Fast atom bombardment-mass spectrometry applications

In line with the policy of Advances to provide periodic coverage of major developments in physical methodology for the study of carbohydrates, A. Dell (London) here surveys the use of fast-atom-bombardment mass spectrometry in application to carbohydrates. This technique has achieved rapid prominence as the soft ionization technique of choice for structural investigation of complex carbohydrate sequences in biological samples. The author s extensive personal involvement in this field makes her chapter a critical, state-of-the-art overview for the specialist, as well as a valuable primer for the reader unfamiliar with this technique. 

Y. Ito, T. Takeuchi, D. Ishii, M. Goto and T. Mizuno, Direct coupling of micro high performance liquid chromatography with fast atom bombardment mass spectrometry. II Application to gradient elution of bile acids, J. Chromatogr., 385 (1986) 201-209. 

S. J. 1992. Applications of fast atom bombardment mass spectrometry (FAB-MS) and continuous-flow FAB-MS to carotenoid analysis. Methods Enzymol. 213 322-336. 

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). 

The following sections summarize the applications of fast atom bombardment mass spectrometry, Mossbauer and NMR spectroscopies, and single-crystal X-ray diffraction studies in the characterization of het-eronuclear gold cluster compounds. 

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. 

Mass spectrometry can give valuable information on the structural details of Sn(II) heterometallic derivatives, subject to stability with respect to the disproportionation reaction in the vapor phase. The mass spectral results demonstrate that fast atom bombardment mass spectrometry (FARMS) could find immense applications in the characterization of heterometallic derivatives, particularly of non-volatile, high molecular weight compounds, such as those of tin. 

Because of the complexity of the polyether antibiotics little progress has been made in structure determination by the chemical degradation route. X-ray methods were the techniques most successfully applied for the early structure elucidations. Monensin, X206, lasalocid, lysocellin, and salinomycin were included in nineteen distinct polyether x-ray analyses reported in 1983 (190). Use of mass spectrometry (191), and 1H (192) and 13C nmr (141) are also reviewed. More recently, innovative developments in these latter techniques have resulted in increased applications for structure determinations. For example, heteronuclear multiple bond connectivity (hmbc) and homonudear Hartmann-Hahn spectroscopy were used to solve the structure of portimicin (14) (193). Fast atom bombardment mass spectrometry was used in solving the structures of maduramicin alpha and co-factors (58). 

An example of an MS application is the work on the determination of total iron in foods by isotope dilution fast atom bombardment mass spectrometry (Gharaibeh etal. (1985). 

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. 

J. S. Cottrell and S. Evans, Characteristics of microchannel electrooptical detection system and its application to the analysis of large molecules by fast atom bombardment mass spectrometry. Anal. Chem. 59, 1990-1995 (1987). 

Gasser, H., Strohmaier, W., Schlag, G. et al. (1991) Characterization of phosphatidylcholines in rabbit lung lavage fluid by positive and negative ion fast-atom bombardment mass spectrometry. J. Chromatogr. Biomed. Applic., 562, 257-66. 

Norwood, D.L., Kodo, N., Milhngton, D.S. (1988) Application of continuous-flow liquid chromatography/ fast-atom bombardment mass spectrometry to the analysis of diagnostic acylcamitines in human urine. Rapid Commun. Mass Spectrom., 2,269-272. 

Ashcroft, A.E., Herod, A.A., Manton, G. (1988) Applications and further developments of liquid chromatography-fast atom bombardment mass spectrometry (LC-FAB-MS) using a continuous flow probe. In Proceedings of the 36th ASMS Conference on Mass Spectrometry and Allied Topics, June 5-10, San Francisco, CA. 

Marinos VA (1992) Application of fast atom bombardment mass spectrometry to the examination of glycoconjugates in grape juice and wine. PhD Thesis, University of Adelaide, Adelaide... 

Siegel MM, McGahren WJ, Tomer KB, Chang TT. Applications of fast atom bombardment mass spectrometry and fast atom bombardment mass spectrometry-mass spectrometry to the maduramicins and other polyether antibiotics. Biomed Environ Mass Spectrom. 1987 14 29-38. 

Yassin, A. F., Haggeni, B., Budzikiewicz, H., and Schaal, K. P. (1993). Fatty acid and polar lipid composition of the genus Amycolatopsis Application of fast atom bombardment-mass spectrometry of underivatized phospholipids. Int. J. Syst. Bacterial. 43 414-420. 

