Determination of zinc and copper in some cereals

Abstract

Rice, glutinous rice, millet and corn collected from markets in Bangkok were analysed for zinc and copper by flame and flameless atomic absorption spectrophotometry respectively. The mean concentrations ± S.D, of zinc and copper in rice, glutinous rice, millet and corn were : rice, 23.6 ± 3.2 µg/g Zn (range 17.5-28.8 µg /g) and 2.3 ± 0.6 µg /g Cu (range 1.1-3.3 µg /g); glutinous rice, 27.1 ± 5.6 µg /g Zn (range 17.8-37.7 µg /g) and 2.5 ± 1.7 µg /g Cu (range 0.7-5.9 µg /g); millet 45.2 ± 8.4 µg /g Zn (range 26.2-67.5 µg /g) and 6.8 + 1.3 µg /g Cu (range 4.9-10.4 µg /g) corn 28.5 ± 11.2 µg /g Zn (range 15.0-56.0 µg /g) and 2.2 ± 0.7 µg /g Cu (range 0.9-3.7 µg /g). The ratios of zinc to copper in these cereals were: rice, 6.1:1-24.0:1; glutinous rice, 5.5:1-36.6:1; millet, 4.0:1-10.4:1 and corn 6.5:1-37.3:1. It indicated, from the results obtained, that these cereals could be good dietary sources for zinc and copper.