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 system perturbation caused by a microvolume of an analyte solution. The system 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 and sodium thiocyanate, implemented in a continuous-flow stirred-tank reactor perturbed by sodium thiosulfate as the analyte, was used as a model reaction to evaluate the performance of this technique. The proposed methods allow the determination of the analyte with good precision and sample throughput. Some notions on the interaction of sodium thiosulfate with the oscillating chemical system are discussed.