The present invention describes compositions comprising at least one compound chosen from hydroquinone and catechol, characterised in that it further comprises between 0.1 and 10,000 ppm of at least one compound chosen from 2-(alkoxy)phenol, 4-(alkoxy)phenol, 2-(alkyl)phenol, 4-(alkyl)phenol, (alkyl)catechol and (alkyl)hydroquinone. Another aspect of this invention concerns a method for preparing a composition comprising at least one compound chosen from hydroquinone and catechol according to the invention, characterised in that it comprises a step (a) of reacting the phenol with hydrogen peroxide in the presence of a catalyst, in a solvent comprising an alcohol.