Normal Phase 2D TLC Separation of Flavonoids and Phenolic Acids from Betula sp. Leaves.

Summary: Two-dimensional thin layer chromatography of twelve flavonoids and three phenolic acids from Betula sp. leaves has been performed in normal-phase systems. Plots showing the dependence of R_M on modifier concentration in some non-aqueous systems were used to optimize the chromatographic separation. R_M values were correlated for all the chromatographic systems investigated and optimum pairs of systems were then selected for use in two-dimensional TLC separations. Complete separation of the compounds investigated was achieved by use of two optimum non-aqueous mobile phases on silica plates. [ABSTRACT FROM AUTHOR]