| Abstract
| - A selective and versatile fluorescence spectroscopic methodfor the determination of nitrite in waters has been developed. Nitrite reacts in the presence of mineral acids withthe nonfluorescent N-methyl-4-hydrazino-7-nitrobenzofurazan forming N-methyl-4-amino-7-nitrobenzofurazan,which can be detected by fluorescence spectroscopy withan excitation maximum at λ = 468 nm and an emissionmaximum at λ = 537 nm in acetonitrile. Three newmethods based on this reaction have been developed: Direct fluorescence spectroscopy, HPLC/fluorescence, orHPLC with UV/vis detector may be selected as detectiontechniques. On microplates, high-throughput fluorescence spectroscopy is achieved, while HPLC/fluorescenceprovides lower limits of detection, and HPLC with UV/vis detection enables evaluation of the reaction withstandard instrumentation. Different water samples wereinvestigated using all detection modes, and a photometricstandard procedure was successfully employed to validatethe new methods with an independent technique.
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