Аннотация:Efforts to replace native peroxidase with its low molecular weight alternatives have stimulated a search for peroxidase mimetics. Herein we describe the oxidation of luminol with hydrogen peroxide catalyzed by commercial available FeIII-TAML activator 1a, which was showed to be more active catalyst than hemin. At FeIII-TAML activator 1a use in chemiluminescent assay for H2O2 determination the limit value (3σ) was 5 x 10-8 M, whereas in the presence of hemin the detection limit was significantly higher and equal to 6 x 10-7 M. The linear ranges (R2 = 0.98) of the assay were 6 x 10-8 – 1 x 10-6 M and 6 x 10-7 – 1 x 10-6 M H2O2 for FeIII-TAML 1a and hemin, respectively. The CV values for FeIII-TAML 1a-based assay measured within the working range varied from 1.0 to 3.7 % (n=4), whereas in the case of hemin – 5.0 to 9.7 % (n=4). Moreover, the sensitivity of FeIII-TAML 1a-based method was 56 times higher than that of hemin-based method. The obtained results open good perspectives to apply FeIII-TAML activator 1a in CL analytical methods instead of hemin, traditionally used peroxidase mimetic.