Fast atom bombardment mass chemistry

In conclusion, I hope that I have shown that fast-atom bombardment mass spectrometry is a potentially useful tool for the synthetic chemist working in many areas of inorganic, organometallic, and coordination chemistry. In addition, as further fundamental research is done in the field with these applications in mind, the technique should become as routine as IR or NMR. Combined with developments in high-resolution NMR of solids, FAB should provide particularly useful data on supported catalytic reactions. Certainly FAB and the other complementary mass spectrometric techniques, mentioned in less detail, constitute a major way of quickly characterizing new compounds. 

Dayal, B. and Salen, G. (1990). Fast atom bombardment mass spectrometry (FAB-MS) studies of conjugated bile alcohols. Presented in part at the 17th International Symposium on the Chemistry of Natural... 

There has been a continued interest in the chemistry and biochemistry of coenzymes, particularly phosphoenolpyruvate, and a book devoted to pyridine nucleotide coenzymes has been published as a tribute to Professor N. O. Kaplan s work on these compounds. Among new techniques which have been applied recently to biologically interesting compounds is fast atom bombardment mass spectrometry, which has been used in the structural elucidation of underivatized phospholipids. ... 

This brief overview of the rich chemistry of the complexes of monolacunary Keggin heteropolyanions was aimed at collecting relevant information for those interested in further studies on these types of complexes and on their potential applications. To keep this review short, only the most common characterisation techniques used in the studies of these systems were described. Other potentially interesting techniques and properties that have recently been used in their study in our laboratory, such as fast atom bombardment mass spectrometry, were not considered. 

Chang,T., Lay, J.Q. Jr., Francel, R.J. (1984) Direct analysis of thin-layer chromatography spots by fast atom bombardment mass spectrometry. Analytical Chemistry, 56, 109-111. 

Chang, T. T., J. 0. Lay, and J. F. Rudolph Direct Analysis of Thin-Layer Chromatography Spots by Fast Atom Bombardment Mass Spectrometry. Analyt. Chemistry 56, 109 (1984). 

NMR spectra were recorded on a Briiker AM 300 instrument. IR spectra were recorded on a Perkin Elmer 1710 IR FT spectrometer. UV spectra were recorded on a Perkin-Elmer Lambda 6 spectrometer. Electrochemical measurements were conducted on a Princeton Applied Research Potentiostat/Galvanostat Model 273. Fast atom bombardment mass spectra were performed at University College, Swansea by the S.E.R.C. mass spectrometry service. All elemental analyses were carried out by the Inorganic Chemistry Laboratory, Oxford. 

Barber M, Bordoli RS, Elliott GJ, Sedgwick RD and Tyler AN (1982) Fast atom bombardment mass spectrometry. Analytical Chemistry 54 645A- 657A. 

A connnon feature of all mass spectrometers is the need to generate ions. Over the years a variety of ion sources have been developed. The physical chemistry and chemical physics communities have generally worked on gaseous and/or relatively volatile samples and thus have relied extensively on the two traditional ionization methods, electron ionization (El) and photoionization (PI). Other ionization sources, developed principally for analytical work, have recently started to be used in physical chemistry research. These include fast-atom bombardment (FAB), matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ES). 

MS involves the separation of ions based on their mass-to-charge ratio (m/z). The concept was invented a century ago1 with a dramatic impact on analytical chemistry.2-3 The fundamental principle of MS requires vaporization of the molecules in the gas phase and in ionization. Early ionization methods such as electron impact (El) and chemical ionization (Cl)4-5 were limited to small organic molecules that were volatile and stable to heat and amenable to transfer into high vacuum. Introduction of the fast-atom-bombardment (FAB) method of ionization6... 

The only mass spectrometric methods available during the era of the first cascade synthesis in 1978 [30] were electron impact (El) and field desorption (FD) mass spectrometry [31]. Fast atom bombardment (FAB) mass spectrometry is limited to fairly low mass ranges and not very suitable for compounds of low polarity. It was not until the development of new and gentle ionisation methods such as MALDI (matrix-assisted laser desorption ionization) [32] and ESI (electrospray ionization) [33] that the conditions were fulfilled for the start of intense research in the field of dendrimer chemistry. The following section will present the special features of these mass-spectrometric methods and their importance in dendrimer analysis. 

Mass spectrometry (MS) and tandem mass spectrometry (MS/MS) play an important role in the identification of unknown compounds. Different ionization techniques have been used in studying isothiazole derivatives, such as electronic ionization (El), desorption chemical ionization (DCI), fast atom bombardment (FAB), field desorption (FD), and chemical ionization (Cl). Different MS/MS experiments have been described, such as investigation of metastable and collision-induced dissociations to study isothiazoles gas-phase ion chemistry. In addition, MS and MS/MS have been used to differentiate isothiazole isomers differing in the position of endocyclic groups or exocyclic substituents <1998THS(2)471, 1999THS(3)369, 2000THS(4)405>. 

