[ctiey]

Hi all, i'm doing the separation of a plant extract. in short, the compound that i've looking for soluble in hexane and it appears almost similar to oestrone in TLC. then i've run HPLC at 280nm with MeOH:H2O in 15min, got the peak at Rt 8.531min (46.6%MeOH: 36.6%H2O).. is there any source that available for me to relate this Rt with oestrone? or steroid? anyone can help me with the prediction of any compound which might lies in this condition..?

[Arkcon]

Not likely.  You haven't mentioned your column media, but its unlikely to be packed with the same exact stuff as your TLC plate, for starters.  You're not using the same solvent system, and anyway, Rf just isn't transferable from a capillary/evaporation driven mechanism to a pressure mechanism.   You could use oestrone as a standard, both alone and as a co-injection, but even that isn't going to prove identity.