A Kinetic Study of the Iron Catalyzed Chlorpromazine-Hydrogen Peroxide Reaction and Its Analytical Implications

Abstract

The iron(II) catalyzed oxidation reaction of chlorpromazine with hydrogen peroxide in hydrochloric acid solution was studied kinetically by an initial-rate method. All reactions were run at constant ionic strength 0.44mol l^-1 and at 30°C and followed by measuring the absorbance at 525nm of the red free radical formed. According to results of a kinetic study of the iron(II) catalyzed reaction, a mechanism is proposed which leads to the following rate equation: R_0cat=[Fe(II)]₀[CP][H⁺][H₂O₂]/(2.0×10^-2[CP][H⁺]+2.2×10^-4[H²O²]+1.8×10^-3[H₂O₂][H⁺]+2.0[CP][H⁺][H₂O₂]). The optimal condition for iron determination by initial rate procedure was predicted using this rate equation and analytical implications of the mechanistic study are discussed.