Analysis of lipid peroxidation kinetics. 1. Role of recombination of alkyl and peroxyl radicals.
The kinetics of the lipid peroxidation reaction is only partly understood. Although the set of reactions constituting the overall reaction are believed to be known, it has not been possible to predict how the reaction will respond to a change of one or more of the parameters, e.g., initial concentrations of reactants or different ways of initiating the reaction, nor has it been possible to predict the time dependence of the products. The reason for these problems is the complicated structure of the kinetic scheme, which includes a chain reaction. In this work we perform an in-depth analysis of the importance of the individual reaction steps, and we introduce a new quasi-stationary concentration method based on the assumption that one or more concentrations vary much slower than the others. We show that it is justified to use a quasi-stationary concentration approximation for the alkyl radical L*, but not for the peroxyl radicals LO2 * as assumed in previous works. The method allows us to derive manageable analytical expressions. On the basis of literature values of the rate constants, we are able to introduce specific simplifications that allow us to obtain simple analytical expressions for the time dependence of all concentrations involved in the process.
Doktorov
A B
AB
Institute of Chemical Kinetics and Combustion, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
Lukzen
N N
NN
Pedersen
J B
JB
D000473:Alkanes / Q000737:chemistry* / Q000378:metabolism; D005609:Free Radicals / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D015227:Lipid Peroxidation; D008054:Lipid Peroxides / Q000737:chemistry* / Q000378:metabolism; D010545:Peroxides / Q000737:chemistry* / Q000378:metabolism
D000473:Alkanes; D005609:Free Radicals; D008054:Lipid Peroxides; D010545:Peroxides; C049375:perhydroxyl radical