moreover, thanks to its excellent lateral resolution (in the order of micrometres), and its minimal sample preparation, ToF-SIMS has become the reference technique for chemical imaging by mass spectrometry. 

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