Absorption spectra hydrogen peroxide

A quite different approach came from Chance and others using heme enzymes (1947). Purified horseradish peroxidase has a characteristic absorption spectrum which was visibly altered in the presence of hydrogen peroxide. When an appropriate substrate was added it was oxidized by the hydrogen peroxide and the spectrum reverted to that of the original state of the enzyme. Similar studies were performed with catalase, showing that prosthetic groups in enzymes underwent reversible changes in the course of their reactions. 

Fig. 7. Absorption spectrum of hydrogen peroxide vapor. The absorption coefficient, a, is defined by the equation / = 70 exp (— atcd), where c is the concentration in molecules/cc. and d is the length of the light path in cm. Curve (a) and point O after Holt et al. (45,46). Curve (b) after Urey et al. (85). This figure based on refs. (46) and (85) with the permission of The Journal of Chemical Physics and the Journal of the American Chemical Society.

A cobalt complex of transferrin has been prepared by addition of Co(II) citrate to the apoprotein. Hydrogen peroxide was added to obtain the absorption spectrum of cobalt transferrin, and susceptibility measurements showed that the metal ion was incorporated as diamagnetic Co (III) (142). 

Fig. 11.8 Mossbauer absorption spectrum of Japanese radish peroxidase a-hydrogen peroxide Compound III at (a) 77°K and (b) 195°K. Reproduced with permission from [145]...

In aqueous solution, hydrogen peroxide possesses only a very feeble electrical conductivity comparable with that of water, and cannot be regarded as an electrolyte.2 As a solvent, however, it exhibits certain characteristics similar to water thus it favours the dissociation of the solute, especially of acids, whilst with salts it tends to form compounds in a manner corresponding with the hydration of substances in aqueous solution3 (p. 333). The absorption spectrum of hydrogen peroxide for ultra-violet light has been examined.4... 

Efficient use of light quanta. The absorption spectrum of hydrogen peroxide does not extend beyond 300 nm and has a low molar absorption coefficient beyond 250 nm. The absorption spectrum of ferric ion,... 

Dawsey, and Rice (21) in the study of the absorption spectrum of hydrogen peroxide. 

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