AbstractThe chemiluminescent oxidation of luminol and an isoluminol cortisol conjugate (ABICOR) by hydrogen peroxide has been studied in cetyltrimethylammonium bromide (CTAB) reversed micelles in octane‐chloroform (1 : 1). The maximum chemiluminescence intensity of both compounds is dependent on the initial concentrations of the H2O2and substrates, the pH value of the micelle polar phase and the H2O/CTAB ratio. The optimum pH ranged from 8.5 to 9.5. Under comparable conditions, the chemiluminescence intensity for luminol was 15‐fold higher than for the ABI‐COR conjugate. A mechanism of oxidation of the substrates in reversed micelles is proposed and the possible mechanisms of inhibition by the substrate and oxidant is disc