FERROCENE AND FERRICENIUM ION AS VERSATILE PHOTOMETRIC TITRANTS OF H2O2 AND D-GLUCOSE IN THE PRESENCE OF PEROXIDASE AND GLUCOSE-OXIDASE - AFERROCENE-PEROXIDASE STAIRWAY

Hydrogen peroxide can routinely be determined in the presence of ferro cene (FcH) and horseradish peroxidase by monitoring at 617 nm the enzy matically produced ferricenium dye. In contrast, D-glucose can be assa yed by following the fading of the ferricenium dye FcH(+)PF(6)(-) in t he presence of glucose oxidase. The change in absorbance in both cases corresponds to the amount of analyte, viz. H2O2 or D-glucose, in solu tion. The routine is very simple, invariant to the concentrations of b oth ferrocenes/ferricenium salt and enzyme and allows numerous ''one p ot'' measurements with the detection limit of 10(-4) M for both the an alytes. It takes 2-4 and 5-10 min to accomplish one analysis of H2O2 a nd D-glucose in the presence of peroxidase and glucose oxidase, respec tively.