Secondary ion mass spectrometry principle

Vickerman J C, Brown A and Reed N M (eds) 1989 Secondary Ion Mass Spectrometry, Principles and Applications (Oxford Clarendon)... 

Vickerman, J.C., Brown, A., and Reed, N.M., Secondary Ion Mass Spectrometry Principles and Applications,... 

J. C. Vickerman, A. Brown, and N. M. Reed (editors) Secondary ion mass spectrometry principles and applications... 

Figure 8.11 A quadrupole analyzer. The oscillations of ions are generated by combined DC and AC electric fields using four cylindrical rods (a) travel path of secondary ions in the analyzer and (b) electrode arrangement of the analyzer. (Reprinted by permission of Oxford University Press from J.C. Vickerman, A. Brown, and N.M. Reed, Secondary Ion Mass Spectrometry Principles and Applications, Clarendon Press, Oxford. 1989 Oxford University Press.)...

Secondary ion mass spectrometry (SIMS) is by far the most sensitive surface teclmique, but also the most difficult one to quantify. SIMS is very popular in materials research for making concentration depth profiles and chemical maps of the surface. For a more extensive treatment of SIMS the reader is referred to [3] and [14. 15 and 16]. The principle of SIMS is conceptually simple When a surface is exposed to a beam of ions... 

The basic principles of fast-atom bombardment (FAB) and liquid-phase secondary ion mass spectrometry (LSIMS) are discussed only briefly here because a fuller description appears in Chapter 4. This chapter focuses on the use of FAB/LSIMS as part of an interface between a liquid chromatograph (LC) and a mass spectrometer (MS), although some theory is presented. 

The measurements that have been made at Rochester and the experience that has been gathered over the years on the operation of sputter ion sources [38] indicate that an analytical tool of unprecedented sensitivity and accuracy for isotopic ratio determinations can be constructed by coupling SIMS technology with the new accelerator technique. The only difference in principle between the experiments that have been conducted to date and the technique as it would be applied in secondary ion mass spectrometry is that the primary beam of cesium would be focussed to a fine probe of pm dimensions rather than the spot diameters of approximately 1 mm that have been used to date. 

The principle of FAB, less frequently referred to as liquid secondary ionization mass spectrometry (LSIMS), is very similar to secondary-ion mass spectrometry (SIMS). However, FAB utilizes a liquid matrix, such as glycerol, in which a sample is dissolved. The matrix is used to enhance sensitivity and ion current stability. 

Fig. 4.1 The principle of secondary ion mass spectrometry (SIMS). Primary ions with an energy between 0.5 and 10 keV cause a collisional cascade below the surface of the sample. Some of the branches end at the surface and stimulate the emission of neutrals and ions. In SIMS, the secondary ions are detected directly with a mass spectrometer, whereas in SNMS the secondary neutrals are ionized before they enter the mass spectrometer.

The Stoddart group has used the principles employed in their catenane studies to synthesise both a molecular trifoil knot and its isomeric large ring in very low yield. These isomers were separated by HPLC and characterised by liquid secondary ion mass spectrometry. The synthetic procedure, which is illustrated schematically in Figure 5.26, was based on the formation of a double-stranded supramolecular complex between an acyclic 7C-electron-rich, 1,5-dioxynaphthalene-based polyether and an acyclic 7i-electron-deficient bipyridinium-based tetracation. The extremely low efficiency of the synthesis in this case appears to reflect an unfavourable solution geometry of the intermediate host-guest complex - the latter... 

Techniques for the Ionization of Molecules The measurability of molecules by MSI is enabled through the local desorption and ionization of the molecules from a surface. In theory, all types of molecules that can undergo these two chemical processes can be measured. Many techniques have been developed or adapted to achieve desorption and ionization of molecules from surfaces, but three different desorption/ioniza-tion techniques made their way to commercially available products. The acronyms of these technologies are desorption electrospray ionization (DESI), MALDI, and secondary ion mass spectrometry (SIMS). The principles of these three methods and a comparison of their possibilities and limitations are outlined throughout this section and summarized in Figure 1 and Table 2, respectively. 

This spectrometer is based on the detection of ions produced from a single temporally well-defined event with high time resolution. The principle is well known and has long been applied in secondary ion mass spectrometry [72] and in laser micro mass spectrometry [73],... 

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