It is the azo compound detection, there are vendors, export, can be detected in the test report, the specific points are as follows: AZO compound materials: cloth, leather, plastic, rubber, paint, colorant. The AZO with FREE control has become the most important quality control project of the international trade of textiles and clothing in the eco textiles, is also one of the basic quality indicators. The provisions of the German government in 1994 issued a decree, which entered the German leather, textile must be detected by AZO, followed by some EU countries have to follow. Structure and formation of AZO azo compounds: azo compounds have anti geometric isomers CIS, CIS trans ratio; stability, two kinds of isomers can convert light or heating conditions. Azo compounds mainly through the coupling reaction of the diazonium salt system; hydrogenated azo compounds and aromatic amines in oxidizing agent (such as NaOBr, CuCl2, MnO2 and Pb (OAc) 4) exist, can be oxidized to the corresponding azo compounds; oxidation of azo compounds and nitro compounds in reducing agent (such as (C6H5) 3P the presence of LiAlH4, etc.), can also be reduction of azo compounds. Azo dyes is a chromophore, azo dye is a kind of synthetic dyes, most varieties of the most widely used. Some azo compounds can be used as a pH indicator in analytical chemistry and metal indicator. Some azo compounds can be used as initiator for polymerization reaction.