The enhanced effect of chemiluminescence (CL) of lucigenin (Luc(2+)) at a flat liquid/liquid interface and at O/W emulsions was demonstrated. The CL was emitted when Luc(2+) was transferred from an organic phase to an aqueous one containing NaOH and H(2)O(2). The CL intensity and emission spectrum depended strongly on the kind of organic solvent. We attempted to apply the CL reaction of Luc(2+) in the O/W emulsion system to the analysis of H(2)O(2). The available analytical conditions were discussed from the aspects of the kind of organic solvent, the reaction time and wavelength detected.