The concentrations of Na, Cl, Mn, Br, Fe, Zn, Rb, Sb, Sc, Cr, Al and Mg were determined in some types of bread and in some brands of milk powder consumed in the city of São Paulo (SP—Brasil), by instrumental neutron activation analysis. Radiochemical separations were carried out by means of retention of24Na on hydrated antimony pentoxide (HAP) from a 8N HCl solution, after digestion of the organic matter. It was possible in this way to determine the radioisotopes64Cu,69mZn and140La in the effluent solution. The detection limits of the trace elements analyzed in bread and milk powder samples were determined using the Currie and Girardi criterions.