Stationary phase thickness determines the quality of thin-layer chromatography/matrix-assisted laser desorption and ionization mass spectra of lipids.

Normal phase thin-layer chromatography (NP TLC) is an established method of (phospho)lipid analysis. The determination of the fatty acyl composition is, however, a more challenging task by NP TLC. The direct coupling of TLC separation with mass spectrometric detection (e.g., matrix-assisted laser desorption/ionization mass spectrometry, MALDI MS), however, enables a detailed characterization of complex lipid mixtures. Here we show that the thickness of the silica gel layer has a considerable effect on the quality of the mass spectra recorded directly from the TLC plate. In particular, the intensity of the matrix background signals can be reduced if "thinner" TLC layers are used.