The effect of buffers and chelators on the reaction of luminol with Fenton's reagent near neutral pH

✍ Scribed by Bottu, G.

• Publisher: John Wiley and Sons
• Year: 1991
• Weight: 361 KB
• Volume: 6
• Category: Article
• ISSN: 0884-3996
• DOI: 10.1002/bio.1170060303

✦ Synopsis

The chemiluminescence o f the system luminol + Fez+ + HzOz was measured in aqueous buffer a t pH 7.2. In veronal (5,5-diethybarbiturate) buffer, the luminescence is strongly quenched by ethanol and mannitol, but only weakly by t-butanol, benzoate and superoxide dismutase (SOD); complexing Fez+ with 1 ,lo-phenanthroline or 2.2'dipyridyl causes a decrease o f light production that can be partially obviated by the simultaneous addition o f SOD. In phosphate buffer, the luminescence is higher than in veronal and it is efficiently quenched by all four OH * quenchers and by SOD. In Tris buffer, n o light production is observed as long as the Fez+ is not complexed. When Fez+ is complexed by pyrophosphate or phytate, there is a strong chemiluminescence in all three buffers, which is quenched by all four OH quenchers and by SOD. When Fez+ is complexed by EDTA or DTPA, very little luminescence is observed. The luminol analogue phthalhydrazide, which was suggested by Merenyi and Lind as a reliable OHdetector, can replace luminol only in phosphate buffer, and thus turns out t o be very specific indeed for free OH * .