碲(Ⅳ)-碘化钾-罗丹明B体系荧光猝灭反应测定痕量碲

Fluorescence Quenching Reaction of Tellurium (Ⅳ)- Iodide-Rhodamine B System for Determination of Trace Tellurium

在高浓度碘化钾溶液中，碲（Ⅳ）与Ｉ－形成［ＴｅＩ８］４－配阴离子，［ＴｅＩ８］４－再与罗丹明Ｂ 形成离子缔合络合物［ＲｈＢ］４［ＴｅＩ８］，使罗丹明Ｂ溶液的荧光明显猝灭。反应适宜介质为０．６０ ～１．００ ｍｏｌ／Ｌ的磷酸溶液；线性范围为 ０～１６μｇ／Ｌ碲；反应有高灵敏度，对于碲的检测限为 ０·９１ μｇ／Ｌ，方法也有较好选择性，可用于某些样品中碲的测定。

In a medium of high concentration of patassium iodide, the latter forms with tel- lurium (Ⅳ) the anion[TeI8]4-,which then reacts with rhodamine B to form an ion-associa- tion complex of [RhB]4[TeI8] and quenches the fluorescence of rhodamine B. The optimum medium of the reaction is 0. 60~1. 00 mol/L phosphoric acid solution. The linear range of the method is 0-16 μg/L and the detection limit is 0.91μg/L. The method has good selec- tivity and can be applied to the determination of trace amounts of tellurium in steel and min- eral water samples.