Determination of selenium concentration in rice and the effect of foliar application of Se-enriched fertiliser or sodium selenite on the selenium content of rice

Atomic fluorescence spectrophotometry was used to determine the selenium (Se) concentration in 30 rice products of different species from Southern China. The Se level ranged from 0.015 to 0.046 mug g(-1). Considering the average daily individual consumption of rice products in Southern China, the average dietary intake of Se supplied by this source is only 6-18 mug day(-1) for an adult. This low Se intake from rice products is mainly responsible for the low total Se intake of inhabitants in Southern China. Foliar spraying of Se-enriched fertiliser or sodium selenite with 14-18 g Se ha(-1) in the heading stage of rice growth increased the Se content to 0.178-0.421 mug g(-1) in rice products. The concentration and amount of Se-enriched fertiliser can be varied to achieve an optimum concentration of Se in rice products. The authors suggest that these Se-enriched rice products can contribute an increase in Se intake of 50-100 mug day(-1) on average if their Se concentration is controlled in the region of 0.15-0.50 mug g(-1). (C) 2002 Society of Chemical Industry.