EFFECT OF THE MOBILE AND STATIONARY PHASES ON RP-HPLC RETENTION AND SELECTIVITY OF FLAVONOID COMPOUNDS

The retention behaviour of an extended set of flavonoid compounds on p henyl and cyano reversed-phase HPLC columns was studied and compared t o behaviour on octadecyl column. The selectivity properties of methano l, acetonitrile and tetrahydrofuran as organic modifiers on each stati onary phase are reported. Both the stationary and the mobile phases ap peared to significantly change HPLC system selectivity. Specific stati onary phase selectivity effects proved more pronounced with methanol: in particular the phenyl phase showed a greater selective retention fo r unsaturated flavonoids while octadecyl proved more selective for gly coside compounds.