Determination of mineral constituents in duplicate portion diets of two university student groups by instrumental neutron activation

Concentrations of 15 elements were determined simultaneously in duplicate p ortion diets of two university student groups from Sao Paulo University con sisting of nine women (20-23 years) and ten men (20-24 years). The diet sam ples were prepared by either freeze-drying or drying in a ventilated oven. About 100-200 mg of diets were irradiated for 2 minutes and 8 hours in the IEA-R1m research reactor and Br, Ca, Cl, Co, Cr, Cs, K, Fe, Mn, Mg, Me, Na, Rb, Se, and Zn were determined by instrumental neutron activation analysis (INAA). The average daily intakes found in the women and men groups were: 2.1 and 4.3 mg of Br, 501 and 707 mg of Ca; 3.1 and 6.0 g of Cl; 12 and 25 mg of Co; 15 and 36 mug of Cs; 53 and 63 mug of Cr; 5.1 and 10.8 mg of Fe, 1.3 and 2.8 g of K; 134 and 306 mg of Mg; 1.3 and 4.1 mg of Mn. 134 and 302 mg of Mo, 2.0 and 4.1 g of Na; 2.4 and 4.6 mg of Rb; 29 and 41 mug of Se; 6.2 and 10.6 mg of Zn, respectively. The daily intakes of Ca, Se and Zn in both groups and Fe in die women groups appeared to be below the U.S. RDA re commendations. For the elements Na and Cl the daily intakes were higher tha n the recommended values by RDA.