ABSTRACT
Chromatography is the common laboratory method for both quantitative and qualitative analysis of drugs, particularly new investigational drugs, in biological fluids. This chapter reviews the basic principles of chromatography and its original development to what is called planar chromatography. The basic principle underlying all types of chromatography is that the system consists of two components, one stationary and one mobile. Paper chromatography was probably the earliest type of chromatography that was enthusiastically developed for analytical purposes. Although the first description of thin-layer chromatography was made as long ago as 1938, it was not until the late 1950s and early 1960s that the technique came into its own. In this type of chromatography the stationary phase, or support, is spread as a thin layer on a flat glass plate. In overpressured layer chromatography, the vapor phase is eliminated entirely, by enclosing the stationary phase in a membrane to which pressure can be applied as the chromatogram is developed.
