Effects of modifier and molecular structure of some coumarins on retention in reversed-phase high-performance...

Coumarins, furocoumarins and pyranocoumarins (29 compounds) were investigated in silanized silica (HPTLC RP-2 and RP-18 and HPLC RP-18)-water organic modifier (methanol, acetonitrile, dioxane, tetrahydrofuran and methanol containing acetic acid) systems. The physico-chemical properties of these compounds were characterized by their hydrophobicity parameters (RMw), determined by extrapolation of the linear relationships for retention data in binary solvent systems [RM = f(phi)] to pure water. The effect of individual substituents on retention was quantified by using the group contribution parameter delta RM or delta log k'.