Identification and Mapping of Phosphocholine in Animal Tissue by Static Secondary Ion Mass Spectrometry and Tandem Mass Spectrometry

Secondary ion mass spectra and images were obtained from animal tissue samples using less than 1013 primary ions/cm2. The mass spectra showed abundant peaks at m/z 184 and m/z 86. Tandem mass spectrometry (MS/MS) was used to identify the source of these ions as phosphocholine. Secondary ion images obtained using MS/MS were used to show that m/z 86 is an abundant gas‐phase fragment ion derived from m/z 184. These results are discussed in terms of the physiology of the samples investigated.