A previously described method for the determination of free and bound sesamol and sesamin in sesame oil was found to be inapplicable in the analysis of sesamin concentrates, because of the low solubility of the sesamin concentrate in isooctane and the presence of an iron-containing substance in the sesamin concentrate.The method was modified by using a mixed solvent (chloroformiso-octane) to dissolve the sesamin concentrate and by centrifugation in the phasic separation of free and bound sesamol to remove substances that interfere with normal color development in the Villavecchia reaction.The accuracy of the spectrophoto-SESAMOL occurs free and in bound form (sesamolin) in sesame oil. In the form of sesamolin, sesamol is combined with an unidentified substance, samin (C13H14O5), from which it is liberated by acid hydrolysis and hydrogenolysis (3). In addition to