Kinetic determination of ascorbic acid by the BZ oscillating chemical system

A new analytical method for the determination of ascorbic acid by the perturbation caused by different amounts of ascorbic acid on the BZ oscillating chemical system involving the Ce(IV)-catalyzed reaction between potassium bromate and malonic acid in a acidic medium is proposed. The method relies on the linear relationship between the change in the oscillation amplitude of the chemical system and the concentration of ascorbic acid, which is in this work exposed for the first time. The calibration curve is linearly proportional to the concentration of ascorbic acid over the range 3.5x10(-6)-4.7x10(-4) M, with the regression coefficient is 0.9975. Two different methodologies were used to address the determination. Some aspects of the potential mechanism of action of ascorbic acid on the BZ oscillating chemical system are discussed in detail.     

Determination of <Emphasis Type="Italic">p</Emphasis>-nitrobenzene-azo-naphthol by an oscillating chemical reaction using the analyte pulse perturbation technique

A simple analytical method for the determination of p-nitrobenzene-azo-naphthol was proposed by a sequential perturbation with different amounts of p-nitrobenzene-azo-naphthol on an oscillating chemical system. The method involves a Cu(II)-catalysed oscillating reaction between hydrogen peroxide and sodium thiocyanate in alkaline medium with the aid of continuous-flow stirred tank reactor (CSTR). A good linear relationship between the changes, oscillation amplitude or/and period, and the concentration of p-nitrobenzene-azo-naphthol was obtained. The use of analyte pulse perturbation technique provides a possibility of sequential determination in a same oscillating system, due to a new steady state that reappeared rapidly after each perturbation. The calibration curve fits a linear equation very well when the concentration of p-nitrobenzene-azo-naphthol ranging from 5.2×10⁻⁷ to 3.3×10⁻³M. Influence of temperature, injection point, flow rate and reactants variables on this system were investigated in detail.     

维生素B1对B-Z振荡反应的影响及反应动力学

维生素是生物生长和代谢所必需的微量有机物,和激素相似,需要量很小,但对生命活动却有重要作用,缺少维生素生物会不能正常生长,甚至发生疾病．本文研究了维生素BI（以下简称VitBl）对B－Z振荡反应的影响,对揭示生命的奥秘,推动医学、药学等方面的研究发展将有一定帮助·实验结果表明,不同VitBI的浓度与振荡周期改变值凸t。及振幅改变值凸A均有良好的线性关系．线性范围为5．1（）X10－’～2．78X10－‘11。of·L－‘,相关系数分别为0．905和0．993．据此可为VitBl的定是分析测试提供信息及依据．1实验1．1仪器与试剂＊SS（…     

Determination of Heroin Based on Analyte Pulse Perturbation to an Oscillating Chemical Reaction

IntroductionOscillating chemical reaction is a complexphysico- chemical system,which deals with manyintermediate processes and intermediate species.Basically,in an oscillating chemical reaction sys-tem,the concentrations of the catalyst and/or in-termediate species undergo oscillations with time.Under specific reaction conditions,the oscillationsare reflected in color change[1] ( the oscillatingspecies exhibit different colors) ,p H change[2 ]( variations in H+ or OH-concentration in themedi…     

Kinetic determination of silver ion by its perturbation on Belousov-Zhabotinskii oscillating chemical reaction using potentiometric method.

Silver ion can perturb the Belousov-Zhabotinskii (B-Z) oscillating chemical reaction. Therefore, the B-Z oscillating system was applied in the determination of silver ion by using a platinum wire as an indicator electrode in the potentiometric method. The amplitude of the potentiometric oscillation increased linearly in proportion to [Ag+] in the range of 9.42 x 10(-6) M to 2.54 x 10(-4) M, with a correlation coefficient of 0.999 under the optimum conditions. The obtained LOD (2sigma) was 8.85 x 10(-6) M and the relative standard deviation (RSD) for five measurements of 1 x 10(-4) M silver ion was 5%. The influence of some potentially interference was also investigated.     

