ABSTRACT
In order to achieve accurate and reliable liquid chromatographic (LC) data, relatively “pure” samples must be analyzed. Therefore, sample pretreatment is an essential part of every chromatographic procedure. For the pretreatment of pharmaceutical formulations, the strategy will be quite different from the strategy for biological samples. In pharmaceutical preparations (e.g., creams, syrups, ointments, tablets), in principle one single analyte in relatively high concentration should be analyzed in a matrix consisting of a limited number of components. One of the most promising chromatographic techniques for the near future will be supercritical fluid chromatography and in sample pretreatment the application of a supercritical solvent represents a new extraction technology. In LC isolation/concentration methods, by means of column-switching techniques, offer a new dimension to the sample preparation technique because in this way automation, throughput, and precision are strongly improved. The chromatographic system should not be damaged by introduction of aggresive chemicals from the derivatization mixture.
