P A9. THE PULSE PERTURBATION of an oscillatory reaction
as the method FOR ANALYSIS OF FOOD SAMPLES

N. Pejić1, S. Blagojević1, V. Vukojević2, S. Anić3 and Lj. Kolar-Anić3

1Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, YU-11000 Belgrade,Serbia, e-mail: bimesel@eunet.yu
2Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
3Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, P.O. Box 137, YU-11001 Belgrade, Serbia

The application of an oscillatory reaction to the analysis of real samples by the analyte pulse perturbation technique is reported. The addition of small amounts of analyte examined to the oscillatory reaction alters some of its properties; this effect can be used for analytical protocol to determine different substances which are of interest. The proposed method developed in oar group is based on potentiometric monitoring of the concentration perturbation of the matrix that is, an oscillatory reaction being in the stable steady state before the bifurcation point (the point in which transition from one to the other dynamic state occurs). In particularly, the reaction involving the catalytic decomposition of H2O2 in the presence of both H+ and IO3- ions (the Bray-Liebhafsky (BL) oscillatory reaction), was used for convenient, automatic determination of several species in purified samples and laboratory mixtures, but was also applied to more complex samples derived from pharmaceuticals or food samples.