Hydrogen peroxide primary absorber

Peroxidase indicator reactions may be used to follow any primary reaction that produces hydrogen peroxide. Peroxidases are very specific for H2O2, but will react with a variety of organic dye species that are colorless in the reduced form, but highly absorbing in the oxidized form. Examples include 2,4-dichlorophenol, O-dianisidine, malachite green, and benzidine. 

In chemical practice, primary amine groups are easily oxidized to oximes [21]. The most convenient oxidant cited is hydrogen peroxide at room temperature, but catalytic oxidation with molecular oxygen is also reported (Scheme 28.3). In thin films, the metal substrate could act as such a catalyst Because oximes absorb light at 1670-1649 cm [22, 23], they can be the cause of the aging band at 1660 cm . However, this reaction path does not fully explain why this band is observed only under humid aging conditions. 

The principal light-absorbing groups of lipids are double bonds, peroxide 0—0 bonds, and carbonyls the last two are most important. The primary mechanism by which ultraviolet radiation initiates lipid oxidation is actually indirect, mediated through homolytic scission of any preformed hydroperoxides to generate the true initiators— LO, HO, and RO —that abstract hydrogens from lipid molecules and form the ab initio L. ... 

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