The ability of micelles to solubilize organic substances is a property of fundamental importance in many practical applications, such as in detergents. In this work, a new method to determine the solubilisation power of SDS, in terms of the amount of captured organic substance, was used for the first time. A photochromic probe has been dispersed into an organic phase and its incorporation in the micellar system was monitored. The volume of the organic phase entrapped within the micellar hydrophobic core has been measured by the absorbance peak of the dye sensitizer. In our work, three organic compounds were used to determine the amount of organic solvent solubilised by SDS/water system.