HYDROGEN PEROXIDE PRODUCTION UNDER VARYING CONDITIONS OF IRRADIATION 



to occur, thus avoiding the major loss of bound oxygen via reaction (6). The 

 loss of oxygen from the sohition should be of no significance when oxygen 

 is in excess, so that hydrogen peroxide decomposition is pH independent 

 with oxygen bubbling. 



Discussion 



The function y = a(\ — e'^^) 



fits the experimental data very closely, and seems to govern the production 

 of hydrogen peroxide for doses used in these experiments. It was shown 

 that the initial yield was independent of oxygen tension. The yield can be 

 derived by differentiating _>) with respect to d, and for small doses it is 



dy 



j^ = ab = c. 



It has been found that for large doses the hydrogen peroxide concentration 

 was proportional to the oxygen tension /. Under these conditions the 

 exponential term of y approaches 0, 



y = a = c^f 



Thxx^ y = cj\\ - e~ ^^f) 



dy -^ 



and^ = q. '^^^ 



The equilibrium value of hydrogen peroxide concentration J^' will be achieved 



if / -^ 0. This condition is fulfilled if — ^, i.e. ^, is very large. The hydrogen 

 dy cj J 



peroxide concentration rises to within 10 per cent of the equilibrium value 



/ 2-3.1 

 It follows that if the dose is low, a small change in oxygen tension leads to 

 a large change in yield at very low but not at high oxygen tensions. It is 

 possible to calculate for different doses d the oxygen tensions / at which 

 the hydrogen peroxide formation becomes independent of oxygen tension. 

 In Table I are listed these doses and the corresponding oxygen tensions. 



Table I. Calculated oxygen tensions for given doses, at which the yields of 

 hydrogen peroxide have reached 90 per cent of the equilibrium values 



The values in Table I reflect the relative probabilities of reactions (1) 

 and (7) for the stated conditions. In living tissue, however, the principal 



36 



