Kinetic Determination of Microquantities of Rutin by Perturbation of the Bray-Liebhafsky Oscillatory Reaction in an Open System

Abstract.

A kinetic method is described for the microquantitative (microconcentration/microvolume) determination of rutin based on potentiometric monitoring of the concentration perturbations of the Bray-Liebhafsky (BL) oscillatory reaction being in a non-equilibrium stationary state close to a bifurcation point. The experiments are carried out in an open reactor. The response of the matrix system to perturbations by different concentrations of rutin ethanolic solutions is followed by a Pt-electrode. In the concentration range between 7.8×10⁻⁸ mol dm⁻³ and 9.1×10⁻⁶ mol  dm⁻³, we found a linear dependence of the maximal potential shift, ΔE_m, on the logarithm of the rutin concentrations. The unknown concentrations can be determined from the calibration curve up to an accuracy of ±5%. The detection limit is 3.6×10⁻⁸ mol  dm⁻³. The amount of required sample can be as small as 10 µL.