Experiments have been performed on the impurity incorporation in the solid layer grown from a binary melt of myristic acid and palmitic acid using a rectangular cell with well-controlled temperature. The binary melt forms a simple eutectic phase diagram. Direct numerical simulations of melt solidification were carried out in order to validate the new theory of interfacial solute distribution proposed by the present authors [J. Chem. Phys. 109, 7468 (1998)]. The theoretical predictions of purity or impurity concentration profile in the solid layer agreed well with the experimental measurements. The purity profile inside the solid layer was found to be basically controlled by the flow structure of melt that essentially contributed to the transport phenomena of heat and mass near the solid layer surface.