Teste dein Wissen mit Aufgaben aus der ChemieOlympiade!: Azofarbstoffe ohne giftige Amine und ohne Eiskühlung

Have you ever read the small printed contents of the dyes on a gummy bear bag? While these are nowadays natural dyes, these used to be almost exclusively azo dyes. For some time now, it has been known that the digestion of some azo dyes can produce toxic degradation products. The german current guideline for safety in the classroom (DGUV) states: "Only those azo dyes may be used at school (...), which are reduced reductively into non-carcinogenic amines by chemical reducing agents or in the body by intestinal bacteria and azoreductases of the liver." And: "The synthesis of azo dyes is only allowed if no carcinogenic substances are used for this purpose." Simplest solution: Instead of harmful amines, only amino acids are used, as they occur in the human body and in food. The "Pauly sample" is a historical detection reaction from the year 1904 and leads without toxic amines and even without ice to harmless azo dyes.