Researches On The Analytical Application Based On Novel Briggs-Rauscher And Belousov-Zhabotinsky Chemical Oscillators

Nonlinear chemical systems mainly include chemical oscillations,chemical chaos,chemical waves and patterns.Among them,chemical oscillation has been extensively and deeply studied.The parameters of oscillating chemical reactions contain,inhibition time?tin?,changes in the oscillation amplitudes?AA?,changes in the period of oscillations??T?,variation in the duration of oscillations?N?.Currently known chemical oscillation systems are Bray-Liebhafsky?BL?chemical oscillation system,Belousov-Zhabotinsky?BZ?chemical oscillation system and Briggs-rauscher?BR?chemical oscillation system.In this dissertation,we mainly introduce the application of BR oscillating system and BZ chemical oscillating system in analytical field.This thesis is divided into four chapters.In the first chapter,we introduce the nonlinear chemical kinetics and its classification,and discuss the historical background and progress on oscillation reaction research.In the second chapter,a new method for the quantitative determination of the quercetin was established by using novel BR chemical oscillation system:H₂SO₄-KIO₃-malonic acid-[NiL]?ClO₄?₂-H₂O₂.The ligand L in the complex is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene.The catalyst[NiL]?ClO₄?₂ was synthesized according to the literature and was identified by elemental analysis and IR.BR chemical oscillation system?H₂SO₄-KIO₃-malonic acid-[NiL]?ClO4?₂-H₂O₂?was established for determination of quercetin.The experimental results have shown that addition of quercetin caused the quenching and regenerating oscillations after a period of inhibition time?tin?.Due to change in inhibition time?tin?is dependent of the concentration of quercetin,an calibrationcurve was thus established to detect the quercetin quantitatively.When the concentration of quercetin was over the range 1.0 × 10-6-4.5 × 10-6 mol/L,a linear calibration curve is obtained in which the inhibition time is proportional to the concentration of quercetin with the regression coefficient of 0.997.When the concentration of quercetin was over the range 4.5 × 10-6-3.5 × 10-5 mol/L,a linear calibration curve is obtained in which the inhibition time is proportional to the concentration of quercetin with the regression coefficient of 0.994.Moreover,we investigated the interfering ions and the optimal concentrations on measurement of quercetin.We followed the results from cyclic voltammetry to infer which reactants may react with quercetin.Finally,the probable mechanism was proposed based on NF and FCA model.In the 3nd chapter,we introduce a method to distinguish four polynuclear aromatic isomers of DHN?1,4-dihydroxynaphthalene?1,4-DHN?,1,5-dihydroxynaphthalene?1,5-DHN?,2,3-dihydroxynaphthalene?2,3-DHN?and 2,7-dihydroxynaphthalene?2,7-DHN??by using BR oscillation system.By putting equal amount of the same concentrations of all the four naphthalene isomers of DHN?1,4-DHN,1,5-DHN,2,3-DHN,2,7-DHN?into BR system,the system could be perturbed,being reflected in their quite different oscillating behaviors after perturbation.At higher concentration?5.0 × 10-5 to 2.5 x 10-4 mol/L?,the addition of 1,4-DHN could hardly disturb the oscillation;the addition of 1,5-DHN produced a spike toward downside and then suddenly resumed oscillation with a short inhibition time;the addition of 2,3-DHN caused the quenching and regenerating oscillations after long inhibition time?tin?while the addition of 2,7-DHN permanently terminated the oscillation without regeneration of it.However,at lower concentration?5.0 x 10-6 to 2.5 × 10-5 mol/L?,the obtained perturbation effect of the three isomers?1,4-DHN,1,5-DHN and 2,3-DHN?were almost the same as that at higher concentration but 2,7-DHN isomer shown a unique perturbation behavior.The addition of 2,7-DHN decrease potential and regenerate oscillations after long inhibition time at low concentrations.These all these four polynuclear aromatic isomers of DHN were identified in their concentration range of 1.0 × 10-6to 5 × 10-4mol/L.Furthermore,we confirmed their oxidation products by several experiments?like UV and IR?.Finally,the probable mechanism was proposed based on NF and FCA model.In the 4nd chapter,we mainly introduce a novel method that identity three isomers of benzenetriol?1,2,3-benzenetriol,1,2,4-benzenetriol and 1,3,5-benzenetriol?by using new BZ oscillating system?H₂SO₄-NaBrO₃-DL-malic acid-[CuL]?ClO₄?₂?.By putting equal amount of the same concentrations of all the three isomers of benzenetriol into BR system,the system could be perturbed,being reflected in quite different oscillating behaviors after perturbation.The presence of 1,2,3-benzenetriol on BZ oscillating system could produce the perturbation with decrease to some extent followed by a sharp increase in the potential;the addition of 1,2,4-benzenetriol on BZ could cause perturbation with great decrease followed by a slow increase in the potential;the addition of 1,3,5-benzenetriol on BZ system could cause perturbation with accompanying by quenching of oscillations before the regeneration of oscillations.These all these three isomers of benzenetriol were identified in their concentration range of 1.0 × 10-6 to 5 × 10-4mol/L.Furthermore,we confirmed their oxidation products by several experiments?like cyclic voltammetry and UV?.Finally,the probable mechanism was proposed based on FKN model.