Some fundamental remarks on the polarographic determination of the catalase activity and the H2O2 production of bacteria

Conclusions and summary 1. Oxygen has two polarographic waves of equal height (h.w.p. –0.05 V and –1.07 V), which disturb the direct polarographic determination of H₂O₂.2. In determining H₂O₂ it is possible to eliminate this disturbance by reducing the total height of the waves by 2 × the height of the first O₂ wave.3. In a decomposing H₂O₂ solution the O₂ concentration exceeds more than 5 × the normal O₂ concentration in an aqueous solution.4. In a decomposing H₂O₂ solution the H₂O₂ concentration at each moment can only be determined by taking into account the O₂ concentration at that moment.5. Determination without this correction presents too small a catalase activity and may even result in characterising catalase positive bacteria as catalase negative.6. It is possible to demonstrate the H₂O₂ production of catalase negative bacteria by the polarographic method.