Tetracycline antibiotics have been determined in bovine liver, kidney, and muscle, and in milk by solid-phase extraction followed by TLC7MS with FAB mass spectrometry (45,46). A reverse-phase C8 bonded phase silica TLC plate was used. Adjacent lanes of standards provided Rf values for the compounds of interest. This area of the chromatogram was cut into a trapezoidal shape, and additional solvent concentrated the sample in one end of the shape. That portion of the chromatogram was then placed on the FAB probe of a high-performance mass spectrometer. Then, the FAB support matrix (thioglycerol) was added to the plate. A detection limit of 0.1 microgram of sample per spot was reported for most of the tetracycline antibiotics. The trapezoidal slice from the TLC plate used to concentrate the sample for TLC/MS analysis was also used in an application of fast atom bombardment mass spectrometry to identify and quantitate the drug midazolam (a depressant and anaesthetic) in plasma extracts by Okamoto et al. (47). 

Cottrell, J.S. Evans, S. Characteristics of a Multichannel Electrooptical Detection System and Its Application to the Analysis of Laige Molecules by Fast Atom Bombardment Mass Spectrometry. Anal. Chem. 1987,59, 1990-1995. 

This section considers the applicability of the four principal surface analytical techniques that are usually applied to catalyst surface characterization. They are XPS (coexisting acronym is ESCA which also includes XAES), AES, SIMS, including its nondestructive static SIMS mode and the use of neutral atoms as primary particles in fast atom bombardment mass spectrometry (FAB-SIMS or FABMS), and last, ISS. 

Hemling M (1987) Fast atom bombardment mass spectrometry and its application to the analysis of some peptides and proteins. Pharmaceutical Research 4 5-5. 

Ashton, A. G., Dwyer, J., Elliott, I. S., Fitch, F. R., Oin, G., Greenwood, M., and Speakman, J. (1984) The application of fast atom bombardment mass spectrometry (FARMS) to the study of zeolotes In Proceedings of the Sixth International Conference, D. Olson and A. Bisio, ed., But-terworths, New York, 704-716. 

Mass spectrometry (MS) in its various forms, and with various procedures for vaporization and ionization, contributes to the identification and characterization of complex species by their isotopomer pattern of the intact ions (usually cation) and by their fragmentation pattern. Upon ionization by the rough electron impact (El) the molecular peak often does not appear, in contrast to the more gentle field desorption (FD) or fast-atom bombardment (FAB) techniques. An even more gentle way is provided by the electrospray (ES) method, which allows all ionic species (optionally cationic or anionic) present in solution to be detected. Descriptions of ESMS and its application to selected problems are published 45-47 also a representative application of this method in a study of phosphine-mercury complexes in solution is reported.48... 

Ayanoglu, E. Wegmann, A. Pilet, O. Marbury, G. D. Hass, J. R. Djerassi, C. Mass spectrometry of phospholipids—some applications of desorption chemical ionization and fast atom bombardment. /. Am. Chem. Soc. 1984, 106, 5246-5251. 

Several years later, the next step in the application of MS-MS for mixture analysis was developed by Hunt et al. [3-5] who described a master scheme for the direct analysis of organic compounds in environmental samples using soft chemical ionisation (Cl) to perform product, parent and neutral loss MS-MS experiments for identification [6,7]. The breakthrough in LC-MS was the development of soft ionisation techniques, e.g. desorption ionisation (continuous flow-fast atom bombardment (CF-FAB), secondary ion mass spectrometry (SIMS) or laser desorption (LD)), and nebulisation ionisation techniques such as thermospray ionisation (TSI), and atmospheric pressure ionisation (API) techniques such as atmospheric pressure chemical ionisation (APCI), and electrospray ionisation (ESI). 

More recently, studies concerning cluster ion formation from solid or deeply cooled liquid alcohols [120-122] have gained new interest. [123,124] Low-temperature fast atom bombardment (LT-FAB) of frozen aqueous solutions of metal salts provides a source of abundant hydrated metal ions. [125-127] Organic molecules can also be detected from their frozen solutions. [128] Such LT-FAB applications are particularly interesting when enabling the detection of species that would otherwise not be accessible by mass spectrometry, because they are either extremely air- and/or water-sensitive [129,130] as the phosphaoxetane intermediate of the Wittig reaction [131] or insoluble in standard FAB matrices. [106,132]... 

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