I am developing the method for simultaneous detection of gallic acid, pyrogallol, ethyl gallate, catechin,epicatechin and quercetin in a plant extract through Reverse Phase Ultra Flow Liquid Chromatography with isocratic mode. Except gallic acid and pyrogallol all the other compound peaks are getting separated clearly ..The retention time of the gallic acid and pyrogallol are very close..I have gone through the literatures and tried all the combinations of Acetonitrile:Water:Orthophosphoric acid (Buffer) and Acetonitrile:Methanol:Glacial acetic acid (Buffer), but I could not separate these two peaks. Can any one get me the solutions for this please...???