Mass Spectral Databases - General Aspects

Although the coverage of these databases is enormous, and an easy-to-use interface is provided, one should be aware of potential pitfalls. The high score of a hit can be wrong, simply because the spectrum of the actual compound is still not included in database. A spectrum may be flawed by superimposition with some impurity peaks, which can in turn mislead the search. As a result, the unknown can generally not be perfectly identified by simple conparison with a library spectrum [83]. Nonetheless, mass spectral databases are highly useful, because even under unfavorable circumstances, they deliver spectra of similar compounds or isomers 

Note There are several mass spectral databases available on the market today [88]. As collections and packages in the software world are subject to rapid changes, it is recommended to do a quick internet search for something like El mass spectral database to identify currait options in this field. 

Franklin, J.L. Electron Impact Phenomena and the Properties of Gaseous Ions, Academic Press New York, t957. 

Some Reflections on the Early Days of Mass Spectrometry at the University of Minnesota. Int. J. Mass Spectrom. lonProc. 1990,100, 1-13. Schaeffer, O.A. An Improved Mass Spectrometer Ion Source. Rev. Sci. Instrum. 1954,25, 660-662. 

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ITie physicochemical aspects of the ionization process in general, ion internal energy, and the principles determining the reaction pathways of excited ions have already been addressed (Chap. 2). Here, we will discuss practical aspects concerning the construction of El ion sources and sample introduction systems. Finally, by considering El mass spectral databases, this chapter directly leads over to the interpretation of El mass spectra (Chap. 6). 

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