Direct mixture analysis of surfactants by combined field desorption-collisionally activated dissociation mass spectrometry using simultaneous ion detection

Abstract The combination of field desorption (FD) and collisionally activated dissociation (CAD) has been used to analyse mixtures of cationic, anionic and neutral surfactants without prior separation of the components. For this study a specially designed tandem mass spectrometer with simultaneous ion detection was employed which allows a complete CAD spectrum to be recorded with 5 picograms of sample. The FD-CAD spectra allow a straightforward and unambiguous structure elucidation (including the determination of the length and branching of the alkyl chains) of cationic and anionic surfactants while the interpretation of the FDCAD spectra of the non-ionic surfactants is more complex.