The Application Of Molecular Spectrum In Chemical Oscillating Reactions And Determination Of Nucleic Acid

Oscillating reactions are complex dynamic systems that involve amplitude or periodic changes responding to concentration of some ingredients (a reactant, a product or an intermediate) with time. Nonlinear and nonequlibrium phenomena in oscillating chemical reactions are existing commonly in nature. Studies on oscillating chemical reaction are mostly important in analytical chemistry, clinical test, life science, chemical industry, and so on. In this contribution, characterized and analyzed qualitative and quantitative analytical information of oscillating chemical reactions based on absorbance, resonance light scattering and fluorescence techniques. We have analyzed the mechanism and essence of the spectra phenomenon, and obtained the useful information which can provide a new analytical method of oscillating chemical systems. The paper consists of three sections as follow:(1) In the medium of Britton-Robinson (BR) buffer solution (pH 2.21), a ternary complex could be formed if cationic surfactant such as CTMAB is present acting as a bridge of the interaction of DNA and and anionic dye, resulting in strong enhanced RLS signals characterized by peak at 346.0 nm. It was found that the enhanced RLS intensities (ΔI_RLS) were in proportion to the concentrations of fsDNA in a certain range. The linear range of I^- is 0.03 -1.0μg/mL The method has been used for the determination of micro amounts of iodine in synthetic samples with the recovery of 95.4%～104.2% and a RSD less than 2.1%.(2) Resonance light scattering (RLS) signals of H₂O₂-KSCN-CuSO₄-NaOH oscillating system are changeable with the time. The RLS time scan intensity was measured atλ, 453.0 nm for the excitation and emission and a method is proposed based on the RLS detection of an oscillating reaction in a close system. The qualitative analytical information could be obtained from this straightforward and expeditious approach of oscillating chemical reactions. The seasonal change of the particle size is examined for the H₂O₂-KSCN-CuSO₄-NaOH oscillating system using the RLS method. Thus, a new analytical method is developed for the oscillating chemical systems. We compared the performance of absorb and the RSL detection and the result was satisfactory.(3) Fe (II)-phen-catalyzed reaction between diacetone and potassium bromate in acidic medium exhibits oscillations in fluorescence. We have observed the seasonal change of the signals by fluorescence mode atλ_em 277.0 nm, andλ_ex, 414.0 nm. Results show that the adding of fsDNA can perturb the oscillating period The effect of influential variables, such as the concentration of reaction components, temperature was studied.