Electrochemical studies of 9,10-anthraquinone interacting with hemoglobin and determination of hemoglobin

Electrochemical investigation of the interaction of 9,10-anthraquinone (AQ) with hemoglobin (HB) on a mercury electrode is reported for the first time. On addition of hemoglobin to an anthraquinone solution, both the reduction and oxidation currents decrease, with increasing peak separation. In the presence of hemoglobin, no new peaks appear, but the electrochemical parameters (standard rate constant k(s) and diffusion coefficient D) change significantly. Reaction of anthraquinone with hemoglobin forms an electrochemically active complex HB-AQ. The equilibrium constant for this complex is calculated to be 3.27 x 10(5) l/mol. A satisfactory result has been obtained for the determination of hemoglobin in clinical blood samples.