ANALYTE PULSE PERTURBATION TECHNIQUE - A TOOL FOR ANALYTICAL DETERMINATIONS IN FAR-FROM-EQUILIBRIUM DYNAMIC-SYSTEMS

This paper reports a new methodological approach for obtaining simple and fast quantitative analytical information from oscillating chemical reactions in a straightforward, expeditious manner based on the syste m perturbation caused by a microvolume of an analyte solution. The sys tem perturbation results in a change in the oscillation amplitude and period, which are both proportional to the analyte concentration. The oscillating, copper(II)-catalyzed reaction between hydrogen peroxide a nd sodium thiocyanate, implemented in a continuous-flow stirred-tank r eactor perturbed by sodium thiosulfate as the analyte, was used as a m odel reaction to evaluate the performance of this technique. The propo sed methods allow the determination of the analyte with good precision and sample throughput. Some notions on the interaction of sodium thio sulfate with the oscillating chemical system are discussed.