Today’s high-performance thin-layer chromatography (HPTLC) combines the advantage of a robust chromatographic separation with high sample throughput and the possibility of simple coupling to additional analytical techniques, like mass spectrometry (MS) or bioassays [1]. This increases the amount of information for a fast and efficient activity-based screening and the identification of raw materials for new cosmetic products.
Lengthy, time-consuming clean-up processes for first activity tests are avoided by adapting the activity test directly on the HPTLC plate. Assays for special target activities can be performed for many samples in parallel after chromatography. The transfer of discovered active substance zones to the mass spectrometer allows the direct characterization of the target substance without additional clean-up steps. Examples for such an "activity based" screening of plant extracts will be presented.