Monte Carlo model of nonlinear chromatography

A stochastic approach to the nonlinear chromatography theory, based on the Monte Carlo simulation method, is presented. A computer program, acting as a "virtual chromatograph" and performing a discrete event simulation, is de scribed. Such a program allows one to choose the column type, operating con ditions, sample composition, injection method, mobile-phase dispersion mode l, and stationary-phase sorption-desorption kinetics. Nonlinearity is accou nted for by continuously monitoring and updating both the column and the so lute status and by moving individual molecules step by step along the colum n according to specific random modes. The program has been validated throug h a series of statistical tests and comparing the results with the well-kno wn achievements of the classical stochastic theory. A first application is presented, referred to a real case benzene elution on a gas solid capillary column, where the Langmuir adsorption isotherm is assumed. The effect of b oth the sorption modes and the site capacity are investigated. Possible app lications to investigate open problems in several fields of separation scie nce are emphasized. In addition, several specific points such as the down-s caling of a real case and the correspondence of specific adsorption dynamic s with the equilibrium Langmuir isotherm are described.