Hoffmann G E, Hiefinger R, Weiss L
J Clin Chem Clin Biochem. 1985 Nov;23(11):759-63.
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.
在本研究中，检测了15种不同重氮盐与血清胆红素的反应。结果表明，非结合胆红素和总胆红素测定的选择性很大程度上取决于两个条件：反应混合物的pH值以及苯环上取代基的性质和位置。引入“推电子”基团，如固红TR的邻甲基，会改变重氮阳离子与胆红素的反应活性，使得在pH值为2至5时，结合部分的共反应可忽略不计。中和至pH 7后，可测定总胆红素。