Kinetic Determination of GA by the BZ Oscillating Chemical System

A new analytic method for the determination of gibberellic acid (GA) by perturbation causing different amounts of GA on the BZ oscillating chemical system involving the Mn(II)‐catalyzed reaction between L‐alanine, potassium bromate, and malonic acid in the acidic medium is proposed. The method relies on the linear relationship between the change in the oscillating period of the chemical system and the concentration of GA, which is in this work exposed for the first time. The calibration curve is linearly proportional to the concentration of GA over the range 1.0 × 10⁸ ?1.0 × 10^?6M, where the regression coefficient is 0.9998, and the detection limit is 5.0 × 10^?9 M of GA. Some aspects of the potential mechanism of action of GA on the BZ oscillating chemical system are discussed in detail.     

酪氨酸-溴酸钾-硫酸-丙酮在三邻菲啰啉合铁(Ⅱ)催化下的B-Z振荡反应

研究了酪氨酸-溴酸钾-硫酸-丙酮在三邻菲啰啉合铁(Ⅱ)催化下的化学振荡反应,对振荡的影响因素进行了研究和讨论.运用正交实验法确立了振荡反应进行的浓度范围,得到一个40多次振荡寿命为60 min的振荡波.获得振荡的诱导期和周期与反应物浓度之间的变化趋势曲线,以及振荡反应在诱导期和振荡期的表观活化能分别为Ein=49.0 kJ/mol和E=57.0 kJ/mol.根据反应过程中的现象和实验数据,建立了振荡反应的模型和反应机理,确定[Br-]是振荡反应自发进行的关键因素.     

A Novel Chemical Oscillator with Tyrosine as the Substrate

A new chemical oscillating 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 chemical oscillating system was obtained.     

超痕量H_2O_2对MnSO_4-KBrO_3-乙酰丙酮化学振荡体系的扰动

化学振荡波和生物体内的生物振荡及生物形态现象的相似性促使人们认识到生命现象和非生命现象之间遵循着某些相同的规律 ,因而化学振荡反应非线性动力学一直是物理化学研究的热点 [1,2 ] .近年来它在分析化学中的应用使其研究扩展到了一个新的领域 ,但仍停留在 1 0 - 7mol/L的水平上 [3] .显然 ,以这个量去研究包含众多基元反应和反应中间体的振荡反应 ,得到的是数目庞大的反应物种群体行为 ,而这种行为并不足以说明生命现象的猝发病变、代谢功能衰竭及运动寿命终止的原因 .　　我们在研究 H2 O2 对 Mn SO4 - KBr O3-乙酰丙酮宏观振荡规…     

超痕量H2O2对MnSO4-KBrO3-乙酰丙酮化学振荡体系的扰动

化学振荡波和生物体内的生物振荡及生物形态现象的相似性促使人们认识到生命现象和非生命现象之间遵循着某些相同的规律, 因而化学振荡反应非线性动力学一直是物理化学研究的热点[1, 2]. 近年来它在分析化学中的应用使其研究扩展到了一个新的领域, 但仍停留在10-7 mol/L的水平上[3]. 显然, 以这个量去研究包含众多基元反应和反应中间体的振荡反应, 得到的是数目庞大的反应物种群体行为, 而这种行为并不足以说明生命现象的猝发病变、代谢功能衰竭及运动寿命终止的原因.     

Determination of gases (NO, CO, Cl(2)) using mixed-mode regimes in the Belousov-Zhabotinskii oscillating chemical reaction

We show a principle possibility of the determination of gases concentrations (NO, CO, Cl(2)) by their affect on mixed-mode oscillations in the Belousov-Zhabotinskii (BZ) oscillating chemical reaction. These oscillations are characterized by single large amplitude oscillation followed by a number of small amplitude oscillations. The method of the determination is based on a construction of a calibration plot given by the dependence of the number of small amplitude oscillations on gas concentration.     

