南京部分市售稻谷和杂粮的Cd Zn Se含量及其健康意义

随机采购了南京市农贸市场部分水稻和杂粮的子粒样品,分别采用火焰原子吸收分光光谱仪、原子荧光光谱仪测定其中Cd、Zn、Se的含量。结果表明:①供试部分粮食的Se含量均低于世界卫生组织推荐的食物硒水平,杂交稻米的Cd含量偏高,且有一半以上的杂粮样本的Cd含量超标,说明居民日常膳食的元素摄入可能存在不平衡;②不同谷类子粒间这些元素含量存在显著差别,以玉米中最低;糙米中的Cd、Zn与除玉米外的杂粮子粒无显著差异;大豆子粒的Cd,Zn含量高于玉米,但Se含量没有显著差异;③供试杂粮中大豆样本有90%超过我国现行杂粮Cd限量标准0.05 mg/kg,而Cd/Zn均未超过Simmons等所提出食物安全值临界值0.015。建议重新拟定杂粮的Cd限量标准。

Grain Cd,Zn,Se Contents of Rice and Other Cereals Sampled in Agro-food Markets from Nanjing,China

Grain samples of some rice and other cereals were collected from agro - markets of Nanjing and their contents of CA, Se and Zn were determined with atomic adsorption spectroscopy （AAS）, atomic fluoresce spectroscopy （AFS） and AAS respectively. The results showed that ： （1） The grain Se contents of the studied cereals fall below the guideline value by WHO of 0,1 mg/kg, while over 50 % of foodstaff grain samples had a grain CA concentration over the China Food Security Guideline of 0.05 mg/kg, indicating potential Se deficiency and over - loading of CA from food exposure for dietary intake; （2） There was much difference in the metal contents between the cereals grains, being more significant with CA and Se than with Zn; Soybean grains contained high contents of CA and Zd hut not Se than corn grains; （3） Most of the foodstaff grains contained CA over 0.05 mg/kg, a limit value of China Food Security Guideline without a Cd/Zn ratio over 0. 015, a threshold value for potential Cd toxicity to human. Taking in account of the small consumption relative to flee, a guideline value of 0.2 mg/kg, same for rice grains is suggested.