The Determination of a Small Amount of a Biological Constituent by the Use of Chemiluminescence. VI. The Flow-Injection Analysis of Protein Using a 1,10-Phenanthroline–Hydrogen Peroxide System

Abstract

Abstract Since the catalytic activity of copper(II) for the chemiluminescent reaction between 1,10-phenanthroline and hydrogen peroxide decreased in the presence of protein, this phenomenon was applied to the determination of protein. The determination of protein was carried out by a flow-injection method, and the conditions for the determination of protein were established. The catalytic activity of copper(II) was enhanced by using an amino acid instead of the conventional biuret reagent. Similar calibration curves were obtained for human serum albumin, bovine serum albumin, human serum γ-globulin, bovine serum γ-globulin, and ovalbumin. According to the present flow-injection method using a chemiluminescent reaction, a small amount of protein could be conveniently and economically determined over a wide range of concentrations, 5.0×10−6 g dm−3–1.0×10−1 g dm−3 at the rate of about 20 samples per hour, with the detection limit of 250 pg as the injected amount and the coefficient of variation of 5.9% (n=9). The sensitivity of the present method was about 40 times that of the previous luminol-hydrogen peroxide system.