MECHANISM FOR THE TRANSFORMATION OF FERRIPROTOPORPHYRIN BY A Co$sup 60$- $gamma$-RAY INITIATED CHAIN REACTION
The mechanism for the Co/sup 60/ gamma -radiation initiated transformation of ferriprotoporphyrin in 0.1 N NaOH to another ferriporphyrin compound was examined by studying the effect of ferriprotoporphyrin concentration, hydrogen peroxide concentration, dose, and dose rate on the yield. The data establish that ferriprotoporphyrin is transformed by a dose rate independent chain reaction initiated by hydrogen peroxide and possibly other products of the radiolysis of water. Initial yields as high as 220 mu M/l/lOOO r were found. To explain the experimental results it is postulated that in alkaline solution ferriprotoporphyrin exists in an equilibrium between a monomeric form and a dimeric form. Several mechanisms are proposed, each of which satisfies the conditions that the average chain length is proportional to the concentration of the monomeric form and that all chains are initiated, propagate, and terminate independently of one another. (auth)
- Research Organization:
- California. Univ., Los Angeles. School of Medicine
- NSA Number:
- NSA-15-023535
- OSTI ID:
- 4035220
- Report Number(s):
- UCLA-479
- Country of Publication:
- United States
- Language:
- English
Similar Records
The action of Co60 gamma rays and of fenton's reagent on aqueous bromal hydrate solutions
Mechanism of chain transfer in low-temperature liquid-phase radiation oxidation of hexafluoropropylene by molecular oxygen