Neutron activation and scanning techniques were applied to the study of localization of impurities in aluminum foil. A mathematical model including the necessary correction factors for the measurement of the distribution ratios of the impurity in the foil is presented. The use of a shielded and collimated NaI(Tl)-CsI dual-crystal detector in scanning is demonstrated. Not only the neutron flux distribution, but also the variation in the side contributions to the localized counting of an irradiated aluminum foil, has been shown to be significant for the localization of impurities. Although the results of this study are semi-quantitative, there is indication that the copper and gallium impurities in commercial-grade aluminum foil are unevenly distributed.