Attenuation of 4-I-phenol-enhanced chemiluminescence by non-enhancer phenols

The intensity of 4-I-phenol-enhanced chemiluminescence from the luminol-H2O2-horseradish peroxidase system is markedly attenuated in the presence of low concentrations of non-enhancer phenols. Under the conditions studied, the effect is not associated with competition between 4-I-phenol and non-enhancer phenol for the enzyme intermediates, Compounds I and II, but involves a competition between non-enhancer phenol and luminol most probably for the 4-I-phenoxy radical.