Mass Spectral Compilations

An easier approach to identifying an organic componnd is to match the spectrum to the existing collection of spectra. There is a caveat that isomeric compounds might yield identical spectra. In such situations, identification of the compound might not be unequivocal. The following collections of libraries are useful resources for this purpose  

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The melting points, optical rotations, and uv spectral data for selected prostanoids are provided in Table 1. Additional physical properties for the primary PGs have been summarized in the Hterature and the physical methods have been reviewed (47). The molecular conformations of PGE2 and PGA have been determined in the soHd state by x-ray diffraction, and special H and nuclear magnetic resonance (nmr) spectral studies of several PGs have been reported (11,48—53). Mass spectral data have also been compiled (54) (see Mass spectrometry Spectroscopy). 

Compilations of Reference Spectra There are several compilations of reference mass spectra available of which the oldest is the American Petroleum Institute (Ref 82) collection of spectra obtained mostiy on the older type instruments. Recent collections index spectra variously, eg, under reference number (Ref 19). molecular weight (Refs 12 19), molecular formula (Ref 19), fragment ion values (Ref 19), and base peak (Refs 12 19). A quarterly journal, Archives of Mass Spectral Data ... 

Cornu R. Massot, Compilation of Mass Spectral Data , Heyden Son, London (1966)... 

T. Cairns, E. G. Siegmund and R. A. Jacobson, Mass Spectral Data Compilation of Pesticides and Industrial Chemicals, Food and Drug Administration, Los Angeles, 1981. 

Sodium valproate was not sufficiently volatile for mass spectral analysis. The mass spectrum of valproic acid as shown in Figure 5 was obtained using an Associated Electrical Industries Model MS-902 Mass Spectrometer with the ionization electron beam energy at 70 eV. High resolution data were compiled and tabulated with the aid of an on-line PDP-11 Computer. 

The comparison can be made manually on the basis of collections of tables (for example, A. Cornu R. Massot Compilation of Mass Spectral Data) or may be effected with computer assistance large databases can be used (e.g. Mass Spectral Data Base, Royal Society of Chemistry, Cambridge). 

As with mass spectral data, detailed information of the UV spectra of azepines is confined to a few sources and for information on particular systems recourse has to be made to the primary literature. Available are compilations of UV data on TV-acyl- and TV-sulfonyl-1//-azepines (B-69MI51600,69JOC2866), benzazepines (74AHC(17)45), dibenz[T>,/]azepines and their 10,11-dihydro derivatives (74CRV101), and the azatropolones (13) and their 1,5-dihydro derivatives (79H(12)1427). 

In this chapter we describe mass spectrometry (MS) in sufficient detail to appreciate its application to organic structure determination. For more details, mass spectrometry texts and spectral compilations are listed at the end of this chapter. ... 

An excellent collection of NMR and IR spectra for reference purposes is found in The Aldrich Library of 13 C and 1H FT NMR Spectra and The Aldrich Library of Infrared Spectra. Both are available in most libraries and the former can be purchased from Aldrich Chemical Co. A variety of compilations of mass spectral data are available seeF. S. McLafferty and D. B. Stauffer, The Wiley/NBS Registry of Mass Spectral Data, 5th ed., Wiley Interscience, New York, 1988. 

Some of the new spectroscopic data are taken from the collections of the School of Chemistry, Thames Polytechnic, and we wish to acknowledge particularly the assistance of Dr E. Vidgeon for specifically recording the majority of the 13C-n.m.r. spectra. We acknowledge the inclusion of other spectroscopic data from the Sadtler Collections, Standard Infrared Spectra, Standard Ultraviolet Spectra and Standard Nuclear Magnetic Resonance Spectra, Sadtler Research Laboratories, Philadelphia, USA, and from Compilation of Mass Spectral Data, A. Cornu and R. Massot (1966-1971), Heyden and Son Ltd in collaboration with Presses Universitaires de France. 

MASS SPECTRAL DATA Many of the monographs in Part 2 contain mass spectral data in the form of the eight most intense ions, in descending order of intoisity. These values have also been used to compile an 8-peak index in Part 3 for rapid se[Pg.262]

Cornu, A., Massot, R. Compilation of mass spectral data. London Heyden and Son 1966. 

Although individual laboratories find it useful to compile their own reference library files, access to very large collections of mass spectra and to published data [55] is essential. A compilation of many thousands of spectra by the Aldermaston Mass Spectrometry Data Centre and the Division of Computer Research and Technology at the National Institutes of Health [56-58] has been made available commercially. The file can be searched in a number of ways using an interactive conversational mass spectral search system via a teletype and acoustic link over telephone lines. 

Mass spectral papers include another compilation of monoterpenoid alcohol spectra, a comparison of fragmentation patterns for camphor and menthone with their oxime, semicarbazone, and nitrophenylhydrazone derivatives, and a comparison of collisional activation mass spectra of ten related acyclic, monocyclic, and bicyclic monoterpenoid hydrocarbons together with derived 7119 ions. ... 

S WGDRUG has compiled a mass spectral library from a variety of sources containing drags and drag-related compounds [71]. All spectra were colleeted using electron-impact MS systems. This library is available for download from its website. 

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