Fast-atom Bombardment Mass Spectrometry FABMS

The treatment of sucrose with anhydrous HF89 results in the formation of a complex mixture of pseudooligo- and poly-saccharides up to dp 14, which were detected by fast-atom-bombardment mass spectrometry (FABMS). Some of the smaller products were isolated and identified by comparison with the known compounds prepared86 88 a-D-Fru/-1,2 2,1 -p-D-Fru/j (1), either free or variously glucosylated, was a major product, and this is in accord with the known stability of the compound. The mechanism of formation of the products in the case of sucrose involves preliminary condensation of two fructose residues. The resultant dianhydride is then glucosylated by glucopyranosyl cation.89 The characterization of this type of compound was an important step because it has permitted an increased understanding of the chemical nature of caramels. 

Thus as a starting point for understanding the bombardment process we have developed a classical dynamics procedure to model the motion of atomic nuclei. The predictions of the classical model for the observables can be compared to the data from sputtering, spectrometry (SIMS), fast atom bombardment mass spectrometry (FABMS), and plasma desorption mass spectrometry (PDMS) experiments. In the circumstances where there is favorable agreement between the results from the classical model and experimental data It can be concluded that collision cascades are Important. The classical model then can be used to look at the microscopic processes which are not accessible from experiments In order to give us further insight into the ejection mechanisms. 

It is evident from the spectra that absolute ion abundances cannot be used for quantitation. However, the ion abundance ratio of the two compounds remained constant over the selected concentration range. Therefore, internal standards must be used for quantitation by SIMS. This has been found to be true for fast-atom bombardment mass spectrometry (FABMS), also [124]. 

Fast atom bombardment mass spectrometry (FABMS) has become an important addition to the ionization techniques available to the analytical chemist in recent years. It has been particularly useful in a number of diverse applications which include molecular weight determinations at high mass, peptide and oligosaccharide sequencing, structural analysis of organic compounds, determination of salts and metal complexes, and the analysis of ionic species in aqueous solutions. This paper will focus on some aspects of the quantitative measurement of ionic species in solution. The reader is referred to a more comprehensive review for more details of some of the examples given here as well as other applications (1). 

In order to assign the disulfide bonds of these molecules fast atom bombardment mass spectrometry (FABMS) which has been used not only to confirm amino acid sequence data but also to elucidate post-translational modifications of proteins, such as disulfide bonds, has been employed. For this purpose a sample of native Er-2, containing four methionines, was subjected to CNBr cleavage and without further fractionation directly... 

Fast atom bombardment mass spectrometry (FABMS) has been used to investigate the selectivity of monocyclic crown ethers for Group IA metal cations in competition experiments (56). We applied this semiquantitative technique for the first time to bis crown ethers (51, 53) and observed that (7) and (8) in competition experiments with Li +, Na+, K+, and Cs+ exhibited exclusive selectivity for K+ (Fig. 9). Ligands (9) and (10) however displayed no preference for any particular alkali metal cation. 

Mass spectrometry is a standard spectroscopic technique for the characterisation of high molecular weight organic and inorganic compounds, but has until recently received little attention from the zeolite community. The surface composition of zeolites has been explored using fast atom bombardment mass spectrometry (FABMS)[66] and secondary ion mass spectrometry [67], but mass spectrometric analysis of the bulk composition of a zeolite or of adsorbed molecules has not until very recently been attempted. The practical difficulty is to vaporise the solid. Two different strategies have been proposed laser ablation and plasma desorption. 

As a result of this reaction, we isolated a violet product with a peak at 1284.3 by fast atomic bombardment mass spectrometry (FABMS). The mass of the molecular ion indicated the incorporation of three cobalt atoms. This result was confirmed by elemental analysis. We tried examining the oxygen-complexing ability of our salen-type complex 71, but... 

Kodama etal (1996) identified TTX in cultured cells of Alexandrtum tamarense, a notorious PSP-producing dinoflagellate. TTX was identified by HPLC-fluoro metric analysis and fast atom bombardment mass spectrometry (FABMS). 

Barber, M., Bordoli, R.S., Elliot, G.J., Sedgwick, R.D., and Tyler, A.N., Fast Atom Bombardment Mass Spectrometry (FABMS)—A Study of Surface Coverage Effects in FABMS, /. Chem. Soc., Faraday Trans. I, 79, 1249, 1983. 

One problem with analyzing polymer surfaces with SIMS is static charging caused by the primary ion current. In Briggs s work [78,79], the ion current was neutralized with an electron gun. Recent developments in the analysis of polymer surfaces by mass spectrometry have included a gun that will bombard the solid surface with neutral atom bombardment, referred to as fast atom bombardment mass spectrometry (FABMS), greatly reduces the static charging problem encountered in the normal SIMS experiment. 

Surface-charging problems can also be minimised by the use of neutral beams to bombard surfaces instead of primary ions, a technique known as fast atom bombardment mass spectrometry (FABMS) [44-47]. A disadvantage of this type of process is that chemical information is limited to a spatial resolution of a few millimetres only, and no information is available on the spatial distribution of specific chemical moieties. 

These techniques are discussed together because the principles behind them are similar. In secondary ion mass spectrometry (SIMS) (79), the ions are produced by bombarding the sample molecules with a beam of fast ions. When the ion beam is replaced by a beam of fast atoms the technique is called fast atom bombardment mass spectrometry (FABMS) (20). Introduced in its modern form by Barber and co-workers (27), FABMS has proved a versatile method for examining natural products. The production of ions in FABMS is illustrated in Fig. 1. 

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