Polarographic Investigation and Determination of Bilirubin

Abstract

A rapid and sensitive polarographic method for the determination of bilirubin is described. In a solution containing 0.03M NaOH, 1.0×10^-3M Na₂SO₃ and 2.0×10^-4M EDTA, bilirubin can cause a polarographic wave at about -0.26V (vs. SCE) when potential sweeps from -0.65V to -0.1V. The peak current varies linearly with bilirubin concentration over a range of 8.0×10^-8M to 6.0×10^-6M as determined by derivative linear sweep polarography. A low detection limit of 5×10^-8M is obtained. The method has been developed for the determination of bilirubin in serum and medicine. In this research, the characteristics of the polarographic wave have been investigated, and it has been confirmed to be an adsorptive wave. The electrochemical mechanism is discussed, the wave is ascribed to the oxidation of mercury.