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 7.8x10(-8) mol dm(-3) and 9.1x10(-6) mol dm(-3), we found a linear dependence of the maximal potential shift, DeltaE(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 3.6x10(-8) mol dm(-3). The amount of required sample can be as small as 10 muL.