I have used a solvent system Toluene:Ethyl acetate: Formic acid (5:4:1) for identifying Quercetin. But I could see different Rf values for this same solvent system in different published articles. Is it possible?
absolutely ; this due to different in interaction between the sample and mobile phase . also we have the similar things with the stationary phase .so you can see different Rf of the same molecule in different solvent ratio.