Abstract: In this paper, it is found firstly that BSA can sensitively react with carboxynitroazo, used as a good colouring reagent of some inorganic ions before, in acid medium and at room temperature. The absorption spectra and its reaction mechanism were studied. BSA binds with carboxynitroazo mainly through the static electric force. The maximum combination number of carboxynitroazo binded on BSA was determined, based on principle of molar ratio method. The results were conform to the change of its spectra. The fundamental conditions of the reaction and the possibility of spectrophotometric determination of proteins using carboxynitroazo were discussed.

Key words: BAS, carboxynitroazo, spectropnotometry

关键词: 牛血清白蛋白, 硝羧偶氮, 分光光度法