NPLC is an underestimated but attractive separation technique: a superior technique for the separation of chemically closely related substances, isomers and diastereomers. NPLC has a strong position in sample preparation techniques, especially for the separation of complex samples of chemical subclasses. The use of inorganic oxide based stationary phases in NPLC had some difficulties e.g. longer column equilibrium times or poorly reproducible gradient analyses. Fortunately most of these problems have been overcome with the advent of chemically modified stationary phases.