食品中硒形态测定的不确定度评价

Evaluation of Uncertainty of Determination of Selenium Species in Food

硒是人体不可缺少的微量元素之一,通过对食品中亚硒酸、硒酸、硒胱氨酸、甲基硒代半胱氨酸及硒蛋氨酸5种硒形态的不确定度进行评定。分析前处理过程和测定方法流程,建立测量不确定度的评定模型并对不确定度进行评判。结果表明:亚硒酸、硒酸、硒胱氨酸、硒代乙硫氨酸及硒蛋氨酸的测量结果及扩展不确定度分别为(2.96±0.23)、(0.63±0.06)、(4.39±0.40)、(6.52±0.72)、(10.48±0.68)mg/kg,取包含因子k为2。该评估模型为食品中硒形态测定的不确定度评价提供了参考依据。

Selenium is one of the essential trace elements in human body.The uncertainty of five selenium species,Se(IV),Se(VI),SeCys2,SeEt and SeMet,in food was assessed.The pretreatment process and determination process were analyzed to establish an evaluation model for assessment of uncertainty of the selenium species in food,based on which the uncertainty was decided.The determination results and expanded combined uncertainties(k=2)of Se(IV),Se(VI),SeCys2,SeEt and SeMet were(2.96±0.23)mg/kg,(0.63±0.06)mg/kg,(4.39±0.40)mg/kg,(6.52±0.72)mg/kg,(10.48±0.68)mg/kg,respectively.This evaluation model can provide a reference for evaluating the uncertainty in determination of selenium species in food.