INSIGHTS INTO THE MECHANISM AND APPLICATIONS OF UNIDIMENSIONAL MULTIPLE DEVELOPMENT IN THIN-LAYER CHROMATOGRAPHY

Multiple development in thin layer chromatography provides a straightforward means of improving on the separation capacity obtained by normal development. Maximum separating power in isocratic multiple development is obtained when the distance between the solvent entry position and the sample application position is minimized and when the solvent entry position and the solvent front are incremented at each development step. As far as resolution is concerned, solvent selectivity is the most important parameter in controlling the ease with which a particular separation can be obtained. A further advantage of multiple development methods is the ease of automation and the possibility of incorporating solvent gradients into the separation strategy.