Mass spectrometry (MS) has been one of the most important analytical methods in chemistry for many decades but its use was originally limited to relatively small and volatile organic molecules. This situation changed dramatically in 1981 when Barber and coworkers [1, 2) introduced a method named Fast Atom Bombardment (FAB). This was the first practical technique which made possible the generation and transfer to the gas phase of ions of polar, nonvolatile, and thermally unstable compounds, including the most important biomolecules such as peptides, nucleic acids, and sugars. Such methods are called mild or soft ionization techniques. Since that time MS has been constantly gaining importance as the major analytical tool in biochemistry as well as in polymer and supramolecular chemistry. 

Since the 1980s a revolution in the use of mass spectrometry for biological analyses has occurred and continues today. A major reason for this development was the introduction of new ionisation techniques such as fast atom bombardment (FAB), plasma desorption (PD) and thermospray (TSP) permitting the production of gas phase ions from charged and polar biopolymers [7—10). It has reached a first culmination with the recent award of the 2002 Nobel prizes in chemistry to two scientists pioneering the development of electrospray-ionisation and laser desorption mass spectrometry, John Fenn and Kuichi Tanaka [11, 12]. 

Moreover, the typical tools of supramolecular chemistry, such as NMR spectrometry, require concentrations usually in excess of 10 " mol/1. and other favorite methods such as mass spectroscopy [fast-atom bombardment (FAB), electrospray ionization (ESI), matrix-assisted laser desorption ionization (MALDI)], and vapor-pressure os-moinetry do not directly provide information about supramolecular behavior in solution. The most favorite method, x-ray analysis, suffers from the limitation posed by the ultimate requirement of being able to grow single crystals. While this is. in numerous instances, possible in the case of pure molecular entities, supramolecules, being mixed molecular objects by nature, are usually difficult to grow in the form of a single crystal. 

A variety of volatilization/ionization methods have been applied to polymers a recent review or key paper is cited here for each. Extensive reviews that include mass spectrometry of pol5mrers can be found in Analytical Chemistry Other to )ical reviews are field desorption, laser desorption, plasma desorption, fast-atom bombardment, pyrolysis, and electrospray ionization. The present review will focus on polymer characterization using secondary-ion mass spectrometry (SIMS) in the high mass range comparison with other methods will be presented where appropriate. 

Hyphenated TLC techniques. TLC has been coupled with other instrumental techniques to aid in the detection, qualitative identification and, occasionally, quantitation of separated samples, and these include the coupling of TLC with high-pressure liquid chromatography (HPLC/TLC), with Fourier transform infra-red (TLC/FTIR), with mass spectrometry (TLC/ MS), with nuclear magnetic resonance (TLC/NMR) and with Raman spectroscopy (TLC/RS). These techniques have been extensively reviewed by Busch (1996) and by Somsen, Morden and Wilson (1995). The chemistry of oils and fats and their TLC separation has been so well established that they seldom necessitate the use of these coupling techniques for their identification, although these techniques have been used for phospholipid detection. Kushi and Handa (1985) have used TLC in combination with secondary ion mass spectrometry for the analysis of lipids. Fast atom bombardment (FAB) has been used to detect the molecular species of phosphatidylcholine on silica based on the molecular ion obtained by mass spectrometry (Busch et al, 1990). 

One of the major problems in analytical chemistry is the detection and identification of non-volatile compounds at low concentration levels. Mass spectrometry is widely used in the analysis of such compounds, providing an exact mass, and hence species identification. However, successful and unequivocal identification, and quantitative detection, relies on volatilization of the compound into the gas phase prior to injection into the analyser. This constimtes a major problem for thermally labile samples, as they rapidly decompose upon heating. In order to circumvent this difficulty, a wide range of techniques have been developed and applied to the analysis of nonvolatile species, including fast atom bombardment (FAB), field desorption (FD), laser desorption (LD), plasma desorption mass spectrometry (PDMS) and secondary-ion mass spectrometry (SIMS). Separating the steps of desorption and ionization can provide an important advantage, as it allows both processes to be... 

Several mass spectrometric techniques including fast atom bombardment (FAB), plasma desorption (PD), matrix-assisted laser desorption/ionization (MALDI), and electrospray (ES) mass spectrometry (MS) are presently available for the analysis of peptides and proteins (Roepstorff and Richter, 1992). Of these techniques, mainly PDMS has gained footing in protein laboratories because the instrumentation is relatively cheap and simple to operate and because, taking advantage of a nitrocellulose matrix, it is compatible with most procedures in protein chemistry (Cotter, 1988 Roepstorff, 1989). Provided that the proper care is taken in the sample preparation procedure most peptides and small proteins (up to 10 kDa) are on a routine basis amenable to analysis by PDMS. Molecular mass information can be obtained with an accuracy of 0.1% or better. Structural information can be gained by application of successive biochemical or chemical procedures to the sample. 

Field, F.H. Fast Atom Bombardment Study of Glycerol Mass Spectra and Radiation Chemistry. J. Phys. Chem. 1982,56,5115-5123. 

Tomer, K.B., F.W. Crow, H.W. Knocke, and M.L. Gross Fast Atom Bombardment and Mass Spectrometry/Mass Spectrometry for Analysis of Ornithine-Containing Lipids from Thiobacillus thiooxidans. Analyt. Chemistry 55, 1033 (1983). 

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