RADIOLYSIS OF HEMIN IN AQUEOUS-SOLUTIONS

gamma-Radiolysis of 10(-5)-1.5.10(-4) mole/dm3 of hemin (ferriprotoporphyrin) in 0.01 mole/dm3 of basic phosphate buffer with pH 8.0 was investigated. The dose range was 10-100 Gy. It was found that the process evolves according to a chain mechanism. The reaction with OH radicals results in the formation of products with a close molecular weight, while the reaction with O2- and HO2- radicals results in products with a higher molecular weight than the hemin. The products of radiolysis inhibit the chain process with a rate approximately one order of magnitude higher than the rate of chain propagation.