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

Abstract

Concentrations of 15 elements were determined simultaneously in duplicateportion diets of two university student groups from Săo Paulo Universityconsisting of nine women (20–23 years) and ten men (20–24 years).Thediet samples were prepared by either freeze-drying or drying in a ventilatedoven. About 100–200 mg of diets were irradiated for 2 minutes and 8hours in the IEA-R1m research reactor and Br, Ca, Cl, Co, Cr, Cs, K, Fe, Mn,Mg, Mo, Na, Rb, Se, and Zn were determined by instrumental neutron activationanalysis (INAA). The average daily intakes found in the women and men groupswere: 2.1 and 4.3 mg of Br, 501 and 707 mg of Ca; 3.1 and 6.0 g of Cl; 12and 25 mg of Co; 15 and 36 µg of Cs; 53 and 63 µg of Cr; 5.1 and10.8 mg of Fe; 1.3 and 2.8 g of K; 134 and 306 mg of Mg; 1.3 and 4.1 mg ofMn; 134 and 302 mg of Mo, 2.0 and 4.1 g of Na; 2.4 and 4.6 mg of Rb; 29 and41 µg of Se; 6.2 and 10.6 mg of Zn, respectively. The daily intakesof Ca, Se and Zn in both groups and Fe in the women groups appeared to bebelow the U.S. RDA recommendations. For the elements Na and Cl the daily intakeswere higher than the recommended values by RDA.