Imaging Melamine in Egg Samples by Surface Desorption Atmospheric Pressure Chemical Ionization Mass Spectrometry

The characteristic fragment (m/z 85) of protonated melamine, generated in MS/MS spectra recorded from the surface of egg slices using surface desorption atmospheric pressure chemical ionization mass spectrometry (SDAPCI-MS), has been used to image melamine in slices of cooked egg. The experimental results showed that the spatial resolution of the imaging using SDAPCI-MS was 0.06 mm2. Egg yolk was proven to have little melamine in this study, and the most melamine was contained in egg white region, although not evenly distributed.