Determination of Alizarin Red S using a novel B-Z oscillation system catalyzed by a tetraazamacrocyclic complex

A new and convenient method for the determination of Alizarin Red S by the perturbations caused by different amounts of Alizarin Red S on a novel B-Z oscillating system is proposed. This new type Belousov-Zhabotinskii involves a macrocyclic copper(II) complex [CuL](ClO₄)₂ as catalyst and malic acid as the substrate. The ligand L in the complex is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene. It is found that the relationship between the change in the oscillation amplitude and the logarithm of the Alizarin Red S concentration in the range of 1.5 × 10⁻⁷ to 1 × 10⁻³ M fits a polynomial model: ΔA = 659 + 184.2 log [Alizarin Red S]+ 12.9 log² [Alizarin Red S]. The RSD obtained with ten samples is 4.4%. The probable mechanism involving the perturbation of Alizarin Red S on the oscillating chemical system is also discussed.      

A new method for determination of uric acid by the lactic acid-acetone-BrO(3)(-)-Mn(2+)-H(2)SO(4) oscillating reaction using the analyte pulse perturbation technique

A new analytical method for the determination of uric acid (UA) by the perturbation of UA on the Belousov-Zhabotinsky oscillating reaction is proposed. The method is based on the linear relationship between the changes in the oscillating period and the concentration of UA. The calibration curve is linear over the range of 2.0 × 10⁻⁵ to 5.0 × 10⁻⁴ M, with a detecting limit of 3.28 × 10⁻⁶ M. The method features good precision (R.S.D.: 3.59%) and excellent throughput (10 samples h⁻¹). The possible mechanism of the perturbation of UA on the oscillating reaction is discussed.     

Determination of vitamin B6 (pyridoxine hydrochloride) based on a novel BZ oscillating reaction system catalyzed by a macrocyclic complex

This paper reports a new method for determination of VB₆ (pyridoxine hydrochloride) by its perturbation effects on a novel Belousov-Zhabotinskii (BZ) oscillating system. This novel BZ system, in which malic acid serves as the substrate, contains an enzyme-like complex, macrocyclic complex {[CuL](ClO₄)₂}, as catalyst. The ligand L in the complex is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene. Results show that the addition of pyridoxine hydrochloride can perturb the oscillation amplitude and period, and the change of the oscillation amplitude is linearly proportional to the concentration of pyridoxine hydrochloride in the range of 5×10^?7?2.5×10^?4 M. The obtained RSD with seven samples is 3.073%. An assay of pharmaceutical tablets of vitamin B₆ was evaluated. Some foreign ions were studied with respect to their possible influence on the determination of pyridoxine hydrochloride. The factors which influence this reaction include the concentration of reactant, the temperature of the reaction, property of catalyst, etc. Furthermore, the possible reaction mechanism has been proposed using the Field-Körös-Noyes (FKN) model.      

Trace determination of cobalt ion by using malic acid-malonic acid double substrate oscillating chemical system

A novel kinetic method for determination of trace amounts of cobalt ion was proposed and validated. The method is based on adding malic acid into classical Belousov-Zhabotinskii （B-Z） oscillating chemical system to form a double substrate one. The results showed that when the concentration of cobalt ion was in the range of 5.27× 10^-8 to 5.37 × 10^-12 mol L^-1, the change of the oscillating period was directly proportional to the negative logarithm of cobalt ion concentration. The sensitivity and precision of the developed method were quite satisfactory. The limit of detection was down to 5.20 × 10^-13 mol L^-1 which was a highest sensitivity found for determination of metal ions using oscillating chemical reaction so far. Some factors influencing the determination were also examined. The method has been successfully used to determine cobalt ion in vitamin B12 injection.     

