Fluorometric determination of hydrogen peroxide with 4-amino-1H-1,5-benzodiazepine-3-carbonitrile hydrochloride.

Abstract
The ring transformation reaction of nonfluorescent 4-amino-1H-1, 5-benzodiazepine-3-carbonitrile hydrochloride (1) with hydrogen peroxide to fluorescent benzimidazole was applied for the determination of hydrogen peroxide by fluorometry. Peroxidase was employed as a catalyst in the reaction. The measurable range was from 5.880×10-7 mol/l to 1.176×10-5 mol/l of hydrogen peroxide. Although the detection limit is not as good as that with diacetyldichlorofluorescin (detection limit of about 10-8 mol/l), 1 has the advantages of better solubility in water and stability against oxidation by air.