Optimization of Chromatographic Conditions in Thin Layer Chromatography of Flavonoids and Phenolic Acids

Flavonoids are one of the largest groups of natural compounds known. They are supposed to have numerous physiological activities. There are many foods that contain flavonoids, but one of the most important sources of flavonoids is propolis. Besides flavonoids, phenolic acids are the main active substances of propolis. The list of uses and preparations of propolis is almost endless and demands an accurate analytical method to define the substances in this natural product. It can be easily analyzed by chromatographic methods, but before testing a new type of propolis it is opportune to optimize chromatographic conditions. The aim of this study is to optimize the chromatographic conditions in TLC of flavonoids and phenolic acids, as standard compounds that may be present in Croatian propolis. We compared 9 different mobile phases, using information theory and numerical taxonomy methods and applying the computer search program KT1, to find the most appropriate mobile phase, the optimal combination of two and three mobile phases for separation of standards