Investigation of TLC in an N-Chamber

Abstract

The N-chamber is the chamber most often used for analytical thin layer chromatography (TLC) (95% of publications). The kinetics of adsorption, in the N-chamber, of the vapor of the mobile phases most often used in TLC (methanol, acetic acid, ethyl acetate, toluene, chloroform, and acetone) have been studied experimentally and theoretically. The kinetics of adsorption of mobile phase vapor by TLC plates are satisfactorily described by an equation, proposed in this research, which relates mobile phase vapor adsorption to time, and to the saturated vapor pressures and diffusion coefficients of the mobile phase components. In approximately 40 years since de Zeeuw’s research on the kinetics of adsorption of mobile phase vapor by TLC plates in an N-chamber was first published, the characteristics of the adsorbent layer have been substantially improved by the manufacturers. As a result the weight of mobile phase adsorbed by Merck plates has increased several fold. The effects of different experimental conditions on the separation of a mixture of dyes, in an N-chamber, by use of a variety of mobile phases, have also been studied experimentally.