8-氨基喹啉-5-偶氮-对苯酚荧光光度法测定微量铬(Ⅵ)

FLUORIMETRIC DETERMINATION OF MICRO AMOUNT CHROMIUM(Ⅵ) WITH 8-AMINOQUINOLINE-5-AZO-PHENOL

在盐酸介质中,铬(Ⅵ)与AQAPOH形成可被氯仿萃取的荧光化合物,其λex/λem=295nm/400nm.线性范围为0-1.0μg Cr(Ⅵ)/25ml(水相),检测限为0.7μg/L.除Mn(Ⅶ)外,常见金属离子无干扰,可在数千倍Cr(Ⅲ)存在下测定废水中微量铬(Ⅵ).初步探讨了荧光反应的机理.

The fluorimetric determination of Cr(Ⅵ) with 8-aminoquinoline-5-azo-phenol(AQAPOH) is described. The optimal conditions of the method is investigated, AQAPOH reacting with Cr(Ⅵ) in dilute HC1 medium forms a new compound that can be extracted into CHC13.Extract has intense fluoresence at λex/ λem = 295nm/ 400nm. The fluoresence intensity is proportional to Cr(Ⅵ ) concentration in O-l.0μg/ 25ml in aqueous phase.The detection limit is 0.7ppb.The method has been applied to fluoresence determination of micro amount Cr(Ⅵ) in some substences. The mechanism of fluorescence reaction has been studied.