【作者】 任杰；

【导师】 高锦章； 杨武；

【作者基本信息】 西北师范大学 ， 分析化学， 2003， 硕士

【摘要】 非平衡非线性问题是自然科学领域中带有普遍性的问题。近年来引起广大科学工作者的广泛兴趣，而化学振荡也成为这一领域的研究热点，研究内容主要包括新体系的设计及其机理的研究和稳定振荡体系在分析测定中的应用。本文对酪氨酸化学振荡体系做了系统的研究，并首次将化学振荡应用于氢醌和咖啡因的测定，结果非常令人满意。论文分为四部分。 第一部分：化学振荡反应及其在分析化学中的应用 本章综述了化学振荡的基本理论，对几类常见的化学振荡反应体系及其机理给予详细的阐述。并系统地评述了化学振荡在分析化学中的应用的整个历史，同时简要论述了化学振荡在分析化学中的应用前景。 第二部分：利用B-Z化学振荡反应测定氢醌 本章研究了用B-Z化学振荡反应测定氢醌的新方法，该法简单易行，而且灵敏度高，选择性好。实验表明当加入氢醌的浓度在2.0×10^-4-1.O×10^-2M范围内时，体系振幅的改变量与所加入氢醌的浓度呈良好的线性关系（r=0.9965），然而当氢醌的浓度在4.0×10^-7-2.5×10^-4M范围内时，二者的关系与一个二次函数相当吻合（r=0.9983）。 第三部分：以酪氨酸为底物的新化学振荡器 本章报道了以Mn2+催化溴酸钾，丙酮和酪氨酸在酸性介质中的化学振荡反应，并计算出诱导期和振荡期的表观活化能分别为E_m=110.61KJ／mol和E_D=159.41KJ／mol。得到一个稳定的振荡体系，并初步讨论了其反应机理， 第四部分：在CSTR中用化学振荡反应测定咖啡因 本章首次报道了在化学振荡反应体系中连续加入咖啡因对其进行测定的新方法。当加入咖啡因的浓度在4.0×10^-6-1.2×10⁴M范围内时，加入咖啡因使体系振幅的改变量与其浓度呈良好的二次函数关系（r=0.9968），并对其可能的反应机理作了初步的探讨。更多还原

【Abstract】 The subjects of nonequilibum and nonlinear are very usual in the field of science. They have attracted the attention of researches for many years. One important investigation is that of chemical oscillation. There has been a focus on the theoretical and experimental chemical kinetics in recent years. Studies of oscillating chemical reactions are in two major aspects; (a) Application of regular chemical oscillation to analytical determination and (b) designing new oscillating chemical reactions and elucidating the intricate underlying mechanisms of them. This work report the oscillating chemical reaction involving tyrosine in details and develops new methods using oscillating chemical reaction for quantitative analytical determination of hydroquinone and caffeine, the results are satisfied. The main content consists of four parts.PART I: Oscillating Chemical reaction and its application in theanalytical chemistryThis part describes the basic thermodynamic theory of oscillating chemical reaction and introduces several usual oscillating chemical reactions and their mechanisms in details. The whole history of the application of oscillating chemical reactions in the analytical chemistry is also reviewed. And the perspective of oscillating chemical reactions is discussed to the point.PART II: Kinetic Determination of Hydroquinone by Belousov-Zhabotinskii Oscillating Chemical ReactionA novel and convenient method with good selectivity and high sensitivity for the determination of hydroquinone (HQ) based on the Belousov-Zhabotinskii (B-Z) oscillating chemical reaction has been presented The optimum condition for the determination has also been investigated, In the B-Z reaction system, when the sample was injected, the change of the amplitude is linearly proportional to the logarithm of theconcentration of HQ in the range 2.0×10-4-1.0×10-2 M (r=0.9965), whereas the concentration of HQ is over the range from 4.0×10-7-2.5×10-4 M, the calibration curve fits a second-order polynomial equation very well (r=0.9983).PART in: A Novel Chemical Oscillator with Tyrosine as the SubstrateA new oscillating chemical reaction system involving the manganese (II)-catalyzed reaction among potassium bromate, acetone and tyrosine in acidic medium was described in this paper. The apparent activation energy of the induction period (Ein) and that of oscillation period (Ep) were calculated, Ein=110.61KJ/mol, Ep=159.41KJ/mol. The optimum concentration of each reactant was investigated and a steady oscillating chemical system was obtained. The influence of temperature was studied as well. The mechanism of the reaction was also explored in detail and a possible quantitative explanation was proposed.PART IV: Determination of Caffeine Using Oscillating ChemicalReaction in a CSTRA new analytical method for the determination of caffeine by the sequential perturbation caused by different amounts of caffeine on the oscillating chemical system involving the manganese(II)-catalysed reaction between potassium bromate and tyrosine in acidic medium in a CSTR was proposed. The method exposed for the first time in this work. It relies on the relationship between the changes in the oscillation amplitude of the chemical system and the concentration of caffeine. The calibration curve fits a second-order polynomial equation very well when the concentration of caffeine over the range 4.0×10-6 to 1.2×10-4 M (r=0.9968). The effects of influential variables were studied. Some aspects of the potential mechanism of action of caffeine on the oscillating chemical system were also discussed.更多还原