Hauser M J, Strich A, Bakos R, Nagy-Ungvarai Z, Müller S C
Abteilung Biophysik, Institut für Experimentelle Physik, Otto-von-Guericke-Universität, Universitätsplatz 2, 39106 Magdeburg, Germany.
Faraday Discuss. 2001(120):229-36; discussion 325-51.
Oscillatory behaviour in the pH value has been observed during the oxidation of sulfite by hydrogen peroxide mediated by hemin, a well known enzyme model compound, in a continuous-flow stirred tank reactor. The dynamics of this reaction has been studied for a variety of flow rates of the reactants. As the flow rates increase, the oscillations evolve from relaxation oscillations to more complex shapes, displaying, among others, bursting behaviour. A reaction mechanism is proposed that involves the autocatalytic oxidation of HSO3- by H2O2, while slow equilibria between different pH-dependent forms of hemin account for the feedback loop which gives rise to oscillatory dynamics. It is shown in experiments that no participation of CO2 is required for oscillations to occur.
在连续流动搅拌釜式反应器中，观察到在由著名的酶模型化合物血红素介导的过氧化氢氧化亚硫酸盐的过程中，pH值存在振荡行为。针对反应物的各种流速，研究了该反应的动力学。随着流速增加，振荡从弛豫振荡演变为更复杂的形状，尤其表现出爆发行为。提出了一种反应机理，其中涉及H2O2对HSO3-的自催化氧化，而血红素不同pH依赖形式之间的缓慢平衡构成了产生振荡动力学的反馈回路。实验表明，振荡的发生不需要CO2的参与。
