TLC run with a crude extract and a pure standard in co-chromatography gives an indication on the presence of the compound in the crude extract based on the Rf and color characteristics (if a derivatisation reagent is used or based on 'quenching' or fluoresence (color) characteristics when viewed under UV light). I do not believe that this is an absolute confirmation tool, it is more or less an indicative tool. The confirmation is to either isolate the compound from the crude extract or run either HPTLC or HPLC of the extract with hyphenated mass spectral detector to confirm the compounds presence. That would be confirmation of the compound's presence in the crude extract.   _{Your Comment}