溴离子对BZ非催化振荡反应的影响

Br~-对Belousov-Zhabotinsky(BZ)振荡反应起着控制作用。近来发现,一些有机物在被BrO_3~-氧化时,即使没有金属离子Ce~(3+),Mn~(2+),Fe(phen)_3~(2+),也可产生振荡反应,称为非催化BZ振荡反应。本文选择酪氨酸(Tyr)-BrO_3~--H_2SO_4 BZ振荡体系,对Br~-的影响作了系统的研究,对机理作了初步探索。     

牛血清白蛋白对Cu2+-SCN--H2O2化学振荡系统影响作用的初步研究

研究了牛血清白蛋白(BSA)对Cu2+-SCN--H2O2化学振荡系统的扰动作用, 观察并分析了BSA对该振荡体系的影响规律, 在此基础上提出了基于化学振荡系统的蛋白质定量检测方法.     

The Effect of Sodium Dodecylbenzenesulfonate (SDBS) Micelles on a BelousovZhabotinsky Oscillating System Catalyzed with a Tetraazamacrocyclic Copper(II) Complex

This article deals with the influence of micelles of the anionic surfactant sodium dodecyl benzene sulfonate (SDBS) on the Belousov? Zhabotinsky (B? Z) oscillating reaction catalyzed by a tetraazamacrocyclic copper(II) complex [CuL](ClO₄)₂, an enzyme‐like catalyst (L=5,7,7,12,14,14‐hexamethyl‐1,4,8,11‐tetraazacyclotetradeca‐4,11‐diene). Unlike the classical B? Z oscillator in which malonic acid is usually used as a substrate, malic acid (an intermediate in the Krebs cycle) is involved in this oscillating system. Experiments reveal that formation of the SDBS micelles markedly affects the behavior of the oscillating reaction. It is found that there is a linear relationship between the change in the oscillation amplitude (ΔA) and the concentration of SDBS, whereas the change in the oscillation period (ΔT) is linearly proportional to the SDBS concentration. The most likely mechanism that involves the formation of the SDBS micelles and the effects of the micelles on the oscillating chemical system can be rationalized by assuming that the SDBS micelles are so negatively charged that they attract more [CuL]³⁺ than [CuL]²⁺. This hypothesis was confirmed by UV/VIS spectrophotometric measurements of a constant concentration of [CuL](ClO₄)₂ in different concentrations of SDBS; as the SDBS concentration increased, the absorbance of [CuL](ClO₄)₂ increased, while the maximum absorption wavelength for [CuL](ClO₄)₂ remained at 502 nm.     

Determination of furfural in an oscillating chemical reaction using an analyte pulse perturbation technique

A rapid and convenient method for the determination of furfural is presented that is based upon sequential perturbation of the Mn(II)-catalyzed B-Z oscillating system with different amounts of furfural using a continuous-flow stirred tank reactor (CSTR). When the sample was injected, the change in the amplitude and/or period was linearly proportional to the logarithm of the concentration of furfural over the range 3×10⁻⁸∼1×10⁻⁵ mol L⁻¹. This method gave a detection limit of 3×10⁻⁹ mol L⁻¹ under optimum conditions. Finally, the possible mechanism of furfural perturbation in the oscillating reaction is discussed. When the furfural was injected into the Mn(II)-catalyzed B-Z oscillating system, the change in the amplitude and/or period was linearly proportional to the logarithm of the concentration of furfural over the range 3×10⁻⁸~1×10⁻⁵ mol L⁻¹, with a detection limit of 3×10⁻⁹ mol L⁻¹ under optimum conditions.      

生物酶振荡器研究谷胱甘肽的抗氧化效应

组装了一种生物酶振荡器（Peroxidase-Oxidase Biochemical Oscillator） 的实验装置、建立了相应的实验方法,在此基础上得到单倍周期、四倍周期、混沌 等丰富的振荡图谱信息,并采用它作为“探针”,检测了谷胱甘肽（GSH）的抗氧 化效应,它可作为定量分析的基础,线性范围为9.38 * 10~(-7) ～ 7.50 * 10~(- 5) mol·L~(-1),探讨了某些可能的反应机理。