新席夫碱BPDIB的分析应用研究Ⅱ．荧光熄灭法测定水中微量铬（Ⅵ）

Analytical Application of a New Schiff Base BPDIBⅡ.Determination of Chromium(Ⅵ)by the Fluorescence Quenching Method

研究了新荧光试剂邻苯二胺缩双吡哆醛（ＢＰＤＩＢ）的分析应用。在稀硫酸（ｐＨ１．７～１．８）溶液中，铬（Ⅵ）能氧化邻苯二胺缩双吡哆醛，使其荧光熄灭，其熄灭程度与铬（Ⅵ）量成线性关系，据此提出了荧光熄灭测定水中微量铬（Ⅵ）的方法。铬（Ⅵ）的检出限为６．１１μｇ／Ｌ。

A new Schiff base,N,N'-bis-pyridoxyl-1,2-diiminobenzene(BPDIB),has been synthesized and Characterized by IR,elemental analysis and paper chromatography.BPDIB shows an intense fluorescence atλex/λem =365/451nm.The oxidation of BPDIB by Cr(Ⅵ)takes place in the pH range of 1.6～2.0,leading to the maximal fluorescence quenching of the Schiff base.The extent of fluorescence quenching is linear over 0.006～0.8μg/mL of chromium(Ⅵ).This simple and selective fluorescence method was developed for the determination of chromium(Ⅵ)in waste water with satisfactory results.