Аннотация:Quantum yields are determined for luminol and FeII in the chemiluminescence of luminol initiated by FeII salt solutions. It is concluded that chemiluminescence is initiated not by superoxide anion but by a more efficient primary oxidant. The quenching of chemiluminescence under the action of dimethyl sulfoxide shows that the hydroxyl radical also cannot be a primary oxidant. It is established that the effect the chelation of FeII by EDTA has on chemiluminescence is not related to loss of the initiating action of FeIIEDTA in the luminol chemiluminescence. Instead, it is associated with its quick transformation into FeIIIEDTA when preparing a mixture of FeII and EDTA-Na2.