离子液体萃取-荧光猝灭法测定富硒保健品和食盐中的硒(Ⅳ)

Determination of Se (Ⅳ) in Se-Enriched Health Food and Salt Samples Using Ionic Liquid Extraction Combined with Fluorescence Quenching Method

建立保健品和食盐中硒(Ⅳ)的离子液体萃取-荧光猝灭法。样品经微波消解,在0.2mol/L盐酸介质条件下,硒(Ⅳ)氧化碘化钾,其反应产物I3-与罗丹明B形成离子缔合物。10g/100mL碘化钾1mL,0.005g/100mL罗丹明B3mL,以0.5mL 1-丁基-3-甲基咪唑六氟磷酸盐将离子缔合物萃取进入离子液体相。结果表明,荧光淬灭值与硒(Ⅳ)的质量浓度呈正比,线性范围2～60μg/L,方法的定量限(RSN=10)为20μg/kg,平均回收率为87.9%～105%。该方法具有操作简易、无污染、灵敏度高等优点,可用于富硒保健品和食盐中微量硒的测定。

Sample was digested by microwave.Potassium iodide is oxidized by Se（Ⅳ） in medium of 0.2 mol/L hydrochloric acid,the product I3-reacts with rhodamine B to form ion complex.Potassium iodide of 1 mL at 10 g/100mL and rhodamine B of 3 mL at 0.005 g/100mL were used.The formed ion complex was extracted into the 0.5 mL ionic liquid phase（C4MIM）PF6.The quenched fluorescence was observed for rhodamine B in the presence of Se（Ⅳ）.The linear determination range of Se（Ⅳ） was between 2 and 60μg/L.The limit of quantification of method（RSN=10）forseleniumwas20μg/kg,and theaveragerecoveries were from 87.9% to 105%.The proposed method has the characteristics of easy operation,no pollution and high sensitivity,and it can be used for the analysis of trace selenium in zinc-selenium health food and fortified nutrient salt.