The Oscillating Chemical Reaction And Its Application In The Analytical Determination

Part 1. The theoretical research and analytical applications of oscillating chemical reactions in the determinationThis literature reviewed introduce the research of chemical oscillating reaction briefly and explained some classical oscillating chemical reaction systems and their mechanisms in detail, and the recent reports were also summarized. At last the perspective of chemical oscillation reactions was discussed simply.Part 2. Kinetic determination of sulfanilamide by using the bifurcation point in B-Z oscillating systemThe paper reported the perturbation of B-Z oscillating system at bifurcation point by added sulfanilamide. The results showed that changes of oscillating period were linearly proportional to the logC (where C is the concentration of sulfanilamide) in the regular oscillatory reaction, ranging from 5.60×10-4 to 3.16×10-7mol/L. For a steady non-equilibrium stationary state close to the bifurcation point, the potential changes were linearly proportional to the logC, ranging from 3.16×10-6 to 7.94×10-9mol/L. The regression coefficients were 0.9971 and 0.9973, respectively. The results implied that this technique (using the bifurcation point) could improve the sensitivity obviously with little interferences.Part 3. Kinetic determination of aminopyrine by using the bifurcation point in Mn(Ⅱ) -catalyzed B-Z oscillating chemical systemA novel and convenient method with good selectivity and high sensitivity was used to determine aminopyrine. The method was based on the perturbation with different amounts of aminopyrine on the Mn(Ⅱ)-catalyzed oscillating system, which was being in a stable non-equilibrium stationary state close to the bifurcation point between non-oscillatory and oscillatory state, using a continuous-flow stirred tank reactor(CSTR). A well linear relationship between the potential difference ( i.e.,ΔEm = Ep– Eb ) and the negative logarithm of the aminopyrine amount was found to be in the range of 7.94×10-5-5.62×10-8 mol L-1 and a lower detection limit of 7.25×10-9 mol L-1 was also obtained. To estimate the reliability, some analytical methods (including regular oscillation) were compared with it together.Part 4. Perturbation of fortum on the KBrO3-CH2(COOH)2-MnSO4-H2SO4oscillating chemical systemThe perturbation of Fortum and the effect of variables on the proposed chemical oscillating system were studied in detail. When the sample was injected, the changes of the period were linearly proportional to the concentrations of Fortum in the range of 1.5×10 -5-6.3×10-8mol/L. The detecting limit was 2.5×10-9mol/L (RSD= 0.9987, n=10) under the optimum conditions. Finally, the possible mechanism of the perturbation of Fortum on the oscillating reaction was discussed.