Figure 1: Positive ion MALDI-TOF mass spectra of the phosphatidylethanolamine (PE) fraction from hen egg yolk recorded directly from TLC plates with different thicknesses (indicated in the figure) of the stationary phase. The spectrum labelled with "Control" was desorbed directly from a conventional stainless steel MALDI target. Abundant PE signals are directly assigned in the figure (in this x:y nomenclature, x denotes the number of carbon atoms and y the number of double bonds per fatty acyl residue) and matrix peaks (DHB, 2,5-dihydroxybenzoic acid) are marked by asterisks. Note that reasonable peak intensities can be exclusively achieved in the case of a reduced silica gel thickness. Reproduced from Griesinger et al. [12] Anal. Biochem., 451, 45-47, 2014 with permission from Elsevier.