Comparing Two Versions of a Separation Map in Reversed Phase Liquid Chromatography

Two types of separation maps are compared for the first time, based on (1) the dependence of the logarithm of the retention factor on the volume fraction of the organic modifier and (2) the means of relative retention analysis. The two types of map agree with each other. Parameters of quadratic equations for the dependence of retention on the volume fraction of the organic modifier, extrapolated to the zero content of the organic modifier in the mobile phase, must be used in order to compare the energies of interaction between sorbates and sorbent. It is established that separation maps of the second type with linear trend lines are convenient for comparing the interaction energies of sorbates with organic modifiers of mobile phases. Additional possibilities of using this approach in special cases are shown. It is concluded that environmentally harmful acetonitrile can be replaced with more benign acetone to separate 3-glucosides of the main six anthocyanidins.