二溴羟基苯基荧光酮荧光猝灭法测定Br^—

A Fluorescence Quenching Method for The De-termination of Bromide Ion in Synthetic Brine with 2,3,7-Trihydroxy-9-Dibromohydroxyphenylfluorone

本文报道了以二溴羟基苯基荧光酮（ＤＢＨ－ＰＦ）为指示剂，在阳离子表面活性剂ＣＰＣ存在下荧光猝灭间接测定Ｂｒ￣－的新方法。在０．６ｍｏｌ／ＬＨ＿２ＳＯ＿４介质中，Ｂｒ￣－和ＢｒＯ反应生成Ｂｒ＿２，Ｂｒ＿２与ＤＢＨ－ＰＦ（λ＿（ｅｘ）＝４９５ｎｍ，λ＿（ｅｍ）＝５２０ｎｍ）生成红色化合物，使体系荧光猝灭。Ｂｒ￣－含量在０．２５～６．２５μｇ／２５ｍＬ范围内有良好的线性关系，检测限为０．２５μｇ／２５ｍＬ。该法灵敏度高，选择性好，用于合成海水样品中Ｂｒ￣－的测定，结果满意。

A highiy sensitive and selective fluorescencequenching method was developed to determine bro-mide ion (Br￣-)with 2,3,7-trihydroxy-9-dibromohy-droxyphenylfluorone(DBH-PF)as the fluorogenicreagent(λ_(ex)=495,λ_(em)=520nm). Br￣- reacts with sodi-um brornate in sulfuric acid solution(0. 6mol/L)giv-ing bromine (Br_2)which then reacts with DBH-PF toproduce a non-fluorescent cornpoud thus quenchingthe fluorescence intensity of the svstem. The linearcalibration range is 0.25～6. 25μg/25mL. The detec-tion limit is 0. 25μg/25mL. The method may be usedto determine microamounts of Br￣-in svnthetic brinewith satisfactory results.The method offers the ad-vantages of simplicity ,rapidity and sensitivity.