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Pages 237–297 from the book:Chapter 8. Soft ionisation mass spectrometry of small molecules
Chapter Summary: This chapter represents the first of the final two chapters devoted to derivatisation for “soft” ionisation mass spectrometry and considers small molecules. “Soft” ionisation methods in mass spectrometry are well known to be tools for producing primary ions (molecular ion radicals, protonated or deprotonated molecules, cationised molecules) possessing sufficiently low internal energy to prevent further extensive fragmentation. The most popular “soft” ionisation mass spectrometric methods are based on either desorption principles, such as fast atom bombardment (FAB) [liquid secondary ion mass spectrometry (LSIMS) may be also classed as a “:soft” ionisation method] and matrix-assisted laser desorption/ionisation (MALDI), or atmospheric pressure ionisation techniques such as electrospray/ionisation (ESI) and atmospheric pressure chemical ionisation (APCI). There are, however, other comparatively rarely applied “soft” ionisation methods which will be briefly noted in connection with the used derivatisation approaches covered at the end of the chapter.