Mass spectrometry of beta-lactam antibiotics with special reference to ionization by fast atom bombardment (FAB)

The mass spectral characteristics of the majority of penicillin and cephalosporin beta-lactam antibiotics in world-wide clinical use are presented and reviewed. Special attention is given to the spectra recorded under fast atom bombardment (FAB) conditions and novel data on many penicillins and cephalosporins are included. Mass spectrometry features of common degradation products of benzylpenicillin and of some synthetic intermediates are also presented. The data illustrate the value of FAB mass spectrometry in identifying members of this closely related group of antibiotics without need for derivatization.