title: [Reaction of unconjugated and conjugated bilirubin with Fast Red TR and related diazonium salts].
abstract: In the present study, the reaction of 15 different diazonium salts with serum bilirubin is examined. It is shown that the selectivity of the determination of non-conjugated and total bilirubin greatly depends on two conditions: the pH-value of the reaction mixture and the nature and position of substituents within the benzene ring. Introduction of "electron-pushing" groups such as the o-methyl group of Fast Red TR will change the reactivity of the diazonium cation towards bilirubin in such a way that the co-reaction of the conjugated fraction becomes negligible at pH-values between 2 and 5. After neutralization to pH 7 the total bilirubin can be determined.
mesh_terms: D000328:Adult; D001663:Bilirubin / Q000097:blood*; D004396:Coloring Agents; D003979:Diazonium Compounds; D006801:Humans; D066298:In Vitro Techniques; D007231:Infant, Newborn; D011485:Protein Binding
chemical_list: D004396:Coloring Agents; D003979:Diazonium Compounds; C027766:Fast Red TA; D001663:Bilirubin
vernacular_title: Reaktion von direktem und indirektem Bilirubin mit Fast Red TR und verwandten Diazoniumsalzen.