荧光素荧光熄灭法测定微量银

A Fluorescence Quenching Method for Determination of Minim Silver with Fluorescein

在pH8．0Tris-HCl缓冲溶液中，荧光素在515nm处有1个荧光峰．当加入银-邻菲罗啉后，荧光峰降低，荧光猝灭强度AF与银离子浓度存在线性关系，其线性范围为1．06×10^-7～1．20×10^-4mol／L，回归方程为△F=3．08×10^5C＋2．452（mol／L）；相关系数为0．9977；检出限为8．08×10^-8mol／L．据此建立了一种灵敏、简便、快速、准确、选择性较高的测定痕量银的荧光分析法．

In pH 8.0 Tris-HC1 buffer solution, there is a sensitive fluorescence peak at 515 run for fluorescein. When sil- ver-phennanthroline is added, the peak decrease sharply. The results show that the intensity of fluorescence quenching AF is linear＇to the silver concentration in the range of 1.06×10^-7～1.20×10^-4mol/L. The regression equation is △F=3.08×10^5C＋2.452（mol/L）, the correlation coefficient is 0.997 7. The detection limit is 8.08 × 10^-8 mol/L. A new fluorescnecemethod has been proposed for the determination of silver in photographic paper, fixer waste and industrial waste water, with the advantages ofhigh sensitivity, selectivity, smiplicity, rapidity and accuracy.