Nonlinear chromatography is a field that borders both chemical engineering and physical chemistry. In turn, the theory of nonlinear chromatography is the foundation of preparative chromatography, a separation process that has lately become of considerable interest in the pharmaceutical industry. Only chromatography is sufficiently flexible and powerful to satisfy the practical requirements encountered in most difficult separations of pharmaceuticals and pharmaceutical intermediates. Since nonlinear behaviour is strictly a mathematical concept, it is difficult to leave mathematics out of any fundamental study of nonlinear chromatography. Therefore, Modeling for Preparative Chromatography will describe the different mathematical models of chromatography, examine the assumptions on which they are based, consider their properties, and discuss their solutions. All this will be done from a mathematical analysis point of view, paying considerable attention to the influence of nonlinear behavior on the results.