Kinetische Untersuchung der Chemilumineszenz von 7-Dimethyl-amino-naphthalin-1.2-dicarbonsäurehydrazid in wäßrig alkalischem Wasserstoffperoxid in Gegenwart von Hämin / Kinetic Investigation of the Chemoluminescence of 7-Dimethyl-amino-naphthalin-1,2-dicarbonic-acid-hydrazid in aqueous alcaline H2O2 in Presence of Hemin

TLDR: In this paper, the authors investigated the chemoluminescence system: DNH/NaOH/H2O2/hemin with the help of a "stopped-flow"technique.

Abstract: The chemoluminescence-system: DNH/NaOHaq/H2O2/hemin was investigated with the help of a “stopped-flow-technique”. By use of an optical cut-off-filter the chemoluminescence- (514 nm), and the absorptionband (325 nm) resp. could be separated which proved impossible with luminol. In this way we could follow the temporal change of chemoluminescence and of absorption of DNH: the latter dropped coutinually with progress of the reaction while the chemoluminescence-intensity passed through a maximum before it decreased according to the same rate law (pseudo first order conditions as for DNH) which governs the absorption change of DNH. The oxidation of DNH is rate-determining and of first order as to DNH, H2O2 and (possibly) NaOH (k1 = 1,5·10-3 s-1-1 M-2). The kinetic interpretation of the chemoluminescence-maxima confirmed this result. The light production occurred in a very fast secondary reaction step (k2 ≫ k1) following the oxidation of the hydrazid and with H2O2 participating. Diazochinone is assumed to be a primary oxidation product.