Contour diagrams for the presentation of separation quality in two‐dimensional thin layer chromatography

Abstract

Several methods for evaluating separation quality in two-dimensional thin layer chromatography are discussed. These include using either the distance between spot centers for the pair of solutes that is the most difficult to separate in a mixture, or the value of a suitable separation function, as criteria of overall separation quality. Contour diagrams may be constructed in which solvent compositions for each of the two-dimensional developments are the independent variables and spot separation or the value of a suitable function is the dependent variable. Such diagrams indicate which are the best and the worst regions of the two-dimensional solvent domain. These diagrams should be of value for comparing different solvent systems for two-dimensional thin layer chromatography.

Strategies for optimizing the mobile phase in planar chromatography

“…85,91 Another use of computer simulation is in the construction of contour diagrams of the two-dimensional solvent domain. 93 An example of such a diagram for the separation of a mixture of steroids is shown in Figure 5, where the dependent variable is the value of the IDF in mm-1 and the two independent variables are the mole fractions of the strong solvent in each of the constituent solvent systems. The darkened area indicates the optimum solvent composition whereas the solvent composition yielding the poorest separation is in the upper right-hand corner.…”