Thin-layer chromatography-nuclear magnetic resonance spectroscopy - a versatile tool for pharmaceutical and natural products analysisa

Thin-layer chromatography (TLC) is a mature and very established technique, frequently used in many fields of applications ranging from natural product analysis to chemical or pharmaceutical applications. The introduction of a commercially available TLC-MS interface was a major step complementing the ease of use of TLC with structural elucidation power of mass spectrometry (MS). The TLC-MS interface simplifies the workflow dramatically to gain structural information directly from TLC separations. This article describes the potential of TLC-nuclear magnetic resonance spectroscopy (NMR) utilizing the TLC-MS interface to straightforwardly characterize zones of interest by NMR spectroscopy with a focus on quantification of active pharmaceutical ingredients (API) in formulations and identification of active principles in plant extracts.