15] Chemical derivatization for mass spectrometry

Abstract

This chapter discusses the use of chemical derivatization in mass spectrometry with particular emphasis on analytical strategy aspects. General considerations with respect to the practical aspects of chemical derivatizations and some general methods are also described. Chemical derivatization has played an imporant role in organic mass spectrometry from the earliest practice of the technique. Although the major impetus for its early use was to confer the necessary volatility to sample compounds, chemical derivatization was also used to increase the information yield from mass spectral data. With decades of progress in mass spectrometry and the development of a wide range of new techniques, chemical derivatization still plays an important role. The reasons for utilizing chemical derivatization in relation to mass spectrometry are (1) enhancement of volatility; (2) degradation of the sample molecule to smaller subunits; (3) enhancement of detectability; (4) enhancement of separability; (5) modification of fragmentation: (a) enhancement of molecular weight related ions and (b) enhancement of structurally informative ions; and (6) determination of functional groups.