采集湖北恩施4个地区的4种大米及相应的土壤样品,采用电感耦合等离子体质谱(ICP-MS)法测定土壤和大米中硒含量,并采用连续浸提的方法测定了土壤硒的赋存形态,最后通过体外胃肠道模型方法探究了大米中硒的生物可给性,并对当地人群硒中毒风险进行评估,以期为当地硒资源的开发管理提供科学依据.结果表明,恩施地区土壤硒含量为0.15 ~5.42 mg/kg,水溶态硒所占比例最低,为1.41%~3.80%;残渣态硒所占比例最高,为36.1%~41.7%.大米硒含量为0.07~1.61 mg/kg;大米硒富集系数为0.22~0.48;大米硒在胃阶段的生物可给性为45.7%~56.4%,在小肠阶段的生物可给性为58.4%~68.5%.鱼塘坝、长平、沙地、太阳河地区人均硒摄入量(PDI)分别为490、26、132、57 μg/d,恩施鱼塘坝地区人群有慢性硒中毒风险,沙地和太阳河地区人群膳食硒水平为丰富,长平地区人群膳食硒水平为缺乏.%In order to provide a scientific basis for the local management and development of the selenium resources,four soil samples and four relevant rice samples were collected in Enshi,the contents of selenium in soils and rice samples were measured by ICP-MS,and the combined forms of selenium were detected by sequencial extraction method,and the bioavailability of selenium of rice was explored by the in vitro gastrointestinal model.The results showed that selenium content of soil was 0.15-5.42 mg/kg in Enshi,the proportion of water soluble selenium was the lowest with 1.41%-3.80%,and the proportion of residual selenium was the highest with 36.1%-41.7%.The selenium contents of rice were 0.07-1.61 mg/kg,the bioconcentration factors of selenium in rice were 0.22-0.48,and the selenium bioaccessibility in rice were 45.7%-56.4% and 58.4%-68.5% in gastric phase and small intestine phase respectively.In addition,the intake of selenium per capita in Yutangba,Changping,Shadi,Taiyanghe were 490,26,132,57 μg/d,indicating that the local residents of Yutangba had potential chronic selenium poisoning risk,and the dietary nutrition belonged to rich level in Shadi and Taiyanghe,and the dietary nutrition belonged to lack level in Changping.
展开▼
