The invention relates to a bis-
triazene compound, in particular to 4,4'-bis(5-sulfo-8-hydroxyl-7-
aminoquinoline azo)-3,5,3',5'-tetrabromo-
diphenyl ether, a method for preparing the same and application thereof. The molecular structure formula of the 4,4'-bis(5-sulfo-8-hydroxyl-7-
aminoquinoline azo)-3,5,3',5'-tetrabromo-
diphenyl ether is shown as the right. The preparation method comprises the following steps: preparation of 5-sulfo-8-hydroxyquinoline, preparation of 5-sulfo-7-
azobenzene-8-hydroxyquinoline, preparation of 5-sulfo-7-amino-8-hydroxyquinoline, bromination of 4,4'-
diaminodiphenyl ether and diazotization of 4,4'-diamino-3,5,3',5'-tetrabromo-
diphenyl ether, and
coupling. The method has the advantages of simple method and low cost; and when being used for detecting heavy
metal ions, the method has the characteristics of good selectivity, high sensitivity and stable performance.