关键词: 氯化血红素, 模拟酶, 十二烷基苯磺酸钠, 溴连苯三酚红

Abstract: A novel catalytic property of hemin is described. In ammonium buffer medium of pH 8.0～8.9, hemin has an ability to catalyze the decoloration of bromopyro-gallol red. Oxygen dissolved in solution plays a role as an oxidant in the reaction. With sodium dodecylbenzenesulfonate and ethanol as effect-enhancing agents, the catalytic system obeys the Michaelis-Menten equation of enzymatic catalysis. The Michaelis constant, catalytic constant and specificity constant of the system are estimated by Lineweaver-Burk plot to be 3.7×10^-5mol/L, 0.64s^-1 and 1.7×10⁴L·mol^-1·s^-1, respectively. The mechanism of the hemin oxidase-like catalytic system is discussed. Based on this, hemin can be spectrophotometrically determined by equilibrium and kinetic procedures with a linear range and 3σ limit of detection being 2.0×10^-8～6.0×10^-7 and 5.0×10^-9mol/L, respectively.

Key words: Hemin, Mimetic enzyme, sodium dodecylbenzenesulfonate, bromopyro-gallol red