建立了微波消解-分子荧光猝灭法测定蜂胶中痕量硒的方法。蜂胶样品经微波消解后,用HCl将消化液中的Se(Ⅵ)全部还原成Se(Ⅳ),再与碘化物和罗丹明B发生显色反应;当I-3与罗丹明B形成离子缔合物时,罗丹明B溶液的荧光猝灭,硒浓度在0~0.100μg/mL线性范围内荧光猝灭值与Se(IV)的浓度成正比。其线性回归方程是y=353 6.1x+4.76,线性相关系数为0.999 5,加标回收率在96.8%~103%,相对标准偏差(n=4)<4.2%,检测限为0.001 0μg/mL。

A method is established to determine trace selenium in propolis by microwave digestion-molecular fluorescence quenching. After microwave digestion,propolis samples reduces Se( Ⅵ) in digestion solution to Se( Ⅳ) with hydrochloric acid. Then,the propolis samples make chromogenic reaction with iodide and Rhodamine B. When I3-and Luo Danming B form an ion association complex,the fluorescence of Luo Danming B solution is suddenly extinguished. When the selenium concentration is in the linear range of 0 ~ 0. 100 μg/mL,the fluorescence quenching is proportional to the concentration of selenium( IV). The linear regression equation is y = 3 536. 1x + 4. 761 9. The linear correlation coefficient is 0. 9995,and the recovery rate is between 96. 8% to 103%. The relative standard deviation( n = 4) is less than 4. 2%. The limit of detection is 0. 001 0μg/mL. The method has high efficiency,less selenium evaporating,accurate measurement and strong practicability.